Valcyte
(valganciclovir hydrochloride) Tablets
Valcyte
(valganciclovir hydrochloride) for Oral Solution
WARNING: HEMATOLOGIC TOXICITY, CARCINOGENICITY, TERATOGENICITY, AND IMPAIRMENT OF FERTILITY
Valcyte contains valganciclovir hydrochloride (valganciclovir HCl), a hydrochloride salt of the L-valyl ester of ganciclovir that exists as a mixture of two diastereomers. Ganciclovir is a synthetic guanine derivative active against cytomegalovirus (CMV).
Valcyte is available as a 450 mg tablet for oral administration. Each tablet contains 496.3 mg of valganciclovir HCl (corresponding to 450 mg of valganciclovir), and the inactive ingredients microcrystalline cellulose, povidone K-30, crospovidone and stearic acid. The film-coat applied to the tablets contains Opadry Pink® .
Valcyte is also available as a powder for oral solution, which when constituted with water as directed contains 50 mg/mL valganciclovir free base. The inactive ingredients of Valcyte for oral solution are sodium benzoate, fumaric acid, povidone K-30, sodium saccharin, mannitol and tutti-frutti flavoring.
Valganciclovir HCl is a white to off-white crystalline powder with a molecular formula of C14H22N6O5·HCl and a molecular weight of 390.83. The chemical name for valganciclovir HCl is L-Valine, 2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]-3-hydroxypropyl ester, monohydrochloride. Valganciclovir HCl is a polar hydrophilic compound with a solubility of 70 mg/mL in water at 25°C at a pH of 7.0 and an n-octanol/water partition coefficient of 0.0095 at pH 7.0. The pKa for valganciclovir HCl is 7.6.
The chemical structure of valganciclovir HCl is:
 |
All doses in this insert are specified in terms of valganciclovir.
Last updated on RxList: 9/9/2009
Treatment of Cytomegalovirus (CMV) Retinitis: Valcyte tablets are indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS) [see Clinical Studies].
Prevention of CMV Disease: Valcyte tablets are indicated for the prevention of CMV disease in kidney, heart, and kidney-pancreas transplant patients at high risk (Donor CMV seropositive/Recipient CMV seronegative [D+/R-]) [see Clinical Studies].
Prevention of CMV Disease: Valcyte for oral solution and tablets are indicated for the prevention of CMV disease in kidney and heart transplant patients (4 months to 16 years of age) at high risk [see Clinical Studies].
Valcyte is not indicated for use in either adult or pediatric liver transplant patients [see Clinical Studies]
The safety and efficacy of Valcyte have not been established for:
Treatment of CMV Retinitis in Adult Patients With Normal Renal Function:
Prevention of CMV Disease: For adult patients who have received a kidney, heart, or kidney-pancreas transplant, the recommended dose is 900 mg (two 450 mg tablets) once a day starting within 10 days of transplantation until 100 days post-transplantation.
Prevention of CMV Disease: For pediatric patients 4 months to 16 years of age who have received a kidney or heart transplant, the recommended once daily dose of Valcyte starting within 10 days of transplantation until 100 days post-transplantation is based on body surface area (BSA) and creatinine clearance (CrCl) derived from a modified Schwartz formula, and is calculated using the equation below:
Pediatric Dose (mg) = 7 x BSA x CrCl (calculated using a modified Schwartz formula), where
Mosteller BSA (m2) = √Height (cm) x Weight (kg)/3600
Schwartz Creatinine Clerance (mL/min/1.73m2) = k x Height (cm)/Serum Creatinine (mg / dL)
where k =
0.45 for patients aged < 1 year,
0.45 for patients aged 1 to < 2 years (note k value is 0.45 instead of the typical value of 0.55),
0.55 for boys aged 2 to < 13 years and girls aged 2 to 16 years, and
0.7 for boys aged 13 to 16 years.
All calculated doses should be rounded to the nearest 25 mg increment for the actual deliverable dose. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. Valcyte for oral solution is the preferred formulation since it provides the ability to administer a dose calculated according to the formula above; however, Valcyte tablets may be used if the calculated doses are within 10% of available tablet strength (450 mg). For example, if the calculated dose is between 405 mg and 495 mg, one 450 mg tablet may be taken.
Prior to dispensing to the patient, Valcyte for oral solution must be prepared by the pharmacist as follows [see HOW SUPPLIED/Storage and Handling]:
The patient package insert, which includes the dosing instructions for patients and 2 oral dispensers, should be dispensed to the patient [see Patient Counseling Information].
Dosage recommendations for adult patients with reduced renal function are provided in Table 1. For adult patients on hemodialysis (CrCl < 10 mL/min), a dose recommendation for Valcyte cannot be given [see Use in Specific Populations, CLINICAL PHARMACOLOGY].
Table 1: Dosage Recommendations for Adult Patients With Impaired
Renal Function
| Valcyte 450 mg Tablets | ||
| CrCl* (mL/min) | Induction Dose | Maintenance/ Prevention Dose |
| ≥ 60 | 900 mg twice daily | 900 mg once daily |
| 40 59 | 450 mg twice daily | 450 mg once daily |
| 25 39 | 450 mg once daily | 450 mg every 2 days |
| 10 24 | 450 mg every 2 days | 450 mg twice weekly |
| < 10 (on hemodialysis) | not recommended | not recommended |
| *An estimated creatinine clearance is calculated from serum creatinine by the following formulas: | ||
| For males = | (140 - age [years]) x (body weight [kg]) |
| (72) x (serum creatinine [mg/dL]) |
For females = 0.85 x male value
Dosing in pediatric patients with renal impairment can be done using the recommended equations because CrCl is a component in the calculation.
Caution should be exercised in the handling of Valcyte tablets and Valcyte for oral solution. Tablets should not be broken or crushed. Because valganciclovir is considered a potential teratogen and carcinogen in humans, caution should be observed in handling broken tablets, the powder for oral solution, and the constituted oral solution [see WARNINGS AND PRECAUTIONS]. Avoid direct contact with broken or crushed tablets, the powder for oral solution, and the constituted oral solution with skin or mucous membranes. If such contact occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with plain water.
Because ganciclovir shares some of the properties of antitumor agents (i.e., carcinogenicity and mutagenicity), consideration should be given to handling and disposal according to guidelines issued for antineoplastic drugs. Several guidelines on this subject have been published. However, there is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate [see References].
450 mg, pink, convex oval tablets with VGC on one side and 450 on the other side.
50 mg/mL, supplied as a white to slightly yellow powder for constitution, forming a colorless to brownish yellow tutti-frutti flavored solution. Available in glass bottles containing approximately 100 mL of solution after constitution. Valcyte for oral solution must be constituted by the pharmacist prior to dispensing to the patient [see DOSAGE AND ADMINISTRATION].
Supplied as 450 mg pink convex oval tablets with VGC on one side and 450 on the other side. Each tablet contains valganciclovir HCl equivalent to 450 mg valganciclovir. Valcyte is supplied in bottles of 60 tablets (NDC 0004-0038-22).
Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [See USP controlled room temperature].
Supplied as a white to slightly yellow powder blend for constitution, forming a colorless to brownish yellow tutti-frutti flavored solution. Available in glass bottles containing approximately 100 mL of solution after constitution. Each bottle can deliver up to a total of 88 mL of solution. Each bottle is supplied with a bottle adapter and 2 oral dispensers (NDC 0004-0039-09).
Prior to dispensing to the patient, Valcyte for oral solution must be prepared by the pharmacist [see DOSAGE AND ADMINISTRATION].
Store dry powder at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [See USP controlled room temperature].
Store constituted solution under refrigeration at 2°C to 8°C (36°F to 46°F) for no longer than 49 days. Do not freeze.
Distributed by: Roche Laboratories Inc. 340 Kingsland Street. Nutley, New Jersey 07110-1199. Revised: August 2009.
Last updated on RxList: 9/9/2009
The following serious adverse events are discussed in greater detail in other sections of the labeling:
The most common adverse events and laboratory abnormalities reported in at least one indication by ≥ 20% of adult patients treated with Valcyte tablets are diarrhea, pyrexia, nausea, tremor, neutropenia, anemia, graft rejection, thrombocytopenia, and vomiting. The most common reported adverse events and laboratory abnormalities reported in > 10% of pediatric solid organ transplant recipients treated with Valcyte for oral solution or tablets are diarrhea, pyrexia, hypertension, upper respiratory tract infection, vomiting, anemia, neutropenia, constipation, nausea, and cough.
Valganciclovir, a prodrug of ganciclovir, is rapidly converted to ganciclovir after oral administration. Adverse events known to be associated with ganciclovir usage can therefore be expected to occur with Valcyte.
Because clinical trials are conducted under widely varying conditions, adverse event rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect rates observed in practice.
Treatment of CMV Retinitis in AIDS Patients: In a clinical study for the treatment of CMV retinitis in HIV-infected patients, the adverse events reported by patients receiving Valcyte tablets (n=79) or intravenous ganciclovir (n=79) for 28 days of randomized therapy (21 days induction dose and 7 days maintenance dose), respectively, included diarrhea (16%, 10%), nausea (8%, 14%), headache (9%, 5%), and catheter-related infections (3%, 11%). The incidence of adverse events was similar between the group who received Valcyte tablets and the group who received intravenous ganciclovir, with the exception of catheter-related infections, which occurred with greater frequency in patients randomized to receive intravenous ganciclovir. The frequencies of neutropenia (ANC < 500/µL) were 11% for patients receiving Valcyte tablets compared with 13% for patients receiving intravenous ganciclovir. Anemia (Hgb < 8 g/dL) occurred in 8% of patients in each group. Other laboratory abnormalities occurred with similar frequencies in the two groups.
Adverse events and abnormal laboratory values data are available for 370 patients who received maintenance therapy with Valcyte tablets 900 mg once daily in two open-label clinical trials. Approximately 252 (68%) of these patients received Valcyte tablets for more than nine months (maximum duration was 36 months). Table 2 and Table 3 show the pooled adverse event data and abnormal laboratory values from these patients.
Table 2: Pooled Selected Adverse Events Reported in ≥
5% of Patients who Received Valcyte Tablets Maintenance Therapy for CMV Retinitis
| Adverse Events According to Body System | Patients with CMV Retinitis |
| Valcyte Tablets (N=370) % |
|
| Gastrointestinal system | |
| Diarrhea | 41 |
| Nausea | 30 |
| Vomiting | 21 |
| Abdominal pain | 15 |
| Body as a whole | |
| Pyrexia | 31 |
| Headache | 22 |
| Central and peripheral nervous system | |
| Insomnia | 16 |
| Peripheral neuropathy | 9 |
| Paresthesia | 8 |
| Special senses | |
| Retinal detachment | 15 |
Table 3: Pooled Laboratory Abnormalities Reported in Patients
Who Received Valcyte Tablets Maintenance Therapy for the Treatment of CMV Retinitis
| Laboratory Abnormalities | Patients with CMV Retinitis |
| Valcyte Tablets (N=370) % |
|
| Neutropenia: ANC/µL | |
| < 500 | 19 |
| 500 < 750 | 17 |
| 750 < 1000 | 17 |
| Anemia: Hemoglobin g/dL | |
| < 6.5 | 7 |
| 6.5 < 8.0 | 13 |
| 8.0 < 9.5 | 16 |
| Thrombocytopenia: Platelets/µL | |
| < 25000 | 4 |
| 25000 < 50000 | 6 |
| 50000 < 100000 | 22 |
| Serum Creatinine: mg/dL | |
| > 2.5 | 3 |
| > 1.5 2.5 | 12 |
Prevention of CMV Disease in Selected Solid Organ Transplantation: Table 4 shows selected adverse events regardless of severity and drug relationship with an incidence of ≥ 5% from a clinical trial (up to 28 days after study treatment) where heart, kidney, kidney-pancreas and liver transplant patients received Valcyte tablets (N=244) or oral ganciclovir (N=126). The majority of the adverse events were of mild or moderate intensity.
Table 4: Percentage of Selected Grades 1-4 Adverse Events
Reported in ≥ 5% of Patients From a Study of Selected Solid Organ Transplant
Patients
| Adverse Event | Valcyte Tablets (N=244) % |
Oral Ganciclovir (N=126) % |
| Diarrhea | 30 | 29 |
| Tremors | 28 | 25 |
| Graft rejection | 24 | 30 |
| Nausea | 23 | 23 |
| Headache | 22 | 27 |
| Insomnia | 20 | 16 |
| Hypertension | 18 | 15 |
| Vomiting | 16 | 14 |
| Pyrexia | 13 | 14 |
Adverse events not included in Table 4, which either occurred at a frequency of ≥ 5% in a clinical study with solid organ transplant patients, or were selected serious adverse events reported in studies with patients with CMV retinitis or in studies with solid organ transplant patients with a frequency of < 5% are listed below.
Allergic reactions: valganciclovir hypersensitivity
Bleeding complications: potentially life-threatening bleeding associated with thrombocytopenia
Central and peripheral nervous system: paresthesia, dizziness (excluding vertigo), convulsion
Gastrointestinal disorders: abdominal pain, constipation, dyspepsia, abdominal distention, ascites
General disorders and administration site disorders: fatigue, pain, edema, peripheral edema, weakness
Hemic system: anemia, neutropenia, thrombocytopenia, pancytopenia, bone marrow depression, aplastic anemia
Hepatobiliary disorders: abnormal hepatic function
Infections and infestations: pharyngitis/nasopharyngitis, upper respiratory tract infection, urinary tract infection, local and systemic infections and sepsis, postoperative wound infection
Injury, poisoning, and procedural complications: postoperative complications, postoperative pain, increased wound drainage, wound dehiscence
Metabolism and nutrition disorders: hyperkalemia, hypokalemia, hypomagnesemia, hyperglycemia, appetite decreased, dehydration, hypophosphatemia, hypocalcemia
Musculoskeletal and connective tissue disorders: back pain, arthralgia, muscle cramps, limb pain
Psychiatric disorders: depression, psychosis, hallucinations, confusion, agitation
Renal and urinary disorders: renal impairment, dysuria, decreased creatinine clearance
Respiratory, thoracic and mediastinal disorders: cough, dyspnea, rhinorrhea, pleural effusion
Skin and subcutaneous tissue disorders: dermatitis, pruritus, acne
Vascular disorders: hypotension
Laboratory abnormalities reported with Valcyte tablets in one study in solid organ transplant patients are listed in Table 5.
Table 5: Laboratory Abnormalities Reported in a Study of
Selected Solid Organ Transplant Patients*
| Laboratory Abnormalities | Valcyte Tablets (N=244) % |
Ganciclovir Capsules (N=126) % |
| Neutropenia: ANC/µL | ||
| < 500 | 5 | 3 |
| 500 < 750 | 3 | 2 |
| 750 < 1000 | 5 | 2 |
| Anemia: Hemoglobin g/dL | ||
| < 6.5 | 1 | 2 |
| 6.5 < 8.0 | 5 | 7 |
| 8.0 < 9.5 | 31 | 25 |
| Thrombocytopenia: Platelets/µL | ||
| < 25000 | 0 | 2 |
| 25000 < 50000 | 1 | 3 |
| 50000 < 100000 | 18 | 21 |
| Serum Creatinine: mg/dL | ||
| > 2.5 | 14 | 21 |
| > 1.5 2.5 | 45 | 47 |
| *Laboratory abnormalities are those reported by investigators. | ||
Valcyte for oral solution and tablets have been studied in 109 pediatric solid organ transplant patients who were at risk for developing CMV disease (aged 4 months to 16 years) and in 24 neonates with symptomatic congenital CMV disease (aged 8 to 34 days), with duration of ganciclovir exposure ranging from 2 to 100 days. The overall safety profile was similar in pediatric patients as compared to adult patients. However, the rates of certain adverse events and laboratory abnormalities, such as upper respiratory tract infection, pyrexia, nasopharyngitis, anemia, and neutropenia, were reported more frequently in pediatric patients than in adults [see Use in Specific Populations, Clinical Studies].
In general, the adverse events reported during the postmarketing use of Valcyte were similar to those identified during the clinical trials and to those reported during the postmarketing use of ganciclovir. Please also refer to the intravenous ganciclovir product information and ganciclovir capsule product information for more information on postmarketing adverse events associated with ganciclovir.
No in vivo drug-drug interaction studies were conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, drug-drug interactions associated with ganciclovir will be expected for Valcyte. Established and other potentially significant drug interactions conducted with ganciclovir are listed in Table 6.
Table 6: Established and Other Potentially Significant Drug
Interactions With Ganciclovir
| Name of the Concomitant Drug | Change in the Concentration of Drug Ganciclovir or Concomitant | Clinical Comment |
| Didanosine | ↓ Ganciclovir ↑ Didanosine |
Patients should be closely monitored for didanosine toxicity |
| Mycophenolate Mofetil (MMF) | ↔ Ganciclovir (in patients with normal renal function) ↔ MMF (in patients with normal renal function) |
Patients with renal impairment should be monitored carefully as levels of MMF metabolites and ganciclovir may increase |
| Probenicid | ↑ Ganciclovir | Patients taking probenicid and Valcyte should be monitored for evidence of ganciclovir toxicity |
| Zidovudine | ↓ Ganciclovir ↑ Zidovudine |
Zidovudine and Valcyte each have the potential to cause neutropenia and anemia. |
Last updated on RxList: 9/9/2009
Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow aplasia, and aplastic anemia have been reported in patients treated with Valcyte or ganciclovir. Valcyte should not be administered if the absolute neutrophil count is less than 500 cells/µL, the platelet count is less than 25,000/µL, or the hemoglobin is less than 8 g/dL. Valcyte should also be used with caution in patients with pre-existing cytopenias, or who have received or who are receiving myelosuppressive drugs or irradiation. Cytopenia may occur at any time during treatment and may worsen with continued dosing. Cell counts usually begin to recover within 3 to 7 days after discontinuing drug.
Due to the frequency of neutropenia, anemia, and thrombocytopenia in patients receiving Valcyte [see ADVERSE REACTIONS], complete blood counts with differential and platelet counts should be performed frequently, especially in patients in whom ganciclovir or other nucleoside analogues have previously resulted in leukopenia, or in whom neutrophil counts are less than 1000 cells/µL at the beginning of treatment. Increased monitoring for cytopenias may be warranted if therapy with oral ganciclovir is changed to Valcyte, because of increased plasma concentrations of ganciclovir after Valcyte administration [see CLINICAL PHARMACOLOGY].
Animal data indicate administration of ganciclovir causes inhibition of spermatogenesis and subsequent infertility. These effects were reversible at lower doses but irreversible at higher doses [see Nonclinical Toxicology]. In men, Valcyte at the recommended doses may cause temporary or permanent inhibition of spermatogenesis. Animal data also indicate suppression of fertility in females may occur.
Animal data indicate ganciclovir is teratogenic and mutagenic. Therefore, Valcyte should be considered to have the potential to cause birth defects and cancers in humans. Women of childbearing potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with Valcyte. Similarly, men should be advised to practice barrier contraception during and for at least 90 days following treatment with Valcyte [see DOSAGE AND ADMINISTRATION, Use in Specific Populations, Nonclinical Toxicology].
Animal data indicate that administration of ganciclovir is carcinogenic. Valcyte should therefore be considered a potential carcinogen in humans [see DOSAGE AND ADMINISTRATION, Nonclinical Toxicology].
Acute renal failure may occur in:
See FDA-Approved Patient Labeling
Valcyte tablets cannot be substituted for ganciclovir capsules on a one-to-one basis. Inform patients switching from ganciclovir capsules of the risk of overdosage if they take more than the prescribed number of Valcyte tablets [see DOSAGE AND ADMINISTRATION, OVERDOSAGE].
Adult patients should use Valcyte tablets, not Valcyte for oral solution [see DOSAGE AND ADMINISTRATION].
Valcyte is changed to ganciclovir once it is absorbed into the body. Inform all patients that the major toxicities of ganciclovir include granulocytopenia (neutropenia), anemia, and thrombocytopenia and that dose modifications may be required, including discontinuation. The importance of close monitoring of blood counts while on therapy should be emphasized. Inform patients that ganciclovir has been associated with elevations in serum creatinine.
Instruct patients to take Valcyte with food to maximize bioavailability.
Advise patients that ganciclovir causes decreased sperm production in animals and may cause decreased fertility in humans. Advise women of childbearing potential that ganciclovir causes birth defects in animals and should not be used during pregnancy. Because of the potential for serious adverse events in nursing infants, instruct mothers not to breast-feed if they are receiving Valcyte. Advise women of childbearing potential to use effective contraception during and for at least 30 days following treatment with Valcyte. Similarly, advise men to practice barrier contraception during and for at least 90 days following treatment with Valcyte.
Although there is no information from human studies, advise patients that ganciclovir should be considered a potential carcinogen.
Convulsions, sedation, dizziness, ataxia and/or confusion have been reported with the use of Valcyte and/or ganciclovir. If they occur, tasks requiring alertness may be affected including the patient's ability to drive and operate machinery.
Inform patients that ganciclovir is not a cure for CMV retinitis, and they may continue to experience progression of retinitis during or following treatment. Advise patients to have ophthalmologic follow-up examinations at a minimum of every 4 to 6 weeks while being treated with Valcyte. Some patients will require more frequent follow-up.
No long-term carcinogenicity studies have been conducted with Valcyte. However, upon oral administration, valganciclovir is rapidly and extensively converted to ganciclovir. Therefore, like ganciclovir, valganciclovir is a potential carcinogen.
Ganciclovir was carcinogenic in the mouse at oral doses that produced exposures approximately 0.1x and 1.4x, respectively, the mean drug exposure in humans following the recommended intravenous dose of 5 mg/kg, based on area under the plasma concentration curve (AUC) comparisons. At the higher dose there was a significant increase in the incidence of tumors of the preputial gland in males, forestomach (nonglandular mucosa) in males and females, and reproductive tissues (ovaries, uterus, mammary gland, clitoral gland and vagina) and liver in females. At the lower dose, a slightly increased incidence of tumors was noted in the preputial and harderian glands in males, forestomach in males and females, and liver in females. Ganciclovir should be considered a potential carcinogen in humans.
Valganciclovir increases mutations in mouse lymphoma cells. In the mouse micronucleus assay, valganciclovir was clastogenic. Valganciclovir was not mutagenic in the Ames Salmonella assay. Ganciclovir increased mutations in mouse lymphoma cells and DNA damage in human lymphocytes in vitro. In the mouse micronucleus assay, ganciclovir was clastogenic. Ganciclovir was not mutagenic in the Ames Salmonella assay.
Valganciclovir is converted to ganciclovir and therefore is expected to have similar reproductive toxicity effects as ganciclovir [see WARNINGS AND PRECAUTIONS]. Ganciclovir caused decreased mating behavior, decreased fertility, and an increased incidence of embryolethality in female mice following intravenous doses that produced an exposure approximately 1.7x the mean drug exposure in humans following the dose of 5 mg/kg, based on AUC comparisons. Ganciclovir caused decreased fertility in male mice and hypospermatogenesis in mice and dogs following daily oral or intravenous administration. Systemic drug exposure (AUC) at the lowest dose showing toxicity in each species ranged from 0.03 to 0.1x the AUC of the recommended human intravenous dose. Valganciclovir caused similar effects on spermatogenesis in mice, rats, and dogs. It is considered likely that ganciclovir (and valganciclovir) could cause inhibition of human spermatogenesis.
Pregnancy Category C. After oral administration, valganciclovir (prodrug) is converted to ganciclovir (active drug) and, therefore, is expected to have reproductive toxicity effects similar to ganciclovir. There are no adequate and well-controlled studies of valganciclovir or ganciclovir use in pregnant women. In animal studies of ganciclovir, embryo-fetal toxicity and structural malformations occurred. Valganciclovir should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
In animal studies, pregnant mice and rabbits received ganciclovir at doses that produced 2 times the human exposure (based on AUC comparison). Treated rabbits had increased rates of fetal resorption, fetal growth retardation, embryolethality, maternal toxicity, cleft palate, anophthalmia/microphthalmia, aplastic organs kidney and pancreas), hydrocephaly and brachygnathia. In mice, increased fetal resorptions and embryolethality occurred in the presence of maternal/fetal toxicity.
Daily intravenous doses of approximately 1.7 times the human exposure (based on AUC) administered to female mice prior to mating, during gestation, and during lactation caused hypoplasia of the testes and seminal vesicles in month-old male offspring, as well as pathologic changes in the nonglandular region of the stomach.
Data from an ex-vivo human placental model showed that ganciclovir crosses the human placenta. The transfer occurred by passive diffusion and was not saturable over a concentration range of 1 to 10 mg/mL [see Nonclinical Toxicology].
It is not known whether valganciclovir (prodrug) or ganciclovir (active drug) are excreted in human milk. Because valganciclovir caused granulocytopenia, anemia and thrombocytopenia in clinical trials and ganciclovir was mutagenic and carcinogenic in animal studies, serious adverse events may occur from ganciclovir exposure in nursing infants [see Boxed Warning]. Because of the potential for serious adverse events in nursing infants, a decision should be made whether to discontinue nursing or discontinue drug, taking into consideration the importance of the drug to the mother. The Centers for
Disease Control and Prevention recommend that HIV-infected mothers not breast-feed their infants to avoid risking postnatal transmission of HIV.
Valcyte for oral solution and tablets are indicated for the prevention of CMV disease in kidney and heart transplant pediatric patients 4 months to 16 years of age at risk for developing CMV disease [see INDICATIONS, DOSAGE AND ADMINISTRATION].
The use of Valcyte for oral solution and tablets for the prevention of CMV disease in pediatric patients 4 months to 16 years of age with kidney or heart transplant is based on pharmacokinetic, safety, and efficacy data from an open-label trial with oral Valcyte (Valcyte for oral solution or tablets) in pediatric solid organ transplant recipients at risk for developing CMV disease. The results of this study were supported by previous demonstration of efficacy in adult patients [see ADVERSE REACTIONS, CLINICAL PHARMACOLOGY, Clinical Studies].
The safety and efficacy of Valcyte for oral solution and tablets have not been established in children for:
The pharmacokinetic profile and safety of Valcyte for oral solution in children were studied in two open-label studies.
Study 1 was an open-label trial with oral Valcyte (Valcyte for oral solution or tablets) in pediatric solid organ transplant recipients at risk for developing CMV disease [see CLINICAL PHARMACOLOGY, Clinical Studies].
Study 2 was a pharmacokinetic and pharmacodynamic evaluation of Valcyte for oral solution in neonates with congenital CMV infection involving the central nervous system. Twenty-four neonates were enrolled in this study. All patients were treated for 6 weeks with a combination of intravenous ganciclovir 6 mg/kg twice daily and Valcyte for oral solution at doses ranging from 14 mg/kg to 20 mg/kg twice daily. The pharmacokinetic results showed that in infants > 7 days to 3 months of age, a dose of 16 mg/kg twice daily of Valcyte for oral solution provided ganciclovir systemic exposures (median AUC0-12h = 23.6 [range 16.8 35.5] ΅g·h/mL; n = 6) comparable to those obtained in infants up to 3 months from a 6 mg/kg dose of intravenous ganciclovir twice daily (AUC0-12h = 25.3 [range 2.4 89.7] ΅g·h/mL; n = 18) or to the ganciclovir systemic exposures obtained in adults from a 900 mg dose of Valcyte tablets twice daily.
The safety and efficacy of intravenous ganciclovir have not been established for the treatment of congenital CMV infection in infants and no similar disease occurs in adults; therefore, efficacy cannot be extrapolated from intravenous ganciclovir use in adults.
No studies of Valcyte for oral solution or tablets have been conducted in adults older than 65 years of age. Clinical studies of Valcyte did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Valcyte is known to be substantially excreted by the kidneys, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection. In addition, renal function should be monitored and dosage adjustments should be made accordingly [see DOSAGE AND ADMINISTRATION, CLINICAL PHARMACOLOGY].
Dose reduction is recommended when administering Valcyte to patients with renal impairment [see DOSAGE AND ADMINISTRATION].
For adult patients on hemodialysis (CrCl < 10 mL/min) Valcyte tablets should not be used. Adult hemodialysis patients should use ganciclovir in accordance with the dose-reduction algorithm cited in the Cytovene®-IV and ganciclovir capsules complete product information section on DOSAGE AND ADMINISTRATION: Renal Impairment [see DOSAGE AND ADMINISTRATION and CLINICAL PHARMACOLOGY].
The safety and efficacy of Valcyte have not been studied in patients with hepatic impairment.
Last updated on RxList: 9/9/2009
Experience With Valcyte Tablets: One adult developed fatal bone marrow depression (medullary aplasia) after several days of dosing that was at least 10-fold greater than recommended for the patient's estimated degree of renal impairment.
An overdose of Valcyte could also possibly result in increased renal toxicity [see DOSAGE AND ADMINISTRATION, Use in Specific Populations].
Because ganciclovir is dialyzable, dialysis may be useful in reducing serum concentrations in patients who have received an overdose of Valcyte [see CLINICAL PHARMACOLOGY]. Adequate hydration should be maintained. The use of hematopoietic growth factors should be considered [see CLINICAL PHARMACOLOGY].
Experience With Intravenous Ganciclovir: Reports of overdoses with intravenous ganciclovir have been received from clinical trials and during postmarketing experience. The majority of patients experienced one or more of the following adverse events:
Hematological toxicity: pancytopenia, bone marrow depression, medullary aplasia, leukopenia, neutropenia, granulocytopenia
Hepatotoxicity: hepatitis, liver function disorder
Renal toxicity: worsening of hematuria in a patient with pre-existing renal impairment, acute renal failure, elevated creatinine
Gastrointestinal toxicity: abdominal pain, diarrhea, vomiting
Neurotoxicity: generalized tremor, convulsion
Valcyte is contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valganciclovir, ganciclovir, or any component of the formulation [see ADVERSE REACTIONS].
Last updated on RxList: 9/9/2009
Valganciclovir is an antiviral drug.
Because the major elimination pathway for ganciclovir is renal, dosage reductions according to creatinine clearance are required for Valcyte tablets and Valcyte for oral solution [see DOSAGE AND ADMINISTRATION].
Pharmacokinetics in adults: The pharmacokinetics of valganciclovir and ganciclovir after administration of valganciclovir tablets have been evaluated in HIV- and CMV-seropositive patients, patients with AIDS and CMV retinitis, and in solid organ transplant patients.
The ganciclovir pharmacokinetic parameters following administration of 900 mg Valcyte tablets and 5 mg/kg intravenous ganciclovir and 1000 mg three times daily oral ganciclovir in HIV-positive/CMV-positive patients are summarized in Table 7.
Table 7: Mean Ganciclovir Pharmacokinetic* Measures in Healthy
Volunteers and HIV-positive/CMV-positive Adults at Maintenance Dosage
| Formulation | Valcyte Tablets | Intravenous Ganciclovir | Ganciclovir Capsules |
| Dosage | 900 mg once daily with food | 5 mg/kg once daily | 1000 mg three times daily with food |
| AUC0-24h (µg.h/mL) | 29.1 ± 9.7 (3 studies, n=57) | 26.5 ± 5.9 (4 studies, n=68) | Range of means 12.3 to 19.2 (6 studies, n=94) |
| Cmax (µg/mL) | 5.61 ± 1.52 (3 studies, n=58) | 9.46 ± 2.02 (4 studies, n=68) | Range of means 0.955 to 1.40 (6 studies, n=94) |
| Absolute oral bioavailability (%) | 59.4 ± 6.1 (2 studies, n=32) |
Not Applicable | Range of means 6.22 ± 1.29 to 8.53 ± 1.53 (2 studies, n=32) |
| Elimination half-life (hr) | 4.08 ± 0.76 (4 studies, n=73) | 3.81 ± 0.71 (4 studies, n=69) | Range of means 3.86 to 5.03 (4 studies, n=61) |
| Renal clearance (mL/min/kg) | 3.21 ± 0.75 (1 study, n=20) | 2.99 ± 0.67 (1 study, n=16) | Range of means 2.67 to 3.98 (3 studies, n=30) |
| *Data were obtained from single and multiple dose studies in healthy volunteers, HIV-positive patients, and HIV-positive/CMV-positive patients with and without retinitis. Patients with CMV retinitis tended to have higher ganciclovir plasma concentrations than patients without CMV retinitis. | |||
The area under the plasma concentration-time curve (AUC) of ganciclovir administered as Valcyte tablets (900 mg once daily) is comparable to the AUC of ganciclovir after administration of intravenous ganciclovir (5 mg/kg once daily). The Cmax of ganciclovir following Valcyte administration is 40% lower than the Cmax following intravenous ganciclovir administration. During maintenance dosing, ganciclovir AUC0-24h and Cmax following oral ganciclovir administration (1000 mg three times daily) are lower relative to Valcyte and intravenous ganciclovir. The ganciclovir Cmin following intravenous ganciclovir and Valcyte administration are less than the ganciclovir Cmin following oral ganciclovir administration. The clinical significance of the differences in ganciclovir pharmacokinetics after administration of Valcyte tablets, ganciclovir capsules, and intravenous ganciclovir is unknown.
Figure 1. Ganciclovir Plasma Concentration Time Profiles in
HIV-positive/CMV-positive Patients*
 |
*Plasma concentration-time profiles for ganciclovir (GCV) from valganciclovir (VGCV) and intravenous ganciclovir were obtained from a multiple dose study (n=21 and n=18, respectively) in HIV-positive/CMV-positive patients with CMV retinitis. The plasma concentration-time profile for oral ganciclovir was obtained from a multiple dose study (n=24) in HIV-positive/CMV-positive patients without CMV retinitis.
In solid organ transplant recipients, the mean systemic exposure to ganciclovir was 1.7 x higher following administration of 900 mg Valcyte tablets once daily versus 1000 mg ganciclovir capsules three times daily, when both drugs were administered according to their renal function dosing algorithms. The systemic ganciclovir exposures attained were comparable across kidney, heart and liver transplant recipients based on a population pharmacokinetics evaluation (see Table 8).
Table 8: Mean Ganciclovir Pharmacokinetic Measures by Organ
Transplant Type
| Parameter | Ganciclovir Capsules | Valcyte Tablets |
| Dosage | 1000 mg three times daily with food | 900 mg once daily with food |
| Heart Transplant Recipients | N=13 | N=17 |
| AUC0-24h (µg·h/mL) | 26.6 ± 11.6 | 40.2 ± 11.8 |
| Cmax (µg/mL) | 1.4 ± 0.5 | 4.9 ± 1.1 |
| Elimination half-life (hr) | 8.47 ± 2.84 | 6.58 ± 1.50 |
| Liver Transplant Recipients | N=33 | N=75 |
| AUC0-24h (µg·h/mL) | 24.9 ± 10.2 | 46.0 ± 16.1 |
| Cmax (µg/mL) | 1.3 ± 0.4 | 5.4 ± 1.5 |
| Elimination half-life (hr) | 7.68 ± 2.74 | 6.18 ± 1.42 |
| Kidney Transplant Recipients* | N=36 | N=68 |
| AUC0-24h (µg·h/mL) | 31.3 ± 10.3 | 48.2 ± 14.6 |
| Cmax (µg/mL) | 1.5 ± 0.5 | 5.3 ± 1.5 |
| Elimination half-life (hr) | 9.44 ± 4.37 | 6.77 ± 1.25 |
| * Includes kidney-pancreas | ||
In a pharmacokinetic study in liver transplant patients, the ganciclovir AUC0-24h achieved with 900 mg valganciclovir was 41.7 ± 9.9 µg·h/mL (n=28) and the AUC0-24h achieved with the approved dosage of 5 mg/kg intravenous ganciclovir was 48.2 ± 17.3 µg·h/mL (n=27).
Absorption: Valganciclovir, a prodrug of ganciclovir, is well absorbed from the gastrointestinal tract and rapidly metabolized in the intestinal wall and liver to ganciclovir. The absolute bioavailability of ganciclovir from Valcyte tablets following administration with food was approximately 60% (3 studies, n=18; n=16; n=28). Ganciclovir median Tmax following administration of 450 mg to 2625 mg Valcyte tablets ranged from 1 to 3 hours. Dose proportionality with respect to ganciclovir AUC following administration of Valcyte tablets was demonstrated only under fed conditions. Systemic exposure to the prodrug, valganciclovir, is transient and low, and the AUC24 and Cmax values are approximately 1% and 3% of those of ganciclovir, respectively.
Food Effects: When Valcyte tablets were administered with a high fat meal containing approximately 600 total calories (31.1 g fat, 51.6 g carbohydrates and 22.2 g protein) at a dose of 875 mg once daily to 16 HIV-positive subjects, the steady-state ganciclovir AUC increased by 30% (95% CI 12% to 51%), and the Cmax increased by 14% (95% CI -5% to 36%), without any prolongation in time to peak plasma concentrations (Tmax). Valcyte should be administered with food [see DOSAGE AND ADMINISTRATION].
Distribution: Due to the rapid conversion of valganciclovir to ganciclovir, plasma protein binding of valganciclovir was not determined. Plasma protein binding of ganciclovir is 1% to 2% over concentrations of 0.5 and 51 µg/mL. When ganciclovir was administered intravenously, the steady-state volume of distribution of ganciclovir was 0.703 ± 0.134 L/kg (n=69).
After administration of Valcyte tablets, no correlation was observed between ganciclovir AUC and reciprocal weight; oral dosing of Valcyte tablets according to weight is not required.
Metabolism: Valganciclovir is rapidly hydrolyzed to ganciclovir; no other metabolites have been detected. No metabolite of orally administered radiolabeled ganciclovir (1000 mg single dose) accounted for more than 1% to 2% of the radioactivity recovered in the feces or urine.
Elimination: The major route of elimination of valganciclovir is by renal excretion as ganciclovir through glomerular filtration and active tubular secretion. Systemic clearance of intravenously administered ganciclovir was 3.07 ± 0.64 mL/min/kg (n=68) while renal clearance was 2.99 ± 0.67 mL/min/kg (n=16).
The terminal half-life (t½) of ganciclovir following oral administration of Valcyte tablets to either healthy or HIV-positive/CMV-positive subjects was 4.08 ± 0.76 hours (n=73), and that following administration of intravenous ganciclovir was 3.81 ± 0.71 hours (n=69). In heart, kidney, kidney-pancreas, and liver transplant patients, the terminal elimination half-life of ganciclovir following oral administration of Valcyte was 6.48 ± 1.38 hours, and following oral administration of ganciclovir capsules was 8.56 ± 3.62.
Renal Impairment: The pharmacokinetics of ganciclovir from a single oral dose of 900 mg Valcyte tablets were evaluated in 24 otherwise healthy individuals with renal impairment.
Table 9: Pharmacokinetics of Ganciclovir From a Single Oral
Dose of 900 mg Valcyte Tablets
| Estimated Creatinine Clearance (mL/min) | N | Apparent Clearance (mL/min) Mean ± SD | AUClast (µg·h/mL) Mean ± SD | Half-life (hours) Mean ± SD |
| 51-70 | 6 | 249 ± 99 | 49.5 ± 22.4 | 4.85 ± 1.4 |
| 21-50 | 6 | 136 ± 64 | 91.9 ± 43.9 | 10.2 ± 4.4 |
| 11-20 | 6 | 45 ± 11 | 223 ± 46 | 21.8 ± 5.2 |
| ≤ 10 | 6 | 12.8 ± 8 | 366 ± 66 | 67.5 ± 34 |
Decreased renal function results in decreased clearance of ganciclovir from valganciclovir, and a corresponding increase in terminal half-life. Therefore, dosage adjustment is required for patients with impaired renal function.
Hemodialysis reduces plasma concentrations of ganciclovir by about 50% following Valcyte administration. Adult patients receiving hemodialysis (CrCl < 10 mL/min) cannot use Valcyte tablets because the daily dose of Valcyte tablets required for these patients is less than 450 mg [see DOSAGE AND ADMINISTRATION and Use in Specific Populations].
Pharmacokinetics in Pediatric Patients: The pharmacokinetics of ganciclovir were evaluated following the administration of valganciclovir in 63 pediatric solid organ transplant patients aged 4 months to 16 years. In this study, patients received oral doses of valganciclovir (either Valcyte for oral solution or tablets) to produce exposure equivalent to an adult 900 mg dose [see DOSAGE AND ADMINISTRATION, ADVERSE REACTIONS, Use in Specific Populations, Clinical Studies].
The pharmacokinetics of ganciclovir were similar across organ types and age ranges. Population pharmacokinetic modeling suggested that bioavailability was approximately 60%. Clearance was positively influenced by both body surface area and renal function. The mean total clearance was 5.3 L/hr (88.3 mL/min) for a patient with creatinine clearance of 70.4 mL/min. The mean Cmax and AUC by age and organ type are listed in Table 10.
Table 10: Mean (SD) Pharmacokinetics of Ganciclovir by Age
in Pediatric Solid Organ Transplant Patients
| PK Parameter | Age Group in Years | |||
| ≤ 2 (n=2) | > 2 to < 12 (n=10)a,b | ≥ 12 (n=19) | ||
| Kidney (N=31) | AUC0-24h (µg·h/mL) | 67.6 (13.0) | 55.9 (12.1) | 47.8 (12.4) |
| Cmax (µg/mL) | 10.4 (0.4) | 8.7 (2.1) | 7.7 (2.1) | |
| t1/2 (h) | 4.5 (1.5) | 4.8 (1.0) | 6.0 (1.3) | |
| ≤ 2 (n=9) | > 2 to < 12 (n=6) | ≥ 12 (n=2) | ||
| Liver (N=17) | AUC0-24h (µg·h/mL) | 69.9 (37.0) | 59.4 (8.1) | 35.4 (2.8) |
| Cmax (µg/mL) | 11.9 (3.7) | 9.5 (2.3) | 5.5 (1.1) | |
| t1/2 (h) | 2.8 (1.5) | 3.8 (0.7) | 4.4 (0.2) | |
| ≤ 2 (n=6) | > 2 to < 12 (n=2) | ≥ 12 (n=4) | ||
| Heart (N=12) | AUC0-24h (µg·h/mL) | 55.4 (22.8) | 59.6 (21.0) | 60.6 (25.0) |
| Cmax (µg/mL) | 8.2 (2.5) | 12.5 (1.2) | 9.5 (3.3) | |
| t1/2 (h) | 3.8 (1.7) | 2.8 (0.9) | 4.9 (0.8) | |
| a There was one subject in this
age group who received both a kidney and liver transplant. The pharmacokinetic
profile for this subject has not been included in this table as it is
not possible to determine whether the effects observed are from the kidney/liver
transplant or neither. b The pharmacokinetic profiles for two subjects in this age group who received kidney transplants have not been included in this table as the data were determined to be non-evaluable. |
||||
Pharmacokinetics in Geriatric Patients: The pharmacokinetic characteristics of Valcyte in elderly patients have not been established. Because elderly individuals frequently have a reduced glomerular filtration rate, renal function should be assessed before and during administration of Valcyte [see DOSAGE AND ADMINISTRATION].
No in vivo drug-drug interaction studies were conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, interactions associated with ganciclovir will be expected for Valcyte [see DRUG INTERACTIONS].
Drug-drug interaction studies were conducted in patients with normal renal function. Patients with impaired renal function may have increased concentrations of ganciclovir and the coadministered drug following concomitant administration of Valcyte and drugs excreted by the same pathway as ganciclovir. Therefore, these patients should be closely monitored for toxicity of ganciclovir and the coadministered drug.
Table 11 and Table 12 provide a listing of established drug interaction studies with ganciclovir. Table 11 provides the effects of coadministered drug on ganciclovir plasma pharmacokinetic parameters, whereas Table 12 provides the effects of ganciclovir on plasma pharmacokinetic parameters of co-administered drug.
Table 11: Results of Drug Interaction Studies With Ganciclovir:
Effects of Coadministered Drug on Ganciclovir Pharmacokinetic Parameters
| Coadministered Drug | Ganciclovir Dosage | N | Ganciclovir Pharmacokinetic (PK) Parameter |
| Zidovudine 100 mg every 4 hours | 1000 mg every 8 hours | 12 | AUC ↓ 17 ± 25% (range: -52% to 23%) |
| Probenecid 500 mg every 6 hours | 1000 mg every 8 hours | 10 | AUC↑53 ± 91% (range: -14% to 299%) Ganciclovir renal clearance ↓ 22 ± 20% (range: -54% to -4%) |
| Mycophenolate Mofetil (MMF) 1.5 g single dose | IV ganciclovir 5 mg/kg single dose | 12 | No effect on ganciclovir PK parameters observed (patients with normal renal function) |
| Didanosine 200 mg every 12 hours administered 2 hours before ganciclovir | 1000 mg every 8 hours | 12 | AUC ↓ 21 ± 17% (range: -44% to 5%) |
| Didanosine 200 mg every 12 hours simultaneously administered with ganciclovir | 1000 mg every 8 hours | 12 | No effect on ganciclovir PK parameters observed |
| IV ganciclovir 5 mg/kg twice daily | 11 | No effect on ganciclovir PK parameters observed | |
| IV ganciclovir 5 mg/kg once daily | 11 | No effect on ganciclovir PK parameters observed | |
| Trimethoprim 200 mg once daily | 1000 mg every 8 hours | 12 | Ganciclovir renal clearance ↓ 16.3% Half-life ↑15% |
Table 12: Results of Drug Interaction Studies With Ganciclovir:
Effects of Ganciclovir on Pharmacokinetic Parameters of Coadministered Drug
| Coadministered Drug | Ganciclovir Dosage | N | Coadministered Drug Pharmacokinetic (PK) Parameter |
| Zidovudine 100 mg every 4 hours | 1000 mg every 8 hours | 12 | AUC0-4 ↑ 19 ± 27% (range: -11% to 74%) |
| Mycophenolate Mofetil (MMF) 1.5 g single dose | IV ganciclovir 5 mg/kg single dose | 12 | No PK interaction observed (patients with normal renal function) |
| Didanosine 200 mg every 12 hours when administered 2 hours prior to or concurrent with ganciclovir | 1000 mg every 8 hours | 12 | AUC0-12 ↑111 ± 114% (range: 10% to 493%) |
| Didanosine 200 mg every 12 hours | IV ganciclovir 5 mg/kg twice daily | 11 | AUC0-12 ↑70 ± 40%(range: 3% to 121%) |
| Cmax↑49 ± 48% (range: -28% to 125%) | |||
| Didanosine 200 mg every 12 hours | IV ganciclovir 5 mg/kg once daily | 11 | AUC0-12 ↑50 ± 26%(range: 22% to 110%) |
| Cmax ↑36 ± 36% (range: -27% to 94%) | |||
| Trimethoprim 200 mg once daily | 1000 mg every 8 hours | 12 | Increase (12%) in Cmin |
Mechanism of action: Valganciclovir is an L-valyl ester (prodrug) of ganciclovir that exists as a mixture of two diastereomers. After oral administration, both diastereomers are rapidly converted to ganciclovir by intestinal and hepatic esterases. Ganciclovir is a synthetic analogue of 2'-deoxyguanosine, which inhibits replication of human cytomegalovirus in cell culture and in vivo.
In CMV-infected cells ganciclovir is initially phosphorylated to ganciclovir monophosphate by the viral protein kinase, pUL97. Further phosphorylation occurs by cellular kinases to produce ganciclovir triphosphate, which is then slowly metabolized intracellularly (half-life 18 hours). As the phosphorylation is largely dependent on the viral kinase, phosphorylation of ganciclovir occurs preferentially in virus-infected cells. The virustatic activity of ganciclovir is due to inhibition of viral DNA synthesis by ganciclovir triphosphate.
Antiviral Activity: The quantitative relationship between the cell culture susceptibility of human herpes viruses to antivirals and clinical response to antiviral therapy has not been established, and virus sensitivity testing has not been standardized. Sensitivity test results, expressed as the concentration of drug required to inhibit the growth of virus in cell culture by 50% (EC50), vary greatly depending upon a number of factors. Thus the EC50 value of ganciclovir that inhibits human CMV replication in cell culture (laboratory and clinical isolates) has ranged from 0.08 to 22.94 µM (0.02 to 5.75 µg/mL). Ganciclovir inhibits mammalian cell proliferation (CIC50) in cell culture at higher concentrations ranging from 40 to > 1000 µM (10.21 to > 250 µg/mL). Bone marrow-derived colony-forming cells are more sensitive (CIC50 = 2.7 to 12 µM (0.69 to 3.06 µg/mL).
Viral Resistance: Viruses resistant to ganciclovir can arise after prolonged treatment with valganciclovir by selection of mutations in either the viral protein kinase gene (UL97) responsible for ganciclovir monophosphorylation and/or in the viral DNA polymerase gene (UL54). Virus with mutations in the UL97 gene is resistant to ganciclovir alone, whereas virus with mutations in the UL54 gene may show cross-resistance to other antivirals that target the same sites on viral DNA polymerase.
The current working definition of CMV resistance to ganciclovir in cell culture assays is EC50 value ≥ 6.0 µM ( ≥ 1.5 µg/mL). CMV resistance to ganciclovir has been observed in individuals (immunocompromized and neonates) receiving prolonged treatment with ganciclovir or valganciclovir. The possibility of viral resistance should be considered in patients who show poor clinical response or experience persistent viral excretion during therapy.
Valganciclovir is converted to ganciclovir and therefore is expected to have reproductive toxicity effects similar to ganciclovir. Ganciclovir has been shown to be embryotoxic in rabbits and mice following intravenous administration, and teratogenic in rabbits. Fetal resorptions were present in at least 85% of rabbits and mice administered doses that produced 2x the human exposure based on AUC comparisons (all dose comparisons presented are based on the human AUC following administration of a single 5 mg/kg infusion of intravenous ganciclovir). Effects observed in rabbits included: fetal growth retardation, embryolethality, teratogenicity and/or maternal toxicity. Teratogenic changes included cleft palate, anophthalmia/microphthalmia, aplastic organs (kidney and pancreas), hydrocephaly and brachygnathia. In mice, effects observed were maternal/fetal toxicity and embryolethality.
Daily intravenous doses administered to female mice prior to mating, during gestation, and during lactation caused hypoplasia of the testes and seminal vesicles in the month-old male offspring, as well as pathologic changes in the nonglandular region of the stomach [see WARNINGS AND PRECAUTIONS]. The drug exposure in mice as estimated by the AUC was approximately 1.7x the human AUC.
Data obtained using an ex vivo human placental model show that ganciclovir crosses the placenta and that simple diffusion is the most likely mechanism of transfer. The transfer was not saturable over a concentration range of 1 to 10 mg/mL and occurred by passive diffusion.
Induction Therapy of CMV Retinitis: In one randomized open-label controlled study, 160 patients with AIDS and newly diagnosed CMV retinitis were randomized to receive treatment with either Valcyte tablets (900 mg twice daily for 21 days, then 900 mg once daily for 7 days) or with intravenous ganciclovir solution (5 mg/kg twice daily for 21 days, then 5 mg/kg once daily for 7 days). Study participants were: male (91%), White (53%), Hispanic (31%), and Black (11%). The median age was 39 years, the median baseline HIV-1 RNA was 4.9 log10, and the median CD4 cell count was 23 cells/mm3. A determination of CMV retinitis progression by the masked review of retinal photographs taken at baseline and Week 4 was the primary outcome measurement of the 3-week induction therapy. Table 13 provides the outcomes at 4 weeks.
Table 13: Week 4 Masked Review of Retinal Photographs in
CMV Retinitis Study
| Intravenous Ganciclovir | Valcyte Tablets | |
| Determination of CMV retinitis progression at Week 4 | N=80 | N=80 |
| Progressor | 7 | 7 |
| Non-progressor | 63 | 64 |
| Death | 2 | 1 |
| Discontinuations due to Adverse Events | 1 | 2 |
| Failed to return | 1 | 1 |
| CMV not confirmed at baseline or no interpretable baseline photos | 6 | 5 |
Maintenance Therapy of CMV Retinitis: No comparative clinical data are available on the efficacy of Valcyte tablets for the maintenance therapy of CMV retinitis because all patients in the CMV retinitis study received open-label Valcyte tablets after Week 4. However, the AUC for ganciclovir is similar following administration of 900 mg Valcyte tablets once daily and 5 mg/kg intravenous ganciclovir once daily. Although the ganciclovir Cmax is lower following Valcyte tablets administration compared to intravenous ganciclovir, it is higher than the Cmax obtained following oral ganciclovir administration [see Figure 1 in CLINICAL PHARMACOLOGY]. Therefore, use of Valcyte tablets as maintenance therapy is supported by a plasma concentration-time profile similar to that of two approved products for maintenance therapy of CMV retinitis.
Prevention of CMV Disease in Heart, Kidney, Kidney-Pancreas, and Liver Transplantation: A double blind, double-dummy active comparator study was conducted in 372 heart, liver, kidney, and kidney-pancreas transplant patients at high-risk for CMV disease (D+/R-). Patients were randomized (2 Valcyte: 1 oral ganciclovir) to receive either Valcyte tablets (900 mg once daily) or oral ganciclovir (1000 mg three times a day) starting within 10 days of transplantation until Day 100 post-transplant. The proportion of patients who developed CMV disease, including CMV syndrome and/or tissue-invasive disease during the first 6 months post-transplant was similar between the Valcyte tablets arm (12.1%, N=239) and the oral ganciclovir arm (15.2%, N=125). However, in liver transplant patients, the incidence of tissue-invasive CMV disease was significantly higher in the Valcyte group compared with the ganciclovir group. These results are summarized in Table 14.
Mortality at six months was 3.7% (9/244) in the Valcyte group and 1.6% (2/126) in the oral ganciclovir group.
Table 14: Percentage of Patients With CMV Disease and Tissue-Invasive
CMV Disease by Organ Type: Endpoint Committee, 6 Month ITT Population
| CMV Disease1 | Tissue-Invasive CMV Disease | CMV Syndrome | ||||
| Organ | VGCV (N=239) |
GCV (N=125) |
VGCV (N=239) |
GCV (N=125) |
VGCV (N=239) |
GCV (N=125) |
| Liver (n=177) | 19% (22/118) | 12% (7/59) | 14% (16/118) | 3% (2/59) | 5% (6/118) | 9% (5/59) |
| Kidney (n=120) | 6% (5/81) | 23% (9/39) | 1% (1/81) | 5% (2/39) | 5% (4/81) | 18% (7/39) |
| Heart (n=56) | 6% (2/35) | 10% (2/21) | 0% (0/35) | 5% (1/21) | 6% (2/35) | 5% (1/21) |
| Kidney / Pancreas (n=11) | 0% (0/5) | 17% (1/6) | 0% (0/5) | 17% (1/6) | 0% (0/5) | 0% (0/6) |
| GCV = oral ganciclovir; VGCV = valganciclovir. 1 Number of Patients with CMV Disease = Number of Patients with Tissue-Invasive CMV Disease + Number of Patients with CMV Syndrome. |
||||||
Prevention of CMV in Pediatric Solid Organ Transplant Recipients: Sixty-three children, 4 months to 16 years of age, who had a solid organ transplant (kidney 33, liver 17, heart 12, and kidney/liver 1) and were at risk for developing CMV disease, were enrolled in an open-label, safety, and pharmacokinetic study of oral Valcyte (Valcyte for oral solution or tablets). Patients received Valcyte once daily as soon as possible after transplant until a maximum of 100 days post-transplant. The daily doses of Valcyte were calculated at each study visit based on body surface area and a modified creatinine clearance [see DOSAGE AND ADMINISTRATION].
The pharmacokinetics of ganciclovir were similar across organ transplant types and age ranges. The mean daily ganciclovir exposures in pediatric patients were comparable to those observed in adult solid organ transplant patients receiving Valcyte 900 mg once daily. No case of CMV disease was reported during the study. CMV viremia was reported in 7 (11%) patients during the study; however, none of these events fulfilled the definition of CMV syndrome. Based on the pharmacokinetic, safety, and efficacy data from this study and extrapolated efficacy data from the adult study, oral Valcyte is indicated for the prevention of CMV disease in kidney and heart transplant children 4 months to 16 years of age at risk for developing CMV disease. Valcyte is not approved in adults for CMV prophylaxis in liver transplant patients; therefore, Valcyte is not recommended for CMV prophylaxis in pediatric liver transplant patients because efficacy cannot be extrapolated from adults.
REFERENCES
Last updated on RxList: 9/9/2009
Read the Patient Information that comes with Valcyte (VAL-site) before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking with your healthcare provider.
What is the most important information I should know about Valcyte?
What is Valcyte?
Valcyte is an antiviral medicine used in:
Adults:
Children (4 months to 16 years of age):
Valcyte may:
Valcyte does not cure CMV retinitis. You may still get retinitis or worsening of retinitis during or after treatment with Valcyte. Therefore, it is important to stay under a doctor's care and have your eyes checked regularly.
The safety and efficacy of Valcyte have not been established in pediatric patients younger than 4 months of age.
The safety and efficacy of Valcyte have not been studied in adults older than age 65.
Who should not take Valcyte?
In addition, Valcyte is not for use in prevention of CMV disease in adults or children who have received a liver transplant. More research is needed before Valcyte can be recommended for use in the prevention of CMV disease in organ transplant patients other than those indicated (such as lung transplant patients).
Before taking Valcyte, tell your doctor:
Tell your doctor if you take medicines such as chemotherapy medicines that can lower your bone marrow function.
How should I take Valcyte?
What should I avoid while taking Valcyte?
What are the possible side effects of Valcyte?
See What is the most important information I should know about Valcyte? for details on the most serious side effects. Valcyte can also cause the following serious side effects:
Common side effects of Valcyte include diarrhea, nausea, vomiting, stomach pain, fever, headache, shaky movements (tremors), graft rejection, swelling of the legs, constipation, back pain, trouble sleeping, and high blood pressure.
Common changes in blood tests for people taking Valcyte include low white blood cells (neutropenia or leukopenia), low red blood cells (anemia), increased blood creatinine levels, increased calcium in the blood, and abnormal liver function.
Talk to your doctor about side effects that bother you or that won't go away.
These are not all the side effects of Valcyte. For more information, ask your doctor or pharmacist.
How do I store Valcyte?
General information about Valcyte
Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use Valcyte for a condition for which it was not prescribed. Do not give Valcyte to other people, even if they have the same symptoms you have. It may harm them.
This leaflet summarizes the most important information about Valcyte. If you would like more information, talk with your doctor. You can ask your doctor or pharmacist for information about Valcyte that is written for health professionals. Information about Valcyte is also available at 1-800-526-6367 (toll-free).
What are the ingredients in Valcyte?
Active Ingredient: valganciclovir HCl
Inactive Ingredients for Tablets: microcrystalline cellulose, povidone K-30, crospovidone, and stearic acid. The film-coating applied to the tablets contains Opadry Pink®.
Inactive Ingredients for Oral Solution: sodium benzoate, fumaric acid, povidone K-30, sodium saccharin, mannitol and tutti-frutti flavoring.
Dosing Instructions for Patients
How do I take Valcyte for oral solution?
Valcyte for oral solution will be prepared by the pharmacist prior to dispensing the medication to you.
Please follow instructions carefully to ensure proper dosing of the oral solution.
Figure 1
 |
Figure 2
 |
Care should be taken to avoid contact of the skin with the solution. If such contact occurs, wash thoroughly with soap and water.
Do not use the solution after the expiration date.
Contact your doctor or pharmacist if your oral dispenser is lost or damaged, and they will advise you on how to continue to take your medication.
Patient Information
VALCYTE®
(valganciclovir hydrochloride) Tablets
VALCYTE®
(valganciclovir hydrochloride) for Oral Solution
Read the Patient Information that comes with Valcyte (VAL-site) before you start using it and each time you get a refill. There may be new information. This information does not take the place of talking with your healthcare provider.
What is the most important information I should know about Valcyte?
What is Valcyte?
Valcyte is an antiviral medicine used in:
Adults:
Children (4 months to 16 years of age):
Valcyte may:
Valcyte does not cure CMV retinitis. You may still get retinitis or worsening of retinitis during or after treatment with Valcyte. Therefore, it is important to stay under a doctor's care and have your eyes checked regularly.
The safety and efficacy of Valcyte have not been established in pediatric patients younger than 4 months of age.
The safety and efficacy of Valcyte have not been studied in adults older than age 65.
Who should not take Valcyte?
In addition, Valcyte is not for use in prevention of CMV disease in adults or children who have received a liver transplant. More research is needed before Valcyte can be recommended for use in the prevention of CMV disease in organ transplant patients other than those indicated (such as lung transplant patients).
Before taking Valcyte, tell your doctor:
Tell your doctor if you take medicines such as chemotherapy medicines that can lower your bone marrow function.
How should I take Valcyte?
What should I avoid while taking Valcyte?
What are the possible side effects of Valcyte?
See What is the most important information I should know about Valcyte? for details on the most serious side effects. Valcyte can also cause the following serious side effects:
Common side effects of Valcyte include diarrhea, nausea, vomiting, stomach pain, fever, headache, shaky movements (tremors), graft rejection, swelling of the legs, constipation, back pain, trouble sleeping, and high blood pressure.
Common changes in blood tests for people taking Valcyte include low white blood cells (neutropenia or leukopenia), low red blood cells (anemia), increased blood creatinine levels, increased calcium in the blood, and abnormal liver function.
Talk to your doctor about side effects that bother you or that won't go away.
These are not all the side effects of Valcyte. For more information, ask your doctor or pharmacist.
How do I store Valcyte?
General information about Valcyte
Medicines are sometimes prescribed for conditions that are not mentioned in patient information leaflets. Do not use Valcyte for a condition for which it was not prescribed. Do not give Valcyte to other people, even if they have the same symptoms you have. It may harm them.
This leaflet summarizes the most important information about Valcyte. If you would like more information, talk with your doctor. You can ask your doctor or pharmacist for information about Valcyte that is written for health professionals. Information about Valcyte is also available at 1-800-526-6367 (toll-free).
What are the ingredients in Valcyte?
Active Ingredient: valganciclovir HCl
Inactive Ingredients for Tablets: microcrystalline cellulose, povidone K-30, crospovidone, and stearic acid. The film-coating applied to the tablets contains Opadry Pink®.
Inactive Ingredients for Oral Solution: sodium benzoate, fumaric acid, povidone K-30, sodium saccharin, mannitol and tutti-frutti flavoring.
Dosing Instructions for Patients
How do I take Valcyte for oral solution?
Valcyte for oral solution will be prepared by the pharmacist prior to dispensing the medication to you.
Please follow instructions carefully to ensure proper dosing of the oral solution.
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Care should be taken to avoid contact of the skin with the solution. If such contact occurs, wash thoroughly with soap and water.
Do not use the solution after the expiration date.
Contact your doctor or pharmacist if your oral dispenser is lost or damaged, and they will advise you on how to continue to take your medication.
Last updated on RxList: 9/9/2009
IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.
VALGANCICLOVIR- ORAL
(val-gan-SIGH-klow-veer)
COMMON BRAND NAME(S): Valcyte
WARNING: Valganciclovir has sometimes caused severe blood problems, including a decrease in red blood cells (anemia), white blood cells (neutropenia), and platelets (thrombocytopenia). Seek immediate medical attention if you develop signs of anemia (new/severe tiredness, fast breathing, weakness, bluish fingernails/lips, pale skin, fast heartbeat). A low level of white blood cells increase the risk of serious (sometimes fatal) infections. Seek immediate medical attention if you develop a new fever, chills, cough, breathing problems, loss of appetite, weight loss, new diarrhea, or sore throat. Severely low platelets can make you more likely to bleed. Seek immediate medical attention if you develop signs of bleeding such as easy bruising, increased nose bleeds, bleeding gums, bloody or black colored bowel movements, vomit that looks like coffee grounds.
USES: This drug is used to help control a serious internal eye infection called CMV (cytomegalovirus) retinitis in patients with AIDS (acquired immunodeficiency syndrome). It is also used to help prevent CMV problems in patients with certain organ transplants (kidney, heart, kidney with pancreas).
Controlling CMV retinitis can help decrease the risk of blindness from the infection. It can also help to prevent CMV from causing disease elsewhere in the body.
Valganciclovir is not a cure for CMV diseases.
HOW TO USE: Read the Patient Information Leaflet provided by your pharmacist before you start taking valganciclovir and each time you get a refill. If you have any questions, consult your doctor or pharmacist.
Take this medication by mouth with food, usually 1-2 times daily or as directed by your doctor. The dose for organ transplant patients is usually once daily. Swallow the tablets whole. Do not crush or break the tablets because doing so increases the risk of side effects. If you are taking this medication for CMV retinitis, your dose will be higher for the first 21 days to help get the infection under control.
Dosage is based on your weight, kidney function, medical condition, and response to therapy.
It is very important to continue taking this medication exactly as prescribed by your doctor.
This medication works best when the amount of drug in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals. To help you remember, take it at the same time(s) each day.
Do not take more or less of this drug than prescribed or stop taking it even for a short time unless directed to do so by your doctor. Skipping or changing your dose without approval from your doctor may cause the amount of virus to increase, make the infection more difficult to treat (resistant), or worsen side effects.
Valganciclovir and ganciclovir are not equal. Do not switch forms without consulting your doctor or pharmacist.
Inform your doctor if your condition worsens (e.g., worsening vision).
Diarrhea, nausea, vomiting, stomach pain, fever, headache, shaking (tremors), swelling of the legs, constipation, back pain, drowsiness, dizziness, and trouble sleeping may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor immediately if any of these unlikely but serious side effects occur: mental/mood changes (slowed thinking, confusion, depression), decrease in the amount of urine, tingling/numbness of hands or feet, seizures, persistent nausea, stomach/abdominal pain, dark urine, yellowing eyes/skin.
A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching, swelling, severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking valganciclovir, tell your doctor or pharmacist if you are allergic to it; or to ganciclovir; or if you have any other allergies.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: inability to make urine (anuria), kidney problems that require dialysis, severely low white/red blood cells, severely low platelets.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems, low white blood cells, low red blood cells, low platelets, bone marrow problems, HIV, liver problems (e.g., hepatitis B or C, cirrhosis), radiation treatment.
Valganciclovir may cause organ rejection problems in transplant patients. Ask your doctor about the symptoms of organ rejection.
This medication may cause cancer. Others should avoid touching the tablets. Avoid contact with broken or crushed tablets. Do not throw any tablets in the garbage or down the drain. Special disposal is required for this medication. Contact your pharmacist for more information.
This drug may make you dizzy or drowsy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages.
Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug.
This medication is not recommended for use during pregnancy due to the risk of harm to an unborn baby. To prevent pregnancy, men with female partners should always use effective barrier protections (e.g., latex or polyurethane condoms) during all sexual activity during treatment and for at least 90 days after stopping the medication. Women who are taking valganciclovir should also use at least 2 forms of effective birth control (e.g., birth control pills and condoms) during treatment and for at least 90 days after stopping the medication. Consult your doctor or pharmacist for more details.
It is not know if this medication passes into breast milk. Because of the possible risks to the infant, breast-feeding is not recommended.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: didanosine, drugs that may lower bone marrow function (e.g., trimethoprim, pyrimethamine, doxorubicin, dapsone, flucytosine, zidovudine), probenecid, drugs that may lower kidney function (e.g., amphotericin B, cisplatin, cyclosporine), mycophenolate.
If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting valganciclovir.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly.
NOTES: Do not share this medication with others.
Laboratory and/or medical tests (e.g., blood counts, kidney test, eye exams) should be performed often to monitor your progress or check for side effects. Consult your doctor for more details.
Keep all medical and laboratory appointments.
MISSED DOSE: If you miss a dose, take it as soon as you remember unless it is within 2 hours of your next dose. In that case, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
STORAGE: Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage is permitted between 59-86 degrees F (15-30 degrees C). Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
MEDICAL ALERT: Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA) or 1-800-668-1507 (Canada).
Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.
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