Significant adverse reactions associated with COPEGUS/PEGASYS combination therapy
include severe depression and suicidal ideation, hemolytic anemia, suppression
of bone marrow function, autoimmune and infectious disorders, ophthalmologic
disorders, cerebrovascular disorders, pulmonary dysfunction, colitis, pancreatitis,
and diabetes.
The PEGASYS Package Insert should be reviewed in its entirety for additional
safety information prior to initiation of combination treatment.
Pregnancy
COPEGUS may cause birth defects and/or death of the exposed fetus. Ribavirin
has demonstrated significant teratogenic and/or embryocidal effects in all animal
species in which adequate studies have been conducted. These effects occurred
at doses as low as one twentieth of the recommended human dose of ribavirin.
COPEGUS therapy should not be started unless a report of a negative pregnancy
test has been obtained immediately prior to planned initiation of therapy.
Extreme care must be taken to avoid pregnancy in female patients and in female
partners of male patients. Patients should be instructed to use at least two
forms of effective contraception during treatment and for 6 months after treatment
has been stopped. Pregnancy testing should occur monthly during COPEGUS therapy
and for 6 months after therapy has stopped [see BOXED WARNING, CONTRAINDICATIONS,
Use In Specific Populations, and PATIENT INFORMATION].
Anemia
The primary toxicity of ribavirin is hemolytic anemia, which was observed in
approximately 13% of all COPEGUS/PEGASYS- treated subjects in clinical trials.
Anemia associated with COPEGUS occurs within 1 to 2 weeks of initiation of therapy.
Because the initial drop in hemoglobin may be significant, it is advised that
hemoglobin or hematocrit be obtained pretreatment and at week 2 and week 4 of
therapy or more frequently if clinically indicated. Patients should then be
followed as clinically appropriate. Caution should be exercised in initiating
treatment in any patient with baseline risk of severe anemia (e.g., spherocytosis,
history of gastrointestinal bleeding) [see DOSAGE AND ADMINISTRATION].
Fatal and nonfatal myocardial infarctions have been reported in patients with
anemia caused by COPEGUS. Patients should be assessed for underlying cardiac
disease before initiation of ribavirin therapy. Patients with pre-existing cardiac
disease should have electrocardiograms administered before treatment, and should
be appropriately monitored during therapy. If there is any deterioration of
cardiovascular status, therapy should be suspended or discontinued [see DOSAGE
AND ADMINISTRATION]. Because cardiac disease may be worsened by drug-induced
anemia, patients with a history of significant or unstable cardiac disease should
not use COPEGUS [see BOXED WARNING and DOSAGE AND ADMINISTRATION].
Hepatic Failure
Chronic hepatitis C (CHC) patients with cirrhosis may be at risk of hepatic
decompensation and death when treated with alpha interferons, including PEGASYS.
Cirrhotic CHC patients coinfected with HIV receiving highly active antiretroviral
therapy (HAART) and interferon alfa-2a with or without ribavirin appear to be
at increased risk for the development of hepatic decompensation compared to
patients not receiving HAART. In Study NR15961 [see Clinical Studies],
among 129 CHC/HIV cirrhotic patients receiving HAART, 14 (11%) of these patients
across all treatment arms developed hepatic decompensation resulting in 6 deaths.
All 14 patients were on NRTIs, including stavudine, didanosine, abacavir, zidovudine,
and lamivudine. These small numbers of patients do not permit discrimination
between specific NRTIs or the associated risk. During treatment, patients' clinical
status and hepatic function should be closely monitored for signs and symptoms
of hepatic decompensation. Treatment with PEGASYS/COPEGUS should be discontinued
immediately in patients with hepatic decompensation [see CONTRAINDICATIONS].
Hypersensitivity
Severe acute hypersensitivity reactions (e.g., urticaria, angioedema, bronchoconstriction,
and anaphylaxis) have been observed during alpha interferon and ribavirin therapy.
If such a reaction occurs, therapy with PEGASYS and COPEGUS should be discontinued
immediately and appropriate medical therapy instituted. Serious skin reactions
including vesiculobullous eruptions, reactions in the spectrum of Stevens-Johnson
Syndrome (erythema multiforme major) with varying degrees of skin and mucosal
involvement and exfoliative dermatitis (erythroderma) have been reported in
patients receiving PEGASYS with and without ribavirin. Patients developing signs
or symptoms of severe skin reactions must discontinue therapy [see ADVERSE
REACTIONS].
Pulmonary Disorders
Dyspnea, pulmonary infiltrates, pneumonitis, pulmonary hypertension, and pneumonia
have been reported during therapy with ribavirin and interferon. Occasional
cases of fatal pneumonia have occurred. In addition, sarcoidosis or the exacerbation
of sarcoidosis has been reported. If there is evidence of pulmonary infiltrates
or pulmonary function impairment, patients should be closely monitored and,
if appropriate, combination COPEGUS/PEGASYS treatment should be discontinued.
Bone Marrow Suppression
Pancytopenia (marked decreases in RBCs, neutrophils and platelets) and bone
marrow suppression have been reported in the literature to occur within 3 to
7 weeks after the concomitant administration of pegylated interferon/ribavirin
and azathioprine. In this limited number of patients (n=8), myelotoxicity was
reversible within 4 to 6 weeks upon withdrawal of both HCV antiviral therapy
and concomitant azathioprine and did not recur upon reintroduction of either
treatment alone. PEGASYS, COPEGUS, and azathioprine should be discontinued for
pancytopenia, and pegylated interferon/ribavirin should not be re-introduced
with concomitant azathioprine [see DRUG INTERACTIONS].
Pancreatitis
COPEGUS and PEGASYS therapy should be suspended in patients with signs and
symptoms of pancreatitis, and discontinued in patients with confirmed pancreatitis.
Laboratory Tests
Before beginning PEGASYS/COPEGUS combination therapy, standard hematological
and biochemical laboratory tests are recommended for all patients. Pregnancy
screening for women of childbearing potential must be performed. Patients who
have pre-existing cardiac abnormalities should have electrocardiograms administered
before treatment with PEGASYS/COPEGUS.
After initiation of therapy, hematological tests should be performed at 2 weeks
and 4 weeks and biochemical tests should be performed at 4 weeks. Additional
testing should be performed periodically during therapy. In the clinical studies,
the CBC (including hemoglobin level and white blood cell and platelet counts)
and chemistries (including liver function tests and uric acid) were measured
at 1, 2, 4, 6, and 8 weeks, and then every 4 to 6 weeks or more frequently if
abnormalities were found. Thyroid stimulating hormone (TSH) was measured every
12 weeks. Monthly pregnancy testing should be performed during combination therapy
and for 6 months after discontinuing therapy.
The entrance criteria used for the clinical studies of COPEGUS and PEGASYS
may be considered as a guideline to acceptable baseline values for initiation
of treatment:
- Platelet count greater than or equal to 90,000 cells/mm³ (as low as 75,000
cells/mm³ in HCV patients with cirrhosis or 70,000 cells/mm³ in patients with
CHC and HIV)
- Absolute neutrophil count (ANC) greater than or equal to 1500 cells/mm³
- TSH and T4 within normal limits or adequately controlled thyroid
function
- CD4+ cell count greater than or equal to 200 cells/mcL or CD4+ cell count
greater than or equal to 100 cells/mcL but less than 200 cells/mcL and HIV-1
RNA less than 5000 copies/mL in patients coinfected with HIV
- Hemoglobin greater than or equal to 12 g/dL for women and greater than or
equal to 13 g/dL for men in CHC monoinfected patients
- Hemoglobin greater than or equal to 11 g/dL for women and greater than or
equal to 12 g/dL for men in patients with CHC and HIV
Patient Counseling Information
Pregnancy
Patients must be informed that ribavirin may cause birth defects and/or death
of the exposed fetus. COPEGUS therapy must not be used by women who are pregnant
or by men whose female partners are pregnant. Extreme care must be taken to
avoid pregnancy in female patients and in female partners of male patients taking
COPEGUS therapy and for 6 months post therapy. Patients should use two reliable
methods of birth control while taking COPEGUS therapy and for 6 months post
therapy. COPEGUS therapy should not be initiated until a report of a negative
pregnancy test has been obtained immediately prior to initiation of therapy.
Patients must perform a pregnancy test monthly during therapy and for 6 months
post therapy.
Female patients of childbearing potential and male patients with female partners
of childbearing potential must be advised of the teratogenic/embryocidal risks
and must be instructed to practice effective contraception during COPEGUS therapy
and for 6 months post therapy. Patients should be advised to notify the healthcare
provider immediately in the event of a pregnancy [see CONTRAINDICATIONS
and WARNINGS AND PRECAUTIONS].
Anemia
The most common adverse event associated with ribavirin is anemia, which may
be severe [see BOXED WARNING, WARNINGS AND PRECAUTIONS and ADVERSE
REACTIONS]. Patients should be advised that laboratory evaluations are required
prior to starting COPEGUS therapy and periodically thereafter [see WARNINGS
AND PRECAUTIONS]. It is advised that patients be well hydrated, especially
during the initial stages of treatment.
Patients who develop dizziness, confusion, somnolence, and fatigue should be
cautioned to avoid driving or operating machinery.
Patients should be advised to take COPEGUS with food.
Patients should be questioned about prior history of drug abuse before initiating
COPEGUS/PEGASYS, as relapse of drug addiction and drug overdoses have been reported
in patients treated with interferons.
Patients should be advised not to drink alcohol, as alcohol may exacerbate
chronic hepatitis C infection.
Patients should be informed about what to do in the event they miss a dose
of COPEGUS. The missed doses should be taken as soon as possible during the
same day. Patients should not double the next dose. Patients should be advised
to call their healthcare provider if they have questions.
Patients should be informed that the effect of PEGASYS/COPEGUS treatment of
hepatitis C infection on transmission is not known, and that appropriate precautions
to prevent transmission of hepatitis C virus during treatment or in the event
of treatment failure should be taken.
Patients should be informed regarding the potential benefits and risks attendant
to the use of COPEGUS. Instructions on appropriate use should be given, including
review of the contents of the enclosed MEDICATION GUIDE, which is not a disclosure
of all or possible adverse effects.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
In a p53 (+/-) mouse carcinogenicity study up to the maximum tolerated dose
of 100 mg/kg/day, ribavirin was not oncogenic. Ribavirin was also not oncogenic
in a rat 2-year carcinogenicity study at doses up to the maximum tolerated dose
of 60 mg/kg/day. On a body surface area basis, these doses are approximately
0.5 and 0.6 times the maximum recommended daily human dose of ribavirin, respectively.
Mutagenesis
Ribavirin demonstrated mutagenic activity in the in vitro mouse lymphoma
assay. No clastogenic activity was observed in an in vivo mouse micronucleus
assay at doses up to 2000 mg/kg. However, results from studies published in
the literature show clastogenic activity in the in vivo mouse micronucleus assay
at oral doses up to 2000 mg/kg. A dominant lethal assay in rats was negative,
indicating that if mutations occurred in rats they were not transmitted through
male gametes. However, potential carcinogenic risk to humans cannot be excluded.
Impairment of Fertility
In a fertility study in rats, ribavirin showed a marginal reduction in sperm
counts at the dose of 100 mg/kg/day with no effect on fertility. Upon cessation
of treatment, total recovery occurred after 1 spermatogenesis cycle. Abnormalities
in sperm were observed in studies in mice designed to evaluate the time course
and reversibility of ribavirin-induced testicular degeneration at doses of 15
to 150 mg/kg/day (approximately 0.1 to 0.8 times the maximum recommended daily
human dose of ribavirin) administered for 3 to 6 months. Upon cessation of treatment,
essentially total recovery from ribavirin-induced testicular toxicity was apparent
within 1 or 2 spermatogenic cycles.
Female patients of childbearing potential and male patients with female partners
of childbearing potential should not receive COPEGUS unless the patient and
his/her partner are using effective contraception (two reliable forms). Based
on a multiple dose half-life (t½) of ribavirin of 12 days, effective
contraception must be utilized for 6 months post therapy (i.e., 15 half-lives
of clearance for ribavirin).
No reproductive toxicology studies have been performed using PEGASYS in combination
with COPEGUS. However, peginterferon alfa-2a and ribavirin when administered
separately, each has adverse effects on reproduction. It should be assumed that
the effects produced by either agent alone would also be caused by the combination
of the two agents.
Animal Toxicology
In a study in rats, it was concluded that dominant lethality was not induced
by ribavirin at doses up to 200 mg/kg for 5 days (up to 1.7 times the maximum
recommended human dose of ribavirin).
Long-term studies in the mouse and rat (18 to 24 months; dose 20 to 75, and
10 to 40 mg/kg/day, respectively, approximately 0.1 to 0.4 times the maximum
daily human dose of ribavirin) have demonstrated a relationship between chronic
ribavirin exposure and an increased incidence of vascular lesions (microscopic
hemorrhages) in mice. In rats, retinal degeneration occurred in controls, but
the incidence was increased in ribavirin-treated rats.
Use In Specific Populations
Pregnancy
Pregnancy: Category X [see CONTRAINDICATIONS]. Ribavirin produced significant
embryocidal and/or teratogenic effects in all animal species in which adequate
studies have been conducted. Malformations of the skull, palate, eye, jaw, limbs,
skeleton, and gastrointestinal tract were noted. The incidence and severity
of teratogenic effects increased with escalation of the drug dose. Survival
of fetuses and offspring was reduced [see CONTRAINDICATIONS and WARNINGS
AND PRECAUTIONS].
In conventional embryotoxicity/teratogenicity studies in rats and rabbits,
observed no-effect dose levels were well below those for proposed clinical use
(0.3 mg/kg/day for both the rat and rabbit; approximately 0.06 times the recommended
daily human dose of ribavirin). No maternal toxicity or effects on offspring
were observed in a peri/postnatal toxicity study in rats dosed orally at up
to 1 mg/kg/day (approximately 0.01 times the maximum recommended daily human
dose of ribavirin).
Treatment and Post treatment: Potential Risk to the Fetus
Ribavirin is known to accumulate in intracellular components from where it
is cleared very slowly. It is not known whether ribavirin is contained in sperm,
and if so, will exert a potential teratogenic effect upon fertilization of the
ova. However, because of the potential human teratogenic effects of ribavirin,
male patients should be advised to take every precaution to avoid risk of pregnancy
for their female partners.
COPEGUS should not be used by pregnant women or by men whose female partners
are pregnant. Female patients of childbearing potential and male patients with
female partners of childbearing potential should not receive COPEGUS unless
the patient and his/her partner are using effective contraception (two reliable
forms) during therapy and for 6 months post therapy [see CONTRAINDICATIONS].
Ribavirin Pregnancy Registry
A Ribavirin Pregnancy Registry has been established to monitor maternal-fetal
outcomes of pregnancies of female patients and female partners of male patients
exposed to ribavirin during treatment and for 6 months following cessation of
treatment. Healthcare providers and patients are encouraged to report such cases
by calling 1-800-593-2214.
Nursing Mothers
It is not known whether ribavirin is excreted in human milk. Because many drugs
are excreted in human milk and to avoid any potential for serious adverse reactions
in nursing infants from ribavirin, a decision should be made either to discontinue
nursing or therapy with COPEGUS, based on the importance of the therapy to the
mother.
Pediatric Use
Pharmacokinetic evaluations in pediatric patients have not been performed.
Safety and effectiveness of COPEGUS have not been established in patients below
the age of 18.
Geriatric Use
Clinical studies of COPEGUS and PEGASYS did not include sufficient numbers
of subjects aged 65 or over to determine whether they respond differently from
younger subjects. Specific pharmacokinetic evaluations for ribavirin in the
elderly have not been performed. The risk of toxic reactions to this drug may
be greater in patients with impaired renal function. The dose of COPEGUS should
be reduced in patients with creatinine clearance less than or equal to 50 mL/min;
and the dose of PEGASYS should be reduced in patients with creatinine clearance
less than 30 mL/min [see DOSAGE AND ADMINISTRATION; Use in Specific
Populations].
Race
A pharmacokinetic study in 42 subjects demonstrated there is no clinically
significant difference in ribavirin pharmacokinetics among Black (n=14), Hispanic
(n=13) and Caucasian (n=15) subjects.
Renal Impairment
Renal function should be evaluated in all patients prior to initiation of COPEGUS
by estimating the patient's creatinine clearance.
A clinical trial evaluated treatment with COPEGUS and PEGASYS in 50 CHC subjects
with moderate (creatinine clearance 30 – 50 mL/min) or severe (creatinine clearance
less than 30 mL/min) renal impairment or end stage renal disease (ESRD) requiring
chronic hemodialysis (HD). In 18 subjects with ESRD receiving chronic HD, COPEGUS
was administered at a dose of 200 mg daily with no apparent difference in the
adverse event profile in comparison to subjects with normal renal function.
Dose reductions and temporary interruptions of COPEGUS (due to COPEGUS-related
adverse reactions, mainly anemia) were observed in up to one-third ESRD/HD subjects
during treatment; and only one-third of these subjects received COPEGUS for
48 weeks. Ribavirin plasma exposures were approximately 20% lower in subjects
with ESRD on HD compared to subjects with normal renal function receiving the
standard 1000/1200 mg COPEGUS daily dose.
Subjects with moderate (n=17) or severe (n=14) renal impairment did not tolerate
600 mg or 400 mg daily doses of COPEGUS, respectively, due to COPEGUS-related
adverse reactions, mainly anemia, and exhibited 20 to 30% higher ribavirin plasma
exposures (despite frequent dose modifications) compared to subjects with normal
renal function (creatinine clearance greater than 80 mL/min) receiving the standard
dose of COPEGUS. Discontinuation rates were higher in subjects with severe renal
impairment compared to that observed in subjects with moderate renal impairment
or normal renal function. Pharmacokinetic modeling and simulation indicates
that a dose of 200 mg daily in patients with severe renal impairment and a dose
of 200 mg daily alternating with 400 mg the following day in patients with moderate
renal impairment will provide plasma ribavirin exposure similar to patients
with normal renal function receiving the approved regimen of COPEGUS. These
doses have not been studied in patients [see DOSAGE AND ADMINISTRATION,
Use In Specific Populations, and CLINICAL PHARMACOLOGY].
Based on the pharmacokinetic and safety results from this trial, patients with
creatinine clearance less than or equal to 50 mL/min should receive a reduced
dose of COPEGUS; and patients with creatinine clearance less than 30 mL/min
should receive a reduced dose of PEGASYS. The clinical and hematologic status
of patients with creatinine clearance less than or equal to 50 mL/min receiving
COPEGUS should be carefully monitored. Patients with clinically significant
laboratory abnormalities or adverse reactions which are persistently severe
or worsening should have therapy withdrawn. [see DOSAGE AND ADMINISTRATION,
CLINICAL PHARMACOLOGY, and PEGASYS Package Insert].
Hepatic Impairment
The effect of hepatic impairment on the pharmacokinetics of ribavirin following
administration of COPEGUS has not been evaluated. The clinical trials of COPEGUS
were restricted to patients with Child-Pugh class A disease.
Gender
No clinically significant differences in the pharmacokinetics of ribavirin
were observed between male and female subjects.
Ribavirin pharmacokinetics, when corrected for weight, are similar in male
and female patients.
Organ Transplant Recipients
The safety and efficacy of PEGASYS and COPEGUS treatment have not been established
in patients with liver and other transplantations. As with other alpha interferons,
liver and renal graft rejections have been reported on PEGASYS, alone or in
combination with COPEGUS [see ADVERSE REACTIONS].
Last reviewed on RxList: 8/18/2011
This monograph has been modified to include the generic and brand name in many instances.