(cysteamine bitartrate) Delayed-Release Capsules, for Oral Use
PROCYSBI contains the bitartrate salt of cysteamine. The chemical name for cysteamine bitartrate is ethanethiol, 2-amino, (2R,3R)-2,3-dihydroxybutanedioate (1:1) (salt). Cysteamine bitartrate is a highly water soluble white powder with a molecular weight of 227.24 and the molecular formula C2H7NS • C4H6O6. It has the following chemical structure:
Each 25 mg delayed-release capsule contains 74 mg cysteamine bitartrate, equivalent to 25 mg cysteamine. Each 75 mg delayed-release capsule contains 221 mg cysteamine bitartrate, equivalent to 75 mg cysteamine. PROCYSBI contains the following inactive ingredients: microcrystalline cellulose, Eudragit® L 30 D-55, hypromellose, talc, triethyl citrate, sodium lauryl sulfate, and purified water. Capsule shell ingredients are gelatin, titanium dioxide, blue ink and white ink.
PROCYSBI is indicated for the treatment of nephropathic cystinosis in adult and pediatric patients 2 years of age and older.
DOSAGE AND ADMINISTRATION
Important Dosing Instructions
- Initiate cysteamine treatment immediately after diagnosis of nephropathic cystinosis.
- Cysteamine-naïve Patients: Start PROCYSBI at a fraction of the maintenance dosage and gradually increase the dosage over 4 to 6 weeks until the maintenance dosage is achieved [see Dosing In Cysteamine-Naïve Patients].
- Patients switching from immediate-release cysteamine: Start the total daily dosage of PROCYSBI at a dosage equal to the previous total daily dosage of immediate-release cysteamine [see Switching Patients From Immediate-Release Cysteamine Bitartrate].
- If adverse reactions occur, decrease the PROCYSBI dosage.
- After the maintenance dosage of PROCYSBI is achieved: The dosage may need to be further increased to achieve a therapeutic target WBC cystine concentration. The maximum daily dosage of PROCYSBI is 1.95 grams/m2 of body surface area per day [see Dosage Titration To Therapeutic Target WBC Cystine Concentration, Laboratory Monitoring].
- Round dose calculations to the nearest incremental dosage that can be administered using the available capsule strengths. Only use whole capsules.
Dosing In Cysteamine-Naïve Patients
- Start treatment with a dosage equal to 1/6 to ¼ of the maintenance dosage.
- The maintenance dosage after initial dose escalation is 1.3 g/m2 of body surface area per day divided into two doses given every 12 hours. Table 1 shows the recommended starting dose of PROCYSBI, converted from body-surface area to body weight using available capsule strengths.
- Gradually increase the dosage over 4 to 6 weeks until the maintenance dosage is achieved. Table 1 also shows the recommended maintenance dosage. The maximum dosage is 1000 mg every 12 every hours in patients weighing more than 50 kg.
- For patients who have initial intolerance, temporarily discontinue PROCYSBI and then re-start at a lower dosage and gradually increase to the maintenance dosage.
- Measure the WBC cystine concentration after reaching a maintenance dosage and adjust the dosage as needed to achieve a therapeutic target WBC cystine concentration [see Laboratory Monitoring].
Table 1: Starting and Maintenance Dosage of PROCYSBI by Body Weight in Cysteamine-
Naïve Patients (Dosage Rounded Using Available Capsule Strengths)
|Weight in kilograms||Starting PROCYSBI Dosage in mg every 12 hours, as a Fraction of the Maintenance Dosage||Maintenance PROCYSBI Dosage in mg every 12 hours*|
|1/6 of dosage||1/4 of dosage|
|0 to 5||25||50||200|
|6 to 10||50||75||300|
|16 to 20||100||125||500|
|21 to 25||100||150||600|
|26 to 30||125||175||700|
|31 to 40||125||200||800|
|41 to 50||150||225||900|
|51 kg and greater||175||250||1000|
|* Higher dosages may be required to achieve target therapeutic WBC cystine concentration [see Dosage Titration To Therapeutic Target WBC Cystine Concentration].|
Switching Patients From Immediate-Release Cysteamine Bitartrate
- When switching patients from immediate-release cysteamine bitartrate to PROCYSBI, the starting total daily dose of PROCYSBI is equal to the previous total daily dose of immediate-release cysteamine bitartrate. Divide the total daily dose by two and administer every 12 hours.
- For patients who may experience temporary intolerance upon starting PROCYSBI, decrease the dosage and then gradually increase to the maintenance dosage.
- Measure the WBC cystine concentration two weeks after initiation of PROCYSBI [see Laboratory Monitoring]. Adjust the PROCYSBI dosage as needed to achieve the therapeutic target WBC cystine concentration [see Dosage Titration To Therapeutic Target WBC Cystine Concentration]. The maximum dosage of PROCYSBI is 1.95 grams/m2 per day.
Dosage Titration To Therapeutic Target WBC Cystine Concentration
- Measure WBC cystine concentration and titrate the PROCYSBI dosage as needed to achieve the therapeutic target WBC cysteine concentration [see Laboratory Monitoring].
- If the measured WBC cystine concentration is above the target level for cystine depletion, consider the following before dose adjustment: adherence to medication and dosing interval, the timing between the last dose and the blood draw for the laboratory measurement, and the timing of PROCYSBI administration in relation to food or other administration instructions.
- If a dose adjustment is required, increase the dosage by 10%, rounded to nearest dosage that can be administered using the available capsule strengths. The maximum dosage of PROCYSBI is 1.95 grams/m2 per day.
- If adverse reactions occur, decrease the PROCYSBI dosage. Some patients may be unable to achieve their therapeutic target due to poor tolerability of PROCYSBI [see WARNINGS AND PRECAUTIONS, ADVERSE REACTIONS].
- WBC cystine concentration may be measured using the mixed leukocyte assay or by using assays for specific WBC subsets (e.g., granulocyte method). The methods used for measuring cystine and total protein content may also vary among individual laboratories [see CLINICAL PHARMACOLOGY].
- Normal WBC cystine ranges and therapeutic target levels for cystine depletion depend upon the assay method used by the individual laboratory. WBC cystine values obtained from using different assay methods may not be interchangeable. Refer to the assay-specific therapeutic target for cystine depletion. When using the mixed leukocyte assay, the recommended target WBC cystine concentration is less than 1 nmol ½ cystine/mg protein.
- The recommended frequency of monitoring WBC cystine concentration is as follows:
- For cysteamine-naïve patients: Obtain measurement after reaching the maintenance PROCYSBI dose, then monthly for 3 months, quarterly for 1 year, and then twice-yearly, at a minimum.
- For patients switching from immediate-release cysteamine to PROCYSBI: Obtain measurement after two weeks of PROCYSBI treatment while titrating the dose, then quarterly for 6 months, then twice yearly, at a minimum.
- Obtain blood samples for WBC cystine concentration measurement 12 hours after dosing with PROCYSBI, prior to administration of the next dose (i.e., trough concentration). In addition, it is important to accurately record the time of the last dose, the actual dose, and the time the blood sample was taken.
- Swallow PROCYSBI capsules whole.
- Do not crush or chew capsules or capsule contents.
- Take PROCYSBI capsules with fruit juice (except grapefruit juice).
- Administer PROCYSBI at least 1 hour before or 1 hour after medications containing bicarbonate or carbonate [see DRUG INTERACTIONS].
- Do not eat for at least 2 hours before taking PROCYSBI and for at least 30 minutes after to maximize absorption. If patients are unable to take PROCYSBI without eating, take with food and limit the amount of food to approximately 4 ounces (½ cup) within 1 hour before taking PROCYSBI through 1 hour after taking PROCYSBI. Take PROCYSBI in a consistent manner in regard to food. Avoid high fat food close to dosing of PROCYSBI.
- Avoid drinking alcohol while taking PROCYSBI [see DRUG INTERACTIONS].
For patients who have difficulty swallowing capsules, follow the instructions below for administration with food or liquid. Administration of PROCYSBI with foods and liquids not included below has not been studied clinically and is not recommended.
Administration With Applesauce Or Berry Jelly
- Place approximately 4 ounces (1/2 cup) of either applesauce or berry jelly into a clean container.
- Open the capsule(s).
- Sprinkle the entire capsule contents of intact granules on applesauce or berry jelly.
- Mix the granules with the applesauce or berry jelly.
- Consume the entire contents within 30 minutes of mixing. Do not chew the granules. Do not save the applesauce or berry jelly and granules for later use.
Administration With Fruit Juice (Except Grapefruit Juice):
- Pour approximately 4 ounces (1/2 cup) of fruit juice into a clean cup.
- Open the capsule(s).
- Sprinkle the intact granules into the juice.
- Gently stir until mixed.
- Drink the entire contents within 30 minutes of mixing. Do not chew the granules. Do not save the fruit juice and granules for later use.
Administration With Applesauce Via A Gastrostomy (G) Tube (14 French Or Larger)
A bolus (straight) feeding tube is recommended.
- Flush the gastrostomy tube button first with 5 mL of water to clear the button.
- Open the capsule and empty the granules into a clean container with approximately 4 ounces (1/2 cup) of applesauce. Use only strained applesauce with no chunks. A minimum of 1 ounce (1/8 cup) of applesauce may be used for children 25 kg or less starting PROCYSBI at a dose of 1 or 2 capsules.
- Mix the intact granules into the applesauce.
- Draw up the mixture into a syringe. Keep the feeding tube horizontal during administration and apply rapid and steady pressure (10 mL/10 seconds) to dispense the syringe contents into the tube within 30 minutes of preparation.
- Repeat step 3 until all of the mixture is administered. Do not save the applesauce and granule mixture for later use.
- Draw up a minimum of 10 mL of fruit juice into another syringe, swirl gently, and flush the tube.
- If a dose is missed, take the dose as soon as possible up to 8 hours after the scheduled time. However, if a dose is missed and the next scheduled dose is due in less than 4 hours, do not take the missed dose and take the next dose at the usual scheduled time. Do not take 2 doses at one time to make up for a missed dose.
Dosage Forms And Strengths
PROCYSBI delayed-release capsules:
- 25 mg: contains 74 mg cysteamine bitartrate, equivalent to 25 mg cysteamine. The capsules are light blue opaque cap imprinted with “Raptor” logo in white ink and light blue opaque body imprinted with “25 mg” in white ink.
- 75 mg: contains 221 mg cysteamine bitartrate, equivalent to 75 mg cysteamine. The capsules are dark blue opaque cap imprinted with “Raptor” logo in white ink and light blue opaque body imprinted with “75 mg” in white ink.
- 25 mg Delayed-release Capsule: A hard gelatin capsule with light blue opaque cap imprinted with “Raptor” Logo in white ink and light blue opaque body imprinted with “25 mg” in white ink, supplied as bottle of 60 capsules (NDC 75987-100-04). Each bottle contains one desiccant canister and one oxygen absorber canister.
- 75 mg Delayed-release Capsule: A hard gelatin capsule with dark blue opaque cap imprinted with “Raptor” Logo in white ink and light blue opaque body imprinted with “75 mg” in white ink, supplied as bottle of 250 capsules (NDC 75987-101-08). Each bottle contains one desiccant canister and two oxygen absorber canisters.
Instructions For The Pharmacist
- Dispense PROCYSBI with a 4 month expiration date
- Specify “Store at room temperature, 20°C to 25°C (68°F to 77°F).”
- Dispense only in original packaging. Do not subdivide or repackage.
Storage And Handling
- PHARMACIST: Prior to Dispensing: Store in a refrigerator, 2°C to 8°C (36°F to 46°F).
- PATIENT: Store at room temperature, 20°C to 25°C (68°F to 77°F).
- Protect from light and moisture.
- Do not remove desiccant or oxygen absorber(s) from the container. Keep bottles tightly closed in a dry place.
Distributed by: Horizon Pharma USA, Inc. Lake Forest, IL 60045. Revised: Sep 2017
The following adverse reactions are also discussed in other sections of the labeling:
- Ehlers-Danlos-like Syndrome [see WARNINGS AND PRECAUTIONS]
- Skin Rash [see WARNINGS AND PRECAUTIONS]
- Gastrointestinal (GI) Ulcers and Bleeding [see WARNINGS AND PRECAUTIONS]
- Central Nervous System Symptoms [see WARNINGS AND PRECAUTIONS]
- Leukopenia and/or Elevated Phosphatase Levels [see WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
The data described below reflect exposure to cysteamine in 328 patients with nephropathic cystinosis (246 patients receiving immediate-release cysteamine as cysteamine hydrochloride or phosphocysteamine, and 63 patients receiving PROCYSBI) in open-label clinical trials.
Clinical Trials Experience With PROCYSBI
Sixty-two patients with cystinosis (38 males and 24 females) received PROCYSBI in two clinical trials at doses ranging from 0.29 grams/m2 per day to 2.19 grams/m2 per day [see Clinical Studies]. All patients were switched from immediate-release cysteamine to PROCYSBI. Forty-three patients, ages 7 to 24 years old, received PROCYSBI in an 8-week, open-label, randomized, cross-over trial comparing PROCYSBI to immediate-release cysteamine bitartrate. Forty of 43 patients continued PROCYSBI treatment in an open-label extension trial, and were treated with PROCYSBI for longer than 2 years. An additional 19 patients (6 transplanted patients and 13 patients aged 2 to 6 years) were enrolled directly into this trial and were treated with PROCYSBI for up to 18 months.
In the open-label, randomized, cross-over trial, a higher incidence of adverse reactions was reported in patients during the PROCYSBI treatment period compared with the immediate-release cysteamine treatment period (see Table 3). Other significant adverse reactions reported during clinical trials included hypersensitivity reactions, including anaphylaxis.
Table 3: Adverse reactions that occurred in ≥5% of patients in the randomized, cross-over
|Adverse Reaction||Immediate-release cysteamine||PROCYSBI|
|(n = 41)
|(n = 43)
|Anorexia/loss of appetite||5||2|
For all patients treated with PROCYSBI in both trials (N=62), the most commonly reported adverse reactions (>5%) were vomiting, nausea, abdominal pain, breath odor, diarrhea, skin odor, fatigue, rash, and headache.
Clinical Trials Experience With Immediate-Release Cysteamine
The most frequent adverse reactions involved the gastrointestinal and central nervous systems and were especially prominent at the initiation of cysteamine therapy. Most patients were able to resume therapy at lower doses. The most common reactions (>5%) were vomiting, anorexia, fever, diarrhea, lethargy, and rash. Other adverse reactions included nausea, bad breath, abdominal pain, headache, dizziness, and urticaria.
Withdrawals due to intolerance, vomiting, anorexia, lethargy, and fever occurred more frequently in those patients receiving 1.95 grams/m2 per day as compared with 1.3 grams/m2 per day of immediate-release cysteamine bitartrate.
The following adverse reactions have been identified during post-approval use of immediate-release cysteamine bitartrate. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
- Musculoskeletal: Joint hyperextension, leg pain, osteopenia, compression fracture, scoliosis, genu valgum [see WARNINGS AND PRECAUTIONS].
- Skin: Erythema multiforme bullosa, toxic epidermal necrolysis, Ehlers-Danlos-like syndrome, molluscoid pseudotumors, skin striae, skin fragility [see WARNINGS AND PRECAUTIONS].
- Central Nervous System: seizures, lethargy, somnolence, depression and encephalopathy [see WARNINGS AND PRECAUTIONS], benign intracranial hypertension (or PTC) and/or papilledema [see WARNINGS AND PRECAUTIONS].
Drugs That Increase Gastric pH
Drugs that increase the gastric pH (e.g., proton pump inhibitors, medications containing bicarbonate or carbonate) may alter the pharmacokinetics of cysteamine due to the premature release of cysteamine from PROCYSBI and increase WBC cystine concentration. Concomitant administration of 20 mg omeprazole did not significantly affect the pharmacokinetics of cysteamine when PROCYSBI was administered with 240 mL of orange juice [see CLINICAL PHARMACOLOGY]. The effect of omeprazole on the pharmacokinetics of cysteamine was not studied after PROCYSBI administration with water. Monitor WBC cystine concentration when drugs that increase the gastric pH are concomitantly used [see DOSAGE AND ADMINISTRATION].
Use With Alcohol
Consumption of alcohol with PROCYSBI may increase the rate of cysteamine release and/or adversely alter the pharmacokinetic properties, as well as the effectiveness and safety of PROCYSBI. Therefore, do not consume alcoholic beverages during treatment with PROCYSBI [see DOSAGE AND ADMINISTRATION].
Other Medications Used For The Management Of Fanconi Syndrome
Included as part of the "PRECAUTIONS" Section
Skin and bone lesions that resemble clinical findings for Ehlers-Danlos-like syndrome have been reported in patients treated with high doses of immediate-release cysteamine bitartrate or other cysteamine salts. These include molluscoid pseudotumors (purplish hemorrhagic lesions), skin striae, bone lesions (including osteopenia, compression fractures, scoliosis and genu valgum), leg pain, and joint hyperextension. One patient on immediate-release cysteamine bitartrate with serious skin lesions subsequently died of acute cerebral ischemia with marked vasculopathy. Monitor patients for development of skin or bone lesions and interrupt PROCYSBI dosing if patients develop these lesions. PROCYSBI may be restarted at a lower dose under close supervision, then slowly increase to the appropriate therapeutic dose [see DOSAGE AND ADMINISTRATION].
Severe skin rashes such as erythema multiforme bullosa or toxic epidermal necrolysis have been reported in patients receiving immediate-release cysteamine bitartrate. If severe skin rashes develop, permanently discontinue use of PROCYSBI [see CONTRAINDICATIONS].
Gastrointestinal Ulcers And Bleeding
Gastrointestinal (GI) ulceration and bleeding have been reported in patients receiving immediate-release cysteamine bitartrate. GI tract symptoms including nausea, vomiting, anorexia and abdominal pain, sometimes severe, have been associated with cysteamine. If severe GI tract symptoms develop, consider decreasing the dose of PROCYSBI [see DOSAGE AND ADMINISTRATION].
Central Nervous System Symptoms
Central Nervous System (CNS) symptoms such as seizures, lethargy, somnolence, depression, and encephalopathy have been associated with immediate-release cysteamine. Neurological complications have also been described in some patients with cystinosis who have not been treated with cysteamine. Carefully evaluate and monitor patients who develop CNS symptoms. Interrupt medication or adjust the dose as necessary for patients with severe symptoms or with symptoms that persist or progress. Inform patients that PROCYSBI may impair their ability to perform tasks such as driving or operating machinery.
Leukopenia And/Or Elevated Alkaline Phosphatase Levels
Cysteamine has been associated with reversible leukopenia and elevated alkaline phosphatase levels. Monitor white blood cell counts and alkaline phosphatase levels. If tests values remain elevated, consider decreasing the dose or discontinuing the drug until values revert to normal.
Benign Intracranial Hypertension
Benign intracranial hypertension (pseudotumor cerebri; PTC) and/or papilledema have been reported in patients receiving immediate-release cysteamine bitartrate treatment. Monitor patients for signs and symptoms of PTC, including headache, tinnitus, dizziness, nausea, diplopia, blurry vision, loss of vision, pain behind the eye or pain with eye movement. If signs/symptoms persist, interrupt dosing or decrease the dose and refer the patient to an ophthalmologist. If the diagnosis is confirmed, permanently discontinue use of PROCYSBI.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION and Instructions for Use)
Advise patients and caregivers that PROCYSBI may cause abnormalities of the skin, bones, and joints. Advise patients to report any skin changes or problems with their bones or joints to their physician [see WARNINGS AND PRECAUTIONS].
Advise patients and caregivers to contact their physician immediately if they experience a skin rash [see WARNINGS AND PRECAUTIONS].
Gastrointestinal Ulcers And Bleeding
Advise patients and caregivers that PROCYSBI may cause ulcers and bleeding. Advise patients to contact their physician immediately if they experience stomach pain, nausea, vomiting, loss of appetite, or are vomiting blood [see WARNINGS AND PRECAUTIONS].
Central Nervous System Symptoms
Advise patients and caregivers that PROCYSBI may impair their ability to perform tasks such as driving or operating machinery. Advise patients to contact their physician immediately if they experience seizures, lethargy, somnolence, depression, and encephalopathy [see WARNINGS AND PRECAUTIONS].
Benign Intracranial Hypertension
Advise patients and caregivers that PROCYSBI may cause benign intracranial hypertension. Advise patients to contact their physician immediately if they experience headache, tinnitus, dizziness, nausea, double vision, blurry vision, loss of vision, or eye pain [see WARNINGS AND PRECAUTIONS].
Use By Pregnant Women
Advise patients and to contact their physician immediately if they suspect they may be pregnant. Discuss with the patient the individual risks and benefits of continuing PROCYSBI during pregnancy [see Use In Specific Populations].
Advise patients that breastfeeding is not recommended while taking PROCYSBI [see Use In Specific Populations].
- Advise patients and caregivers to follow the instruction below for taking PROCYSBI capsules whole.
- Swallow PROCYSBI capsules whole. Do not crush or chew capsules or capsule contents
- Take PROCYSBI capsules with fruit juice (except grapefruit juice)
- Administer PROCYSBI at least 1 hour before or 1 hour after medications containing bicarbonate or carbonate
- Do not eat for at least 2 hours before and for at least 30 minutes after taking PROCYSBI. If unable to take PROCYSBI without eating, take with food but limit the amount of food to approximately 4 ounces (½ cup) 1 hour before through 1 hour after administration. Avoid high fat food close to dosing of PROCYSBI
- Avoid drinking alcohol while taking PROCYSBI
- For patients who have difficulty swallowing capsules or those with a Gastrostomy (G) tube, follow the instructions in the Instructions for Use for opening the capsule and administering with food or liquid.
- Take PROCYSBI consistently and to not miss doses. If a dose is missed, take the dose as soon as possible up to 8 hours after the scheduled time. However, if a dose is missed and the next scheduled dose is due in less than 4 hours, do not take the missed dose, and to take the next dose at the usual scheduled time. Do not take 2 doses at one time to make up for a missed dose [see DOSAGE AND ADMINISTRATION].
Discuss with the patient and caregivers the importance of required laboratory testing to determine the correct dose of PROCYSBI [see DOSAGE AND ADMINISTRATION].
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Cysteamine has not been tested for its carcinogenic potential in long-term animal studies.
PROCYSBI was not mutagenic in the Ames test. It produced a negative response in an in-vitro sister chromatid exchange assay in human lymphocytes, but a positive response in a similar assay in hamster ovarian cells.
Repeat breeding reproduction studies were conducted in male and female rats. Cysteamine was found to have no effect on fertility and reproductive performance at an oral dose of 75 mg/kg per day (450 mg/m2 per day, 0.4 times the recommended human dose based on body surface area). At an oral dose of 375 mg/kg per day (2250 mg/m2 per day, 1.7 times the recommended human maintenance dose based on body surface area), it reduced the fertility of the adult rats and the survival of their offspring.
Use In Specific Populations
There are no available data on PROCYSBI use in pregnant women to inform any drug-associated risks for birth defects or miscarriage [see Data]. Cysteamine (administered as cysteamine bitartrate) was teratogenic and fetotoxic in rats at doses less than the recommended human maintenance dose.
The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Advise pregnant women of the potential risk to a fetus.
Embryo-fetal development studies were conducted in rats using oral administration of cysteamine bitartrate, with a dose range of 37.5 to 150 mg/kg per day of cysteamine equivalent (about 0.2 to 0.7 times the recommended human maintenance dose based on body surface area). Cysteamine bitartrate was fetotoxic and produced adverse developmental effects. Observed teratogenic findings were cleft palate, kyphosis, heart ventricular septal defects, microcephaly and exencephaly.
There is no information on the presence of cysteamine in human milk, the effects on the breast-fed infant, or the effects on milk production. Cysteamine is present in the milk of lactating rats [see Data]. Because of the potential for serious adverse reactions in breastfed infants from cysteamine, breastfeeding is not recommended.
A decrease in survival occurred in neonatal rats nursed by mothers receiving cysteamine [see Nonclinical Toxicology].
The safety and effectiveness of PROCYSBI have been established in pediatric patients aged 2 years and older for the treatment of nephropathic cystinosis. Use of PROCYSBI is supported by evidence from an open-label, randomized, cross-over trial in adult and pediatric patients aged 6 years and older, and an open-label extension trial which included patients aged 2 years and older [see Clinical Trials].
The safety and effectiveness of PROCYSBI in pediatric patients under 2 years of age have not been established.
No studies with PROCYSBI have been conducted in geriatric patients.
One case of overdosing with PROCYSBI has been reported. A 16-year old male patient suffered nausea and vomiting after he mistakenly took a second dose of PROCYSBI 30 minutes after his usual dose.
Two cases of overdosing with immediate-release cysteamine bitartrate have been reported in two patients. In the first case, the patient immediately vomited after ingesting an unknown dose and did not develop any symptoms. The second case involved an accidental ingestion of a 200 to 250 mg/kg dose by a healthy 13-month-old child. Vomiting and dehydration were experienced. The child was hospitalized and fluids were administered. The patient fully recovered from the overdosing.
Should overdosing occur, the respiratory and cardiovascular systems should be supported appropriately. No specific antidote is known. Hemodialysis may be considered since cysteamine is poorly bound to plasma proteins.
The use of PROCYSBI is contraindicated in patients with a serious hypersensitivity reaction, including anaphylaxis, to penicillamine or cysteamine.
Mechanism Of Action
Cysteamine is an aminothiol that participates within lysosomes in a thiol-disulfide interchange reaction converting cystine into cysteine and cysteine-cysteamine mixed disulfide, both of which can exit the lysosome in patients with cystinosis.
Normal individuals and persons heterozygous for cystinosis have WBC cystine concentrations of less than 0.2 and usually below 1 nmol ½ cystine/mg protein, respectively, when measured using the mixed leukocyte assay. Untreated patients with nephropathic cystinosis have elevations of WBC cystine concentration above 2 nmol ½ cystine/mg protein.
After the administration of a single dose of PROCYSBI, peak concentrations of WBC cystine were observed at 3 hours post-dose. The nadir of WBC cystine closely followed the peak concentrations at 3.5 hours post-dose, and returned to baseline WBC concentrations at 12 hours-post dose. The cystine concentration in WBC lysate was measured with LC/MS/MS and total protein content in human WBC lysate was measured using the bicinchoninic acid (BCA) assay. A correction factor was applied to the total protein content for the difference in results from the Lowry method. The cystine concentration in nmol ½ cystine/mg protein was calculated by multiplying nmol cystine/mg protein by 2 [see DOSAGE AND ADMINISTRATION].
The pharmacokinetics of PROCYSBI were evaluated in 43 patients with cystinosis and with an estimated glomerular filtration rate of > 30 mL/minutes/1.73 m2. Table 4 shows the mean PK parameters for PROCYSBI and immediate-release cysteamine bitartrate after one dose at steady state. The mean Cmax and AUCinf were 3.6 mg/L and 726 min*mg/L for PROCYSBI and 2.7 mg/L and 380 min*mg/L for immediate-release cysteamine bitartrate.
Table 4: PK parameters for cysteamine after a single dose of PROCYSBI or immediate-release cysteamine bitartrate at steady state
|Immediate-release cysteamine bitartrate||PROCYSBI|
|Cmax (mg/L)||2.7± 1.4||3.6 ± 1.8|
|AUC0-6h (min*mg/L)||351 ± 153||NA|
|AUC0-12h (min*mg/L)||NA||726 ± 339|
|AUCinf (min*mg/L)||380 ± 157||785 ± 358|
|Tmax (min)||73 ± 31||188 ± 88|
|t½ (min)||90 ± 24||253 ± 403|
|Cl/F (L/min)||1.4 ± 0.8||1.2 ± 0.8|
|Vd/F (L)||198 ± 159||382 ± 404|
The pharmacokinetics of PROCYSBI are consistent with a delayed-release formulation; the mean Tmax for PROCYSBI was 188 minutes compared with 73 minutes for immediate-release cysteamine bitartrate.
The systemic exposure to cysteamine was similar when PROCYSBI was administered with orange juice as a whole capsule and sprinkled in applesauce in the fasted state. In a food effect study conducted in healthy subjects (n=20), administration of a meal 30 minutes following PROCYSBI administration (intact capsules) decreased Cmax by 34% and AUC0-t by 32% compared to administration of a meal 2 hours post-dose [see DOSAGE AND ADMINISTRATION].
Cysteamine was moderately bound to human plasma proteins, predominantly to albumin, with mean protein binding of about 52%. Plasma protein binding was independent of concentration over the concentration range achieved clinically with the recommended doses. The volume of distribution (Vd/F) was 382 L for PROCYSBI compared with 198 L for immediate-release cysteamine bitartrate.
After each dose of PROCYSBI the cysteamine concentration in the blood continues to decline for approximately 30 minutes and the WBC cystine concentration increases accordingly.
The apparent plasma clearance (Cl/F) was similar between PROCYSBI (1.2 L/min) and immediate-release cysteamine bitartrate (1.4 L/min).
The half-life was 253 minutes for PROCYSBI and 90 minutes for immediate-release cysteamine bitartrate.
Drug Interaction Studies
An in vitro study indicates cysteamine bitartrate is not an inhibitor of CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4). The potential for cysteamine to affect the pharmacokinetics of other drugs via these enzymes is low.
A single PROCYSBI dose of 600 mg was administered with 240 mL of orange juice in healthy subjects after administration of 20 mg of omeprazole once daily for 5 days. The pharmacokinetic parameters of cysteamine were not significantly different when PROCYSBI was administered with omeprazole compared to when PROCYSBI was administered alone [see DRUG INTERACTIONS]. The effect of omeprazole on the pharmacokinetics of cysteamine was not studied after administration of PROCYSBI with water [see DOSAGE AND ADMINISTRATION].
Clinical Trials With Immediate-Release Cysteamine
Efficacy of immediate-release cysteamine bitartrate was demonstrated in open-label clinical trials of cysteamine hydrochloride and phosphocysteamine.
An open-label clinical trial of cysteamine hydrochloride was conducted in 94 pediatric patients (mainly from the United States) with nephropathic cystinosis. Patients were treated with increasing doses of cysteamine hydrochloride (mean dose 54 mg/kg per day) to attain WBC cystine concentrations of less than 2 nmol ½ cystine/mg protein 5 to 6 hours post-dose. The clinical outcomes were compared with a historical control group of 17 pediatric patients who had been in the placebo group of a randomized placebo-controlled trial of ascorbic acid. Cysteamine-treated patients had been diagnosed at a mean age of 22 months and had a mean age of 46 months old at study entry; placebo patients had been diagnosed at about 29 months and had a mean age of about 52 months old at trial entry. The principal measures of effectiveness were serum creatinine and calculated creatinine clearance and growth (height).
The average median WBC cystine concentration during treatment was 1.7 ± 0.2 nmol 1/2 cystine/mg protein. There were 70 cysteamine-treated patients with a baseline serum creatinine of less than 2 mg/dL who were followed for at least 1 year, and 17 placebo patients. Twelve of the 94 cysteamine-treated patients required early dialysis or renal transplant. Median follow-up of cysteamine patients was over 32 months, and 20% were followed more than 5 years. Median follow-up of the placebo group was 20 months; only 1 patient was followed more than 24 months. Glomerular function among cysteaminetreated patients was maintained over time. Placebo-treated patients experienced a gradual rise in serum creatinine. Renal tubular function was not affected by treatment.
Calculated creatinine clearances were evaluated for two groups of pediatric patients, one with poor WBC cystine depletion (defined as median WBC cystine concentrations greater than 3 nmol ½ cystine/mg protein or WBC cystine concentrations not measured at least 2 times per year) and one with good WBC cystine depletion. The final mean creatinine clearance of the good depletion group was 20.8 mL/min/1.73 m2 greater than the mean for the poor-depletion group.
Height-for-age measurements of treated patients were compared with height-for-age measurements of 143 patients initially screened for inclusion in the trial. Patients on treatment maintained growth (i.e., did not show increasing growth failure compared with normal scales) although growth velocity did not increase enough to allow patients to catch up to age norms for height.
In another open-label clinical trial, 46 patients who had completed the clinical trial of cysteamine hydrochloride (averaging 6.5 years of treatment) and 93 treatment naïve patients were treated with either cysteamine hydrochloride or phosphocysteamine (patient's choice). Patients had cystinosis diagnosed by elevated WBC cystine (mean 3.63 nmol ½ cystine/mg). Newly enrolled patients and the 46 continuing patients were required to have serum creatinine less than 3 mg/dL and 4 mg/dL, respectively. Patients were randomized to doses of 1.3 or 1.95 grams/m2 per day and stratified according to whether the serum creatinine was above 1.2 mg/dL or not. Doses could be raised if WBC cystine concentrations were approximately 2 nmol ½ cystine/mg protein and lowered due to intolerance. The mean age of the newly enrolled patients was about 49 months for the cysteamine group and about 34 months for the phosphocysteamine group. The mean age of the patients in the long-term follow-up group was about 9 years.
Mean doses were 1.27 grams/m2 per day and 1.87 grams/m2 per day in the two groups and WBC cystine concentrations averaged 1.72 ± 1.65 nmol ½ cystine/mg protein and 1.86 ± 0.92 nmol ½ cystine/mg protein in the 1.3 grams/m2 per day and 1.95 grams/m2 per day in the two groups, respectively. In new patients, serum creatinine was essentially unchanged over the period of follow-up (about half of the patients were followed for 24 months) and phosphocysteamine and cysteamine hydrochloride had similar effects. The long-term follow-up group also had essentially no change in renal function (almost 80% were followed at least 2 years). In four studies of patients with untreated cystinosis, renal death (need for transplant or dialysis) occurred at median age of less than 10 years. Both new patients and patients in the long-term follow-up group maintained height (although they did not catch up from baseline). There was no apparent difference in height maintenance between the two doses.
Clinical Trials With PROCYSBI
Multi-Center, Open-Label, Randomized Clinical Trial
This clinical trial comparing immediate-release cysteamine bitartrate and PROCYSBI was conducted in 43 (40 pediatric and 3 adult) patients with nephropathic cystinosis. Patient age ranged from 6 to 26 years (mean age 12 years) and 56% were male. Patients with WBC cystine concentrations greater than 2 nmol ½ cystine/mg protein (measured using the mixed leukocyte assay) and estimated glomerular filtration rate (eGFR corrected for body surface area) less than 30 mL/minute/1.73 m2 at the time of screening were excluded from the trial. Prior to randomization, patients were to be on a stable dose of immediate-release cysteamine bitartrate administered every six hours. PROCYSBI dose adjustments of up to approximately 100% of the total daily dose of immediate-release cysteamine bitartrate were allowed by trial criteria. The average total daily dose of PROCYSBI for patients completing the clinical trial was approximately 91% of the average total daily dose of immediate-release cysteamine bitartrate for patients at trial entry.
This trial demonstrated that at steady-state, PROCYSBI administered every 12 hours was non-inferior to immediate-release cysteamine bitartrate administered every 6 hours with respect to the depletion of WBC cystine concentrations (Table 5). Using a linear mixed effects statistical analysis model, the least-squaremean value of WBC cystine was 0.52 ± 0.06 nmol ½ cystine/mg protein after 12 hours under PROCYSBI and 0.44 ± 0.06 nmol ½ cystine/mg protein after 6 hours under immediate-release cysteamine; a difference of 0.08 ± 0.03 nmol ½ cystine/mg protein (95.8% Confidence Interval = 0.01 to 0.15).
Table 5: Comparison of WBC cystine concentrations in open-label, randomized, crossover
clinical trial participants, who were on a stable dose of immediate-release cysteamine prior to randomization, with WBC cystine less than 2 nmol ½ cystine/mg protein throughout the trial 1
|Immediate-release cysteamine bitartrate||PROCYSBI|
|WBC cystine concentration in nmol ½ cystine/mg protein
(LS Mean ± SE)
|0.44 ± 0.06||0.52 ± 0.06|
|Difference in Treatment effect
(LS mean ± SE)
[95.8% CI; p-value]
|0.08 ± 0.03
[0.01 to 0.15; <0.0001]
|1 Per-Protocol (PP) Population (N=39)|
Multi-Center, Single-Arm, Open-Label, Long-Term Extension Clinical Trial
Forty of the 41 patients completing the randomized trial continued treatment with PROCYSBI in an ongoing, open-label extension trial, for a total treatment duration ranging from 3 to 35 months. Thirty-four of the 36 patients continued treatment with PROCYSBI for at least 22 months in the extension trial and maintained their mean WBC cystine concentrations below 1 nmol ½ cystine/mg protein (measured using the mixed leukocyte assay) over this time period.
Thirteen pediatric patients, aged 2 to 6 years, were also enrolled in the extension trial. All of them were on treatment with immediate-release cysteamine bitartrate at the time of enrollment. Twelve of the 13 patients received at least 12 months of treatment with PROCYSBI, and their mean ± SD WBC cystine concentration (measured using the mixed leukocyte assay) decreased from 1.40 ± 1.08 nmol ½ cystine/mg protein at screening to 1.13 ± 0.56 nmol ½ cystine/mg protein after 12 months of treatment. Seven of these pediatric patients were able to achieve a WBC cystine concentration (measured using the mixed leukocyte assay) of less than 1.0 nmol ½ cystine/mg protein after 12 months of treatment; their mean ± SD dose of PROCYSBI increased from 0.84 ± 0.22 grams/m2 per day at screening to 1.06 ± 0.33 grams/m2 per day after 12 months of treatment.
During extended treatment with PROCYSBI, mean estimates of renal function, as measured by the estimated glomerular filtration rate (eGFR), were maintained.
(cysteamine bitartrate) Delayed-Release Capsules
What is PROCYSBI?
PROCYSBI is a prescription medicine used to treat nephropathic cystinosis in adults and children 2 years of age and older.
It is not known if PROCYSBI is safe and effective in children under 2 years of age.
Who should not take PROCYSBI?
Do not take PROCYSBI if you are allergic to penicillamine or cysteamine.
What should I tell my doctor before taking PROCYSBI?
Before you take PROCYSBI, tell your doctor if you:
- drink alcohol
- have a skin rash or bone problems
- have or have had stomach or bowel (intestinal) problems including ulcers or bleeding
- have a history of seizures, lack of energy, unusual sleepiness, depression, or changes in your ability to think clearly
- have liver or blood problems
- have any other medical conditions
- are pregnant or plan to become pregnant. It is not known if PROCYSBI will harm your unborn baby. Tell your doctor right away if you think that you are pregnant. Talk with your doctor about the benefits and risks of taking PROCYSBI during pregnancy.
- are breastfeeding or plan to breastfeed. You should not breastfeed during treatment with PROCYSBI. Talk with your doctor about the best way to feed your baby if you take PROCYSBI.
Tell your doctor about all medicines that you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.
How should I take PROCYSBI?
- Take PROCYSBI exactly as your doctor tells you to.
- Your doctor may start you on a low dose of PROCYSBI and slowly increase your dose to help avoid side effects, especially if you have not taken a medicine that contains cysteamine bitartrate before.
- Do not change your dose of PROCYSBI unless your doctor tells you to.
- PROCYSBI is taken 2 times each day, every 12 hours.
- Take PROCYSBI the same way each time, either without eating or with a small amount of food, as follows:
- If you take PROCYSBI without eating, do not eat for at least 2 hours before taking PROCYSBI and at least 30 minutes after taking PROCYSBI.
- If you are not able to take PROCYSBI without eating, you can eat a small amount of food (½ cup) within 1 hour before you take PROCYSBI through 1 hour after you take it.
- Avoid eating foods that are high in fat close to the time that you will take a dose of PROCYSBI.
- Talk to your doctor or pharmacist if you have questions about how to take PROCYSBI.
- Swallow PROCYSBI capsules whole.
- Take PROCYSBI with fruit juice, except for grapefruit juice, if you swallow the capsule whole.
- Do not crush or chew PROCYSBI or the capsule contents.
- If you cannot swallow the capsule whole, you can open it and take the capsule contents with certain foods and juices. Read the “Instructions for Use” in the package that comes with your PROCYSBI for information about the right way to use PROCYSBI if you cannot swallow the capsules whole or if you have a gastrostomy tube (G-tube).
- Take PROCYSBI at least 1 hour before or 1 hour after you take medicines that contain bicarbonate or carbonate.
- If you miss a dose, take it as soon as possible, up to 8 hours after the scheduled time of the missed dose. If it is less than 4 hours of the time the next dose is due, skip the missed dose. Take the next dose at your regularly scheduled time. Do not take 2 doses at one time to make up for a missed dose.
- If you take too much PROCYSBI, call your doctor or go to the nearest hospital emergency room right away.
- Your doctor should do blood tests to measure the amount of cystine inside your white blood cells or to measure the amount of PROCYSBI in your blood before you start taking it and regularly during treatment with PROCYSBI. This will help your doctor to prescribe the dose of PROCYSBI that is right for you.
- Take supplements if prescribed by your doctor, such as salt or mineral replacement supplements, vitamin D, or thyroid hormone.
What should I avoid while taking PROCYSBI?
- Do not drive or operate machinery until you know how PROCYSBI affects you. PROCYSBI can make you sleepy or less alert than normal.
- Do not drink alcohol if you take PROCYSBI. Drinking alcohol while taking PROCYSBI may change how PROCYSBI works and may cause an increase in the amount of PROCYSBI in your blood that may cause serious side effects.
What are the possible side effects of PROCYSBI?
PROCYSBI can cause serious side effects, including:
- Skin, bone, and joint problems. People treated with high doses of cysteamine bitartrate may develop abnormal changes of their skin and bones. These changes may include stretch marks, bone injuries (such as fractures), bone deformities, and joint problems. Check your skin while taking PROCYSBI. Tell your doctor if you notice any skin changes or problems with your bones or joints. Your doctor will check you for these problems.
- Skin rash. Skin rash is common with cysteamine bitartrate and may sometimes be severe. Tell your doctor right away if you get a skin rash. Your dose of PROCYSBI may need to be decreased until the rash goes away. If the rash is severe, your doctor may tell you to stop taking PROCYSBI.
- Stomach and bowel (intestinal) problems. Some people who take other medicines that contain cysteamine bitartrate develop ulcers and bleeding in their stomach or bowel. Tell your doctor right away if you get stomach-area pain, nausea, vomiting, loss of appetite, or vomit blood.
- Central nervous system symptoms. Some people who take other medicines that contain cysteamine bitartrate develop seizures, depression, and become very sleepy. The medicine may affect how your brain is working (encephalopathy). Tell your doctor right away if you develop any of these symptoms.
- Low white blood cell count and certain abnormal liver function blood tests. Your doctor should check you for these problems.
- Benign intracranial hypertension (pseudotumor cerebri) has happened in some people who take immediate-release cysteamine bitartrate. This is a condition where there is high pressure in the fluid around the brain. Your doctor should do eye examinations to find and treat this problem early.
Tell your doctor right away if you develop any of the following symptoms while taking PROCYSBI: headache, buzzing or "whooshing" sound in the ear, dizziness, nausea, double vision, blurry vision, loss of vision, pain behind the eye, or pain with eye movement.
The most common side effects with PROCYSBI include:
- stomach (abdominal) pain
- breath odor
- skin odor
- skin rash
These are not all of the possible side effects of PROCYSBI. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
General information about PROCYSBI
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use PROCYSBI for a condition for which it was not prescribed. Do not give PROCYSBI to other people, even if they have the same symptoms that you have. It may harm them. You can ask your doctor or pharmacist for information about PROCYSBI that is written for health professionals.
What are the ingredients in PROCYSBI?
Active ingredients: cysteamine bitartrate
Inactive ingredients: microcrystalline cellulose, Eudragit® L 30 D-55, hypromellose, talc, triethyl citrate, sodium lauryl sulfate, and purified water
Capsule shell ingredients: gelatin, titanium dioxide, blue ink and white ink
Instructions for Use
(cysteamine bitartrate) Delayed-Release Capsules
PROCYSBI capsules should be swallowed whole. If you cannot swallow the capsule whole, you can open it and take the capsule contents with certain foods and juices. PROCYSBI can also be given through a gastrostomy tube (G-tube).
Opening PROCYSBI capsules:
- Do not pinch the PROCYSBI capsule in the center.
- Do not crush the PROCYSBI capsule.
- Use both hands to open the PROCYSBI capsule.
- Hold each end of the PROCYSBI capsule with your thumb and index (pointer) fingers and gently twist the two ends in opposite directions to open.
Taking PROCYSBI with applesauce or berry jelly:
Do not take PROCYSBI with any food other than applesauce or berry jelly.
Step 1: Place about ½ cup (4 ounces) of applesauce or berry jelly into a clean container. Do not use any other food.
Step 2: Open the PROCYSBI capsule. See “Opening PROCYSBI capsules” above. You may need to use more than 1 PROCYSBI capsule for the dose prescribed by your doctor.
Step 3: Sprinkle the granules that are inside the capsule or capsules onto the applesauce or berry jelly.
Step 4: Mix the granules with the applesauce or berry jelly.
Step 5: Swallow the applesauce or berry jelly and granules mixture within 30 minutes after preparing. Do not chew the granules. Do not save the applesauce or berry jelly and granules for later use.
Taking PROCYSBI with fruit juice:
Do not take PROCYSBI with grapefruit juice.
Step 1: Pour about ½ cup (4 ounces) of fruit juice into a clean cup.
Step 2: Open the PROCYSBI capsule. See “Opening PROCYSBI capsules” above. You may need to use more than 1 PROCYSBI capsule for the dose prescribed by your doctor.
Step 3: Sprinkle the granules that are inside the capsule or capsules into ½ cup (4 ounces) of fruit juice.
Step 4: Stir gently until mixed.
Step 5: Drink all of the fruit juice and granules mixture within 30 minutes of mixing. Do not chew the granules. Do not save the fruit juice and granules for later use.
Giving PROCYSBI through a gastrostomy tube (G-tube):
It is best to use a straight (bolus) feeding tube.
For people who have a gastrostomy tube (G-tube) that is size 14 French or larger, PROCYSBI may be given as follows:
Use only strained applesauce with no chunks when giving PROCYSBI through agastrostomy tube (G-tube).
Step 1: Flush the gastrostomy tube button with 5 mL of water to clear the button.
Step 2: Place about ½ cup (4 ounces) of applesauce into a clean container. Use at least 1/8 cup (1 ounce) of applesauce for children ≤ 25 kg starting PROCYSBI at a dose of 1 or 2 capsules.
Step 3: Open the PROCYSBI capsule. See “Opening PROCYSBI capsules” above. You may need to use more than 1 PROCYSBI capsule for the dose prescribed by your doctor.
Step 4: Sprinkle the granules that are inside the capsule or capsules on the applesauce. Gently mix the granules with the applesauce.
Step 5: Place the tip of a catheter tip syringe at the bottom of the container of applesauce and granules mixture. For an adult dose, draw up about 40 mL of the mixture. When giving to a child, draw up at least 10 mL of the mixture for doses of 1 or 2 capsules.
Step 6. Place the tip of the catheter tip syringe into the feeding tube that will be connected to the gastrostomy tube. Fill the feeding tube with the applesauce and granules mixture.
Step 7: Hold the feeding tube in a horizontal (straight across) position. Give the applesauce and granules mixture through the gastrostomy tube at a quick and steady rate of 10 mL over 10 seconds.
Step 8. Repeat Steps 5 through Step 7 until all of the applesauce and granules mixture is given. Give all of the applesauce and granules mixture through the gastrostomytube within 30 minutes of mixing. Do not save the applesauce and granules mixture for later use.
Step 9: Draw up at least 10 mL of fruit juice into another catheter tip syringe. Do not use grapefruit juice. Gently swirl the syringe. Flush the gastrostomy tube with the fruit juice. Use enough fruit juice to flush the gastrostomy tube so that there is no applesauce and granules mixture left in the gastrostomy tube.
How should I store PROCYSBI?
- Store PROCYSBI at room temperature, 20°C to 25°C (68°F to 77°F).
- Dispose of by date on bottle.
- Discard expired capsules per your local or state regulations.
- Store PROCYSBI in a dry place away from light.
- Keep PROCYSBI tightly closed in the original bottle.
- The PROCYSBI bottle (25 mg) contains a desiccant canister and one oxygen absorber canister.
- The PROCYSBI bottle (75 mg) contains a desiccant canister and two oxygen absorber canisters.
- Do not eat or throw away the desiccant canister or oxygen absorber canister(s).
Keep PROCYSBI and all medicines out of the reach of children.
This Instructions for Use has been approved by the U.S. Food and Drug Administration.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.