Medical Editor: John P. Cunha, DO, FACOEP
Procysbi (cysteamine bitartrate) is a cystine depleting agent used to treat a rare genetic condition called nephropathic cystinosis in patients over the age of six years old. Common side effects of Procysbi include:
- abdominal pain/discomfort,
- decreased appetite,
- bad breath odor,
- skin odor,
- lethargy, and
Procysbi should be prescribed by a physician experienced in management of nephropathic cystinosis. Procysbi capsules should be swallowed whole or after sprinkling on food or in recommended liquids. The total daily dose of Procysbi is 1.3 gram/m2/day in two divided doses, every 12 hours. Procysbi should be taken at least two hours after a meal and at least 30 minutes before eating. Drug interactions with Procysbi have not been described, but this does not mean that these may not develop. Procysbi has not been studied in pregnant women and should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Breastfeeding is not recommended while taking Procysbi.
Procysbi (cysteamine bitartrate) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
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].
Read the entire FDA prescribing information for Procysbi (Cysteamine Bitartrate Delayed-release Capsules)