Cysteamine
Mechanism :
Reacts with cystine within the lysosome to convert it to cysteine and to a cysteine-cysteamine mixed disulfide, both of which can then exit the lysosome in patients with cystinosis, an inherited defect of lysosomal transport.
Indication :
Contraindications :
Hypersensitivity to cysteamine, penicillamine, or any component of the formulation.
Dosing :
Immediate Release Capsule
Initial: Give one-sixth to one-fourth of maintenance dose
Maintenance (<12 years): 1.3 g/m²/day or 60 mg/kg/day of free base PO divided q6hr; not to exceed 1.95 g/m²/day or 90 mg/kg/day.
Maintenance (≥12 years or >110 lbs): 2 g/day PO divided q6hr; dose should be reached after 4-6 weeks of incremental dosage increases; not to exceed 1.95 g/m²/day or 90 mg/kg/day.
Adverse Effect :
Vomiting, Anorexia, Diarrhea, Fever, Lethargy, Rash, Seizures, Ataxia, Encephalopathy, Somnolence, Depression, Nightmare, Impaired cognition, Hypertension.
Interaction :
Alcohol (Ethyl): May enhance the adverse/toxic effect of Cysteamine.
Antacids: May diminish the therapeutic effect of Cysteamine.
Histamine H2 Receptor Antagonists: May diminish the therapeutic effect of Cysteamine.
Proton Pump Inhibitors: May diminish the therapeutic effect of Cysteamine.
Hepatic Dose :
Use with caution. It is associated with reversible elevated transaminases.