Nurses Compass
Drug Guide
Cysteamine Bitartrate
Classification
Therapeutic: Antirheumatic, Mucolytic
Pharmacological: Cysteamine analog, free thiol agent
FDA Approved Indications
- Cystinosis (a rare inherited lysosomal storage disorder)
Mechanism of Action
Cysteamine reduces cystine levels inside lysosomes by forming cysteine-cysteamine disulfides that can exit the lysosome, thereby decreasing cystine accumulation.
Dosage and Administration
Adult: Start at 1.3 to 1.95 grams/m2/day divided into 2-4 doses; titrate based on response and tolerability.
Pediatric: Dosing based on body surface area; adjustment necessary for renal impairment.
Geriatric: Use with caution; closely monitor renal function.
Renal Impairment: Adjust dose based on renal function, with close monitoring.
Hepatic Impairment: Data limited; use cautiously and monitor for adverse effects.
Pharmacokinetics
Absorption: Rapid gastrointestinal absorption.
Distribution: Widely distributed in body tissues.
Metabolism: Metabolized in the liver and tissues to form metabolites.
Excretion: Primarily excreted via urine.
Half Life: Approximately 3 hours.
Contraindications
- Hypersensitivity to cysteamine or any component of the formulation.
Precautions
- Monitoring for nephrolithiasis, bone marrow suppression, and nephrotoxicity. Use with caution in patients with liver disease. Regular blood tests required. Consider pregnancy and lactation; risk-benefit ratio needed.
Adverse Reactions - Common
- Gastrointestinal symptoms (nausea, vomiting, diarrhea) (Common)
- Odor of body and urine due to cysteamine (Common)
Adverse Reactions - Serious
- Nephrotoxicity (Rare, but requires monitoring)
- Bone marrow suppression (neutropenia, thrombocytopenia) (Rare)
- Allergic reactions (rash, anaphylaxis) (Rare)
Drug-Drug Interactions
- Amifostine may increase risk of neutropenia.
- Other nephrotoxic drugs may increase risk of renal impairment.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor renal function, blood cell counts, and for signs of nephrolithiasis.
Diagnoses:
- Risk for infection related to neutropenia.
- Risk for renal impairment.
Implementation: Administer doses as prescribed, monitor laboratory values, counsel on hydration.
Evaluation: Assess for reduction in cystine levels, monitor for adverse effects, ensure compliance.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Report any signs of kidney problems, blood disorders, or allergic reactions.
- Maintain adequate hydration.
- Understand the importance of regular blood tests.
Special Considerations
Black Box Warnings:
- Potential for nephrotoxicity and myelosuppression requiring careful monitoring.
Genetic Factors: Consider genetic counseling for families with cystinosis.
Lab Test Interference: May interfere with certain laboratory tests; inform lab personnel.
Overdose Management
Signs/Symptoms: Nausea, vomiting, diarrhea, hypotension, hypersensitivity reactions.
Treatment: Supportive care, monitor vital signs, renal function, blood counts, and provide symptomatic treatment.
Storage and Handling
Storage: Store at room temperature, away from moisture and light.
Stability: Stable as per manufacturer guidelines for the duration specified.