indication
Given intravenously or orally to treat radiation sickness. The bitartrate has been used for the oral treatment of nephropathic cystinosis and cystinurea.
pharmacology
People born without the ability to metabolize the amino acid cystine suffer from cystinosis, a rare inherited disorder characterized by the deposition and accumulation of cystine crystals throughout the body. These crystals cause considerable damage, particularly in the kidney. Kidney failure can occur by the age of 10 in untreated patients. Cysteamine prevents the accumulation of cystine crystals and is prescribed to prevent further kidney damage. Cysteamine helps to convert cystine into less harmful chemical forms that can be removed from cells.
mechanism of action
The free thiol cysteamine depletes cystinotic leukocytes and other cells of cystine, whose accumulation is considered the cause of organ damage in cystinosis. Cysteamine cleaves the disulfide bond with cystine to produce molecules that can escape the metabolic defect in cystinosis and cystinuria.
toxicity
Symptoms of overdose may include convulsions (seizures), increased thirst and unusual tiredness or weakness.