Tiopronin
Mechanism :
As an active reducing agent, tiopronin undergoes thiol-disulfide exchange with cystine to form tiopronin-cystine disulfide, which is more water soluble than cystine.
Indication :
- Prevention of kidney stone (cysteine) formation in patients with severe homozygous cystinuria who have urinary cysteine >500 mg/day who are resistant to treatment with high fluid intake, alkali and diet modification, or who have had adverse reactions to penicillamine.
Contraindications :
Prior history of developing agranulocytosis, aplastic anemia, or thrombocytopenia on this medication.
Dosing :
Oral: Children ≥9 years: Initial: 15 mg/kg/day in 3 divided doses. Titrate dose to maintain urinary
cysteine <250 mg/L.
Adverse Effect :
Fever, skin complications, hypersensitivity reactions, taste and smell impairment, generalized rash, SLE-like syndrome, hypogeusia, skin wrinkling, jaundice, leukopenia, thrombocytopenia, aplastic anemia, agranulocytosis, Goodpasture’s syndrome, myasthenia gravis.
Interaction :
There are no known significant interactions.
Hepatic Dose :
Dose adjustment guidelines are not available, dose adjustment may be required.
Therapy can cause abnormal liver function tests and/or jaundice, if this occurs stop therapy.