Medication Monitor

Generic Name (Trade Name—Company)
July 8, 2019


New formulation of tiopronin treatment for cystinuria can be taken with or without food

Retrophin announced FDA approval of 100-mg and 300-mg tablets of tiopronin, a new enteric-coated formulation, for treatment of cystinuria. This rare inherited disorder causes a buildup of cystine levels in the urine, resulting in the formation of recurring cystine kidney stones. 

The new formulation can be administered with or without food, whereas the original formulation of 100 mg tiopronin is recommended to be taken at least 1 hour before or 2 hours after meals.

The recommended initial dosage of tiopronin in adult patients is 800 mg per day. In clinical studies, the average dose was approximately 1,000 mg, or 10 tablets per day.

The most common adverse reactions are nausea, diarrhea or soft stools, oral ulcers, rash, fatigue, fever, arthralgia, proteinuria, and emesis.