Tiopronin (trade name Thiola) is a prescription thiol drug used to control the rate of cystine solidification and excretion in the disease cystinuria. It is a white crystalline powder. Due to its rarity, it falls under the classification of "orphan drug".
Tiopronin may present a wide variety of side effects, but side effects are usually limited and subside over time with continued usage. With the rarity of the disease, tiopronin has not been studied substantially, with an extremely low percentage of individuals available for testing.
Other uses
Tiopronin is used primarily for cystinuria and is well known in the cystinuric community. It may also be used for Wilson's disease (an overload of copper in the body), and certain types of rare arthritis. It should be mentioned though, that tiopronin is not an anti-inflammatory.
Depending on the severity of a person's cystinuria, tiopronin may be taken for life, possibly starting in early childhood.