TIOPRONIN
Chemistry - A sulfhydryl compound related to penicillamine, tiopronin has a molecular weight of 163.2. It is also known as thiopronine or N-(2-Mercaptopropionyl)-glycine (MPG).
Uses, Indications - Tiopronin is indicated for the prevention of cystine urolithiasis in patientswhere dietary therapy combined with urinary alkalinization is not completely effective. It may alsobe useful in combination with urine alkalinization to dissolve stones.
There is limited information on the reproductive safety of tiopronin. Skeletal defects, cleft palatesand increased resorptions were noted when rats were given 10 times the human dose ofpenicillamine and, therefore, may also be of concern with tiopronin. Other animals studies havesuggested that tiopronin may affect fetus viability at high doses. Because tiopronin may be excretedin milk, at present it is not recommended for use in nursing animals.
Should this effect occur, the drug should be discontinued and appropriate treatment started(corticosteroids, blood component therapy prn). Adverse effects noted in humans that occur morefrequently include dermatologic effects (ecchymosis, itching, rashes, mouth ulcers, jaundice) and GIdistress. Less frequently allergic reactions (specifically adenopathy), arthralgias, dyspnea, fever, hematologic abnormalities, edema, and nephrotic syndrome have been noted in humans.
Storage, Stability, Compatibility
Store tablets at room temperature in tight containers.Pharmacology - TIOPRONIN
Tiopronin is considered to be an antiurolithic agent. It undergoes thiol-disulfideexchange with cystine (cysteine-cysteine disulfide) to form tiopronin-cystine disulfide. Thiscomplex is more water soluble and is readily excreted thereby preventing cystine calculi fromforming.Uses, Indications - Tiopronin is indicated for the prevention of cystine urolithiasis in patientswhere dietary therapy combined with urinary alkalinization is not completely effective. It may alsobe useful in combination with urine alkalinization to dissolve stones.
Pharmacokinetics - TIOPRONIN
Tiopronin has a rapid onset of action and in humans, up to 48% of a dose isfound in the urine within 4 hours of dosing. Tiopronin has a relatively short duration of action andits effect in humans disappears in about 10 hours. Elimination is primarily via renal routes.Contraindications, Precautions, Reproductive Safety
Tiopronin's risks versus its benefitsshould be considered before using in patients with agranulocytosis, aplastic anemia, thrombocytopenia or other significant hematologic abnormality, impaired renal or hepatic function, or sensitivity to either tiopronin or penicillamine.There is limited information on the reproductive safety of tiopronin. Skeletal defects, cleft palatesand increased resorptions were noted when rats were given 10 times the human dose ofpenicillamine and, therefore, may also be of concern with tiopronin. Other animals studies havesuggested that tiopronin may affect fetus viability at high doses. Because tiopronin may be excretedin milk, at present it is not recommended for use in nursing animals.
Adverse Effects, Warnings
There is limited information available on the adverse effect profile oftiopronin in dogs. While tiopronin is thought to have fewer adverse effects than penicillamine inhumans, it has been associated with Coombs'-positive regenerative spherocyte anemia in dogs.Should this effect occur, the drug should be discontinued and appropriate treatment started(corticosteroids, blood component therapy prn). Adverse effects noted in humans that occur morefrequently include dermatologic effects (ecchymosis, itching, rashes, mouth ulcers, jaundice) and GIdistress. Less frequently allergic reactions (specifically adenopathy), arthralgias, dyspnea, fever, hematologic abnormalities, edema, and nephrotic syndrome have been noted in humans.