Tiopronin

Tiopronin is a prescription medication used to prevent the symptoms of nephrolithiasis.

• Tiopronin is available under the following different brand names: Thiola, Tiopronin DR, Tiopronin-K DR, Thiola EC.

Common side effects of Tiopronin include:

• itching,
• changes in taste,
• skin wrinkling,
• nausea,
• vomiting,
• diarrhea,
• loss of appetite,
• abdominal pain,
• bloating,
• gas,
• sore throat,
• mouth sores,
• shortness of breath,
• chills,
• weakness,
• fatigue,
• muscle pain,
• high levels of protein in the urine, and
• anemia

Serious side effects of Tiopronin include:

• hives,
• difficulty breathing,
• swelling of the face, lips, tongue, or throat,
• dizziness,
• rash,
• fever,
• swollen glands, and
• joint pain

Rare side effects of Tiopronin include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Tablet (Thiola)

• 100 mg

Tablet, delayed-release (Thiola EC)

• 100 mg
• 300 mg

Prevention of Nephrolithiasis

Adult dosage

• Initial: 800 mg/day orally divided thrice daily
• Adjust the dose to maintain urinary cystine below 250 mg/L (the average daily dose is ~1000 mg/day)
• Consider starting at a lower dose with a history of severe toxicity to d-penicillamine

Pediatric dosage

• Below 20 kg: Safety and efficacy not established
• Above 20 kg
• 15 mg/kg/day orally divided thrice daily; not to exceed 50 mg/kg/day
• Adjust the dose to maintain urinary cystine levels below 250 mg/L
• Consider starting at a lower dose with a history of severe toxicity to d-penicillamine

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Tiopronin has severe interactions with no other drugs.
• Tiopronin has serious interactions with no other drugs.
• Tiopronin has moderate interactions with the following drug:
  • ethanol
• Tiopronin has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• Hypersensitivity

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Tiopronin?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Tiopronin?”

Cautions

• Hypersensitivity reactions reported including drug fever, rash, fever, arthralgia, and lymphadenopathy
• Not recommended if breastfeeding
• Proteinuria
  • Proteinuria reported, including nephrotic syndrome and membranous nephropathy
  • Pediatric patients receiving more than 50 mg/kg/day may be at increased risk
  • Monitor for the development of proteinuria and discontinue therapy in patients who develop proteinuria
• Drug interaction overview
  • Thiola EC: Tiopronin is released faster from Thiola EC in the presence of alcohol and the risk for adverse events associated when taken with alcohol is unknown
  • Avoid alcohol consumption 2 hours before and 3 hours after taking Thiola EC

Pregnancy and Lactation

• Available published case report data with tiopronin have not identified a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes
• Clinical considerations
• Renal stones in pregnancy may increase the risk of adverse pregnancy outcomes (eg, preterm birth, low birth weight)
• Lactation
  • There are no data on the presence of tiopronin in either human or animal milk or on the effects of the breastfed child
  • Prescribing information describes a published study suggesting tiopronin may suppress milk production
  • Because of the potential for serious adverse reactions, including nephrotic syndrome, advise patients that breastfeeding is not recommended during treatment