Why should you consider THIOLA?

For some people with cystinuria, making therapeutic lifestyle changes such as drinking more water and reducing your protein and sodium intake may not be enough to stop cystine stones from forming. If you or your loved one is still forming cystine stones, THIOLA can help. See Important Safety Information below.

Download the enrollment form and talk to your doctor about how the right dose of THIOLA, in conjunction with making healthy lifestyle choices, can help you become—and stay—stone-free.

How does THIOLA work?

THIOLA reduces the risk of stone formation by lowering the amount of cystine in your urine.

Picture of excess cystine

In people living with cystinuria, cystine does not get reabsorbed from the urine properly. This leads to an increase of cystine in the urine. When there’s too much cystine in the urine (what doctors call above the solubility limit—more than 250 mg of cystine per liter of urine), cystine stones form.

Picture of THIOLA binding to excess cystine

THIOLA combines with cystine in the urine, allowing cystine to dissolve more easily. This lowers the amount of cystine in the urine, which reduces the risk of cystine kidney stone formation. 


Do you know your cystine level?

Don’t let your cystine level control you. Keep your urinary cystine level in check—talk to your doctor about 24-hour urine collection.

Is THIOLA right for you?

Talk to your doctor about THIOLA if

  • You are still forming stones with your current treatment plan  
  • Your cystine level is above the line of solubility (>250 mg/L)

THIOLA is an adjunctive therapy to diet modification, urinary alkalinization, and high fluid intake, or for those who have adverse reactions to

Taking THIOLA can be an effective way to control your cystinuria

Living with cystinuria can be a challenge. Fortunately, THIOLA can help reduce stone burden. Imagine what your life could be like if you were stone-free.

A clinical trial showed that THIOLA stopped stones from forming completely or reduced the rate of stone formation, in the majority of study participants, regardless of whether participants had already taken d-penicillamine. 

The table shows the trial results in greater detail. 

Efficacy results in people treated with THIOLA

  Study group previously treated with d-penicillamine (43 participants)

Study group not previously treated with d-penicillamine (14 participants)

Rate of stone reduction



Rate of stone prevention




THIOLA can be an important part of treatment by either reducing or stopping stones from forming whether or not people with cystinuria have taken d-penicillamine.

Effective treatment

Effective treatment on THIOLA relies on finding an optimal dose and adhering to healthy lifestyle choices. Work with your doctor to find the THIOLA dose that’s right for you.

Optimal management relies on

  • Starting on the right dose for you
  • Monitoring your cystine levels through 24-hour urine collection to determine necessary dosing adjustments
  • Telling your doctor about any reactions you may have to THIOLA

THIOLA is associated with fewer or less severe adverse reactions than d-penicillamine.  Despite this apparent reduced toxicity to THIOLA relative to d-penicillamine, THIOLA treatment may potentially be associated with all the adverse reactions reported with d-penicillamine.

See Important Safety Information below.


THIOLA® (tiopronin) tablets are a prescription medicine used to help prevent the formation of cystine (kidney) stones in patients who were not successfully treated with dietary changes and increased fluid intake, or patients who have had side effects with the drug d-penicillamine.

Important Safety Information 

THIOLA is not for everyone. You should not take THIOLA if you:

  • Are pregnant or plan to become pregnant
  • Are breastfeeding or plan to breastfeed
  • Have a history of blood disorders including aplastic anemia (your bone marrow does not make enough new cells), agranulocytosis (decrease in certain white blood cells), or thrombocytopenia (decrease in the number of platelets)

The safety and effectiveness of THIOLA have not been established in children under 9 years of age, and there are no well-controlled studies in pregnant women. High doses of THIOLA in pregnant laboratory animals have been shown to harm the fetus, so you should talk about these risks with your doctor to determine whether THIOLA is right for you. No long-term animal studies have been performed to see whether THIOLA can cause cancer, so you should discuss these risks with your doctor.

While you are taking THIOLA, your doctor will monitor you closely for signs and symptoms of possible complications. Your doctor will routinely do certain blood and urine tests, and yearly scans of your abdomen to look at the size and appearance of kidney stones. THIOLA should only be used under the close supervision of your doctor.

THIOLA can cause serious side effects or potential complications, and some of these could be fatal. Therefore, it is important to call your doctor right away if you have any side effects.

Side effects associated with THIOLA include a drug-related fever that typically occurs during the first month of treatment. If this occurs, talk with your doctor, who may discontinue treatment until the fever goes away. 

You may notice a reduced sense of taste while taking THIOLA, which will eventually go away. Some patients also report wrinkling or thin, fragile skin during long-term treatment.

Other side effects of THIOLA may include an itchy rash that is found on many parts of your body. This typically occurs during the first few months of treatment, and antihistamines can help reduce the itching. The rash will usually disappear once you stop taking THIOLA. Less often, patients who take THIOLA for more than 6 months may develop a rash that is usually located on the upper body and is very itchy. It typically goes away slowly after discontinuing treatment and returns after re-starting treatment.

Some patients may develop a drug hypersensitivity reaction to THIOLA that includes fever, joint pain, and swollen lymph nodes. If this occurs, your doctor may discontinue THIOLA.

THIOLA can cause serious and potentially fatal blood disorders, including aplastic anemia (your bone marrow does not make enough new cells), agranulocytosis (decrease in certain white blood cells), or thrombocytopenia (decrease in the number of platelets). Call your doctor immediately if you have any signs or symptoms such as fever, sore throat, chills, bleeding, or if you are bruising more easily.

Although THIOLA may be less toxic than d-penicillamine, it could potentially cause all of the serious side effects reported for d-penicillamine. No deaths have been reported as a result of THIOLA treatment; however, fatal outcomes have been reported with certain complications of d-penicillamine therapy, including reduced white blood cells, red blood cells, or platelets; Goodpasture's syndrome (an autoimmune disorder that affects the lungs and kidneys); and myasthenia gravis (an autoimmune disorder that causes muscles to weaken). Do not take THIOLA if you have a history of these conditions.

Additional side effects that have been reported during treatment with d-penicillamine and that might occur during THIOLA treatment include:  decreased sense of smell, nausea, vomiting, diarrhea or soft stools, loss of appetite, abdominal pain, bloating, gas, sore throat, sores in the mouth, hives, warts, swelling of the throat, difficulty breathing, shortness of breath, fatigue or weakness, muscle or joint pain, swelling in your legs or fluid build-up in the lungs, lung or kidney problems, and blood or high amounts of protein in urine. These side effects are more likely to develop during THIOLA therapy in patients who had previous reactions to d-penicillamine. Talk to your doctor about any unusual side effects.

Seek immediate medical attention and discontinue THIOLA if you notice symptoms such as fever, sore throat, chills, bleeding, easy bruising, coughing up blood, muscle weakness, blistering or raw areas on the skin or mucous membranes, joint pain, swelling of the lymph nodes, or swelling in your legs, as these may be signs of a serious reaction to the drug.

Jaundice (yellow appearance of the skin and whites of the eyes) and abnormal liver function tests have been reported during THIOLA treatment for conditions unrelated to cystine stones.

Call your doctor for medical advice about side effects. You may report negative side effects to Retrophin® Medical Information at 1-877-659-5518, or to the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Please see full Prescribing Information.