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Tiopronin Side Effects

For the Consumer

Applies to tiopronin: oral tablet

As well as its needed effects, tiopronin may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking tiopronin, check with your doctor immediately:

More common:
  • Yellow skin or eyes
Less common:
  • Muscle pain
  • sore throat and fever
  • unusual bleeding or bruising

Severity: Moderate

If any of the following side effects occur while taking tiopronin, check with your doctor or nurse as soon as possible:

More common:
  • Pain, swelling, or tenderness of the skin
  • skin rash, hives or itching
  • ulcers or sores in mouth
Less common:
  • Bloody or cloudy urine
  • chills
  • difficulty in breathing
  • high blood pressure
  • hoarseness
  • joint pain
  • swelling of feet or lower legs
  • tenderness of glands
  • unusual bleeding
  • Chest pain
  • cough
  • difficulty in chewing, talking, or swallowing
  • double vision
  • general feeling of discomfort, illness, or weakness
  • muscle weakness
  • spitting up blood
  • swelling of lymph glands

Minor Side Effects

Some tiopronin side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Abdominal or stomach pain
  • bloating or gas
  • diarrhea or soft stools
  • loss of appetite
  • nausea and vomiting
  • warts
  • wrinkling or peeling or unusually dry skin
Less common:
  • Changes in taste or smell

For Healthcare Professionals

Applies to tiopronin: oral tablet


Hepatic side effects have included jaundice and abnormal liver function tests.[Ref]


Hypersensitivity side effects have included fever, rash (erythematous, maculopapular, or morbilliform), and pruritus. Laryngeal edema, dyspnea, respiratory distress, chills, arthralgia, weakness and adenopathy have also been reported.[Ref]

Patients experiencing immediate hypersensitivity reactions can be treated with antihistamines and tiopronin treatment restarted at a lower dose. Those experiencing a rash later in treatment (at least 6 months into therapy) usually cannot be restarted on tiopronin.[Ref]


Immunologic side effects have included a simulated lupus erythematous occasionally associated with a positive antinuclear antibody test.[Ref]


Gastrointestinal side effects have included hypogeusia. Nausea, emesis, diarrhea or soft stools, anorexia, abdominal pain, and bloating or flatulence have also been reported.[Ref]


Metabolic side effects have rarely included vitamin B6 deficiency.[Ref]


Dermatologic side effects have included wrinkling and friability of the skin. Ecchymosis, urticaria, warts, pemphigus, and elastosis perforans serpiginosa have also been reported.[Ref]


Hematological side effects have included increased bleeding, anemia, leukopenia, thrombocytopenia, and eosinophilia.[Ref]


Renal side effects have included proteinuria, nephrotic syndrome, and hematuria.[Ref]


Respiratory side effects have included pharyngitis, bronchiolitis, hemoptysis, and pulmonary infiltrates.[Ref]

Nervous system

Nervous system side effects have included myasthenic syndrome.[Ref]


1. "Product Information. Thiola (tiopronin)." Mission Pharmaceutical Company, San Antonio, TX.

It is possible that some side effects of tiopronin may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.