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Thiola Side Effects

Generic Name: tiopronin

Note: This document contains side effect information about tiopronin. Some of the dosage forms listed on this page may not apply to the brand name Thiola.

For the Consumer

Applies to tiopronin: oral tablet

Along with its needed effects, tiopronin (the active ingredient contained in Thiola) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking tiopronin:

More Common

  • Yellow skin or eyes

Less Common

  • Muscle pain
  • sore throat and fever
  • unusual bleeding or bruising

Check with your doctor as soon as possible if any of the following side effects occur while taking tiopronin:

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

Some side effects of tiopronin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More Common

Less Common

  • Changes in taste or smell

For Healthcare Professionals

Applies to tiopronin: oral tablet


Common (1% to 10%): Proteinuria, nephrotic syndrome, hematuria

Frequency not reported: Jaundice, abnormal liver function tests[Ref]


Common (1% to 10%): Laryngeal edema, dyspnea, respiratory distress, fever, chills, arthralgia, weakness, fatigue, myalgia, adenopathy[Ref]


Frequency not reported: Simulated lupus erythematous (occasionally associated with a positive antinuclear antibody test)[Ref]


Very common (10% or more): Nausea (17%), emesis (17%), diarrhea/soft stools (17%), abdominal pain (17%), bloating/flatus (17%)[Ref]


Very common (10% or more): Anorexia (17%)[Ref]


Very common (10% or more): Pharyngitis (17%), oral ulcers (17%), rash (17%), ecchymosis (17%), pruritus (17%), urticaria (17%), warts (17%), skin wrinkling (17%), pemphigus (17%), elastosis perforans serpiginosa (17%)

Frequency not reported: Rash (e.g., erythematous, maculopapular, morbilliform), pruritus, wrinkling/friability of skin[Ref]


Common (1% to 10%): Adenopathy, bleeding, anemia, leukopenia, thrombocytopenia, eosinophilia[Ref]


Common (1% to 10%): Proteinuria, nephrotic syndrome, hematuria[Ref]


Common (1% to 10%): Laryngeal edema, dyspnea, respiratory distress, bronchiolitis, hemoptysis, pulmonary infiltrates[Ref]

Nervous system

Common (1% to 10%): Myasthenic syndrome, dysgeusia, anosmia, hypogeusia[Ref]


Common (1% to 10%): Arthralgia[Ref]


Common (1% to 10%): Fever, chills, weakness, fatigue

Uncommon (0.1% to 1%): Vitamin B6 deficiency

Frequency not reported: Drug fever[Ref]


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

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.