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Tiopronin Side Effects

The most commonly reported side effects of tiopronin include drug dose omission, nausea, and rash, based on 2,380 FDA adverse event reports from 2004 to 2025. 30.9% of reports found the drug to be ineffective.

Tiopronin side effects

Percentages show how often each reaction appears relative to total reports for tiopronin.

1
Drug Ineffective30.9%736
2
Drug Dose Omission10.8%257
3
Nausea7.5%179
4
Rash5.1%121
5
Pain5.0%119
6
Fatigue4.7%112
7
Pyrexia4.3%102
8
Nephrolithiasis3.8%90
9
Arthralgia3.3%78
10
Headache3.2%77
11
Vomiting3.2%76
12
Pruritus2.9%70
13
Diarrhoea2.7%65
14
Dyspepsia2.3%55
15
Myalgia2.2%53

These are voluntary reports and do not establish that tiopronin caused these reactions.

Report severity

20.2%Serious481 reports
12.9%Hospitalizations306 reports
3.6%Fatal85 reports

Seriousness is determined by the reporter, not by OpenClaim.

Tiopronin drug interactions

Other drugs that appear in adverse event reports alongside tiopronin. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Potassium-citrate7.0%167
2
Prednisolone0.5%13
3
Ibuprofen0.5%13
4
Cyclophosphamide0.5%11
5
Adalimumab0.4%10
6
Trastuzumab0.4%9
7
Gabapentin0.3%8
8
Infliximab0.3%7
9
Methotrexate0.3%7
10
Prednisone0.3%7
11
Amoxicillin0.3%7
12
Carboplatin0.3%7
13
Atezolizumab0.3%7
14
Doxorubicin-hydrochloride0.3%6
15
Bevacizumab0.3%6

Taken alongside

1
Potassium-citrate8.2%195
2
Omeprazole4.5%108
3
Amlodipine4.0%95
4
Aspirin3.7%87
5
Tamsulosin-hydrochloride3.4%80
6
Acetaminophen3.1%74
7
Atorvastatin-calcium2.8%66
8
Ergocalciferol2.7%64
9
Diphenhydramine2.4%58
10
Albuterol2.3%54
11
Furosemide2.3%54
12
Metoprolol2.1%49
13
Cyanocobalamin2.0%48
14
Metformin2.0%47
15
Fluticasone1.9%45

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports tiopronin side effects

50.4% of tiopronin adverse event reports involve female patients and 48.0% involve male patients. The largest age group is adult at 71%. These figures reflect who reports side effects, not underlying risk.

Sex

Female50.4%
Male48.0%
Unknown1.6%

Age group

< 20.1%
2–112.0%
12–177.6%
18–6470.7%
65+19.6%

What is tiopronin used for

Conditions and purposes for which patients were taking tiopronin when the adverse event was reported.

Abdominal PainAdjuvant TherapyAmino Acid Catabolism DisorderAmino Acid Level AbnormalAmino Acid Level DecreasedAmino Acid Metabolism DisorderArthralgiaAsthmaAcute Myeloid LeukaemiaAlanine Aminotransferase IncreasedAmino Acid Metabolism DisorderAspartate Aminotransferase IncreasedCalculus UrinaryChronic HepatitisChronic Hepatitis C

Showing 15 of 63 indications

Tiopronin brand names and reporting trend

Tiopronin is sold under the brand name Thiola Ec.

Brand names

Thiola Ec281

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking tiopronin with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.