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Ethionamide Side Effects

Medically reviewed by Last updated on Apr 2, 2023.

Applies to ethionamide: oral tablet.

Serious side effects of Ethionamide

Along with its needed effects, ethionamide 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 ethionamide:

Less common


Incidence not known

Other side effects of Ethionamide

Some side effects of ethionamide 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

Incidence not known

For Healthcare Professionals

Applies to ethionamide: oral tablet.


The most commonly reported side effects included abdominal pain, diarrhea, nausea, and vomiting.[Ref]


Approximately 50% of patients are unable to tolerate 1 gram (as a single dose).[Ref]

Very common (10% or more): Adverse gastrointestinal effects (up to 50%)

Common (1% to 10%): Abdominal pain, diarrhea, excessive salivation, gastrointestinal disturbances, nausea, stomatitis, vomiting[Ref]


Common (1% to 10%): Anorexia, weight loss

Rare (0.01% to 0.1%): Pellagra-like syndrome

Frequency not reported: Hypoglycemia[Ref]

Nervous system

Common (1% to 10%): Metallic taste

Rare (0.01% to 0.1%): Neurotoxic effects, peripheral neuritis

Frequency not reported: Dizziness, drowsiness, headache[Ref]


Rare (0.01% to 0.1%): Blurred vision, diplopia, optic neuritis[Ref]


Rare (0.01% to 0.1%): Photosensitivity, rash

Frequency not reported: Acne[Ref]


Rare (0.01% to 0.1%): Purpura, thrombocytopenia[Ref]


Rare (0.01% to 0.1%): Hypersensitivity reactions[Ref]


Frequency not reported: Hepatitis with/without jaundice, transient ALT increases, transient AST increases, transient serum bilirubin increases[Ref]


Frequency not reported: Mental depression, psychotic disturbances, restlessness[Ref]


Frequency not reported: Gynecomastia, hypothyroidism[Ref]


Frequency not reported: Postural hypotension[Ref]


Frequency not reported: Impotence[Ref]


1. Product Information. Trecator-SC (ethionamide). Wyeth-Ayerst Laboratories. 2001;PROD.

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.