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Thiabendazole Side Effects

Applies to thiabendazole: oral suspension, oral tablet chewable.

Serious side effects of Thiabendazole

Along with its needed effects, thiabendazole 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 thiabendazole:

More common

Less common

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


Other side effects of Thiabendazole

Some side effects of thiabendazole 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

This medicine may cause the urine to have an asparagus-like or other unusual odor while you are taking it and for about 24 hours after you stop taking it. This side effect does not need medical attention.

For Healthcare Professionals

Applies to thiabendazole: compounding powder, oral suspension, oral tablet chewable.


Gastrointestinal side effects have commonly included nausea, vomiting, anorexia, and abdominal pain. These side effects generally only last 1 to 2 days and do not require drug discontinuation. Epigastric distress and abdominal pain have also been reported.[Ref]

Nervous system

Nervous system side effects have included drowsiness, dizziness, giddiness, headache, paresthesias, weariness, numbness, hyperirritability, convulsions, collapse, confusion, depression, floating sensation, weakness, and lack of coordination.[Ref]


Hypersensitivity adverse effects have included pruritic rash reactions, fever, facial flush, chills, conjunctival injection, angioedema, anaphylaxis, skin rashes (including perianal), erythema multiforme (including Stevens-Johnson syndrome), toxic epidermal necrolysis, and lymphadenopathy.[Ref]

Erythema multiforme (including Stevens-Johnson syndrome) and toxic epidermal necrolysis generally do not occur for several weeks after thiabendazole is discontinued. The reaction generally starts with a skin eruption which quickly progresses. Two reported cases had complete recovery after several weeks of therapy.[Ref]


Hepatic side effects reported have included liver damage. It may manifest as jaundice, cholestasis, sicca syndrome, malaise, light-colored stools, and gastrointestinal upset. These symptoms generally do not occur for several weeks following thiabendazole therapy completion. Therapy usually consists of only supportive measures. In most cases the hepatic damage is reversible, although at least one patient has died as a result of hepatic damage. Sicca complex has also been reported.[Ref]

Sicca complex has been frequently noted with the hepatic changes associated with thiabendazole. This clinical picture includes keratoconjunctivitis sicca and xerostomia. This also appears to be reversible in most cases without medical intervention.[Ref]


Ocular side effects have included abnormal sensation in eyes, xanthopsia, blurred vision, and transient disturbances in vision.


Cardiovascular side effects have included hypotension.


Metabolic side effects have included hyperglycemia.


Hematologic side effects have included transient leukopenia.


Genitourinary side effects have included hematuria, enuresis, malodor of the urine, and crystalluria.


Psychiatric side effects have included psychic alterations.


Other side effects have included tinnitus, drying of mucous membranes, and live Ascaris in the mouth and nose.


1. Grove DI (1982) "Treatment of strongyloidiasis with thiabendazole: an analysis of toxicity and effectiveness." Trans R Soc Trop Med Hyg, 76, p. 114-8

2. Nauenberg W, Edelman MH, Spingarn CL (1970) "Observations on the treatment of strongyloidiasis with thiabendazole in New York City." Mt Sinai J Med, 37, p. 607-11

3. Gann PH, Neva FA, Gam AA (1994) "A randomized trial of single- and two-dose ivermectin versus thiabendazole for treatment of strongyloidiasis." J Infect Dis, 169, p. 1076-9

4. Tanowitz HB, Wittner M (1970) "Probable thiabendazole allergy after repeated administration." J Trop Med Hyg, 73, p. 141-2

5. Rex D, Lumeng L, Eble J, Rex L (1983) "Intrahepatic cholestasis and sicca complex after thiabendazole: report of a case and review of the literature." Gastroenterology, 85, p. 718-21

6. Manivel JC, Bloomer JR, Snover DC (1987) "Progressive bile duct injury after thiabendazole administration." Gastroenterology, 93, p. 245-9

7. Roy MA, Nugent FW, Aretz HT (1989) "Micronodular cirrhosis after thiabendazole." Dig Dis Sci, 34, p. 938-41

8. Jalota R, Freston JW (1974) "Severe intrahepatic cholestasis due to thiabendazole." Am J Trop Med Hyg, 23, p. 676-8

9. Fink AI, MacKay CJ, Cutler SS (1979) "Sicca complex and cholangiostatic jaundice in two members of a family probably caused by thiabendazole." Ophthalmology, 86, p. 1892-6

10. Bion E, Pariente EA, Maitre F (1995) "Severe cholestasis and sicca syndrome after thiabendazole." J Hepatol, 23, p. 762-3

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.