Thiabendazole, side effects

Benzimidazoles include albendazole, mebendazole and thiabendazole and constitute a major class of broad-spectrum anthelmintics. They work through an effect on helminth microtubular function, with considerable selectivity in this respect for worms as compared to humans. Mebendazole is much used, and is usually the drug of choice, and is relatively free of side-effects. Albendazole is a more recent agent that is better absorbed. These agents can be used for most worm infections, but not for flukes. 

In the mode of action of benzimidazoles, the carrier of the fungicidal action is the benzimidazole ring, common to all of the derivatives. The substituents, however, particularly in position 2, strongly influence this action. Therefore, in addition to the common mode of action, different side-effects can be observed for certain active substances. Thus, a respiration-inhibiting action was observed for thiabendazole (Allen and Gottlieb, 1970) and an acaricidal action for benomyl, thiophanates and MBC (Nakashima and Croft, 1974), while 2-trifluoromethyl benzimidazole are primarily acaricides. 

Thiabendazole is absorbed rapidly from the gastrointestinal tract. It is metabolized by hydroxylation and conjugation with glucuronic acid. The commonly occurring side effects are anorexia, nausea, and dizziness. It should be used with caution in patients with decreased hepatic function. 

What is the side effect of mebendazole and thiabendazole on skeletal muscle ... 

The clinical utility of thiabendazole in adults is compromised by its toxicity, which has diminished its clinical use. Frequent side effects include GI upset, fatigue, drowsiness, and headache. Occasional fever, rash, erythema multiforme, hallucinations, and sensory disturbances have been reported. Angioedema, shock, tinnitus, convulsions, and intrahepatic cholestasis, and crystalluria are rare complications. Transient leukopenia has been noted. Thiabendazole is hepatotoxic and should be used with caution in patients with hepatic disease. The effects of thiabendazole in pregnant women have not been studied adequately, so it should be used in pregnancy only when the potential benefit justifies the risk. 

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