Thiabendazole

The drug can be administered orally, topically and rectally. Using unspecific assays the disposition of the drug was studied in four healthy volunteers given 1.0 g of l4C-labelled thiabendazole. The drug was quickly absorbed and peak plasma levels of 13-18 µg/ml were obtained 1-2 hours after drug administration. Drug plasma levels declined rapidly and approached essentially zero between 24 and 48 hours. About 87% of the radioactivity was excreted with the urine during the first 48 hours mainly in the form of glucuronides or sulphates of 5-hydroxythiabendazole. Less than 1% was excreted as the parent drug. A further 5% of the radioactivity was excreted with the faeces during the same period (4). Thiabendazole has also been reported to be significantly absorbed and drug levels sustained for longer periods of time after rectal administration attained peak plasma levels after 4 hours (5). In an anephric patient with Strongyloides infection, the pharmacokinetics of thiabendazole and its metabolites were determined during haemodialysis and haemoperfusion after giving a single

mg/kg given twice daily for 3 days) was compared to ivermectin (200 µg/kg given as a single dose in 1 or 2 days). Three months after treatment, only 1 of 34 subjects who received thiabendazole, and 2 of 19 patients who received ivermectin had stool positives for Strongyloides larvae (8). Against Trichostrongylus species, a single dose of thiabendazole, 50 mg/kg had a cure rate above 90% (9). Similar results have been reported after treatment of creeping eruptions (cutaneous larva migrans) with topical applications of 14% thiabendazole suspensions applied 5-6 times for 2 weeks (10) as well as oral treatment with thiabendazole, 25 mg/kg twice daily for 3 days (11). Amelioration of the disease has been reported during treatment of Capillaria philippinensis (12) and Trichinella spiralis (13).