Thiabendazole (MK-360), a new anthelmintic compound, was administered orally to 88 African adults and children infected with Strongyloides stercoralis and proved to be very effective in either large- or small-particle formulations. Of 61 patients who received a single dose of 38.9 to 153.5 mg per kg of body weight, 55 had a satisfactory therapeutic response. Dosages of 50.0 mg or more gave a high rate of effectiveness. All 28 patients (including one in whom the single dose regime had failed) receiving equal daily doses of 25.0 to 36.7 mg per kg of body weight on two successive days had a satisfactory therapeutic response.
With the large particle formulation given in capsules in single dosages side effects were frequent and consisted of transitory nausea, vomiting, dizziness and drowsiness. With the small particle formulation given in an oral suspension, these side effects were infrequent and mild.
In the dosages used, thiabendazole appeared to suppress the egg production of hookworm, roundworm and whipworm.