Abstract: | A double-blind, randomized phase I clinical trial was carried out to compare mefloquine with sulfadoxine—pyrimethamine for safety and tolerance. Twenty adult male Brazilian subjects from areas endemic for malaria were studied for a period of 66 days, which included 2 days of basal studies and a 63-day follow-up after drug administration. Subjects received either mefloquine, given as a single oral dose of 1000 mg (4 × 250-mg tablets) or sulfadoxine—pyrimethamine (2 tablets, each containing 500 mg of sulfadoxine plus 25 mg of pyrimethamine). Clinical examination, electrocardiogram, chest X-ray, and haematological, biochemical, stool, and urine analyses were carried out before drug administration and at various intervals afterwards. Peripheral blood smears were examined for malarial parasites. |