Dose-finding trial using Oltipraz to treat schoolchildren infected with Schistosoma mansoni in Gezira, Sudan

A field trial has been carried out in Sudan to determine the optimum dosage regimen for the use of Oltipraz in the treatment of Schistosoma mansoni in schoolchildren. A total of 294 children were treated in six groups to test 15 mg/kg, 20 mg/kg, and 25 mg/kg, using a single oral dose and a divided dose taken some 6 h apart. The children were interviewed before and then 24 h after treatment to determine the prevalence of drug-induced side-effects. Most of the children having complained of abdominal pain before treatment, insisted that they suffered further abdominal pain as a result of the drug. Four children complained of fingertip pain and 17 of blurred vision. The latter side-effect had not previously been recorded in Sudan and, with the fingertip pain, is a cause for concern. There was no difference in the cumulative failure rates between the single and the divided doses, but there was a significant improvement in the efficacy from the 15 mg/kg to the higher doses. The cumulative failure rate increased with higher pretreatment egg count. However, at each level the reduction in egg count among failures at the 5-week follow-up, was significant at the 95% probability level. The efficacy of the drug was satisfactory when used at 20 or 25 mg/kg, but the strange side-effects need to be explained before any further use can be recommended.