The chemotherapy of onchocerciasis I

Abstract

Eighteen patients with mostly mild to moderate infections with Onchocerca volvulus received metrifonate 10 mg/kg body weight either as a single dose, as six daily doses or three times at two-week intervals. Significant (more than 90%) microfilarial destruction, assessed two weeks after the completion of treatment, occurred in patients receiving multiple daily doses and in most patients who received the intermittent dose regime. The multiple daily dose regime produced severe gastrointestinal side effects and also, in one patient, a reversible proximal muscle paralysis. Each dose in the intermittent dose regime produced a clinical reaction, although with diminishing severity. There was no clinical or indirect parasitological evidence of a significant macrofilaricidal effect, as assessed three to six months after completion of treatment. A further study of the microfilaricidal potency of metrifonate in a larger group of more heavily infected patients would be useful. A comparative trial with the standard microfilaricidal drug diethylcarbamazine is needed in order to evaluate both the relative efficacy and severity of the side effects of the two anthelmintics.