Metrifonate in onchocerciasis and lymphatic filariasis.

Metrifonate, in doses of 10 mg/kg for 3 consecutive days, demonstrated partial microfilaricidal activity against Onchocerca volvulus in humans. Higher doses were not investigated because of the toxic reactions obtained and the absence of monitoring of the blood cholinesterase levels. Spaced doses of 10 mg/kg every 2 weeks or once monthly up to 3 doses showed neither micro- nor macrofilaricidal activity against Wuchereria bancrofti.