AN IMPROVED DOSING SCHEDULE FOR IVERMECTIN AS A MICROFILARICIDAL AGENT AGAINST ONCHOCERCIASIS

The introduction of ivermectin therapy has proved to be the most impor tant advance in the management and control of onchocerciasis. By using the standard dosing schedule (150 mu g/kg) in a mass chemotherapy cam paign in Awhum, Nigeria, 128 (14.6%) of 875 eligible subjects used in this study were underdosed while 696 (79.6%) and 51 (5.8%) were overdo sed and correctly dosed, respectively. Since underdosing is more serio us than overdosing, an improved dosing schedule (300 mu g/kg) is hereb y suggested, bearing in mind that ivermectin is safe at doses well in excess of the standard dose. 824 (94.2%) And 51 (5.8%) of these eligib le subjects would be overdosed and correctly dosed respectively, if th is improved dosing schedule (<15kg, 0 mg (0 tablet); 15-20 kg, 6 mg (1 tablet); 21-40 kg, 12 mg (2 tablets); 41-60 kg, 18 mg (3 tablets); > 60 kg, 24 mg (4 tablets)) were to be employed. This dosing schedule is worth adopting and an investigation of the effects of these high sing le doses of ivermectin on adult Onchocerca volvolus worms is advocated . Furthermore 'non-responders' may be investigated for doses administe red. (C) 1997 Elsevier Science B.V.