Ivermectin effect on microfilariae of Onchocerca volvulus after a single oral dose in humans
Soboslay, P.T.; Newland, H.S.; White, A.T.; Erttmann, K.D.; Albiez, E.J.; Taylor, H.R.; Williams, P.N.; Greene, B.M.
Tropical Medicine and Parasitology Official Organ of Deutsche Tropenmedizinische Gesellschaft and of Deutsche Gesellschaft für Technische Zusammenarbeit 38(1): 8-10
1987
ISSN/ISBN: 0177-2392 PMID: 3602843 Document Number: 286391
The effects of ivermectin on motility of mf of O. volvulus following administration to humans in Liberia was examined. When ivermectin was given in dosages of 100, 150 and 200 micro g/kg on day 1 there was a clear reduction in motility of mf obtained on day 3 when compared to mf from the placebo group. The mean motility scores in mf from ivermectin recipients were 3.1, 2.3 and 2.2 at 0, 12, and 24 h of incubation compared to 3.3, 2.9, and 2.5, respectively, in mf from placebo recipients. Examination of the effect according to dose suggested a dose-response relationship. Mf in the anterior chamber of the eye 2 days after a single oral dose of ivermectin showed abnormal and reduced winding and coiling. Mf in 50% of ivermectin recipients showed abnormal motility compared to no such effects in subjects examined concurrently who received oral DEC, DEC lotion or placebo. These observations indicate that ivermectin has an effect on the motility of mf of O. volvulus following administration to humans. A single dose of 100-200 micro g ivermectin/kg given to patients in Liberia infected with Onchocerca volvulus caused a progressive and apparently dose-dependent reduction in the motility in vitro of microfilariae obtained 2 days after treatment and incubated for 24 h. In vivo, microfilariae in the anterior chamber of the eye of up to 50% of patients treated with ivermectin (but of none treated with diethylcarbamazine) exhibited abnormal motility 2 days later.Carolyn A. Brown.