THE CHEMOTHERAPY OF ONCHOCERCIASIS .2. IVERMECTIN IN COMBINATION WITHALBENDAZOLE

Ivermectin is a potent microfilaricide that also blocks microfilarial release while albendazole is toxic to all intrauterine stages. We inve stigated whether their combination would permanently sterilize tile ad ult worms. In the first open phase, all 69 patients received 150 mu g/ kg of ivermectin. In the second double-blind phase one week later, 35 patients were randomized to receive 800 mg of albendazole with a fatty breakfast for three consecutive days while 34 patients received match ing placebo tablets. Detailed clinical and laboratory examinations wer e done before treatment and were repeated at intervals over one year. Nodules were excised at three and six months. There was a rapid reduct ion in skin microfilariae, maximal at four weeks (99.9%). Counts incre ased subsequently and were between 11 and 18% of initial values at one year. Nodule histology showed no macrofilaricidal activity of the com bination. A high proportion of the stretched intrauterine microfilaria e were degenerate in both groups. Anterior chamber microfilarial count s were unchanged until day 18 and then fell successively. Low levels p ersisted in several patients at one year. Dead corneal microfilariae a nd corneal punctate opacities increased initially, fell with time and then disappeared in most patients. Systemic and ocular reactions were mild to moderate and biochemical abnormalities were minor. A pronounce d posttreatment eosinophilia subsided by day 30. There was no signific ant difference between the two groups in clinical and laboratory toler ance or in alterations in skin and ocular parasites and no important d ifferences in the effect on the adult worms. The combination of iverme ctin with albendazole given one week apart is well tolerated but produ ces no additional effect against Onchocerca volvulus when compared to ivermectin given alone