The chemotherapy of onchocerciasis VII

Abstract

Forty-four patients with onchocerciasis who were treated with diethylcarbamazine (DEC) were entered into a double-blind study using prednisone or placebo to try to alleviate the reactions to treatment. Prednisone was given in an initial dose of 20 mg t.i.d. starting the day before DEC and was decreased stepwise over the next week. The reactions to treatment were quantitated using a recently described scoring system.

The mean (±S.D.) microfilarial count in the placebo group prior to treatment was 279 ± 177·6 and in the prednisone group was 283±222±6. Prednisone produced a significant reduction in the severity of the reaction to treatment with DEC, the peak mean score being 88 in the placebo group and 25 in the prednisone group. Prednisone almost completely abolished the cardiovascular and glandular components of the reaction but pruritus was not prevented and the skin rash still occurred although it appeared later than in the control group.

Prednisone also significantly reduced the effectiveness of DEC. In the placebo group, the mean microfilarial count one week after stopping DEC was reduced by 94·8% compared to the initial value while in the prednisone group it was reduced by only 79·8% of the control value. Further studies are in progress to find the optimum dose of prednisone which will alleviate the reactions to treatment without reducing the effect of DEC.