Influence of dosing interval and in-patient versus out-patient status on incidence of side-effects of niridazole.

The side-effects of niridazole used for urinary schistosomiasis were studied prospectively over a 3-month period in male patients receiving the standard dose of 25 mg day-1 kg-1 for 7 days. Side-effects were detected in 80% of in-patients but only in 33% of out-patients. The range of side-effects was greater in in-patients taking their daily doses in two portions than in those taking theirs in three. Cure rates and degree of schistosoma egg suppression were significantly lower in out-patients suggesting that compliance with treatment was poorer.