INITIAL EXPERIENCES WITH PRAZIQUANTEL IN THE TREATMENT OF HUMAN INFECTIONS DUE TO SCHISTOSOMA-HAEMATOBIUM

Abstract

Initial studies of the tolerance and efficacy of praziquantel in the treatment of human infections due to S. haematobium were conducted at the WHO Tropical Diseases Research Center, Ndola, Zambia. The first stage of the trial was a double-blind assessment against placebo of the tolerance and efficacy of oral doses of 1 .times. 20, 2 .times. 20 or 3 .times. 20 mg/kg in patients with a minimum schistosome egg excretion of 50/random 10 ml sample of urine. Later a single-blind trial was carried out of the efficacy of 3 oral doses, each of 20 mg/kg, given at 4 h intervals, or of a single oral dose of 50 mg/kg. In 79 young Zambians with S. haematobium infections (and often other parasitic infections), patients tolerance to the drug was very good, only minor post-treatment symptoms of intermittent epigastric pain, anorexia and headache being noted, all of short duration. No changes of clinical relevance were detected in the results of a battery of hematological and biochemical tests. Post-treatment eosinophilia occurred in 42% of drug-treated patients but also in 30% of those given placebo. Serial ECG revealed no changes of significance. At 6 mo. after treatment, of 73 patients followed up only 1 case of parasitological failure was detected. At 1 yr, 66 (83.5%) of 79 patients with S. haematobium infection were followed up and 2 (2.5%) parasitological failures were detected. Two years after treatment, 45 (57%) of 79 patients with S. haematobium showed negative urines, 7 (9%) had positive hatching tests and 27 (34%) were absent.