The profile of the trematodicidal compound praziquantel.

From the start onwards of testing praziquantel (2 - cyclohexyl - carbonyl - 1,2,3,6,7,11 b - hexahydro - 4H - pyrazino[2,1-a]isoquinolin-4-one, EMBAY 8440, Biltricide) proved to be very promising. By testing numerous trematode species in different host animals, high efficacy was established. There were no limitations due to the geographical origin of all those parasite species. Pharmacokinetic studies in animals and man showed similarly favourable results. The compound passes the blood-liquor barrier into the brain. No toxic alterations of vital functions and organs were revealed. After demonstrating satisfactory tolerability in healthy volunteers, therapeutic trials were begun. As to schistosomiasis, studies started double-blind in close cooperation with WHO, Geneva, with emphasis on future large scale treatment campaigns. Up to now safe and successful treatment of over 25,000 patients has been documented in Africa, Asia and South America with single dose or single day dosage schemes against all five schistosome species pathogenic to man. The analysis of allegedly drug-related adverse reactions often revealed their presence before treatment already, particularly in intestinal schistosomiasis. Irrespective of origin all symptoms and reactions were generally mild, transient and did not require additional treatment. No drug-related risks were detectable in patients with hepatosplenic and other complications of advanced stages of infection. High cure rates were also obtained in infections due to C. sinensis, O. viverrini and Paragonimus species. Infections with Metagonimus yokogawai, Fasciolopsis buski and Heterophyes heterophyes responded well to treatment, too.(ABSTRACT TRUNCATED AT 250 WORDS)