Drugs five years later: praziquantel.

PURPOSE: To identify advances in knowledge of the pharmacokinetics, mechanism of action, clinical use, and side effects of the antihelminthic drug praziquantel in the 5 years since its introduction in the United States. DATA IDENTIFICATION: Studies reported from 1983 to July 1988 were identified by computer searches of MEDLINE and TOXLINE, and review of textbooks and review articles. STUDY SELECTION: Of 57 articles originally identified, 39 were selected by two readers. DATA EXTRACTION: Study quality and significance were independently assessed by each reader. RESULTS OF DATA ANALYSIS: The pharmacokinetics and clinical efficacy of praziquantel have been well documented. Yet, despite extensive in vivo and in vitro laboratory studies, the drug's mechanism of action in killing parasites is unknown. Although the efficacy of praziquantel was first established for treating schistosomiasis, in the last 5 years its clinical use has been expanded to the treatment of intestinal, tissue, and lung flukes, and intestinal and tissue cestode infections, including neurocysticercosis. The introduction of praziquantel was a significant advance in antihelminthic therapy, in that it was effective therapy for several parasites that had been previously considered untreatable. Availability of a safe, effective broad-spectrum oral antihelminthic agent consolidated the central role of chemotherapy in population-based control of many trematode and cestode parasites. Randomized trials have shown, however, that older, cheaper agents may be more cost-effective in controlling Schistosoma mansoni and Schistosoma haematobium in some endemic areas.
CONCLUSIONS: Although praziquantel is the treatment of choice for most human trematode and cestode infections, cost factors have limited its use in developing countries.