Anthelminthic agents: some recent developments and their clinical application.

Until the 1960s, the chemotherapy of human intestinal and systemic helminthiases was extremely unsatisfactory;' piperazine compounds, bephenium hydroxynaphthoate and pyrantel embonate were, for example, widely used for the former, and diethylcarbamazine (DEC), niridazole, and bithionol for the latter. Table I summarizes some important agents which have recently become available. The first of the benzimidazole compounds, thiabendazole (which had formerly been widely used in veterinary medicine and which has many undesirable side effects) was introduced into clinical medicine in the early 1960s; others soon followed, and the most recently introduced is albendazole. This group of compounds is of value in the management ofmany intestinal and systemic nematode infections.24 Praziquantel (introduced during the 1970s) has proved of immense value in many cestode and trematode (fluke) infections; numerically it has been most extensively used in the human schistosomiases.2'3'5'6 Ivermectin, which had also been widely used in veterinary medicine first became available in clinical medicine in the early 1 980s;78 as well as being effective in a wide range of intestinal nematode infections it has proved to be a valuable and safe microfilaricidal agent in onchocerciasis (see below). In addition to these 3 agents, oxamniquine and metriphonate have been introduced into clinical medicine for Schistosoma mansoni and S. haematobium infections, respectively (see below). They have the advantage that in most countries they are cheaper than praziquantel; however, both are species specific and the latter compound is often cheaper to administer, overall, in areas where mixed S. mansoni and S. haematobium infections are common.