Anthelmintic Drugs

Introduction & terminology

• Anthelmintics (deworming agents) — drugs that either kill (vermicidal) or expel (vermifuge) the worms infesting the host; helminthiasis affects roughly one-third of the world's population and >1 billion harbour intestinal nematodes.
• Helminth classes — nematodes (roundworms) — soil-transmitted helminths (Ascaris, Trichuris, hookworms, Strongyloides) + filariae; cestodes (tapeworms) — Taenia, Echinococcus; trematodes (flukes) — Schistosoma, Fasciola.
• Four globally dominant agents — the benzimidazoles albendazole & mebendazole, the macrocyclic lactone ivermectin, and praziquantel — among the most widely used drugs worldwide, the backbone of WHO mass drug administration (≈1.24 billion treated in 2019).
• Principles of drug choice — efficacy, low toxicity, ease of single-dose administration and low cost; identify the parasite before treatment; clinical resistance has historically been rare in humans (in contrast to veterinary use).