Antifilarial

Antifilarial refers to drugs and therapies that kill, suppress, or otherwise inhibit filarial nematodes, the parasites responsible for diseases such as lymphatic filariasis, onchocerciasis, and loiasis. Antifilarial agents may act against microfilariae (the larval stages circulating in the blood or skin), adult worms, or both. In clinical practice they are used to reduce microfilarial load, interrupt transmission by vectors, and, in some regimens, kill or sterilize adult worms over time. The choice of drug often depends on the species involved and considerations of safety, tolerability, and local transmission dynamics.

Key antifilarial drugs and characteristics include:

- Diethylcarbamazine (DEC): effective against many filarial species with activity on microfilariae and some adult worms; commonly used in elimination programs but can cause severe reactions in certain infections (notably loiasis) and is cautioned or avoided in onchocerciasis in some settings.

- Ivermectin: a potent microfilaricidal agent with limited adulticidal effect; widely used in mass drug administration for lymphatic filariasis and onchocerciasis; can provoke Mazzotti reactions in heavy infections and requires careful management in areas with high parasite loads.

- Albendazole: broad-spectrum anthelmintic with some macrofilaricidal activity; often used in combination regimens (for example with ivermectin or DEC) to enhance efficacy in lymphatic filariasis control.

- Doxycycline: targets Wolbachia endosymbionts essential for many filarial species; primarily macrofilaricidal over months and used in select regimens, not for acute rapid clearance.

Public health programs emphasize combination therapies, monitoring for adverse reactions, and vector control to achieve elimination goals.