Used primarily as an anthelmintic medication to treat certain parasitic worm infections, particularly lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi, and Brugia timori. It is effective in reducing microfilariae in the blood and alleviating symptoms associated with these infections. Additionally, it is employed in the management of tropical pulmonary eosinophilia and, in some cases, for treating loiasis, though caution is required due to potential severe adverse reactions. The drug works by immobilizing the microfilariae, making them more susceptible to the host's immune system. It is often administered in mass drug administration programs in endemic regions to control and eliminate filarial infections.