Diethylcarbamazine citrate (DEC) is a medication mainly used in the treatment of lymphatic filariasis, a parasitic infection transmitted through mosquitoes that can lead to severe and debilitating conditions such as elephantiasis. DEC works by selectively targeting and eliminating the microfilariae, the larval forms of the filarial parasites responsible for the disease. Additionally, DEC has been utilized in the management of other parasitic infections, such as loiasis and tropical pulmonary eosinophilia. Its mechanism of action involves disrupting the metabolism and structure of the parasites, ultimately leading to their demise. Despite its effectiveness, DEC may cause side effects, and its use should be guided by medical professionals to ensure proper dosage and monitoring for adverse reactions.