Diethylcarbamazine (DEC) is an anthelmintic drug that does not resemble other antiparasitic compounds. It is a synthetic organic compound which is highly specific for several parasites and does not contain any toxic metallic elements.
In cases of onchocerciasis, another common filarial parasite, the drug is not used. This is because of the intense and unbearable itching associated with the dead subcutaneous parasites.
DEC continues to be the mainstay for treatment of patients with lymphatic filariasis and loiasis. DEC is also used in the prevention of dog heartworm Dirofilaria immitis.