QUINACRINE

also called mepacrine synthetic drug introduced into medicine in the early 1930s as a substitute for quinine in treating malaria. Quinacrine is a more effective antimalarial than quinine. It inhibits the development of the malarial parasites (Plasmodium species) in the erythrocytic stage, in which they circulate in the bloodstream of the host, within the red blood cells. When supplies of quinine from Southeast Asia became unavailable to many countries during World War II, quinacrine became the most important antimalarial drug. Since its introduction as an antimalarial, quinacrine also has become widely used as an anthelmintic drug (worming agent), especially in the treatment of tapeworm infections caused by the beef tapeworm (Taenia saginata), the pork tapeworm (T. solium), the dwarf tapeworm (Hymenolepis nana), and the fish tapeworm (Diphyllobothrium latum). Quinacrine is administered orally in the form of its hydrochloride salt. It also can be given by intramuscular injection. Side effects include nausea, abdominal cramps, headache, and dizziness.