Generic Aralen (Chloroquine) – An Antimalarial Drug Description Generic Aralen is a medicine with active ingredient chloroquine, a widely-prescribed antimalarial drug. Doctors often recommend taking this medication to treat or prevent malaria, a disease caused by certain strains of the malarial parasite. Generic Aralen is commonly available in two potencies – 250 mg and 500 mg. The U.S Food and Drug Administration (FDA) approved chloroquine for the treatment and prevention of malaria in 1949. It is quite similar to another malarial drug called hydroxychloroquine, which is sold under the brand name Plaquenil. Apart from treating or preventing malaria, Generic Aralen helps treat extra-intestinal amebiasis, an infection caused by ameba.