Acetaminophen is a pain reliever and a fever reducer. Dichloralphenazone is a sedative that slows the central nervous system. Isometheptene causes narrowing of blood vessels (vasoconstriction). The combination of acetaminophen, dichloralphenazone, and isometheptene is used to treat migraine headaches or severe tension headaches. Acetaminophen, dichloralphenazone, and isometheptene may also be used for purposes not listed in this medication guide.