Isometheptene/Dichloralphenazone/Acetaminophen

**Semantic type:** Pharmacologic Substance

**Definition:** A combination preparation containing isometheptane, dichloralphenazone and acetaminophen with analgesic activity. Isometheptene is an indirect-acting sympathomimetic agent with vasoconstricting activity, thereby reducing the pulsation in cerebral arteries by constricting dilated cerebral blood vessels. Dichloralphenazone, a complex of chloral hydrate, which possesses hypnotic and sedative activity, and antipyrine, a pyrazolone analgesic and an antipyretic. Acetaminophen inhibits prostaglandin synthesis, thereby exerting analgesic activity. This preparation is used for the relief of migraine and tension headaches.

**Synonyms:** - Midrin