Methysergide

Methysergide (UML-491) is a prescription drug used for prophylaxis of migraine headaches and is sold under the brand names Sansert and Deseril in 2 mg dosages.

Pharmacology
Methysergide interacts with serotonin (5-HT) receptors. Its therapeutic effect in migraine prophylaxis has been associated with its antagonism at the 5-HT2B receptor. Furthermore, it is an antagonist at the 5-HT2C receptor and at the 5-HT1A receptor. It is known to have partial agonist effects on some of the other 5-HT receptors as well. Methysergide is metabolised into methylergometrine in humans, which is responsible for its psychedelic effects.

Uses
Methysergide is used to treat headaches such as migraine and other recurrent throbbing headaches. Methysergide is one of the most effective medications for the prevention of migraine, but not for the treatment of an acute attack.

It is also used in carcinoid syndrome to treat severe diarrhea.

Side effects
It has a known side effect, retroperitoneal fibrosis, which is severe, although uncommon. Other severe but uncommon side effects include pleural fibrosis, and subendocardial fibrosis.

In addition, there is an increased risk of left-sided cardiac valve dysfunction.

History
Methysergide was approved by the U.S. Food and Drug Administration (FDA) in 1962.

Novartis withdrew it from the U.S. market after taking over Sandoz, but currently lists it as a product.

Related compounds
Its molecular structure is closely related to that of LSD.

Like LSD, methysergide also produces psychedelic and hallucinogenic effects.

About 4 mg is equal to 25mcg of LSD.

Sandoz does not currently list this on their product guide.