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 2mg dosages.

Pharmacology
It is a receptor antagonist for the 5-HT receptor 2C. It also is a 5-HT1A receptor antagonist.

It is known to have partial agonists effects on 5-HT receptors as well.

Uses
Methysergide is one of the most effective medications for the prevention of migraine, but not for the treatment of an acute attack.

Side effects
It has a known side effect, retroperitoneal fibrosis, which is severe, although uncommon.

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

History
Methysergide was approved by the 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 above a dosage of about 4mg. Full effects are felt with dosages of 8-20mg.

About 4 mg is equal to 25mcg of LSD.