Drug Groups

approved

Description

An ergot derivative that is a congener of lysergic acid diethylamide. It antagonizes the effects of serotonin in blood vessels and gastrointestinal smooth muscle, but has few of the properties of other ergot alkaloids. Methysergide is used prophylactically in migraine and other vascular headaches and to antagonize serotonin in the carcinoid syndrome. [PubChem]

Indication

For the treatment of vascular headache

Pharmacology

Methysergide has been shown, in vitro and in vivo, to inhibit or block the effects of serotonin, a substance which may be involved in the mechanism of vascular headaches. Serotonin has been variously described as a central neurohumoral agent or chemical mediator, as a "headache substance" acting directly or indirectly to lower pain threshold, as an intrinsic "motor hormone" of the gastrointestinal tract, and as a "hormone" involved in connective tissue reparative processes.

Toxicity

Few cases of acute methysergide intoxication have been reported. The possible symptom complex is therefore not fully known. The following symptoms are based on these few case reports. Euphoria, hyperactivity, tachycardia, dilated pupils, and dizziness have been reported in a child with a dose of 20-24 mg of methysergide. In adults, peripheral vasospasm, with diminished or absent pulses, coldness, mottling and cyanosis, has been observed at a dose of 200 mg. Ischemic tissue damage has not been reported in acute overdosage with methysergide.

Affected Organisms

Biotransformation

Hepatic

Absorption

Rapid

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