THERAPEUTICS

Brands

• Methergine

Generic?

• Yes

Class

• Ergot

Commonly Prescribed for

(FDA approved in bold)

• Prevention and control of post-partum hemorrhage

• Migraine prophylaxis

• Cluster headache

How the Drug Works

• 5-HT2A/B/C receptor antagonist and 5-HT1B/D agonist

• Used to prevent or control excessive bleeding following childbirth and spontaneous or elective abortion. Causes uterine contractions to aid in expulsion of retained products of conception after miscarriage and to help deliver the placenta after childbirth

• Migraine/cluster: proposed mechanisms include vasoconstrictive actions or inhibition of the release of inflammatory neuropeptides, such as calcitonin gene-related peptide. Prevention of cortical spreading depression may be one mechanism of action for all migraine preventatives. An active metabolite of methysergide

How Long Until It Works

• Obstetrical: hours, or minutes as an injection

• Migraines: within 2 weeks, but can take up to 2 months on a stable dose to see full effect

If It Works

• In migraine, the goal is a 50% or greater decrease in migraine frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if considering pregnancy

If It Doesn't Work

• Increase to highest tolerated dose

• Migraine: address other issues, such as medication overuse, other coexisting medical disorders, such as anxiety, and consider changing to another drug or adding a second drug

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Migraine: usually used in refractory cases of migraine and cluster headache, usually as an adjunctive agent. May use in combination with AEDs, antidepressants, natural products, and non-pharmacological treatments, such as biofeedback, to improve headache control

Tests

• Monitor blood pressure. In patients on long-term continuous therapy, consider screening for fibrotic disorders

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Actions on serotonin receptors, including vasoconstriction. Fibrotic complications are related to 5-HT2B actions