(FDA approved in bold)

• Uterine contractions/bleeding after delivery
  
• Migraine prophylaxis
  
• Cluster headache

• 5-HT2_A/B/C receptor antagonist and 5-HT1_B/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 the mechanism of action for all migraine preventatives. An active metabolite of methysergide

• 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

• 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

• 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

• 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-pharmacologic treatments, such as biofeedback, to improve headache control

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