Medical Pharmacology Chapter 23:  Ergot Alkaloids

Ergot Alkaloids: Clinical Pharmacology

• Migraine

  • "Migraine 101:  A 3-Step Guide to Managing Headaches"

    Attribution: Cowan R "Migraine 101:  A 3-Step Guide to Managing Headaches" https://www.youtube.com/watch?v=jHffEt-MXjI (3/2013) Stanford Health Care YouTube Channel:    https://www.youtube.com/channel/UCl_mlar6gQ3z94OLr7YPkbA

  • Clinical Presentations

    • Often accompanied by brief aura (visual scotomas, hemianopia, beach abnormalities

    • Severe, throbbing, usually unilateral headache (few hours to a few days in duration)

    • Familial disease:

      1. More common in women

      2. Onset: early adolescence; less common in older patients

      3. Migraine associated with stress

      4. Headache frequency: Range -- to or more per week to once a year

  • Migraine Pathophysiology

    • Migraine Headaches

      Attribution: Barad M "Stanford Hospital's Meredith Barad, MD, Discusses Migraine Headaches" https://www.youtube.com/watch?v=XJWMKkRdxZI (6/2011) Stanford Health Care YouTube Channel:  https://www.youtube.com/channel/UCl_mlar6gQ3z94OLr7YPkbA

    •  Vasomotor mechanism is inferred from:

      1. Increased temporal artery pulsation magnitude

      2. Pain relief (by ergotamine) occurs with decreased artery pulsations

    • Migraine attack associated with (based on histological studies):

      • Sterile neurogenic perivascular edema

      • Inflammation (clinically effective antimigraine medication reduce perivascular inflammation)

    • Serotonin involvement (evidence for):

      • Throbbing headache: associated with decreased serum and platelet serotonin

      • Presence of serotonergic nerve terminals at meningeal blood vessels

      • Antimigraine drugs influence serotonergic neurotransmitter

      • Some migraine chemical triggers may work through serotonin pathways, i.e. decreasing estrogen (associated with the menstrual cycle) and increased prostaglandin E₁.

Burkhalter, A, Julius, D.J. and Katzung, B. Histamine, Serotonin and the Ergot Alkaloids (Section IV. Drugs with Important Actions on Smooth Muscle), in Basic and Clinical Pharmacology, (Katzung, B. G., ed) Appleton-Lange, 1998, pp 261-286.;  New "Triptans" and Other Drugs for Migraine, The Medical Letter, Vol. 40 (Issue 1037); October 9, 1998