Pharmacy Exam Review

Migraine

Last updated on: May 16th, 2020

Background

  • Migraine can be caused by trigeminal nerve and imbalance in neurotransmitters, including 5HT, which decreases during migraine, causing a chemical release that triggers vasodilation in the cranial blood vessels.
  • Signs symptoms: headache (last 4-72 hrs, unilateral, pulsating), N/V, photophobia, phonophobia.
  • Nonpharmacological treatment: avoid triggers, acupuncture, stress management, massage.
  • Natural products: caffeine combined with APAP or ASA, Co Q10, feverfew, riboflavin.
  • Drug therapies: serotonin agonist (triptans), ergotamine, butalbital-containing products, and some opioids (not recommended due to abuse potentials), and diclofenac (Cambia).
  • OTC: APAP, Advil migraines (ibuprofen), Excedrin (ASA/APAP/caffeine), Aleve(naproxen).

 

Triptans

  • Drugs: Sumatriptan (Imitrex, Zecuity transdermal, Onzetra Xsail), Naratriptan (Amerge), Almotriptan (Axert), Frovatriptan (Frova), Rizatriptan (Maxalt, Maxalt MLT ODT), Eletriptan (Replax), Zolmitriptan (Zomig nasal), palosetron (Aloxi),
  • MOA: serotonin-receptor agonist (5HT-1 agonist) that causes vasoconstriction in cranial vessels. 1st line for acute migraine.
  • SE: triptan sensation (pressure in the chest/neck, nausea), paresthesia (tingling numbing), ↑BP; CI: CV events or uncontrolled HTN.
  • DI: Caution in combining serotonergic drugs and ergots (powerful vasoconstriction ↑BP), contradicted with MAOIs (↑ 5HT), avoid strong 3A4 inhibitors (↑ drug levels).
  • If the headache is not relieved after 1st dose, repeat in 2 hours, max: 2 doses/day.
  • ODT, nasal, and injections work faster, and are useful if nausea is presented; do not prime nasal spray, only 1 dose.
  • Palosetron: longest t1/2. What patients would need longer coverage? Maybe those with more debilitating migraine.
  • Exam tip: do not confuse this class with serotonin antagonists (5HT3 antagonist “setron”s such as ondansetron), which are used for treating nausea and vomiting.

 

Ergotamine alkaloids

  • Drugs: ergotamine, dihydroergotamine
  • MOA: non-selective agonist of serotonin receptors; causes a lot of vasoconstriction. What do you think the effects of ergo compared to a 5HT-agonist such as triptan? It’s probably going to be more potent.
  • Warnings: do not use with strong 3A4 inhibitor (raise ergo level) due to risk of cardiovascular effects such as cerebral ischemia, uncontrolled hypertension (vasoconstriction ↑BP). 

 

NSAIDs

  • Drug: diclofenac (Cambia), sumatriptan/naproxen (Treximet, SC Alsuma)
  • MOA: it relives pain and causes vasoconstriction.
  • Often used in acute migraine treatment.

 

Analgesics

  • Drugs: Fioricet (APAP/butalbital/caffeine), Fiorinol (ASA/butalbital/caffeine); codeine formula is CIII, not recommended due to dependence issue. Counsel on possible nausea, constipation
  • Opioids are sometimes used for more severe pain that provides symptomatic relief. E.g.: butorphanol (Stadol, intranasal spray): opioid agonist-antagonist, C-IV.
  • Do not mix with EtOH: CNS depressive effect.

 

 

Prophylaxis

  • It’s very important to know what types of meds can be used for migraine prevention, as well as what is used for acute management. Don’t mix them up. E.g., “triptans” can’t be used for prevention.
  • Antiepileptic drugs: topiramate, valproic acid: topiramate has a good SE profile, can cause weight loss.
  • Beta-blockers: non-selective BBs are used such as propranolol, timolol, possible depression due to lipophilic properties. (“Selective”s would be too restrictive to certain areas, you want a general one that can act everywhere including in the cranial tissues)
  • Divalproex acid (Depakote): primarily in seizure treatment, however, the stabilizing effect can perhaps ease the prodrome of migraine?
  • TCA antidepressants: such as amitriptyline used at a lower dose. SNRI venlafaxine is also sometimes used.
  • Selective contraceptives such as POP, avoid estrogen-containing (estrogen might cause migraine). Triptan or NSAID can be taken prior to menses: they also possess vasoconstrictive effects.
  • Botulinum toxin (Botox) is for prophylaxis and chronic migraine only.

 

Quiz

  1. What are the drugs that can be used in migraines? Select all the apply:
    1. Valproic acid
    2. Topiramate
    3. Ondansetron
    4. Propranolol
    5. Frova

 

ABDE, frova is 5HT agonist, ondansetron is 5HT antagonist.

 

Which of the following is a contraindication to the use of sumatriptan? (Select ALL that apply.)

  1. Concomitant use of naproxen
  2. Peripheral arterial disease (PAD)
  3. Uncontrolled hypertension
  4. Concomitant use of phenelzine
  5. History of a stroke

BCDE. Triptans cause vasoconstriction and cannot be used with ischemic heart or cerebrovascular disease. Patients with uncontrolled hypertension, history of a cerebrovascular accident or ischemic attack, or vasospastic condition should avoid the use of any triptan. Triptans also may cause serotonin syndrome if used within 2 weeks on an MAOI such as phenelzine.

 

 




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