Pharmacology of Headache Flashcards
For an acute migraine with nausea or vomiting, how should treatment be given?
Non-oral routes should be used
What are examples of nonspecific drugs fro acute headaches?
- Analgesics
- NSAIDS
- Opioids
- Neuroleptics
What are examples of simple and combination analgesics?
- Aspirin
- Acetaminophen
- Caffeine.
What are examples of NSAIDS used for acute headache?
- Naproxen sodium
- Ibuprofen
- Ketorolac
- Indomethacin
What are examples of opioids used for acute headache?
hydrocodone, oxycodone
What are examples of neuroleptics for acute headache?
- Anitidopaminergic
- Prochlorperazine iv
- Chlorpromazine iv
What are specific acute migraine treatments?
- Ergotamine (with caffeine, mostly of historical interest)
- Dihydroergotamine
- “Triptans”
How does ergotamine work?
1) Activates receptors: serotonin, adrenergic, dopaminergic.
2) Suppress neurogenic inflammation ( agonists at
5-HT1B and 5HT 1D receptors)
3) Vasoconstrictors (avoid in CAD)
In what population should ergotamine be avoided?
Pregnant women
Describe the kinetics of ergotamine.
- Narrow therapeutic window (nausea, vomiting)
- DHE with 10 hour half-life.
- Used mainly iv, im, intranasal.
- Very effective
How do triptans work?
- Sumatriptan (Imitrex®) the prototype
- Similar to serotonin but with an amino-ethyl group and a sulfonamide group
- 5-HT1B (blood vessels) and 5-HT 1D (neurons) agonists.
- Vasoconstrictors
Describe the efficacy of triptans.
- Efficacy 60-80% at 2 hours
- 40% recurrence in 24 hours.
What are the adverse effects of triptans?
- Chest/neck tightness, flushing, sedation
What contraindications are associated with triptans?
- CAD, stroke
Which triptans have the shortest and longest half lives?
Sumatriptan and Rizatriptan => 2 hours
Frovatriptan => 25 hours
Which triptans have the lowest and highest bioavailability?
Sumatriptan => 15%
Naratriptan and Almotriptan => 70%
What are the major drug interactions of triptans?
- SSRIs/ SNRIs
- MAOIs
- Rizatriptan levels are increased by propranolol
- Eletriptan/zolmitriptan are metabolized by the cytochrome P450 system
When should preventative management be implemented with migraines?
1) Migraine significantly interferes with the patient’s daily routine
2) Acute medications are contraindicated, ineffective, or intolerable adverse effects
3) Frequent headache
4) Uncommon migraine conditions
5) Cost consideration
6) Patient preference (fear of migraine)