Serotonin Agonists - Treatment of Migraines

Question 1

What are the 5HT-1b/1d agonists called?

Answer 1

The “triptans”. Most have short half-lives of about 3 to 6 hours

Question 2

Which is the prototype triptan?

Answer 2

Sumatriptain (Imitrex)

Question 3

Which are the triptans?

Answer 3

• Sumatriptan (Imitrex)
• Zolmitriptan (Zomig)
• Rizatriptan (Maxalt)
• Naratriptan (Amerge)
• Almotriptan (Axert)
• Eletriptan (Replax)
• Frovatriptin (Frova)

Question 4

What is the mechanism of action of the triptans?

Answer 4

• Stimulation of the 5HT-1D receptors on the terminals of trigeminal afferents inhibits the release of the vessel dilating peptides (substance P, neurokinin A, and CGRP) thus blocking the sterile inflammatory process and mast cell activation.
• Stimulation of the 5HT-1B receptor on the smooth muscle of blood vessels causes vasoconstriction in large arteries (also constricts anastomoses)

Question 5

What is the effectiveness of the triptans?

Answer 5

70-80% effective in reducing migraine within one hour

Question 6

Which is the longest lasting triptan?

Answer 6

Frovatriptin has a half-life of one day and therefore may be less likely to produce rebound headache

Question 7

Which are the drugs of choice for treating migraine headaches?

Answer 7

The triptans

Question 8

What does the 1B receptor do in cerebral blood vessels?

Answer 8

It is a direct vasoconstrictor

Question 9

What stage of migraines are the triptans effective at treating?

Answer 9

All stages

Question 10

What are the side effects of the triptans?

Answer 10

Side effects are minimal and are dosage related.

• pressure sensation; tightness/pressure in the chest, neck, or throat
• tingling/paresthesias
• dizziness/vertigo
• feeling of warmth or heat
• fatigue, sedation, weakness
• pain at injection site

Question 11

What are the contraindications of the triptans?

Answer 11

• Ergotamine or DHE within the prior 24 hours (because they are also potent vasoconstrictors)
• MAOI within the past two weeks because of risk of serotonin syndrome
• heart attack or ischemia
• strong family history of coronary heart disease
• Prinzmetal’s (variant) angina
• pregnant or children
• renal impairment, seizure disorders, cerebral ischemia, brain hemorrhage

Question 12

What is scintillating scotoma?

Answer 12

Jagged edge in the visual field usually on the left side. It is a migraine prodrome (happens before the migraine)