Antimigraine and Antiemetic Drugs

Question 1

What is the pathophys of migraines?

Answer 1

Cerebral vasodilation with activation of pain fibers

Question 2

MOA of Triptans:

Answer 2

5HT 1B/1D agonists in the vasculature which results in potent vasoconstriction of intracranial blood vessels, inhibition of vasoactive peptides, and interruption of pain signal transmission

Question 3

Triptans are known as _____ migraine therapy and how are they available?

Answer 3

Specific

SQ, IM, Nasal

Question 4

Examples of Triptans include:

Answer 4

Sumatriptan (Imitrex)
Rizatriptan (Maxalt)
Almotriptan (Axert)
Frovatriptan (Frova)
Eletriptan (Relpax)
Zolmitriptan (Zomig)
Naratriptan ( Amerge)

Question 5

Which triptan has the slowest rate of action but also the lowest recurrence rate?

Answer 5

Naratriptan (Amerge)

Question 6

Which triptan has the fastest onset of action and with what drug should the dose be adjusted?

Answer 6

Rizatriptan (Maxalt)

Propranolol (inhibits the met. of rizatriptan)

Question 7

In what type of patients are triptans CI in and why?

Answer 7

Ischemic heart disease, uncontrolled HTN, ischemic stroke, pregnancy
They causes potent vasoconstriction

Question 8

How are most triptans metabolized?

Answer 8

MAO

exceptions eletriptan (CYP3A4), frovatriptin, naratriptan

Question 9

Which drugs should triptans be avoided in?

Answer 9

MAOI’s (except eletriptan, frovatriptin, and naratriptan

SSRI’s and SNRI’s =increase risk for serotonin syndrome

Question 10

Two commonly used preparations of Ergots:

Answer 10

Ergotamine

DHE 45

Question 11

MOA of Ergots:

Answer 11

5HT 1B/1D agonists (potent vasoconstriction of intracranial blood vessels)

Question 12

Why is Ergotamine not used for the most part?

Answer 12

• Poor bioavail with PO and rectal dosing
• May worsen N/V
• Dose associated vascular occlusion and rebound HA
• Avoid in patients with CAD, PVD, HTN, hepatic or renal disease

Question 13

Which patients might Ergotamine be most helpful in treating?

Answer 13

Patients with prolonged duration of attacks, >48hrs

Question 14

DHE45 should be used with an ______ drug. What formulations are they available in?

Answer 14

antiemetic
(overall less SE, no phys. dependence, no rebound headaches)
IM, IV, SubQ, nasal

Question 15

DHE45 is CI in what type of patients?

Answer 15

HTN, Ischemic heart disease, combo with MAOIs, elderly

Question 16

Other first line agents for acute migraines include:

Answer 16

High dose NSAIDs
ASA (650-1000mg)
APAP (1000mg)
Combination products (ASA-APAP-caffeine)

Question 17

What types of drugs can be used as adjunct therapy for the treatment of migraines?

Answer 17

Antiemetics
Benzos
Opioids
Barbiturates

Question 18

Prevention of migraine and tension HA treatment can include:

Answer 18

Beta-blockers
Ca channel blockers
TCA's
Anticonvulsants (phenytoin, carbamazepine, valproate, gabapentin, topiramate)
Ergot derivatives

Question 19

Which receptors are located in the midbrain involved in emesis?

Answer 19

Dopamine
Muscarinic- cholinergic
Histaminic
5HT3

Question 20

Which antiemetic agents antagonize dopamine?

Answer 20

Benzamides (metoclopramide-Reglan)
Butyrophenones (Droperidol, haloperido-Haldol)
Phenothiazines (Chlorpromasine, prochlorperazine-Compazine, promethazine-Phenergan)

Question 21

What antiemetic agents are highly bound to 5HT3 receptors both centrally and peripherally?

Answer 21

5HT3 antagonists

Ondansetron (Zofran), Dolasetron (Anzemet), gransetron (Kytril)

Question 22

Corticosteroids are used mostly in the prevention of what type of emesis and what is an example of one drug?

Answer 22

Chemo induced N/V

Dexamethasone

Question 23

Which anticholinergic agents are used to block cholinergic muscarinic receptors and decrease emesis?

Answer 23

Scopolamine

Meclizine

Question 24

How to antihistamines prevent emesis and what are some examples?

Answer 24

Act directing on the vomiting center and vestibular pathways

Cyclizine, hydroxyzine (Atarax), diphenhydramine (Benadryl)

Question 25

Which antiemetic affects both dopamine and histaminic receptors?

Answer 25

Phenothiazine