Exam 4 Migraine medications Flashcards Preview

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Flashcards in Exam 4 Migraine medications Deck (24):
1

What is the role of serotonin in pain modulation?

-Serotonin (5-HT) receptors are important for pain modulation
_especially chronic pain

*****5-HT= 5-hydroxytryptamine

_Biogenic monoamine
_receptors are found pre-synaptically and post-synaptically
_ many different receptors subclasses

2

What is the role of Serotonin and Serotonergic Neurons in pain modulation?

-in platelets= causes vasoconstriction
-in enterochromaffin cells in gut mucosa

-in CNS:
--in periaqueductal gray (PAG)
--modulates nociception on a spinal level
--stimulation ***produced analgesia in midbrain
--MOST projections from PAG are tryptaminergic
--Dorsal raphe nuclei
--ALL laminae of dorsal horn
*****modulates pain/ nociception in descending pathways

3

What the role of 5- HT in pain modulation?

-Associated w/ psychiatric disorders
--learned this roll when LSD (hallucinogen) was shown to antagonize (block) 5-HT function

--Drugs that affect 5-HT system are used as treatments for these disorders

4

What are the known that 5-HT is involved in many behavioral and psychiatric disorders?

1) Schizophrenia
2) OCD
3) Depression
4) Anxiety

5

What are the drugs that affect 5-HT transmission?

1) antidepressants
2) hallucinogens
3) anxiolytics
4) antiemetics
5) antimigraine agents
6) atypical antipsychotics
7) appetite suppressants
8) Other drugs are assumed to affect 5-HT receptors because they influence conditions linked to 5-HT dysregulation= migraine

6

What is the correlation with Migraine and 5-HT?

-Data supports that migraine is caused by chronic 5-HT dysregulation

-in people w/ migraines:
● Increased 5-HIAA(metabolite) of 5-HT in urine
● Increases in plasma 5-HT
● decreases in plasma 5-HT
● Increases in 5-HIAA content in CSF
● PET scans show increased blood flow in highly serotonergic dorsal raphe nucleus during a migraine

7

What are the several classes of medications that can be used to manage migraines?

1) Ergot derivatives
2) Triptans
3) isometheptene (Midrin)

8

What are Ergot Derivatives?

**Vasoconstrictors**
-constricts peripheral and cranial blood vessels
--partial agonist and/or antagonist activity against
- tryptaminergic
-dopaminergic
-alpha-adrenergic receptors

***Inhibits depolarization of dural blood vessel-associated nociceptors

**Possibly blocks neurogenic inflammation through pre junctional inhibition of neuropeptide release
--produces depression of central vasomotor centers
--highly active uterine stimulant

9

What is Ergot Derivatives used for?

“abort” migraine= taken at onset of migraine attack

-take early in onset because absorption + distribution are impaired as gastric symptoms of migraine INCREASE
-addition of caffeine speed

s gastric absorption getting medication into system more rapidly

10

Ergot Derivatives:

The two kinds _______ and ___________
(tablet or suppository form)
-side effects: ________damage, ________
--dihydroergotamine (Migranal)
-Alpha-adrenergic blocker that directly _____ vascular smooth muscle to__________peripheral and cerebral vessels

-______ antagonist at dopaminergic receptors
-partial agonist/antagonist for _______receptors
-given parenterally: IV, IM, SC, _____
-_____ half life: chronic migraine, unresponsive migraine

***ergotamine (Ergomar)
***ergotamine and caffeine (Cafergot, Migergot)

- blood vessel damage
- gangrene
-stimulates
- vasoconstrict
-nonselective

- 5-HT receptors
-nasal spray
-Longer

11

Triptans:
Selective agonists of_________ and _____ receptors in cranial arteries
-causes __________ and reduces ___________
○ also provides relief from _____= antiemetic
○ sumatriptan was _____ drug in this class

- 5-HT 1B
- 5-HT 1D
- vasoconstriction
-reduces neurogenic inflammation
- nausea
- first

12

What are the Preparations for triptans?

end in “triptan”
■ sumatriptan (Imitrex,Sumavel, DosePro)
■ naratriptan (Amerge)
■ zolmitriptan (Zomig)
■ rizatriptan (Maxalt)
■ frovatriptan (Frova)
■ eletriptan (Relpax)
■ almotriptan (Axert)

13

What is isometheptene (Midrin) ?

-also contains acetaminophen + dichloralphenazone

--isometheptene= ****vasoconstrictor

***acetaminophen= analgesic
--dichloralphenazone= mild ***tranquilizing effect
-Used for migraines + tension headaches
- MUST be taken at onset; delay DECREASES efficacy

14

What are antiemetics?
--What do they control?

-Phenothiazine derivatives **(antipsychotics)
***Control nausea and gastric irritation associated with migraine.

-Tablet, suppository and parenteral forms
-Antagonists of D2 receptors

***May cause extrapyramidal effects

15

What are the Preparations for antiemetics?

1) ***prochlorperazine (Compro)
2) ***metoclopramide (Reglan, Metozolv)
3) ***promethazine (Phenergan, Phenadox, Promethegan)
4) trimethobenzamide (Tigan)

16

What are the several classes (8) of medications that can be used for migraine prophylaxis?

1) Tricyclic antidepressants
2) SSRI’s
3) Selective 5-HT and NE reuptake inhibitor
4) Beta blockers
5) Antiseizure medications
6) Calcium channel blockers
7) NSAIDS
8) Corticosteroids

17

Describe Tricyclic antidepressants (for migraine prophylaxis)

-Down regulates 5 HT receptors that are associate w/ excitatory perivascular inflammation; inhibits repute of BOTH 5-HT and NE

18

Describe SSRI's (for migraine prophylaxis)

Inhibits repute of 5-HT

19

Describe Selective 5-HT and NEW eruption inhibitors (for migraine prophylaxis)

venlafaxine (Effexor); also modulates anxiety

20

Describe **Beta blockers (for migraine prophylaxis) ?

-Unknown mechanism : vasoactivity
1) propranolol (Inderal)
2) nadolol (Corgard)
3) atenolol (Tenormin)

21

Describe **Antiseizure medications (for migraine prophylaxis) ?

1) topiramate
2)valproic acid
3) gabapentin

22

Describe **Calcium channel blockers (for migraine prophylaxis) ?

-verapamil (Calan)= interferes w/ release of Ca++ dependent release of substance P (pain modulatory substance) and other neurotransmitters

23

Describe NSAIDS (for migraine prophylaxis) ?

***indomethacin (Indocin) = anti-inflammatory analgesic; alters cerebral blood flow w/o inducing vasospasm

-able to modulate cerebral blood flow thru nitric oxide pathway

24

What is the MOA for Corticosteroids

1) *** Modulation of GABA receptors

2) **Suppresses neurogenic inflammation

3) **Block neurogenic extravasation mediated by release of neuropeptides like substance P

4) **Block effects of high-voltage activated Ca++ currents by blocking Ca++ channels

Note: ****Treat intractable migraine that has not responded to other interventions