Exam 4 Migraine medications Flashcards
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
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
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
What are the known that 5-HT is involved in many behavioral and psychiatric disorders?
1) Schizophrenia
2) OCD
3) Depression
4) Anxiety
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
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
What are the several classes of medications that can be used to manage migraines?
1) Ergot derivatives
2) Triptans
3) isometheptene (Midrin)
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
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
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
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
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)
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
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
What are the Preparations for antiemetics?
1) **prochlorperazine (Compro)
2) **metoclopramide (Reglan, Metozolv)
3) ***promethazine (Phenergan, Phenadox, Promethegan)
4) trimethobenzamide (Tigan)
