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29 Cards in this Set
- Front
- Back
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What is the neurovascular theory of Migrain HA?
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It is a two part theory.
1. the Trigeminal sensory nerve 2. Vascular components contribute to the HA |
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Explain the Neurovascualr theory of a Migraine HA?
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1. Abnormal activation of trigeminal sensory nerve endings loacted within the meninges and their vasculature.
**During Migraine=Nocireceptor endings activated by stretch and inflammatory mediators. Stretch= VSM relaxation causing dilitation and inc. flow and/or edema of the vessel wall. Inflammatory= neuropeptides released from non-myelinated trigeminal snsory fibers; sustained by autocoids released by vessel wall. |
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What is the rationale for use of seroternergic agonists and NSAIDS for migraine from Vascular component?
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-intracranial vessels have 5HT1D receptors = vasoconstriction
-activate vascular receptor = ↓ extravasation = ↓ vessel wall stretch = ↓ inflammatory transmitters = ↓ C fiber activation |
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What is the rationale for use of seroternerfic agonists and NSAIDS fro migraine from Neurologic component?
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5-HT1B/D Receptors also in the nerve endings of the cranial sensory afferents; activation reduces teh release of inflammatory peprtides from the nerve endings and reduces the activation of the nociceptive fibers by stretch and autacoids. NSAIDS= reduce sensitizing effects of PGI on the nerve ednings and give analgesia to area.
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What is Sumatriptan?
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IMITREX
first generation of Triptans Seretonin agonist that is structurally related to 5-HT. |
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What are the properties of Sumatriptan?
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*Orally active, SQ, intra-nasal (fastest)
*Elim: 80% hepatic, 20% renal *half: 2 hrs, no accumulation of active metabolites ***BBB penetration low for sumatripitan, higher for second generation triptans |
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What is the mechanism of Sumatriptan?
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1. Anti-migraine mechanism:
*Activates 1B/1D recept. in cerebral conducatance vessels and meningeal AV shunts; constriction *Activates inhibitory presyn. receptors (1d/1b) on trigeminal sensory nerve endings *Activ. 1F Rec. in trigeminal nucleus (central mech) reduced synaptic transmission btwn trig. noci. afferents and second-order neurons 2. Other clinical impt. effects *Coronary circulation can be adversley effected |
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What is the therapeutic use of Sumatriptan?
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1. Migraine and Cluster HA
*70-80% respond *Maintained p several uses *Can come back in 24 hrs, prob. short half |
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What are the SE of Sumatriptan?
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*Major: coronary vasospasm, avoid CAD or Printzmetal angina
**Major drug interaction: Not use with SSRIs or MAOIs |
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What is ergotamine?
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ergot alkaloid related to LSD
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What is Dihydroergotamine?
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ergot alkaloid related to LSD
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What are the properties of ergotamine and dihydroergotamine?
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- partial agonist activity of multiple receptors (serotonergic, dopaminergic, and alpha-adrenergic)
*very low, erratic oral bioavail **Ergotamine is SL, nasal, IM **Dihydroergotamine is intranasal or IV,IM, SQ |
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What are the SE of ergotamine and dihydroergotamine?
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peripheral vasoconstriction/capillary endothelium damage= ergotism,
Stimulate uterine contractions, can cause vomiting, dependence (stop=severe HA) |
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What is the mechanism of Ergotamine and dihydroergotamine?
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Use in migraine b/c activation of 5HT 1B/D receptors but less selective than tripatns
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What are the therapeutic uses of ergotamine and dihydroergotamine?
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1.Abort migraine attacks and in cluster HA
**Not used anymore because of triptans |
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What patients are ergotamine and dihydroergotamine counterindicated in?
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pregnancy, PVD, HTN, ischemic HD, renal or hepatic dz
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How are NSAIDs used in migraine treatment?
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NSAIDs or acetaminophen effecteve for tx of mild migraine pain and can add codeine to boost efficacy.
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What antiemetic is used in Migraine headacges?
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Metoclopramide; most commonly used when there is N/V as major Sx. Combo analgesics contain muscarinic blockers that alleviate nausea.
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How is butalbital used in migraine HAs?
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It is used as a sedative + NSAID + caffeine; also instead of caffeine, use codeine; Not used much in US because of dependence
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What agents are used as prophylaxis of Migraine HAs?
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1. B-adrenergic antagonists: propranolog and timidol
2. TCA: amitriptyline and nortryptyline 3. valproate 4. calcium channel antagonists 5. methysergide |
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Which B-adrenergic antagonists are used for migraine prophylaxis?
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FDA approved are propranolol and timolol
60-80% effective; Firt line agents; no sure why work |
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What is the first line agent for migrain prophylaxis?
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B-adrenergic antagonists: propanolol and timolol
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What TCAs are used for migraine prophylaxis?
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Amitriptyline and nortyptyline;
2nd line agents at low doses |
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What is Methysergide?
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semi-synthetic ergot derivative;
non-specific 5-HT antagonist; esp. 5-HT2 (peripheral vasocontraction, platelet aggreg and CNS depol) ***Action may be secondary to metabolite with sertonergic and a1-agonist properties |
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What are the therapeutic uses of Methysergide?
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1. NOT USE FOR CHRONIC MIGRAINE
2. 3rd line agent, b/c of serious inflammatory fibrosis of the lung, heart and peritoneal acvity **Use with drug holiday q 6 mos. |
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What patients is Methysergide counterindicated in?
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PVD, HTN, angina, not use B-blockers
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What drugs do you use with Mild Migraines?
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*i.e. no major impairments, throbbing HA occnl
**Mild analgesics; antiemetics PRN |
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What drugs do you use with a moderate migraine?
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*i.e. mod-sev HA; some impair fucn; nausea common
Use: Triptan perferable to ergotamine, or possibly, "combination analgesics" if cornary disease present |
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What drugs do you use with a severe migraine?
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*More than 3 sev HA/month; sign functional impair; Mark N/V
Use: Sumatriptan (or ergot alkaloid), Antiemetics ***Prophylactic meds-give for 6 mos. then reassess |
