Pharmacology - Agents for headaches and migraines Flashcards
Butalbital
Combination with other drugs for common headaches
Barbiturate
Incr GABAa channel opening–>CNS depressant
Almotriptan
Triptan
Migraine treatment
Metab by cyto P450 and MAO-A
Eletriptan, frovatriptan, naratriptan
Triptans
Migraine treatment
Metab by cyto P450, thus contraind with hepatic/renal impairment
Rizatriptan, sumatriptan, zolmitriptan
Triptans
Migraine treatment
Metab by MAO-A, thus contraind when taking MAO inhibitors
Triptans
Migraine treatment
Selective agonists of 5HT1b and 5HT1d
Inhib release of vasodilators–>vasoconstriction–>prevent abnormal dilation of intracranial blood vessels
Sumatriptan adverse effect
Injection site reactions
Nasal preparation–>bitter taste
Triptan adverse effects
Parasthesias Asthenia and fatigue Flushing Feelings of pressure Tightness Pain in chest, neck, jaw Drowsiness Dizziness Nausea Sweating coronary vasospasm-->contraind in pts with CAD
Ergot and ergot alkaloids
Migraine treatment
Act on alpha and serotonin recep (5HT1b/5HT1d recep)
Agonist and partial agonist at CNS dopamine recep
Low bioavailability
Constrict most blood vessels
Contract uterus
Ergotamine
Ergot and ergot alkaloid Migraine treatment Longer half life and longer acting than dihydroergotamine Sublingual, oral, inhaler, suppository IM or IV for severe attacks
Dihydroergotamine
Ergot and ergot alkaloid Migraine treatment Shorter half life and shorter acting than ergotamine Nasal spray IM or IV for severe attacks
Ergot and ergot alkaloid adverse reactions
Nausea, vomiting, leg weakness, muscle pain, numbness and tingling of fingers and toes
Toxic doses–>prolonged vasospasm–>limb gangrene and bowel infarction
Contraind in pregnancy, PVD, CAD, htn, impaired hepatic/renal function
Rebound headache with abrupt discontinuation
Common headache treatment
OTC
Combination
Migraine treatment
Triptans
Ergot and ergot alkaloids
Migraine prevention
Antihypertensives - b blockers, CCBs
Antidepressants - TCAs, MAOIs, serotonin recep antagonists
Antiepileptic - topiramate, gabapentin, valproic acid
Methysergide
B blockers
Migraine prevention
Only antihypertensive drug indicated for migraine prophylaxis
Several weeks for onset
CCBs
Migraine prevention Inhib Ca entry-->relaxation of vasc smooth muscle and vasodilation Efficacy for migraine prophylaxis weak Off label May dev tolerance
Propranolol, timolol, metoprolol, nadolol, atenolol
B blockers
Migraine prevention
Verapamil
CCB
Migraine prevention
Tricyclic antidepressants (TCAs)
Migraine prevention
Off label
Sedating
Amitriptyline, nortriptyline, imipramine, doxepin, protriptyline
TCAs
Migraine prevention
Amitriptyline most common and efficacious
Monoamine oxidase inhibitors (MAOIs)
Migraine prevention
Off label
Phenelzine
MAOI
Migraine prevention
Substantial side effects
Questionable efficacy
Serotonin receptor antagonists
Migraine prevention
Block 5HT2 and 5HT3 recep
Off label
Mirtazapine
Serotonin recep antagonist
Migraine prevention
Topiramate
Migraine prevention Blocks voltage Na channels Activates hyperpol K current Enhances GABAa Blocks AMPA
Topiramate adverse effects
Somnolence, fatigue, wt loss, nervousness
Gabapentin
Migraine prevention
No biotransformation
Gabapentin side effects
Somnolence, dizziness, ataxia, fatigue
Usually subsides after 2wks of use
Valproic acid
Migraine prevention
Interfere with NMDA and GABA signaling
Extensive metab by liver
Valproic acid adverse effects
GI symptoms, sedation, ataxia, tremor
Serious rare ones are pancreatitis, hyperammonemia, teratogenic, fulminant hepatitis
Methysergide
Migraine prevention Ergot derivative Mixed agonist/antagonist on serotonin recep No benefit during acute attack Not available in US
Methysergide side effects
Inflammatory fibrosis and dependence (req tx interruption)
Tension headache treatment
Amitriptyline
Cluster headache treatment
Abortive: sumatriptan
Preventive: verapamil, lithium, prednisone, indomethacin, topiramate, frovatriptan
