Drugs For Migraine Flashcards
Eletriptan
Moa:action at 5ht1b/1d receptors appears to reduce calcitonin gene related peptide levels & modulate nociception.
Indication: acute migraine
Precaution: Contraindication of use within 24 hrs or ergometrine and within 48 hours of ketoconazole oral, itraconazole, erythromycin, clarithromycin, fosamprenavir or ritonavir
Renal: effect greater in renal impairment reduce max dose.
Hepatic: CI in severe impairment
Dose:
Age more than 17yo: 40mg oral asap after onset of headache, dose maybe repeated after at least 2 hrs if migraine recurs. Max single dose of 80mg and Max daily dose of 160mg
Clcr less than 50ml/min:20-40mg; Max daily dose 40mg
Naratriptan
Indication: acute migraine
Precaution: tx with ergometrine may increase risk of vasospasm,avoid combination
Renal: CI if clcr is less than 15ml/min,reduce max daily dose if clcr is between 15-50ml/min
Hepatic: CI in severe impairment,reduce max daily dose in mild-moderate impairment
Dosage: oral 2.5mg asap after onset of headache.. dose can be repeated after at least 4 hours if migraine occurs. Max daily dose 5mg
Renal/hepatic impairment: Max daily dose 2.5mg in mild to moderate impairment or if clcr 15-50ml/min
Rizatriptan
Indication
Acute migraine
Precautions: Phenylketonuria -wafers and some tabs contains phenylalanine
Drugs:propranolol increases rizatriptan conc, reduce rizatriptan dose
Manufacturers contradicts use with or within 14 days of stopping MAOI. Use within 6 hours of ergometrine is not recommended
Renal: reduce dose and use with caution if clcr less than 10ml/min
Adr common: Dyspnoea
Dose:oral 10mg asap after onset of headache repeat after at least 2 hrs if migraine recurs. Max daily dose 30mg
With propranolol 5mg taken as above max daily dose 15mg
Clcr less than 10ml/min: 5mg taken as above,max daily dose 15mg
Counseling: place wafer on top of your tongue to dissolve then swallow. Take a glass of water to help absorb more quickly. It may take longer to work if you take it with food.
Rizatriptan has been used in those aged 6yo and above under specialist advice
Sumatriptan
Indication: acute migraine,acute cluster headache (injection)
Precautions
Other drugs-manufacturer contradicts use with or within 24 hours of stopping a MAOI and use with or within 24 hours of stopping ergometrine
Hepatic: CI in severe impairment
Adr common: transient pain in injection site, burning sensation in the nose & throat,taste disturbances (nasal spray) and dyspnoea
Dosage: use asap after onset of headache
Dosage:50-100mg, repeat doses if migraine recurs. Max daily dose 300mg. S/C 6mg. Dose maybe repeated after at least 1hr if migraine recurs. Max daily dose 12mg
Age more than 12yo: 10-20mg into 1 nostril. Dose may be repeated after at least 2 hrs if migraine recurs. Max daily dose 40mg.
Administration: do not give IV we there’s increase risk of coronary vasospasm,give first sc injection under medical supervision
Practice points
100mg is a little better than 50mg but has more ADR
S/C admin more effective than oral but more ADR
Intranasal has a quicker onset than oral
If vomiting prevents oral use, S/C route preferred as absorption from the intranasal route depends largely on ingestion. The bitter taste of nasal spray maybe unacceptable
Zolmitriptan
Indication
Acute migraine
Precautions: tx with ergometrine , contraindicated use of zolmitriptan
Hepatic: reduce max daily dose in severe impairment
Dosage:oral:2.5mg after onset of headache. Dose may be repeated after at least 2 hours if migraine recurs, 5mg maybe given at onset if lower dose tolerated but ineffective in previous attack. Max dose 10mg
Calcitonin gene related peptide antagonist
Eptinezumab
Moa:inhibit cgrp vasodilation by binding to cgrp (eptinezumab(iv),fremanezumab,galcanezumab) (sc)or by blocking CGRP receptors (erenumab)(SC)
Precautions: cardio or cerebrovascular disease
Eptinezumab
Indication: prevention of migrain
Dosage: IV infusion 100mg q 12 weeks, if inadequate increase to 300mg q 12 weeks under specialist advice..if no response in 3-6months cease tx
Adr common: injection site reaction, erythema,pain
Erenumab
Indication: prevention of migraine
Precautions: Hx of or risk factors for hpt, erenumab worsens hpt within 7 days of the first or 2nd dose
Adr common: constipation,itch
Dose: s/C 70mg q 4 weeks if inadequate after 2-3 doses, increase to 140mg q 4 weeks under specialist advice. If no response after 12 weeks, cease tx
Counseling: allow injection to stand at room temperature 30 mins before using it
Fremanezumab
Indication: prevention of migraine
Dose: SC 225mg once a month, SC 675mg q 3 months. If inadequate after 12 weeks consider stop tx. If switching dose regimens, start the new dose when the next dose of the previous regimen is due
Counseling
Allow injection to stand at room temperature for 30mins before using it
Galcanezumab
Indication: migraine prevention.
Adr common: itch, rash, constipation, vertigo
Dose:adult SC initial dose 240mg then 120mg once a month. If no response after 12 weeks stop tx
Others drug to prevent migraine: Pizotifen
Moa: 5HT2 antagonist with antihistaminic and weak anticholinergic properties
Indication: prevention of recurrent migraine or cluster headache
Precautions
Risk factor for angle closure glaucoma, prostate hypertrophy, epilepsy
Preg/BF: Limited data
Dose: initially 0.5mg od at night gradually 1.5mg daily in a single dose at night or divided doses. Max 3-4.5mg daily in 2-3 doses
Adr: sedation, fatigue,nausea, increased appetite,wt gain
Practice points: reduce dose gradually when stopping tx, abrupt cessation may lead to acute withdrawal SX, anxiety,tremor,wt loss, insomnia, dizziness
Counseling: Pizotifen causes drowsiness when first taken and may increase effects if alcohol
Other drugs to tx migraine
Botulinum toxin
Moa
What is the mechanism of action of onabotulinumtoxinA in chronic migraines?
Through inhibition of these sensory nerve endings, onabotulinumtoxinA reduces the number of pain signals that reach the brain and consequently prevents activation and sensitization of central neurons postulated to be involved in migraine chronification
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Drugs to treat Alzheimer’s disease
Donepezil
Galantamine
Rivarastigmine
Moa: Decrease breakdown of Ach reducing the apparent deficiency if cholinergic neurotransmitter activity in Alzheimer’s disease
Indication: Alzheimer’s disease
Precautions
CI in ureteric obstruction
CI in active peptic ulcer
Risk of aggravation in ppl with hx of peptic ulcer, seizures,heart block,bradyarrythmias, Parkinson’s disease, asthma,cold
Tx with drugs with anticholinergic effects: antagonise therapeutic effects,avoid combination
Tx with drugs causing bradycardia: risk of bradycardia & hypotension
Preg/bf: avoid use
Adr common: nausea,vomiting, diarrhoea,anorexia,vivid dreams,wt loss,muscle cramps, depression, fatigue, hypertension, fainting
