Migraine

=Migraine=

What it is
Migraine is a potentially disabling condition that can affect normal day-to-day function.

For many people, migraines are triggered by specific things. These may also trigger nonmigrainous headaches in susceptible people. Some triggers include: - Medications: analgesics (overuse and withdrawal), oral contraceptives, oestrogens, NSAIDs (particularly indomethacin), nitrates, erectile dysfunction agents (sildenafil, tadalafil, vardenafil), calcium channel blockers, proton pump inhibitors, cimetidine, fluoxetine, fenfluramine, nicotine, alcohol, cocaine - Stress - Sensory stimulation – glare, smells - Weather (barometric pressure changes) - Smoke, particularly from cigarettes - Foods including: chocolate, citrus fruit, caffeine (intake or withdrawal), aspartame, food additives (MSG, nitrites, phenylethylamine), tyramine-containing foods (red wine, aged cheeses) - Hormonal changes, menstruation, pregnancy - Strenuous exercise - Inadequate sleep, insomnia - Hypoglycaemia (from lack of food or medication induced).
 * Causes:**

Symptoms
//Migraines last from 4-72 hours// - Unilateral headache - Moderate to severe throbbing pain - Usually photophobia and phonophobia and/or nausea and vomiting.

Pain worsens if the person continues routine activity and most sufferers have to stop and rest.

__Aura:__ (found in a third of migraine sufferers) //Lasts up to an hour// - Visual disturbances (shimmering borders, zigzagging forms, loss of vision, lights, spots) - Numbness, pins and needles - Speech disturbances

They can recur regularly (every few weeks, once a month) or may only occur once or twice a year.

How to Treat
People with recurring migraines should keep a diary of attacks to try to identify triggers. Avoiding these as much as possible can reduce the number and severity of attacks. - Massage and meditation, - Relaxation training with biofeedback and cognitive behavioural therapy
 * Prophylaxis:**

Prophylactic medications for migraine all have significant adverse effects. They are usually considered for those who suffer 2-3 migraines a month. Treatment for acute attacks will still be required as preventive therapy only reduces frequency and severity of attacks; also it may take 1–3 months for the full effect of the preventive drug to be seen. - Propranolol and metoprolol: considered first-line therapies and are generally better tolerated. - Valproate: consistent evidence for the effectiveness in reducing migraine frequency even though it is not approved for this indication - Amitriptyline: has been shown to be effective, although not marketed for this indication - Pizotifen (//5HT2 antagonist with antihistaminic and weak anticholinergic properties//) : drowsiness and weight gain (//appetite stimulant//) can be a problem. - Methysergide (//5HT2 antagonist)//: reserved for more severe cases. Long-term use is associated with serious side effects (retroperitoneal, cardiac or pulmonary fibrosis), although the risk is reduced if a six months on/one month off regimen is followed. Methysergide should be withdrawn over a period of a week to prevent rebound migraine.

All preventive drugs need dose titration to limit side effects and full effect may take several months.

Initial treatment is with a simple analgesic – ideally soluble for rapid onset of action. Higher doses are usually used – 600-900mg aspirin or 1-1.5g of paracetamol, four-hourly if required (up to max paracetamol 4g/day). Ibuprofen 800-1200mg or other NSAIDs can be used but have not been shown to be more effective than aspirin.
 * Initial attack:**

Ergotamine 1-2mg is taken at onset of migraine or aura (max 6mg/day, 10mg/week) - repeat if necessary after 30–60 minutes. Side effects can include exacerbated nausea, dizziness and vasospasm (muscle pain, numbness, tingling, cold extremities). Ergotamine should not be taken concomitantly with macrolide antibiotics or other CYP3A4 inhibitors, due to possible increased toxicity.

Three triptans are currently available in Australia (sumatriptan, naratriptan, zolmitriptan). Triptans are selective for 5-HT1B and 5-HT1D and cause vasoconstriction of cerebral blood vessels without reducing blood flow. They may also inhibit trigeminal nerve activity. Triptans are used at the onset of migraine pain (not during aura). If there is no response to the initial dose, a second dose will not be effective. Dose can be repeated after at least 2 or 4 hours (depending on triptan and formulation) if migraine recurs.

A triptan should not be used if ergotamine has been used in the previous 24 hours. Ergotamine should not be taken if a triptan has been used in the last six hours

In severe nausea and vomiting suppositories or injectable preparations may be used. Pethidine is not recommended for analgesia in migraine due to side effects, dependence and short duration of action.

Other advice
In many people migraines abate in later life (over 50) and there is little evidence that they are progressive or cause long-term damage

Additional Resources
[|Self-care Card: Migraine] [|Facts behind the Fact Card - Headache and Migraine] [|NPS - Medicines for Headache and Migraine]: starting on page 6 [|NPS Newsletter - Headache and Migraine] [|Better Health - Migraines] Headache and Migraine]]
 * Lecture Notes:**[[http://www.twango.com/download/pharmacyunisa.10121|