Rizatriptan

Rizatriptan is a selective serotonin (5-HT1B/1D) receptor agonist, commonly known as a triptan, used for the acute treatment of migraine attacks with or without aura.

It is one of the fastest-acting triptans available, with onset of relief typically within 30 minutes of oral administration.

Rizatriptan works by stimulating serotonin receptors on cranial blood vessels, causing vasoconstriction and reducing the release of pro-inflammatory neuropeptides.

This reverses the cranial vasodilation and neurogenic inflammation that characterise a migraine attack. It also inhibits pain signal transmission in the trigeminal nucleus.

Rizatriptan is available as conventional tablets and orodispersible wafers (which dissolve on the tongue without water), making it particularly convenient for patients who experience nausea or vomiting during migraine attacks.

Clinical trials have demonstrated that rizatriptan 10 mg provides headache relief at 2 hours in approximately 70% of patients.

Take as early as possible once migraine headache begins — triptans are most effective when taken early in an attack.

Swallow tablets whole with water, or place the orodispersible wafer on the tongue and allow it to dissolve.

If the first dose provides relief but the headache returns, a second dose may be taken after at least 2 hours.

Do not use to prevent migraines or treat headache during the aura phase before the headache starts.

Adults: 10 mg as a single dose at migraine onset. If the headache recurs after initial relief: a second 10 mg dose may be taken after at least 2 hours. Maximum: 20 mg in 24 hours.

If taking propranolol concurrently: use the 5 mg dose (maximum 10 mg in 24 hours). Not recommended for children under 18 except under specialist guidance.

Common (1 in 10 to 1 in 100): dizziness, drowsiness, tingling or numbness (paraesthesia), headache, and fatigue.

Uncommon (1 in 100 to 1 in 1,000): nausea, dry mouth, palpitations, tachycardia, and flushing.

Rare (less than 1 in 1,000): chest tightness or pressure (triptan sensations — usually benign but should be evaluated if persistent), coronary vasospasm, and serotonin syndrome when combined with serotonergic drugs.

Triptan sensations (pressure or tightness in the chest, throat, or jaw) occur in a minority of patients and are generally transient.

Do not use within 24 hours of another triptan or an ergotamine-type medication. Not suitable for hemiplegic or basilar migraine.

Use with caution in patients with cardiovascular risk factors — a cardiovascular assessment may be warranted before first use.

Overuse (more than 10 days per month) can lead to medication-overuse headache. Avoid combining with MAO inhibitors or within 2 weeks of stopping one.

Uncontrolled hypertension. Established coronary artery disease, history of myocardial infarction, Prinzmetal's angina, or peripheral vascular disease. History of stroke or transient ischaemic attack.

Concurrent use of MAO inhibitors or within 2 weeks of discontinuation. Concurrent use of other triptans or ergotamine preparations. Severe hepatic or renal impairment.