Adult: For cases with or without aura: Initially, 5 mg or 10 mg as a single dose. If migraine headache recurs within 24 hours after relief from the initial attack, a further 10 mg dose may be taken after at least 2 hours. If there is no response to the initial dose, a 2nd dose must not be taken for the same attack. Max: 20 mg or 30 mg/24 hours. Dosage recommendations may vary among countries or individual products (refer to specific product guidelines).
Special Patient Group
Patients taking concomitant propranolol: Initially, 5 mg. Max: 10 mg or 15 mg/24 hours. Doses of rizatriptan must be separated by at least 2 hours from the administration of propranolol. Dosage recommendations may vary among countries or individual products (refer to specific product guidelines).
Renal Impairment
Mild to moderate: Initially, 5 mg. If migraine headache recurs after relief from the initial attack, a further 5 mg dose may be taken after at least 2 hours. Max: 10 mg/24 hours. Severe: Contraindicated.
Hepatic Impairment
Mild to moderate: Initially, 5 mg. If migraine headache recurs after relief from the initial attack, a further 5 mg dose may be taken after at least 2 hours. Max: 10 mg/24 hours. Severe: Contraindicated.
Administration
tab: May be taken with or without food. orally-disintegrating tab: May be taken with or without food. Place on the tongue & allow to dissolve; it can then be swallowed w/ the saliva.
Contraindications
Established coronary artery disease, including ischaemic heart disease (e.g. angina pectoris, documented silent ischaemia, history of MI) or other significant CV disease, signs or symptoms of ischaemic heart disease, coronary artery vasospasm including Prinzmetal’s angina, history of CVA or TIA, peripheral vascular disease, ischaemic bowel disease, moderate to severe or uncontrolled hypertension, untreated mild hypertension; hemiplegic or basilar migraine. Severe renal and hepatic impairment. Concomitant use with or within 2 weeks of discontinuing MAOIs. Concurrent use of rizatriptan with or within 24 hours of taking ergotamine, ergot derivatives (e.g. methysergide), and other 5-HT1B/1D receptor agonists.
Special Precautions
Patient with risk factors for coronary artery disease (e.g. strong family history of coronary artery disease, hypertension, hypercholesterolaemia, bundle branch block, diabetes, obesity, postmenopausal women, smoker, males >40 years). Not indicated for the prophylaxis of migraine or cluster headache. Mild to moderate renal and hepatic impairment. Pregnancy and lactation.
Adverse Reactions
Significant: Angioedema, peripheral vascular ischaemia, colonic ischaemia, gastrointestinal ischaemia or infarction, splenic infarction, Raynaud’s syndrome; sensation of pain, pressure or tightness in the precordium throat, neck, and jaw; worsening of headache or medication overuse headache (prolonged use). Rarely, significant blood pressure elevation, including hypertensive crisis; partial vision loss, transient or permanent blindness. Cardiac disorders: Palpitation. Eye disorders: Blurred vision. Gastrointestinal disorders: Nausea, vomiting, dry mouth, diarrhoea, dyspepsia. General disorders and administration site conditions: Fatigue, asthenia. Metabolism and nutrition disorders: Neck pain, stiffness, regional heaviness or tightness, muscle weakness, myalgia. Nervous system disorders: Headache, dizziness, somnolence, paraesthesia, hypoaesthesia, decreased mental acuity, tremor. Psychiatric disorders: Insomnia, euphoria. Respiratory, thoracic and mediastinal disorders: Pharyngeal discomfort, dyspnoea. Skin and subcutaneous tissue disorders: Pruritus, rash, urticaria, sweating. Vascular disorders: Flushing. Potentially Fatal: Serious cardiac events (e.g. coronary artery vasospasm, transient ischaemia, MI, ventricular tachycardia or fibrillation, cardiac arrest), cerebrovascular events (e.g. cerebral or subarachnoid haemorrhage, stroke).
This drug may cause dizziness or somnolence, if affected, do not drive or operate machinery.
Monitoring Parameters
Perform CV evaluation in patients with multiple CV risk factors prior to initiation of therapy and periodically (for intermittent long-term use). Monitor ECG during 1st dose in a medically supervised setting in patients with multiple CV risk factors who have negative CV evaluation. Monitor for headache severity and signs and symptoms suggestive of angina.
Overdosage
Symptoms: Dizziness, somnolence, hypertension and other serious CV symptoms. Management: Gastrointestinal decontamination (e.g. gastric lavage followed by activated charcoal) may be considered. Clinical and electrocardiographic monitoring must be continued for at least 12 hours (even if symptoms are not observed).
Drug Interactions
Plasma concentrations may be increased by propranolol. Potentially Fatal: Increased risk of coronary vasoconstriction and hypertensive effects with ergotamine, ergot derivatives (including dihydroergotamine or methysergide), and other 5-HT1B/1D receptor agonists (e.g. sumatriptan, zolmitriptan). Increased risk of serotonin syndrome with MAOIs, SSRIs, serotonin-norepinephrine reuptake inhibitors (SNRIs), or TCAs.
Food Interaction
Increased risk of adverse effects with St. John’s wort.
Action
Description: Rizatriptan is a selective agonist of serotonin (5-HT1B and 5-HT1D receptors) located in the intracranial blood vessels and sensory nerves of the trigeminal system. It causes the vasoconstriction of the intracranial blood vessels and the inhibition of neuropeptide release resulting in decreased sensitive tissue inflammation and reduced central trigeminal pain signal transmission. Onset: Within 2 hours. Pharmacokinetics: Absorption: Rapidly and completely absorbed after oral administration. Food may delay the absorption of conventional tab by approx 1 hour. Bioavailability: Approx 40-45%. Time to peak plasma concentration: Approx 1-1.5 hours (conventional tab); 1.6-2.5 hours (orodispersible tab). Distribution: Volume of distribution: 140 L (males); 110 L (females). Plasma protein binding: 14%. Metabolism: Metabolised mainly via oxidative deamination by monoamine oxidase type A (MAO-A) to form the inactive indole acetic acid metabolite, N-monodesmethyl-rizatriptan (formed to a minor degree), and other inactive minor metabolites. Undergoes significant first-pass metabolism. Excretion: Mainly via urine (82%; 14% s unchanged drug); faeces (12%). Elimination half-life: 2-3 hours.