Adult: For cases with or without aura: Initially, 1 mg or 2.5 mg as a single dose taken at the 1st sign of pain. Dose may be repeated after at least 4 hours if symptoms recur. Max: 5 mg/24 hours. If there is no response to the initial dose, a 2nd dose must not be taken for the same attack.
Mild to moderate: Initially, 1 mg as a single dose. Max 2.5 mg/24 hours.
Mild to moderate (Child-Pugh class A or B): Initially, 1 mg as a single dose. Max 2.5 mg/24 hours. Severe (Child-Pugh class C): Contraindicated.
May be taken with or without food.
Ischaemic coronary artery disease (CAD) including angina pectoris, silent ischaemia, history of MI; signs or symptoms consistent with ischaemic heart disease, coronary artery vasospasm including Prinzmetal's angina; moderate and severe hypertension, uncontrolled hypertension, Wolff-Parkinson-White syndrome or arrhythmias associated with cardiac accessory conduction pathway disorders; peripheral vascular disease, ischaemic bowel disease; history of stroke or TIA, history of hemiplegic migraine. Severe renal (CrCl <15 mL/min) and hepatic (Child-Pugh class C) impairment. Concomitant use of ergotamine, ergotamine derivatives and other 5-HT1 receptor agonists.
Patient with risk factors for coronary artery disease (e.g. diabetes, strong family history of CAD, hypertension, hypercholesterolaemia, postmenopausal women, males >40 years, obesity, smoking); known hypersensitivity to sulfonamides. Not indicated for migraine prophylaxis or for the management of cluster headache, hemiplegic, basilar or ophthalmoplegic migraine. Mild to moderate renal and hepatic impairment. Elderly. Pregnancy and lactation.
Significant: Sensation of pressure, pain and tightness in the chest, throat, jaw or neck; peripheral vascular ischaemia, colonic ischaemia, gastrointestinal vascular ischaemia and infarction, splenic infarction, Raynaud's syndrome; exacerbation of headache or medication overuse headache (frequent/prolonged use); CNS depression (e.g. dizziness, drowsiness, weakness), significant partial vision loss, transient or permanent blindness. Rarely, significant blood pressure elevation, including hypertensive crisis with acute organ systems impairment. Ear and labyrinth disorders: Vertigo. Eye disorders: Photophobia. Gastrointestinal disorders: Nausea, vomiting, xerostomia. General disorders and administration site conditions: Malaise, fatigue, sensation of heat, hot and cold flushes, pain. Musculoskeletal and connective tissue disorders: Musculoskeletal pain. Nervous system disorders: Paraesthesia. Potentially Fatal: Hypersensitivity reactions including anaphylaxis and angioedema; serious cardiac events (e.g. coronary artery vasospasm, MI, transient ischaemia, ventricular tachycardia and fibrillation, cardiac arrest), cerebrovascular events (e.g. cerebral or subarachnoid haemorrhage, stroke), serotonin syndrome.
This drug may cause dizziness, weakness, or drowsiness, if affected, do not drive or operate machinery.
Assess for a clear diagnosis of migraine before starting the treatment. Perform CV evaluation prior to therapy initiation and periodically in patients with multiple CV risk factors. Monitor ECG during 1st dose in patients with multiple CV risk factors who have negative CV evaluation. Monitor headache severity, blood pressure; signs and symptoms of serotonin syndrome and hypersensitivity reactions.
Symptoms: Increased blood pressure resulting in light-headedness, neck tension, tiredness, loss of coordination and ischaemic ECG changes. Management: Supportive treatment. Monitor the patient for at least 24 hours.
Oral contraceptives may reduce the total clearance of naratriptan. Potentially Fatal: Increased risk of coronary vasospasm with ergotamine, ergotamine derivatives (including dihydroergotamine or methysergide), and other 5-HT1 receptor agonists. Increased risk of serotonin syndrome with MAOIs, SSRIs, TCAs and serotonin norepinephrine reuptake inhibitors (SNRIs).
May increase the incidence of undesirable effects with St John's wort.
Description: Naratriptan is a selective agonist for serotonin (5-HT1B and 5-HT1D) receptors in intracranial blood vessels which causes cranial vasoconstriction and inhibition of neuropeptide release. This activity reduces inflammation associated with antidromic neuronal transmission which is correlated with migraine relief. Onset: Approx 1-2 hours. Pharmacokinetics: Absorption: Rapidly and well absorbed. Bioavailability: Approx 70%. Time to peak plasma concentration: 2-3 hours. Distribution: Volume of distribution: 170 L. Plasma protein binding: 28-31%. Metabolism: Metabolised in the liver by CYP450 enzymes. Excretion: Via urine (50% as unchanged drug, 30% as inactive metabolites). Elimination half-life: 6 hours.