APO-SUMATRIPTAN

What it is

APO-SUMATRIPTAN is sumatriptan succinate, available in tablet form. The tablets are available in two strengths, 50 mg and 100 mg. The 50 mg tablets are pink coloured, capsule shaped biconvex film coated tablets, plain on both sides. The 100 mg tablets are white to off-white coloured, capsule shaped biconvex film coated tablets, plain on both sides. Sumatriptan is a specific vascular 5-hydroxytryptamine-1 (5HT1) receptor agonist with no effect at other 5HT receptor subtypes. The vascular 5HT1 receptor is found predominantly in cranial blood vessels and mediates vasoconstriction; sumatriptan selectively constricts the carotid arterial circulation without altering cerebral blood flow, addressing the underlying mechanism of migraine which involves dilatation and oedema formation in the meninges and related vessels. Experimental evidence also suggests that sumatriptan inhibits trigeminal nerve activity, and both these actions contribute to its antimigraine effect.

Approved indications

— Acute relief of migraine attacks with or without aura. — Acute intermittent relief of cluster headache.

Dosing overview

The initial recommended adult dose is 50 mg, although some patients may require 100 mg, with the dose adjusted according to the individual's response. If symptoms recur, further doses may be given in the next 24 hours provided not more than 300 mg are taken in any 24 hour period. Treatment should be started at the first sign of a migraine headache or associated symptoms such as nausea, vomiting or photophobia, with efficacy independent of the attack duration when treatment begins. If a patient does not respond to the first dose, a second dose should not be taken for the same attack, although APO-SUMATRIPTAN may be used for subsequent attacks. The medicine should not be used prophylactically.

Key safety warnings

It is strongly recommended that sumatriptan not be given to patients in whom risk factors for unrecognised coronary artery disease are present—including hypertension, hypercholesterolaemia, smoking, obesity, diabetes, strong family history of coronary artery disease, females with surgical or physiological menopause, or males over 40 years of age—unless a cardiovascular evaluation provides satisfactory evidence that the patient is reasonably free of coronary artery and ischaemic myocardial disease. Serious cardiac events, including some that have been fatal, have occurred within a few hours following use of sumatriptan tablets, though these events are extremely rare (less than 1 in 10,000), and the majority of case reports involved patients with pre-existing heart disease or risk factors for ischaemic heart disease. Sumatriptan can be associated with transient symptoms including chest pain and tightness which may be intense and involve the throat; if such symptoms consistent with ischaemic heart disease occur, appropriate investigations should be carried out and further doses should not be given until results are known. Cerebral haemorrhage, subarachnoid haemorrhage, stroke and other cerebrovascular events have been reported in patients treated with oral sumatriptan, and some have resulted in fatalities, though the relationship of sumatriptan to these events is uncertain, and in some cases the cerebrovascular events may have been primary and sumatriptan administered in the incorrect belief that symptoms were a consequence of migraine. Sumatriptan should not be administered if the headache being experienced is atypical of the patient, and before treating headaches in patients not previously diagnosed as migraineurs, care should be taken to exclude other potentially serious neurological conditions. Overuse of acute migraine treatments has been associated with exacerbation of headache (medication overuse headache) in susceptible patients, and withdrawal of the treatment may be necessary. Co-administration of sumatriptan within 24 hours of other 5-HT1 agonists is not recommended due to the potential for vasoconstrictive effects.

Contraindications

APO-SUMATRIPTAN should not be used in patients with hypersensitivity to any component of the preparation, a history of myocardial infarction, peripheral vascular disease or symptoms or signs consistent with ischaemic heart disease, Prinzmetal's angina or coronary vasospasm, uncontrolled hypertension, cerebrovascular accident or transient ischaemic attack, or severe hepatic impairment. Sumatriptan should not be used within 24 hours of treatment with an ergotamine-containing or ergot-type medication such as dihydroergotamine or methysergide. Sumatriptan should not be given to patients receiving monoamine oxidase inhibitors (MAOIs) or within two weeks of discontinuation of MAOI therapy. Sumatriptan should not be administered to patients with hemiplegic, basilar or ophthalmoplegic migraine.

PBS listing

The 50 mg tablet formulation is listed on the PBS with one item, restricted listing, at an ex-manufacturer price of A$2.90.

Regulatory history

APO-SUMATRIPTAN was first approved on 11 May 2012. ARTG registration 160188 for APO-SUMATRIPTAN 50 mg tablet was first listed on 18 June 2010 under licence category RE (restricted export).