Information

Rizatriptan is a selective serotonin receptor agonist. It is used to treat the symptoms of migraine headaches. It works by narrowing blood vessels in the brain, stopping pain signals from being sent to the brain, and blocking the release of certain natural substances that cause pain, nausea, and other symptoms of migraine. Rizatriptan doesn't reduce the frequency of future migraine attack.

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Therapeutic Class

Serotonin Receptor Agonist, Anti Migraine agent

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Dose and Direction of Use

Take this medication as directed by your doctor. You don't need water or any other fluid to intake the tablet. Use your dry hands and place the tablet on your tounge, allow it to dissolve and swallow with your saliva. You may take it with or without food but works better in empty stomach. You shouldn't break or crush the tablet. Dosage is based upon your age, medical condition and response to the treatment.

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Mode of Action

Three distinct pharmacological actions have been implicated in the antimigraine effect of the triptans:

(1) stimulation of presynaptic 5-HT1D receptors, which serves to inhibit both dural vasodilation and inflammation

 (2) direct inhibition of trigeminal nuclei cell excitability via 5-HT1B/1D receptor agonism in the brainstem

(3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.

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Uses

Acute treatment of the headache phase of migraine attacks, with or without aura in adults and relieve the migraine symptoms like nausea, vomiting and sensitivity to light and sound.

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Contraindications

• Hypersensitivity to Rizatriptan.
• Concurrent administration of monoamine oxidase (MAO) inhibitors or use within two weeks of discontinuation of MAO inhibitor therapy.
• Severe hepatic or severe renal insufficiency.
• Previous cerebrovascular accident (CVA) or transient ischaemic attack (TIA).
• Moderately severe or severe hypertension or untreated mild hypertension.
• Established coronary artery disease, including ischaemic heart disease (angina pectoris, history of myocardial infarction, or documented silent ischaemia), signs and symptoms of ischaemic heart disease, or Prinzmetal's angina.
• Peripheral vascular disease.

Concomitant use of rizatriptan and ergotamine, ergot derivatives (including methysergide), or other 5-HT_1B/1D receptor agonists

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Precautions and Warning

• Rizatriptan should only be administered to patients in whom a clear diagnosis of migraine has been established. Rizatriptan should not be administered to patients with basilar or hemiplegic migraine.
• Rizatriptan should not be used to treat 'atypical' headaches, i.e. those that might be associated with potentially serious medical conditions, (e.g. CVA, ruptured aneurysm) in which cerebrovascular vasoconstriction could be harmful.
• Rizatriptan can be associated with transient symptoms including chest pain and tightness which may be intense and involve the throat. Where such symptoms are thought to indicate ischaemic heart disease, no further dose should be taken and appropriate evaluation should be carried out.
• As with other 5-HT1B/1D receptor agonists, rizatriptan should not be given, without prior evaluation, to patients in whom unrecognized cardiac disease is likely or to patients at risk for coronary artery disease (CAD). Cardiac evaluations may not identify every patient who has cardiac disease and, in very rare cases, serious cardiac events have occurred in patients without underlying cardiovascular disease when 5-HT1agonists have been administered. Those in whom CAD is established should not be given Rizatriptan.
• 5-HT1B/1D receptor agonists have been associated with coronary vasospasm. In rare cases, myocardial ischaemia or infarction have been reported with 5-HT1B/1D receptor agonists including Rizatriptan.
• Other 5-HT1B/1D agonists (e.g. sumatriptan) should not be used concomitantly with Rizatriptan.
• Serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) has been reported following concomitant treatment with triptans and selective serotonin reuptake inhibitors (SSRIs) or serotonin noradrenaline reuptake inhibitors (SNRIs).These reactions can be severe. If concomitant treatment with rizatriptan and an SSRI or SNRI is clinically warranted, appropriate observation of the patient is advised, particularly during treatment initiation, with dose increases, or with addition of another serotonergic medication.
• Undesirable effects may be more common during concomitant use of triptans (5-HT1B/1D agonists) and herbal preparations containing St John's wort (Hypericum perforatum).
• Angioedema (e.g. facial oedema, tongue swelling and pharyngeal oedema) may occurin patients treated with triptans, among which is rizatriptan. If angioedema of the tongue or pharynx occurs, the patient should be placed under medical supervision until symptoms have resolved. Treatment should promptly be discontinued and replaced by an agent belonging to another class of drugs.
• The potential for interaction should be considered when rizatriptan is administered to patients taking CYP 2D6 substrates.
• Prolonged use of any painkiller for headaches can make them worse. If this situation is experienced or suspected, medical advice should be obtained and treatment should be discontinued. The diagnosis should be suspected in patients who have frequent or daily headaches despite (or because of) the regular use of headache medications.
• Store the tablet properly away from sunlight and moisture.

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