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Rizatriptan
- indication:For treatment of acute migraine attacks with or without aura.
- pharmacologypharmacology:
- mechanism: 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 and (3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.
- toxicity: Symptoms of overdose include dizziness, fainting, heart and blood vessel problems, high blood pressure, loss of bowel and bladder control, slow heartbeat, and vomiting.
- absorprion: Rapid following oral administration. Bioavailability is 45%. Food has no effect on the bioavailability of rizatriptan. However, administering rizatriptan with food will delay by 1 hour the time to reach peak plasma concentration. The rate of absorption is not affected by the presence of a migraine attack.
- halflife: 2-3 hours
- roouteelimination: Approximately 14% of an oral dose is excreted in urine as unchanged rizatriptan while 51% is excreted as indole acetic acid metabolite, indicating substantial first pass metabolism.
- volumedistribution: * 140 L [male] * 110 L [female]
- clearance: