| Item |
Information |
|
Drug Groups
|
approved |
|
Description
|
Rizatriptan is a triptan drug used for the treatment of migraine headaches. It is a selective 5-hydroxytryptamine1 receptor subtype agonist. |
| Indication |
For treatment of acute migraine attacks with or without aura. |
| Pharmacology |
Rizatriptan is a selective agonist of serotonin (5-hydroxytryptamine; 5-HT) type 1B and 1D receptors. It is structurally and pharmacologically related to other selective 5-HT1B/1D receptor agonists and has only a weak affinity for 5-HT1A, 5-HT5A, and 5-HT7 receptors and no significant affinity or pharmacological activity at 5-HT2, 5-HT3 or 5-HT4 receptor subtypes or at alpha1-, alpha2-, or beta-adrenergic, dopamine1,; dopamine2; muscarinic, or benzodiazepine receptors. This action in humans correlates with the relief of migraine headache. In addition to causing vasoconstriction, experimental data from animal studies show that Rizatriptan also activates 5-HT1 receptors on peripheral terminals of the trigeminal nerve innervating cranial blood vessels, which may also contribute to the antimigrainous effect of Rizatriptan in humans. |
| 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. |
| Affected Organisms |
| • |
Humans and other mammals |
|
| Biotransformation |
Rizatriptan is metabolized by monoamine oxidase A isoenzyme (MAO-A) to an inactive indole acetic acid metabolite. In addition, several other inactive metabolites are formed. An active metabolite, N-monodesmethyl-rizatriptan, with pharmacological activity similar to that of the parent compound has been identified in small concentrations (14%) in the plasma. |
| Absorption |
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. |
| Half Life |
2-3 hours |
| Protein Binding |
14% |
| Elimination |
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. |
| Distribution |
* 140 L [male]
* 110 L [female] |
| References |
| • |
Wellington K, Plosker GL: Rizatriptan: an update of its use in the management of migraine. Drugs. 2002;62(10):1539-74.
[Pubmed]
|
| • |
Wellington K, Jarvis B: Spotlight on rizatriptan in migraine. CNS Drugs. 2002;16(10):715-20.
[Pubmed]
|
| • |
Ikemoto F, Toru T, Aijima H, Natsumeda Y: [Rizatriptan (Maxalt), a new entity of triptan for migraine: pharmacology and therapeutic relevance] Nippon Yakurigaku Zasshi. 2004 Apr;123(4):295-302.
[Pubmed]
|
| • |
Villalon CM, Centurion D, Valdivia LF, De Vries P, Saxena PR: An introduction to migraine: from ancient treatment to functional pharmacology and antimigraine therapy. Proc West Pharmacol Soc. 2002;45:199-210.
[Pubmed]
|
| • |
Tfelt-Hansen P, De Vries P, Saxena PR: Triptans in migraine: a comparative review of pharmacology, pharmacokinetics and efficacy. Drugs. 2000 Dec;60(6):1259-87.
[Pubmed]
|
|
| External Links |
|
|