| Item |
Information |
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Drug Groups
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approved; investigational |
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Description
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Naratriptan is a triptan drug used for the treatment of migraine headaches. It is a selective 5-hydroxytryptamine1 receptor subtype agonist. |
| Indication |
For the acute treatment of migraine attacks with or without aura in adults. |
| Pharmacology |
Naratriptan 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 agonist. Naratriptan 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 Naratriptan 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 Naratriptan in humans. |
| Toxicity |
Symptoms of overdose include light-headedness, loss of coordination, tension in the neck, and tiredness. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Primarily hepatic. In vitro, naratriptan is metabolized by a wide range of cytochrome P450 isoenzymes into a number of inactive metabolites. |
| Absorption |
Well absorbed (74% oral biovaility), absorption is rapid with peak plasma concentrations after 2-5 hours. The rate of absorption is slower during a migraine attack. |
| Half Life |
5-8 hours |
| Protein Binding |
28%-31% (over the concentration range of 50 to 1000 ng/mL) |
| Distribution |
* 170 L |
| Clearance |
* 6.6 mL/min/kg |
| References |
| • |
Massiou H: Naratriptan. Curr Med Res Opin. 2001;17 Suppl 1:s51-3.
[Pubmed]
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| • |
Lambert GA: Preclinical neuropharmacology of naratriptan. CNS Drug Rev. 2005 Autumn;11(3):289-316.
[Pubmed]
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| • |
Villalon CM, Centurion D, Valdivia LF, de Vries P, Saxena PR: Migraine: pathophysiology, pharmacology, treatment and future trends. Curr Vasc Pharmacol. 2003 Mar;1(1):71-84.
[Pubmed]
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| External Links |
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