Triptans in migraine acts on which receptor
Ans. is 'b' i.e. 5 HTIB/ID Triptans are new class of antimigrane drugs that act by safe actively activating serotonin receptor (5-HT IB/ID)Serotonin (5 Hydroxytryptamine (5 HT)) is a potent depolarizer of nerve endings and mediates various physiological action in the body. But serotonin has no application as drug. However several drugs act on various receptor subtypes of serotonin and are effective in various diseases.Serotonin mediates its action through following receptors:5-HT15 HT1A5HTIb/Id,5HT2A5-HT35-HT4The Triptans act on 5 HTIB/m receptor of the serotoninThe 5-HT] receptor is localized to the brain and is classified into two types 5HT1a - present in raphe nuclei 5HTib/id - constricts cranial blood vesselsTriptans are selective activators of 5-HTIB/ID receptor.The selective activation of 5HT1B/1D receptor results in vasoconstriction of cranial vessels. This relieves migraine as migraine is believed to be caused by the dilatation of extracerebral cranial blood flow.Dilation of blood vessels during migraine attack is believed to divert blood away from the brain parenchyma.Triptans also inhibit the release of vasodilating peptides and antiseizure agents.Sumatriptan and its congeners are currently the first line therapy for acute severe migraine attacks in most patients.The efficacy of Triptan 5-HT1B/1D agonist in migraine is equal to or greater than that of other acute drug treatments e.g. alkaloid.More on triptans * All these drugs are given orally.They are contraindicated in patients with coronary artery disease because they can cause coronary vasospasm (chest discomfort occurs in 1-5% of patients).Although the pharmacological mechanism of the Triptans is similar, their pharmacokinetic properties are distinct:Bioavailability of Triptan ranges from 14% sumatriptan to 74% naratriptan.Half life of ranges from 2 hours for sumatriptan to 25 hours for rovatriptan.
5HT IA
5HT IB/ID
5HT IF
5 HT 3
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