Eletriptan

Eletriptan (also known as eletriptan hydrobromide) is a second generation triptan drug marketed and manufactured by Pfizer Inc for the treatment of migraine headaches. It is sold in the US under the brand name Relpax.

Approval and availability
Eletriptan was approved by the U.S. Food and Drug Administration (FDA) on December 26, 2002 for the acute treatment of migraine with or without aura in adults. It is available only by prescription in the United States and Canada. It is not intended for the prophylactic therapy of migraine or for use in the management of hemiplegic or basilar migraine. It is available in 40 mg and 80 mg strengths.

Eletriptan is covered by and ;  the FDA lists the patents as scheduled for expiration on December 26, 2016 and August 29, 2017, respectively.

Mechanism of action
Treatment with Eletriptan is believed to reduce swelling of the blood vessels surrounding the brain. This swelling is associated with the head pain of a migraine attack. Eletriptan blocks the release of substances from nerve endings that cause more pain and other symptoms like nausea, and sensitivity to light and sound. It is thought that these actions contribute to relief of symptoms by Eletriptan.

Eletriptan is a serotonin agonist. Specifically, it is a selective 5-hydroxytryptamine 1B/1D (5-HT1B) receptor agonist.

Eletriptan binds with high affinity to the 5-HT[1B, 1D, 1F] receptors.

It has a modest affinity to the 5-HT[1A, 1E, 2B, 7] receptors. And little to no affinity at the 5-HT[2A, 2C, 3, 4, 5A, 6] receptors.

Eletriptan has no significant affinity or pharmacological activity at adrenergic alpha1, alpha2, or beta; dopaminergic D1 or D2; muscarinic; or opioid receptors. Eletriptan could be efficiently co-administrated with nitric oxide synthase (NOS's) inhibitors for the treatment of NOS-dependent diseases (US patent US 2007/0254940)

Two theories have been proposed to explain the efficacy of 5-HT receptor agonists in migraine. One theory suggests that activation of 5-HT1 receptors located on intracranial blood vessels, including those on the arteriovenous anastomoses, leads to vasoconstriction, which is correlated with the relief of migraine headache. The other hypothesis suggests that activation of 5-HT1 receptors on sensory nerve endings in the trigeminal system results in the inhibition of pro-inflammatory neuropeptide release.

Additional Chemical Names

 * Merck Index: 3-[[(2R)-1-Methyl-2-pyrrolidinyl]methyl]-5-[2-(phenylsulfonyl)ethyl]-1H-indole
 * 5-[2-(benzenesulfonyl)ethyl]-3-(1-methylpyrrolidin-2(R)-ylmethyl)-1H-indole
 * (R)-5-[2-(phenylsulfonyl)ethyl]-3-[(1-methyl-2-pyrrolidinyl)methyl]-1H-indole