Eletriptan, sold under the brand name Relpax and used in the form of eletriptan hydrobromide, is a second-generation
triptanmedication intended for treatment of
migraineheadaches.[3][4] It is used as an
abortive medication, blocking a migraine attack which is already in progress. Eletriptan is marketed and manufactured by
Pfizer Inc.
Approval and availability
Eletriptan was approved by the US
Food and Drug Administration (FDA) on December 26, 2002, for the acute treatment of migraine with or without
aura in adults.[5] 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 20 mg and 40 mg strengths.
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 has no significant affinity or pharmacological activity at
adrenergicα1,
α2, or
β;
dopaminergicD1 or
D2;
muscarinic; or
opioid receptors. Eletriptan could be efficiently co-administered 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-HT1 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.
Side effects
Common side effects include
hypertension,
tachycardia, headache, dizziness, drowsiness and symptoms similar to
angina pectoris. Severe allergic reactions are rare.[8]
Contraindications
Eletriptan is contraindicated in patients with various diseases of the heart and circulatory system, such as angina pectoris, severe hypertension, and
heart failure, as well as in patients that have had a stroke or heart attack. This is due to the unusual side effect of coronary vasoconstriction due to serotonin 5HT1B antagonism, which can precipitate a
heart attack in those already at risk. It is also contraindicated in severe
renal or
hepatic impairment due to its extensive liver metabolism through
CYP3A4.[8]
Interactions
Strong inhibitors of the liver enzyme CYP3A4, such as
erythromycin and
ketoconazole, significantly increase blood plasma concentration of eletriptan and should be separated by at least 72 hours.
Ergot alkaloids, such as
dihydroergotamine, add to the drug's hypertensive effect and should be separated by at least 24 hours.[8]
It is sold in the United States, Canada, Australia, and the United Kingdom under the brand name Relpax,[2][9][1] and in several other countries under the brand name Relert.[citation needed]