indication

For the treatment of acute migraine headache in adults

pharmacology

Almotriptan is a selective 5-hydroxytryptamine receptor subtype agonist indicated for the acute treatment of migraine attacks with or without aura in adults. Almotriptan is not intended for the prophylactic therapy of migraine or for use in the management of hemiplegic or basilar migraine. Almotriptan is an agonist for a vascular 5-hydroxytryptamine receptor subtype (probably a member of the 5-HT_1D family) having only a weak affinity for 5-HT_1A, 5-HT_5A, 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 Almotriptan 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 Almotriptan in humans.

mechanism of action

Almotriptan binds with high affinity to human 5-HT_1B and 5-HT_1D receptors leading to cranial blood vessel constriction.

half life

3-4 hours

route of elimination

Almotriptan is eliminated primarily by renal excretion (about 75% of the oral dose), with approximately 40% of an administered dose excreted unchanged in urine. Approximately 13% of the administered dose is excreted via feces, both unchanged and metabolized.

drug interactions

Citalopram: Increased risk of CNS adverse effects

Conivaptan: CYP3A4 Inhibitors (Strong) may increase the serum concentration of Almotriptan. Use an initial almotriptan dose of 6.25mg when using almotriptan with a strong CYP3A4 inhibitor, and do not exceed 12.5mg of almotriptan in any 24-hour period. Avoid concurrent use of almotriptan with a strong CYP3A4 inhibitor in patients with impaired hepatic or renal function.

Desvenlafaxine: Increased risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome.

Dihydroergotamine: Possible severe and prolonged vasoconstriction

Dihydroergotoxine: Possible severe and prolonged vasoconstriction

Ergonovine: Possible severe and prolonged vasoconstriction

Ergotamine: Possible severe and prolonged vasoconstriction

Escitalopram: Increased risk of CNS adverse effects

Fluoxetine: Increased risk of CNS adverse effects

Fluvoxamine: Increased risk of CNS adverse effects

Isocarboxazid: The MAO inhibitor, isocarboxazid, may decrease the metabolism and clearance of the serotonin 5-HT receptor agonist, almotriptan. Concomitant therapy is contraindicated.

Itraconazole: This potent CYP3A4 inhibitor increases the effect and toxicity of the triptan

Ketoconazole: This potent CYP3A4 inhibitor increases the effect and toxicity of the triptan

Methylergonovine: Possible severe and prolonged vasoconstriction

Methysergide: Possible severe and prolonged vasoconstriction

Nefazodone: Increased risk of CNS adverse effects

Paroxetine: Increased risk of CNS adverse effects

Phenelzine: The MAO inhibitor, phenelzine, may decrease the metabolism and clearance of the serotonin 5-HT receptor agonist, almotriptan. Concomitant therapy is contraindicated.

Sertraline: Increased risk of CNS adverse effects

Sibutramine: Increased risk of CNS adverse effects

Tramadol: Increased risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome.

Tranylcypromine: The MAO inhibitor, Tranylcypromine, may reduce the metabolism and clearance of the serotonin 5-HT1D receptor agonist, Almotriptan. Risk of serotonin syndrome and Almotriptan toxicity. Concomitant therapy should be avoided.

Trazodone: Increased risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome.

Trimipramine: Increased risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome.

Venlafaxine: Increased risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome.

Voriconazole: Voriconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of almotriptan by decreasing its metabolism. The initial and maximum doses should not exceed 6.25 mg and 12.5 mg, respectively during concomitant therapy. Concomitant therapy should be avoided in patients with impaired hepatic or renal function.

Zolmitriptan: Concomitant use of two serotonin 5-HT1D receptor agonists, such as zolmitriptan and almotriptan, may result in additive vasoconstrictive effects. Concomitant use within 24 hours is contraindicated.