Naratriptan

Naratriptan is a selective 5-HT(1B/1D) receptor agonist, with a high affinity at the 5-HT(1B), 5-HT(1D) and 5-HT(1F) receptor subtypes. Naratriptan contracts a number of large isolated cerebral arteries from several species, and has little contractile effect on peripheral blood vessels. It has an inhibitory effect on the cranial neurogenic inflammation model. The clinically recommended dose is 2.5 mg. It was found significantly superior to placebo on headache relief and pain free at 2 and 4 hours, and in relieving nausea, photophobia and phonophobia. It also has a good within-patient consistency, and a low recurrence rate. The side-effect profile is that of the triptan class, wih an incidence no different from placebo at the 25 mg dose. The contraindications are similar to any triptan, including coronary disease. Naratriptan is unlikely to affect metabolism of other drugs. In comparison sumatriptan 100 mg, naratriptan 2.5 mg has a slower onset of action and a lower response rate at 4 h, but it has a lower recurrence rate, and is better tolerated.