Naratriptan related compound B. Naratriptan impurity B.
pki: 8.9 of naratriptan for human 5-ht1b3,4-dihydro naratriptan is a selective serotonin 5-ht1b agonist.5-ht1b receptors are widely distributed throughout the cns with the highest concentrations found in the basal ganglia, frontal cortex, striatum, and the hippocampus. the function of the 5-ht1b receptor differs depending upon its location.
3,4-dihydro naratriptan is an impurity formed during the preparation of naratriptan. naratriptan had high affinity for human recombinant 5ht1b and 5ht1d receptors and could cause contractions of dog isolated basilar and middle cerebral artery. naratriptan also caused small contractions of human isolated coronary arteries [1].
in anaesthetized dogs, naratriptan caused selective vasoconstriction of the carotid arterial bed and, in anaesthetized rats, naratriptan selectively inhibited neurogenic plasma protein extravasation in the dura. in various antinociceptive tests, naratriptan had no effect even at high doses. in conscious rats and dogs, naratriptan had high oral bioavailability [1].
[1] connor he, feniuk w, beattie dt, north pc, oxford aw, saynor da, humphrey pp. naratriptan: biological profile in animal models relevant to migraine. cephalalgia. 1997 may;17(3):145-52.
[2] dulli da. naratriptan: an alternative for migraine. ann pharmacother. 1999 jun;33(6):704-11.
