Gastric motor effects of triptans: Open questions and future perspectives

Sumatriptan is a 5-HT1B/D receptor agonist of documented efficacy in reliev ing migraine and associated symptoms such as nausea and vomiting. In the pa st decade, several studies reported an important delay of gastric emptying induced by sumatriptan in healthy humans. The impact of this gastric motor effect of sumatriptan in migraineurs is difficult to predict: a further del ay in gastric emptying could be detrimental (i.e. increased nausea and epig astric symptoms) in patients already having delayed gastric emptying. Howev er, in patients with functional dyspepsia, sumatriptan is also reported to improve gastric accommodation to a meal and reduce perception of gastric di stention, hence relieving epigastric symptoms. Thus, reduced visceral perce ption could be a mechanism involved in reducing nausea during a migraine at tack. Paradoxically, sumatriptan is reported both to relieve the nausea of a migraine attack and to have nausea as a side effect. Although careful ana lysis of the time of onset of nausea may offer a clue as to the origin of t his symptom, available data do not support definite conclusions, all the mo re so because the gastric motor effect of second-generation triptans are st ill unexplored. Taken together, the available evidence warrants further stu dies to clarify the following issues: first, the mechanism responsible for the gastric motor effect of sumatriptan [receptor subtype(s) involved; cent ral vs peripheral mechanism]; secondly, the effects on gastric motility/vis ceral sensitivity of second-generation triptans (which are 5-HT1B/D recepto r agonists) and more recent selective 5-HT1D receptor agonists (proposed as investigational antimigraine agents with less potential to induce coronary vasoconstriction through 5-HT1B receptors); finally, the possible use of d rugs improving gastric accommodation to a meal in the management of those d yspeptic patients with impaired fundic relaxation/altered visceral sensitiv ity. (C) 2001 Academic Press.