AIM:To determine the effect of oral sumatriptan on gastric emptying using a continuous 13 C breath test(BreathID system).METHODS:Ten healthy male volunteers participated in this randomized,2-way crossover study.The subjects fasted overnight and were randomly assigned to receive a test meal(200 kcal/200 mL) 30 min after pre-medication with sumatriptan 50 mg(sumatriptan condition),or the test meal alone(control condition).Gastric emptying was monitored for 4 h after administration of the test meal by the 13 C-acetic acid breath test performed continually using the BreathID system.Then,using Oridion Research Software(β version),the time taken for emptying of 50% of the labeled meal(T 1/2) similar to the scintigraphy lag time for 10% emptying of the labeled meal(T lag),the gastric emptying coefficient(GEC),and the regression-estimated constants(β and κ) were calculated.The statistical significance of any differences in the parameters were analyzed using Wilcoxon’s signed-rank test.RESULTS:In the sumatriptan condition,significant differences compared with the control condition were found in T 1/2 [median 131.84 min(range,103.13-168.70) vs 120.27 min(89.61-138.25);P = 0.0016],T lag [median 80.085 min(59.23-125.89) vs 61.11 min(39.86-87.05);P = 0.0125],and β [median 2.3374(1.6407-3.8209) vs 2.0847(1.4755-2.9269);P = 0.0284].There were no significant differences in the GEC or κ between the 2 conditions.CONCLUSION:This study showed that oral sumatriptan significantly delayed gastric emptying of a liquid meal. AIM: To determine the effect of oral sumatriptan on gastric emptying using a continuous 13 C breath test (BreathID system). METHODS: Ten healthy male volunteers participated in this randomized, 2-way crossover study. The subjects fasted overnight and were randomly assigned to receive a test meal (200 kcal / 200 mL) for 30 min after pre-treatment with sumatriptan 50 mg (sumatriptan condition), or the test meal alone (control condition). Gastric emptying was monitored for 4 h after administration of the test meal by the 13 C-acetic acid breath test performed continually using the Breath ID system. Chen, using Oridion Research Software (β version), the time taken for emptying of 50% of the labeled meal (T 1/2) similar to the scintigraphy lag time for 10% emptying of the labeled meal (T lag), the gastric emptying coefficient (GEC), and the regression-estimated constants (β and κ) were calculated. The statistical significance of any differences in the parameters were analyzed using Wilcoxon’s signed- rank test.RESUL TS: In the sumatriptan condition, significant differences compared with the control condition were found in T 1/2 [median 131.84 min (range, 103.13-168.70) vs 120.27 min (89.61-138.25); P = 0.0016], T lag [median P = 0.0125], and β [median 2.3374 (1.6407-3.8209) vs 2.0847 (1.4755-2.9269); P = 0.0284]. There were no significant differences in the GEC or κ between the 2 conditions. CONCLUSION: This study showed that oral sumatriptan significantly delayed gastric emptying of a liquid meal.