Antiperistaltic effect and safety of l‐menthol oral solution on gastric mucosa for upper gastrointestinal endoscopy in Chinese patients: Phase III, multicenter, randomized, double‐blind, placebo‐controlled study

OBJECTIVE: The topical antispasmodic agent l‐menthol is commonly used for gastric peristalsis suppression during diagnostic upper gastrointestinal (GI) endoscopy. We evaluated the efficacy and safety of a single dose l‐menthol solution in suppressing gastric peristalsis during upper GI endoscopy in Chinese patients. METHODS: In this phase III, multicenter, randomized, double‐blind, placebo‐controlled study (ClinicalTrials.gov: NCT03263910), 220 patients scheduled to undergo upper GI endoscopy at five Chinese referral centers received a single dose of either 160 mg of l‐menthol (n = 109) or placebo (n = 111). Both treatments were sprayed endoscopically on the gastric mucosa. An independent committee evaluated the degree of gastric peristalsis (peristaltic score: grade 1–5). RESULTS: At baseline, the proportion of patients with grade 1 peristalsis (no peristalsis) did not differ between the groups. The proportion of patients with grade 1 peristalsis post‐treatment was significantly higher in the l‐menthol group (40.37%, 44/109) versus the placebo group (16.22%, 18/111; P < 0.001); the difference between the groups was 24.15% (95% confidence interval: 12.67%–35.63%; P < 0.001). In the l‐menthol group, 61.47% of patients had grade 1 peristalsis after endoscopy versus 24.55% in the placebo group (P < 0.001). The ease of intragastric examination correlated significantly with the grade of peristalsis. The incidence of adverse events was comparable between the groups (P = 0.340). CONCLUSIONS: During upper GI endoscopy, a single dose of l‐menthol solution (160 mg) sprayed on the gastric mucosa significantly attenuated gastric peristalsis versus placebo, thereby improving the visual stability without any safety concerns.