Antiperistaltic Effect and Safety of L‐menthol Oral Solution on Gastric Mucosa for Upper Gastrointestinal Endoscopy in Chinese Patients: A 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.