TABLE 5.

Peppermint Oil Usage During Endoscopic Procedures

Reference	Population	Design	Findings
Leicester (1982)62	Adult patients undergoing colonoscopy (n=20)	PMO administered during colonoscopy Primary objective: Relief of colonic spasm	Colonic spasm relieved within 30 seconds in all patients
Asao (2001)61	Adult patients undergoing colonoscopy (n= 445)	Open label study of PMO (n=409) vs. control (n=36) 8 mL PMO and 0.2 mL Tween 80 mixed in 1 L water. Given throughout colon and patients repositioned as needed. Primary objective: Control of colonic spasm. Colonic spasm assessed during colonoscopy (graded 0-3 indicating no movement (contractions) to severe spasm)	Satisfactory (Grade 0 or 1) spasmolytic effect seen in 362 (88.5%) of PMO vs. 12 (33.3%) control (P<0.0001).an time to PMO onset 21.6 ± 15 sec (tested in n=31). Effect continued for at least 20 minutes (assumed - not measured based on colonoscopy time)
Yamamoto (2006)54	Adult patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) (n=40)	4 groups: Group 1, 20 mL 1.6% PMO to papilla (n=10); Group 2, 40 mL 1.6% PMO to antrum and papilla (n=9); Group 3, 20 mL 3.2% PMO to papilla (n=10); Group 4, 20 mL 3.2% PMO to antrum and papilla (n=10). Compared with historical group (n=20) Primary objective: To investigate PMO as an antispasmodic for ERCP Endoscopist’s subjective duodenal motility scores during ERCP graded 0-3 indicating none to severe. Number of duodenal movements per minute	Subjective score of grade 0 or 1 made in 7 (70%) of Group 1, 6 (66.7%) of Group 2, 8 (80%) of Group 3, and 5 (50%) of Group 4 vs. 11 (58.8%) in Controls. Non-significant reduction in duodenal contractions with PMO (6.1 ± 3.8 to 4.4 ± 2.9 per minute, P=0.39) with no differences between groups
Shavakhi (2012)63	Adult patients undergoing colonoscopy (n=65)	Double blind randomized study Given PMO premedication (n=33) vs. placebo (n=32) 4 hrs. prior to colonoscopy Primary objective: Efficacy (total procedure time and time required for intubation to the cecum) of enteric-coated PMO as orally administered antispasmodic premedication before colonoscopy	PMO vs. Placebo decreased: – Total procedure time (minutes) 12.2 ± 1.8 vs 15.9 ± 2.8 (P<0.001) – Cecal intubation time (minutes) 6.87 ± 1.63 vs. 10.6 ± 2.8 (P<0.001) More patients 30/33 (90%) receiving PMO vs. 6/32 (19%) receiving placebo willing to repeat the colonoscopy
Sola-Bonada (2012)55	Adult patients undergoing ERCP (n=8)	Patients received 20 ml of 1.6% PMO to the duodenum Effectiveness of PMO rated from 0 to 5 indicating absence of effect to disappearance of peristaltic movement	7/8 had decreased duodenal peristalsis PMO effect started in 2-5 minutes of administration
Inoue (2014)64	Adult patients undergoing colonoscopy (n=226)	Single-blind placebo-controlled 20 mL (1.6%) L-menthol (n=118) vs. placebo (n=108) sprayed onto colonic mucosa Primary objectives: Adenoma detection rate Secondary objective: No peristalsis	Adenoma detection rate significantly higher with L-menthol (vs. placebo): 71 (60.2%) vs. 46 (42.6%) (P<0.01). Proportion of patients with no peristalsis after treatment higher with PMO (vs. placebo): 84 (71.2%) vs. 33 (30.9%) (P<0.0001).