BACKGROUND:

During endoscopic retrograde cholangiopancreatography (ERCP), hyoscine-N-butylbromide (Buscopan) or glucagon is used to inhibit duodenal motility. However, they may cause adverse effects. Peppermint oil has an antispasmodic effect and is used as a less hazardous antispasmodic during colonoscopy and upper gastrointestinal endoscopy. The purpose of the present paper was therefore to investigate peppermint as an antispasmodic for ERCP.

METHODS:

Forty patients were enrolled prospectively. They were assigned to four groups according to the peppermint oil concentration and site of administration: group 1, 20 mL of 1.6% solution around duodenal papilla; group 2, 20 mL of 1.6% solution both to the antrum of the stomach and around the duodenal papilla; group 3, 20 mL of 3.2% solution around the duodenal papilla; and group 4, 3.2% solution both to the antrum and around the duodenal papilla. Glucagon or hyoscine-N-butylbromide was added when duodenal peristalsis was not adequately diminished. Sixteen patients undergoing ERCP with glucagon were employed as historical controls.

RESULTS:

The ERCP was attempted in all except one patient in group 2 who had bleeding from invaded tumor to the duodenum. Peppermint administration equally reduced duodenal motility in the groups. Duodenal movement was none or mild in 69.2% of patients. The ERCP was successfully performed with peppermint alone in 91.4% of patients (37/39). Glucagon or hyoscine-N-butylbromide was needed in one patient each in groups 1 and 4. Serious complications related to peppermint oil did not occur. Inhibitory effect of peppermint appears to be identical to that of glucagon.

CONCLUSION:

Duodenal relaxation was obtained with 20 mL of 1.6% peppermint oil solution in the duodenum, but additional administration may be required. Peppermint oil is useful as an antispasmodic agent for ERCP.