Table 8.

Peppermint Oil (PMO) Randomized Double Blind Controlled Trials for Functional Dyspepsia

Reference	Population	Design	Findings	Adverse Events
Madisch (1999)74	Adults with functional dyspepsia (n=120); 2 withdrawals	Double-blind randomized 4 week study comparing PMO/Caraway oil (90mg/50mg) (n=60) vs. cisapride (10 mg tid) (n=58) × 4 weeks Primary objective: Mean reduction in pain score using a visual analogue scale	No significant differences between groups (4.6 vs. 4.6)	Frequency of adverse events similar; PMO, n=12; cisapride, n=14
May (2000)76	Adults with functional dyspepsia (n=96)	Double-blind randomized trial comparing PMO/Caraway oil () vs. placebo × 28 days Primary outcome was intra-individual change in pain intensity; sensation of pressure, heaviness, and fullness; global improvement using a clinical global impressions item 2) on day 29	Average intensity of pain was reduced further relative to baseline in the PMO/Caraway oil group vs. placebo (40% vs. 22%, P<0.005)) Sensation of pressure, heaviness, and fullness was reduced further relative to baseline in the PMO/Caraway oil group vs. placebo (43% vs. 20%, P<0.005) Using CGI item 2, more patients receiving PMO/Caraway oil vs. placebo were described as much or very much improved (67% vs. 21%, P<0.005).	PMO adverse events unattributed to study drug, n=5
Madisch (2004)75	Adults with functional dyspepsia	Double-blind, randomized, placebo-controlled trial comparing herbal combination (contains bitter candy tuft, matricaria flower, peppermint leaves, caraway, licorice root, and lemon balm) vs. placebo. Four treatment groups random herbal vs. placebo 4 week treatment period combinations. Primary objective: Standardized gastrointestinal symptom score at 4 and 8 weeks	PMO vs. placebo at 4 weeks had lower mean symptom score (6.2 ± 5.1 vs. 12.3 ± 5.6, P<0.001) PMO for full 8 weeks vs. placebo had a lower mean symptom score (3.9 ± 3.8 vs. ± 9.7 ± 4.9, P<0.001)	No differences between groups