Freise J, Köhler S
223 patients with non-ulcer dyspepsia (dysmotility type dyspepsia or essential/idiopathic dyspepsia, also in combination with irritable bowel syndrome) were included in a prospective, randomised, reference- and double-blind controlled multicentre trial to compare two different preparations of a fixed combination of peppermint oil and caraway oil. The aim of the trial was to evaluate the equivalence of the efficacy and tolerability of these two preparations. The test formulation consisted of the drug combination in an enteric coated capsule containing 90 mg peppermint oil and 50 mg caraway oil, while an enteric soluble formulation containing 36 mg peppermint oil and 20 mg caraway oil was used as the reference. The main target item defined was the “difference in pain intensity between the beginning and the end of therapy”, measured by the patient on a visual analogue scale (0 = no pain, 10 = extremely strong pain). In 213 patients (n = 108 on the test preparation, n = 105 on the reference preparation) with mean pain intensity baseline measurements of 6.1 points in the test preparation group and 5.9 points in the reference group a statistically significant decline in pain intensity was observed in the two groups (-3.6 resP. -3.3 points; p < 0.001; two-sided one-sample t-test). Equivalent efficacy of both preparations was demonstrated (p < 0.001; one-sided t-test for equivalence). With respect to concomitant variables, the results in both groups were also similar. Regarding “pain frequency”, the efficacy of the test preparation was significantly better (p = 0.04; two-sided t-test for difference). Both preparations were well tolerated. Despite the higher dose, the adverse event “eructation with peppermint taste” was less frequent in the group treated with the test formulation, due to the enteric coated capsule preparation.
Freise J, Köhler S. Peppermint oil-caraway oil fixed combination in non-ulcer dyspepsia–comparison of the effects of enteric preparations. Pharmazie. 1999;54(3):210-215.