A randomized, placebo-controlled, cross-over study of ginger extracts and ibuprofen in osteoarthritis

Alternative medicine is used extensively by patients with chronic pain due to e.g., osteoarthritis. Only few of these drugs have be tested in a controlled setting and the present study was undertaken to examine the effect of ginger extract, one of the most popular herbal medications.

Ginger extract was compared to placebo and Ibuprofen in patients with osteoarthritis of the hip or knee in a controlled, double blind, double dummy, cross-over study with a wash-out period of one week followed by three treatment periods in a randomized sequence, each of three weeks duration. Acetaminophen was used as rescue medication throughout the study. The study was conducted in accordance with Good Clinical Practice (European Guideline for GCP).

A ranking of efficacy of the three treatment periods: Ibuprofen>ginger extract>placebo was found for visual analogue scale of pain (Friedman test: 24.65, P< 0.00001) and the Lequesne-index (Friedman test: 20.76, P< 0.00005). In the cross-over study, no significant difference between placebo and ginger extract could be demonstrated (Siegel-Castellan test), while explorative tests of differences in the first treatment period showed a better effect of both Ibuprofen and ginger extract than placebo (Chi-square, P< 0.05). There were no serious adverse events reported during the periods with active medications.

In the present study a statistically significant effect of ginger extract could only be demonstrated by explorative statistical methods in the first period of treatment before cross-over, while a significant difference was not observed in the study as a whole.