Ginkgo biloba for intermittent claudication.

BACKGROUND

People with intermittent claudication suffer from pain in the muscles of the leg occurring during exercise which is relieved by a short period of rest. Symptomatic relief can be achieved by (supervised) exercise therapy and pharmacological treatments. Ginkgo biloba is a vasoactive agent and is used to treat intermittent claudication.

OBJECTIVES

To assess the effect of Ginkgo biloba on walking distance in people with intermittent claudication.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases (PVD) Group searched their Trials Register (last searched 3 February 2009) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched 2009, Issue 1). We searched MEDLINE/PUBMED (January 1966 to May 2008) and EMBASE (January 1985 to May 2008) and contacted manufacturers.

SELECTION CRITERIA

Randomised controlled trials of Ginkgo biloba extract, irrespective of dosage, versus placebo in people with intermittent claudication.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for selection, assessed study quality and extracted data. We extracted number of patients, mean walking distances or times and standard deviations. To standardise walking distance or time, caloric expenditures were used to express the difference between the different treadmill protocols, which were calculated from the speed and incline of the treadmill.

MAIN RESULTS

Fourteen trials with a total of 739 participants were included. Eleven trials involving 477 participants compared Ginkgo biloba with placebo and assessed the absolute claudication distance. Following treatment with Ginkgo biloba at the end of the study the absolute claudication distance increased with an overall effect size of 3.57 kilocalories (confidence interval -0.10 to 7.23, P = 0.06), compared with placebo. This translates to an increase of just 64.5 (confidence interval -1.8 to 130.7) metres on a flat treadmill with an average speed of 3.2 km/h. Publication bias leading to missing data or "negative" trials is likely to have inflated the effect size.

AUTHORS' CONCLUSIONS

Overall, there is no evidence that Ginkgo biloba has a clinically significant benefit for patients with peripheral arterial disease.