Ginkgo effective in intermittent claudication
In this randomized, controlled, double-blind German study, Ginkgo
biloba L. (Ginkgoaceae) was significantly superior to placebo in
improving symptoms of intermittent claudication, a type of peripheral
arterial disease which causes pain in the legs due to obstructed blood
flow [Peters, 1998]. The severity of intermittent claudication is evaluated
by measuring pain-free walking distance, an indication of how long patients
can walk before experiencing symptoms. After six months of treatment,
pain-free walking distance in the ginkgo group improved by almost 50
percent, compared to baseline measurements.
Results of the study lend further support to the positive results
of earlier studies on the use of ginkgo in peripheral arterial disease,
a number of which were reported in a meta-analysis of five placebo-controlled
studies involving a total of 174 patients [Schneider, 1992]. Most of
these studies have utilized EGb 761 (W. Schwabe, Karlsruhe, Germany),
a concentrated ginkgo extract standardized to 24 percent ginkgo flavone
glycosides and 6 percent terpene lactones.
For this 26-week study, 111 patients with confirmed peripheral
occlusive arterial disease were randomized into two treatment groups.
After a two-week run in placebo phase, subjects received treatment with
either one tablet of standardized ginkgo extract three times a day,
a total daily dose of 120 mg, or placebo. Results were assessed by comparing
pain-free walking distance at the beginning of the trial with changes
after eight, 16, and 24 weeks of treatment. The superior efficacy of
ginkgo was statistically significant at all three evaluation points.
Both treatment groups had increases in pain-free walking distance during
the study, but after six months of treatment, the increase in pain-free
walking distance in the ginkgo group was almost twice that of the placebo
group. Increases in maximum walking distance were also significantly
greater with ginkgo treatment. No side effects were reported in the
ginkgo group; one patient in the placebo group complained of heartburn
and gastric pain.
Evelyn Leigh, HRF
[Peters H, Kieser M, Hölscher U. Demonstration of the efficacy
of ginkgo biloba special extract EGb 761® on intermittent claudication
-- a placebo controlled, double-blind multicenter trial (German). VASA
1998; 27: 106-110.
Schneider B. Ginkgo biloba Extrakt bei peripheren arteriellen Verschlusskrankeheiten
(German with English summary). Arzneim Forsch/Drug Res 1992;