Ginkgo Biloba Less Effective for Raynaud's Disease Than Nifedipine

Richard Hyer

October 08, 2007

October 8, 2007 (Chicago) — The blanching, cyanosis, and rubor in the hands known as Raynaud's disease is often treated with the calcium channel blocker nifedipine, but it has been shown that it can also be effectively treated with ginkgo biloba extract. A poster presented at the American Academy of Family Physicians Annual Scientific Assembly reported on a randomized trial performed in Korea to compare the efficacy of the two therapies.

The trial concluded that that nifedipine SR was pharmacologically more effective than ginkgo biloba, although both had a positive effect on disease symptoms. The poster's lead author was Whan-Seok Choi of the Catholic University School of Medicine in Seoul.

Medscape Family Medicine asked the opinion of Lynn Nevin, MD, of White Cloud, Michigan. Dr. Nevin is on leave from a practice at a federally qualified health center.

"I'm surprised ginkgo worked at all," she said.

Patients have asked her about ginkgo, Dr. Nevin reported, but never specifically for Raynaud's disease. Medscape Family Medicine wondered whether, having read the poster, Dr. Nevin would now direct a patient with Raynaud's to ginkgo?

"That's correct," she declared, "especially if for some reason they did not want to use a calcium channel blocker."

Raynaud's disease was first described in 1862 and, according to the poster, currently has a prevalence of about 5% in primary care settings. It is typically treated with lifestyle modification and nifedipine. No studies comparing the efficacy of nifedipine with ginkgo biloba have previously been done in Korea.

This was a randomized, phase 4, multicenter, flexible-dose, open study. Patients (N = 134) were at least 18 years of age, of both sexes, and had confirmed diagnosis of Raynaud's disease. Exclusion criteria included previous or present medical conditions, previous or concomitant medication (including beta-blockers, H 2 blockers, calcium channel blockers, and nitrates), and any laboratory abnormalities such as creatinine or RA factor.

Patients were selected from 3 clinical trial centers and randomly assigned to either the nifedipine SR group (N) or the ginkgo biloba extract group (G). After a 2-week run-in period, patients received treatment for 8 weeks. The primary efficacy evaluation was observed percentage change in the attack rate between the reference value before treatment and after, when patients were exposed to a condition likely to cause an attack from Raynaud's. Comparisons were based on therapeutic evaluation, patient observations, and change in quality of life. A safety evaluation was also made.

Of the 134 patients in the total intent-to-treat population, 64 completed the trial (24 in group N, 22 in group G).

According to the poster, the percentage change of attack rate after 8 weeks of treatment was 50.1% in the group N and 31% in the group G. The improvement rate was more rapid in group N. On the basis of thermographic assessment, nifedipine "prevented the reduction of blood flow and contributed to recovery of blood flow after cold challenge in patients with Raynaud's disease more effectively than ginkgo" ( P = .027). However, both agents were well tolerated without serious adverse events.

When asked whether it would occur to her to prescribe ginkgo biloba for Raynaud's Syndrome, conference attendee Beth Boyer Vehre, MD, of Greenville, Ohio, a family doctor at a federally qualified health center, told Medscape Family Medicine, "It wouldn't have occurred to me, no," she said, "and I try to keep up on alternative medicine.

"... If the patient felt strongly about not using the nifedipine, I probably would tell them [gingko] is something you could use, but it's not as effective," Dr. Boyer said. "[T]his is the only study I've seen on it," she added. "It's a good study; you can tell they put a lot of work into it. I think they did a beautiful job of demonstrating what they're doing."

American Academy of Family Physicians 2007 Annual Scientific Assembly. Presented October 6, 2007.


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