To compare the efficacy and safety of nifedipine sustained release with Ginkgo biloba extract to treat patients with primary Raynaud's phenomenon in South Korea; Korean Raynaud study (KOARA study).

This study examined the efficacy and safety of nifedipine sustained release (nifedipine SR) compared with Ginkgo biloba extract as treatment for primary Raynaud's phenomenon (RP) in Korea. Primary RP were screened and assigned to either the nifedipine SR group (Group N) or the Ginkgo biloba extract group (Group G) in the ratio of 2:1. After a run-in period of 2 weeks, patients received treatment for 8 weeks. We observed the percent improvement of the RP attack rate between before and after the 8-week treatment. Ninety-three subjects were randomly assigned. The percent improvement in Group N was 50.1% at 8 weeks after treatment, while it was 31.0% in Group G (p = 0.03). No serious adverse events occurred, and almost adverse events were mild and improved without specific treatment. nifedipine SR was more effective than Ginkgo biloba extract for treatment of primary RP in Korean patients. Both drugs were tolerable with primary RP patients.