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.