The authors propose a promising new therapy for the treatment of Raynaud's phenomenon, with parenteral prostacyclin (carbaprostacyclin) and a serotonergic S2-receptor antagonist (ketanserin) given orally. They studied 31 patients, 22 treated with ketanserin and carbaprostacyclin, 9 with carbaprostacyclin alone. Both groups demonstrated successful results and a significant improvement in measurements performed by photoplethysmography and transcutaneous pulse oximetry.