Efficacy of tadalafil in secondary Raynaud's phenomenon resistant to vasodilator therapy: a double-blind randomized cross-over trial

Objective. To evaluate the efficacy of tadalafil as add-on therapy in secondary RP resistant to vasodilators. Methods. Patients with scleroderma and MCTD having four or more RP attacks per week despite being on vasodilators were randomized to receive either placebo or tadalafil (20 mg) on alternate days as add-on therapy to their current vasodilators for 6 weeks. After a 7-day washout, patients were crossed over to the other arm. Primary endpoints were improvement in the daily frequency and duration of RP episodes and RP condition score (RCS). Secondary outcome measures were healing of existing and appearance of new digital ulcers (DUs) and improvement in scleroderma-specific HAQ (SHAQ), quality of life (QoL), flow-mediated dilatation (FMD), patient and physician global assessment. Results. Twenty-four of 25 recruited patients completed the study. All the patients were receiving calcium channel blockers and in addition 18 were receiving other vasodilators. During tadalafil therapy significant improvement in mean daily frequency, mean daily duration of RP and mean daily RCS were observed as compared with baseline and placebo. All the 24 digital lesions healed during tadalafil therapy as compared with 3/13 during the placebo treatment (P < 0.0001). One new DU was reported during tadalafil therapy vs 13 during placebo therapy (P = 0.0005). QoL, SHAQ, FMD, patient and physician global assessment significantly improved while on tadalafil. No serious adverse event was observed. Conclusion. Tadalafil as add-on therapy improves symptoms of RP, heals and prevents new DUs and improves QoL in patients with resistant secondary RP.