Background Raynaud’s phenomenon (RP) is a reversible vasoconstriction of digital arteries that causes pain and discoloration. Calcium channel blockers (CCB) such as amlodipine are commonly used as the first-line treatment. However, in severe cases, additional vasodilators of other classes are needed. Udenafil, a new reversible selective PDE5 inhibitor, causes smooth muscle relaxation of the macro- and microvascular circulation and is well tolerated.
Objectives This study compared the efficacy of the new phosphodiesterase type 5 inhibitor udenafil to the calcium channel blocker amlodipine in the treatment of secondary RP.
Methods A total of 29 patients with secondary RP associated with connective tissue diseases were enrolled in this double-blind, randomized, cross-over study. The patients were randomized to receive udenafil 100 mg per day or amlodipine 10 mg per day for 4 weeks. After a washout period, they were crossed over to the other drug for another 4 weeks. The primary outcome was RP frequency before and after treatment. The secondary outcomes were RP condition scores, RP duration, number of digital ulcers, health assessment questionnaire, physician global assessment, and digital artery flow as peak systolic velocity (PSV) before and after treatment.
Results Amlodipine and udenafil both decreased the rate of RP attack significantly (Figure A). The drugs did not differ in terms of RP frequency or any of the secondary outcomes except for digital blood flow; udenafil improved it significantly better than amlodipine (p = 0.021) (Figure B). Udenafil was well tolerated without serious adverse effects.
Conclusions Udenafil has a comparable efficacy to reduce RP attacks as amlodipine. In addition, udenafil is superior to improve resting digital blood flow than amlodipine.
Acknowledgements We thank the Medical Research Collaborating Center (MRCC) at Seoul National University for their assistance in the statistical analyses.
Disclosure of Interest None Declared