Viagra Effective Against Severe Raynaud’s Phenomenon
Viagra (sildenafil) has shown efficacy for refractory Raynaud’s phenomenon, researchers reported here.
The drug significantly reduced the frequency and duration of Raynaud attacks and improved capillary flow velocity by 400%, according to a study led by Roland Fries, M.D., of the University of Saarland here and published online in the Circulation, Journal of the American Heart Association.
The randomized crossover study evaluated the effectiveness of sildenafil in 16 patients with secondary Raynaud’s phenomenon resistant to vasodilator therapy.
Patients were treated with 50 mg of Viagra or placebo twice daily for four weeks. Symptoms were assessed by diary cards, which included a 10-point Raynaud’s Condition Score. Capillary flow velocity was measured in digital capillaries with a laser Doppler anemometer.
While taking sildenafil, the mean frequency of Raynaud attacks was significantly lower (35±14 attacks during the four weeks versus 52±18; P=0.0064), the cumulative attack duration was significantly shorter (581±133 minutes versus 1046±245 minutes; P=0.0038), and the mean Raynaud’s Condition Score was significantly lower (2.2±0.4 versus 3.0±0.5; P=0.0386).
Capillary blood flow velocity increased in each individual patient, and the mean capillary flow velocity of all patients more than quadrupled after treatment with sildenafil (0.53±0.09 versus 0.13±0.02 mm/s, P=0.0004).
In Raynaud’s phenomenon, exposure to the cold or strong emotions trigger blood vessel spasms that result in interruption of blood flow to the fingers, toes, ears, and nose. Raynaud’s phenomenon can occur without any other associated symptoms or disease.
Causes, incidence, and risk factors
Raynaud’s phenomenon can be associated with diseases of the arteries such as Buerger’s disease and Atherosclerosis, Rheumatoid Arthritis, scleroderma and Systemic lupus erythematosus. It can also follow repeated trauma, particularly vibrations such as those caused by typing or playing the piano. An overdose of ergot compounds or methysergide may also be a cause of Raynaud’s phenomenon.
Strong emotion or exposure to the cold causes the fingers, toes, ears or nose to become white, due to a lack of blood flow in the area. They then turn blue, which is a result of tiny blood vessels dilating to allow more blood to remain in the tissues. When the flow of blood returns, the area becomes red and then later returns to normal color. There may be associated tingling, swelling, and painful throbbing. The attacks may last from minutes to hours.
If the condition progresses, blood flow to the area could become permanently decreased causing the fingers to become thin and tapered, with smooth, shiny skin and slow growing nails. If an artery becomes blocked completely, gangrene or ulceration of the skin may occur.
The risk factors include associated diseases and Smoking. Women are affected more often than men.
In all six patients with chronic digital ulcerations, the lesions began to visibly heal during treatment with Viagra, the researchers added.
Two patients reported side effects leading to discontinuation of the study drug: one from headache and one from muscle pain in the legs. No patients reported side effects during placebo, most likely because all patients correctly identified when they were on treatment or placebo, the study authors said.
“Overall, our results demonstrate for the first time in a randomized study the efficacy of treatment with sildenafil on microcirculation and symptoms in patients with therapy-resistant Raynaud’s phenomenon,” they concluded.
Primary Raynaud’s phenomenon is characterized by temperature-sensitive vasospasms leading to pale and cyanotic skin in the fingers and toes, with accompanying numbness, tingling, or pain. The secondary form, occurring in connective tissue disease, presents more severely with ulceration or tissue necrosis.
Current treatments include vasodilators such as calcium channel blockers and angiotensin II receptor agonists, but they don’t work for all patients, the researchers said.
“Overall, our results demonstrate for the first time in a randomized study the efficacy of treatment with sildenafil on microcirculation and symptoms in patients with therapy-resistant Raynaud’s phenomenon,” they concluded.
Primary source: Circulation
Revision date: July 6, 2011
Last revised: by Sebastian Scheller, MD, ScD