Viagra May Treat Other Ailments

Nov. 7, 2005 - The drug made famous for its treatment of erectile dysfunction appears to have another therapeutic use.

A study in the journal Circulation suggests Viagra could help treat a circulatory disorder called Raynaud's phenomenon, which affects about 5% of the population. Raynaud's phenomenon can be associated with other diseases such as lupus.

Raynaud's phenomenon causes episodes of numbness, tingling, and pain in the fingers and toes, as well as skin sores or gangrene in severe cases. The attacks are spawned by spasms in small blood vessels in response to cold temperatures or emotional stress.

These spasms cause blood vessels to constrict and compromise blood flow to distal areas such as toes and fingers. The disorder is sometimes treated with medications to relax the blood vessels, but this is not always successful.

The Viagra study involved 18 patients (mostly women) whose Raynaud's symptoms were not responsive to conventional therapies. While taking Viagra twice a day for four weeks, the patients experienced improved blood flow in the capillaries and fewer Raynaud's attacks. Symptoms improved and the duration of attacks was also shorter. In those who had skin sores, the ulcers began to heal visibly.

These effects did not occur while patients were taking a placebo. At the end of the study, 16 of the participants asked to continue taking Viagra off-label (that is, for a purpose other than its FDA-approved use).

Viagra causes blood vessels to dilate in a different way from other vasodilating drugs, which may explain why it helped Raynaud's patients who didn't respond to standard treatments. The researchers conclude that drugs like Viagra could offer "a promising new approach in patients with microcirculatory disorders."

Although Viagra has risk for serious side effects such as heart attack, stroke, and vision loss, none of the study participants reported any such adverse effect. The side effects reported by study participants included headache, muscle pain, flushing, mild nausea, dizziness, and nasal congestion.

One of the researchers has served as a consultant and speaker for Viagra's manufacturer, Pfizer. Pfizer is a WebMD sponsor.