Seventy-nine percent of Viagra (sildenafil citrate) patients who tried both new PDE5 inhibitors to treat erectile dysfunction (ED) preferred not to switch to the new medicines, according to results of an open-label study presented this week at the European Society for Sexual Medicine.

"We found only 21 per cent of men preferred the new oral ED treatments Cialis (tadalafil) or Levitra (vardenafil) at the conclusion of the study," said Hubert Claes, MD, PhD, University Clinic, Gastuisberg, Belgium. "Most long-term users of Viagra find the medicine works for them and are content to stay with the treatment."

All patients in the study were Viagra users who requested a refill of Viagra. They were then asked to use vardenafil and tadalafil at least four times each and to report their experience using a validated questionnaire at the conclusion of the trial period with each product. At the end of the study, patients also were asked to identify the product they preferred. Only 19 of the 91 men in the study said they preferred to switch from Viagra to one of the new medications.

The results of this study by Dr. Claes are consistent with long-term efficacy and patient satisfaction studies conducted by Pfizer, which showed that after four years 96 per cent of men remained satisfied with Viagra. No oral PDE5-inhibitor has been shown to be more effective than Viagra. Viagra is a prescription medication indicated for the treatment of ED.

Viagra is available only from health care providers and should always be used in accordance with its approved labeling. Viagra is contraindicated in patients who use nitrates in any form at any time.

Before treating ED, physicians should consider the impact of resuming sexual activity and the mild and transient vasodilatory effects of Viagra on blood pressure. Physicians should carefully consider whether vasodilatory effects, especially in combination with sexual activity, could adversely affect patients with underlying cardiovascular disease or other more unusual conditions.

The most common side effects of Viagra are headaches, flushing and dyspepsia. Adverse events, including visual effects, were generally transient and mild to moderate.

Viagra is a breakthrough oral treatment for erectile dysfunction that has been found to be effective and well tolerated in over 130 completed and ongoing clinical studies. Viagra has been approved by regulatory authorities in over 120 countries around the world and is among the most widely prescribed medications, with over 130 million prescriptions written for more than 20 million men worldwide.