NEW YORK (Reuters Health) - The phosphodiesterase type 5 (PDE5) inhibitor tadalafil is effective in the treatment of erectile dysfunction in men with diabetes, according to researchers in North America and Spain.

Dr. Inigo Saenz de Tejada of Fundacion para la Investigacion y el Desarrollo en Andrologia, Madrid, and colleagues note that as many as 75% of diabetic men may experience such dysfunction at some point. The risk has been estimated to be almost twice that of the general population.

Tadalafil, they also observe in the December issue of Diabetes Care, is a potent selective inhibitor of PDE5 in development for oral treatment of mild-to-severe erectile dysfunction of psychogenic, organic or mixed etiology. Blockade of PDE5 potentiates the nitric oxide-mediated erectile response.

To determine the drug's safety and efficacy in men with type 1 or type 2 diabetes, the researchers enrolled 216 such subjects with erectile dysfunction for at least 3 months. They were randomized in a double-blind fashion to tadalafil 10 mg or 20 mg taken as needed no more than once daily, or to placebo.

Among the 191 men who completed the study, there was a significant improvement over baseline as measured by responses to questionnaire on erectile function and in entries in a sexual encounter diary. The results were not associated with the baseline level of dysfunction.

In all, 64% of men in the 20-mg group reported improved erections, as did 56% of those in the 10-mg group. Both of these improvements were significantly greater (p < 0.001) than that experienced by men in the placebo group (25%).

The researchers observe that tadalafil was well tolerated, did not alter mean hemoglobin A1c levels and significantly enhanced erectile function. This was the case, they point out, "when taken as needed with no restrictions on either food or alcohol intake or the timing of dose administration."

Diabetes Care 2002;25:2159-2164.

Copyright © 2003 Reuters Limited. All rights reserved. Republication or redistribution of Reuters Limited content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters Limited. Reuters Limited shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.