Lower urinary tract symptoms (LUTS) caused by benign prostatic enlargement (BPE) are often associated with erectile dysfunction, with research now suggesting a pathophysiological link between the two conditions. Treatment for LUTS is also often associated with an adverse impact on both the erection and ejaculation components of the sexual response.

A study, in the British Journal of Urology, has used the database of the Prostate Cancer Educational Council in the US to perform a linear regression analysis of almost 8,000 men who had completed a prostate symptom score and the Sexual Health Inventory for Men (SHIM). It found that uroselective alpha-blockers preserve sexual function in men with LUTS.

Patients were divided into three groups: those taking tamsulosin (234 patients), those on other alpha-blockers or 5a-reductase inhibitors (291 patients), and those on no medication for LUTS (7,449 patients).

In the second and third groups, as symptoms increased on the symptom score, SHIM scores deteriorated, indicating the negative effect on sexual function of worsening symptoms.

However, men on tamsulosin had significantly better SHIM scores with increasing symptom scores compared with those on other or no medication for LUTS, suggesting that sexual function was relatively preserved.

These findings need to be taken in context. It is well known that tamsulosin has a significant correlation with ejaculatory dysfunction, but there is some suggestion that this has less impact on patients' sexual 'wellbeing' than erectile dysfunction. Alfuzosin has traditionally been thought of as having less effect on sexual function than tamsulosin, but this drug was not analysed separately in this study.

The main message for GPs would appear to be that while old unselective alpha-blockers and 5a-reductase inhibitors may have a deleterious impact on sexual function, the newer 'uroselective' alpha blockers have less effect on patients' sexual health. There is even a suggestion that these drugs may improve sexual function in men with LUTS, but randomised controlled trials would be required to test this hypothesis.

Barqawi AB, Myers JB, O'Donnell C et al. The effect of a-blocker and 5a-reductase inhibitor intake on sexual health in men with lower urinary tract symptoms. BJU Int 2007;100:853-57