Alpha-blockers may improve erectile dysfunction in men with LUTS

Denver-Studies in recent years have shown a strong correlation between lower urinary tract symptom severity and erectile dysfunction, but there have also been contradictory reports on the effect of BPH medications on sexual health.

Now researchers from two studies presented at the AUA annual meeting-a U.S. study using tamsulosin (Flomax) and a European study of alfuzosin (Uroxatral)-report an expected improvement in patients' lower urinary tract symptoms, but also improvement in sexual dysfunction in men taking the study medications.

Tamsulosin: Higher SHIM scores

Dr. Crawford said among those taking medications versus no medications, the percent of comorbidities was higher, age was higher, and the AUA-SS was slightly higher, but the SHIM score was also lower. (AUA-SS is scored 0 to 35, with a rise indicating increased symptom severity; SHIM is scored 0 to 20, with declining scores indicating less sexual activity.)

Linear regression analysis showed that patients taking no medication had a significant drop in SHIM score as the AUA symptom score increased.

"In men taking tamsulosin with the worst AUA symptom scores, they maintained a better SHIM score than men who were taking other alpha-blockers or 5-alpha-reductase inhibitors," Dr. Crawford said.

Among the three study arms, men taking tamsulosin (234 men) had a mean AUA-SS score of 13.0 and a mean SHIM score of 11.7; men on other prescription medications for BPH (291) had a mean AUA-SS score of 12.7 and a mean SHIM score of 12.0; and mean scores for men not on any BPH medication (7,494) were 6.9 and 15.6, respectively.

"Adjusting for age and AUA-SS, men on Flomax showed a significant increase in SHIM scores, with an increasing AUA-SS score when compared to men on other medications, offsetting the observed negative correlation between AUA-SS and SHIM," Dr. Crawford reported. "Moreover, the men on Flomax were more likely to have higher AUA-SS and lower SHIM scores when compared to controls and [to] men on other medications, suggesting more severe symptoms in this cohort of men."

The proposed mechanism of alpha-blockers on penile tissue is contractile response, mediated by the alpha-adrenergic receptors to increase sympathetic tone, according to Dr. Crawford.

"In BPH patients, alpha-1 selective androgen blockers may have a direct relaxation effect on the corpus cavernosa," he said.

In addition to aging, he continued, LUTS severity appears to exert an independent negative effect on overall sexual health in men treated with alpha-blockers and 5-alpha-reductase inhibitors. However, when compared with other BPH medications, tamsulosin appears to maintain higher SHIM scores in men with LUTS, particularly in men with severe LUTS.

"Men taking Flomax for the treatment of LUTS appear to have an advantage over other alpha-blockers when the effect of LUTS on sexual health is considered," Dr. Crawford said. "Further, this effect is more profound in patients with more severe LUTS compared to mild and moderate symptoms."