Lower urinary tract symptoms and sexual dysfunction: a common approach

Alpha(1)-adrenergic blockers (alpha(1)-blockers) are considered the most effective monotherapy for lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia. Phosphodiesterase type-5 (PDE-5) inhibitors are the first-line treatment for erectile dysfunction (ED). As LUTS and ED are strongly linked, co-prescription of both drug classes is likely to increase. Interaction studies have confirmed that tadalafil, a long-acting PDE-5 inhibitor, has only marginal effects on blood pressure when co-administered with the selective alpha(1)-blockers, alfuzosin or tamsulosin. alpha(1)-blockers show an incidence of ED similar to placebo; they may even have some benefit on sexual function in men with concomitant LUTS and sexual dysfunction, with the exception of tamsulosin which causes anejaculation. On the other hand, PDE-5 inhibitors have a beneficial effect on LUTS. These agents are likely to act via different mechanisms of action, providing the rationale for combining them to treat LUTS and ED. Indeed, alfuzosin and tadalafil show an additive relaxant effect on human detrusor muscle, human prostate tissue and human corpus cavernosum in vitro. A pilot study also suggests that daily intake of alfuzosin 10 mg and sildenafil 25 mg is well tolerated and may be more effective than monotherapy to improve LUTS and ED. Further research is warranted to establish the value of this combination therapy in LUTS and ED.