Combination of phosphodiesterase-5 inhibitors and alpha-blockers in patients with benign prostatic hyperplasia: treatments of lower urinary tract symptoms, erectile dysfunction, or both?
As the prevalence of both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) increases with age, physicians could be in the position to manage these two conditions simultaneously. Moreover, medical therapies for either one of these conditions can affect the other and this should be carefully considered when making treatment decisions. Pharmacotherapy for benign prostatic hyperplasia (BPH)/LUTS can cause side-effects affecting sexual function. Hence, 5alpha-reductase inhibitors such as finasteride and dutasteride are associated with a greater risk of ED, ejaculatory disorders (EjD) and decreased libido than is placebo. Among alpha1-adrenergic blockers, tamsulosin is associated with an increased risk of EjD. However, some alpha1-adrenergic blockers can also have a positive impact on erection. This is the case for alfuzosin, which has been shown to enhance erectile function in experimental models, probably by reducing the sympathetic tone and thus relaxing corpus cavernosum smooth muscle cells. Phosphodiesterase 5 (PDE-5) inhibitors are commonly used to treat ED. There is increasing evidence that they might also have a beneficial effect on LUTS, probably through the nitric-oxide pathway. Nitric oxide is an important mediator of the relaxation of isolated bladder and urethral smooth muscle, and could modulate prostatic smooth muscle tone. Alpha1-adrenergic blockers and PDE-5 inhibitors can therefore have a positive impact on both ED and LUTS. Although placebo-controlled studies are needed to confirm the impact of these drugs, alone or combined, on both ED and LUTS, this reinforces the need for a common approach to managing these two highly prevalent and bothersome conditions.
Carson
Culley C
CC
University of North Carolina, Chapel Hill, North Carolina, USA. carson@med.unc.edu
D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000187:drug effects; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D004358:Drug Therapy; D004359:Drug Therapy, Combination; D007172:Erectile Dysfunction / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D010727:Phosphoric Diester Hydrolases; D011470:Prostatic Hyperplasia / Q000150:complications / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D014555:Urination Disorders / Q000150:complications / Q000188:drug therapy*
D000317:Adrenergic alpha-Antagonists; D010726:Phosphodiesterase Inhibitors; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human