BPH and Erectile Dysfunction
Medically reviewed by Dr. J. Kellogg Parsons M.D
If you have been diagnosed with an enlarged prostate, you may be concerned that it will have an impact on your erectile function. At one time, the relationship between BPH and erectile dysfunction was believed to be based solely on age: as men get older, their chances of having BPH increases, and thus so does the risk of erectile dysfunction. Older men are also more likely to have other risk factors for erectile dysfunction, including high blood pressure, diabetes, and cardiovascular disease, or to have undergone a procedure for prostate cancer.
However, several studies have indicated that BPH and the lower urinary tract symptoms that accompany it are associated with an increased incidence of erectile dysfunction. There’s also evidence that many of the treatments for an enlarged prostate can contribute to erectile dysfunction as well. First let’s look at the effect of an enlarged prostate on the ability to get and maintain an erection.
Does An Enlarged Prostate Cause Erectile Dysfunction?
A number of studies have explored this question. One of the most important was the Male Cologne Survey, in which 4,489 men aged 30 to 80 were questioned about their sexual activities and related factors. The researchers discovered a high percentage of men who had lower urinary tract symptoms due to BPH also had erectile dysfunction: 38 percent among men ages 30 to 39; 43 percent in those 40 to 49; 72 percent in those 50 to 59; 79 percent among those 60 to 69; and 75 percent among those aged 70 to 80. The percentage of men without urinary symptoms who had erectile dysfunction was much lower in each age group.
More evidence of a link between BPH and lower urinary tract symptoms and erectile dysfunction come from two other large studies. One was conducted in 3,230 men in Europe, Russia, the Middle East, Latin America, and Asia. Investigators found that men with severe urinary symptoms were about twice as likely to experience erectile dysfunction.
In the Multinational Survey of the Aging Male (MSAM-7), a survey or more than 14,000 men ages 50 to 80 years, the high prevalence of BPH associated with lower urinary tract symptoms in aging men was confirmed. Most of the men surveyed had urinary tract symptoms ranging from mild to severe, with about one-third of them in the moderate-to-severe range. Approximately 60 percent of the men in the study also experienced erectile dysfunction, and the study’s authors also noted that ejaculatory problems were nearly as common as erection difficulties. Overall, the increased risk of erectile dysfunction among men who have BPH with associated lower urinary tract symptoms is twofold to 11-fold.
Scientists are still uncertain why BPH and its lower urinary tract symptoms are associated with erectile dysfunction. One idea concerns the sympathetic nervous system, which studies show is hyperactive in animals and men with BPH-associated urinary tract symptoms. Nerve fibers in the sympathetic nervous system transmit signals that have an impact on stress and stress-related symptoms. An increase in these signals may lead to overactivity in the sympathetic nervous system, which is associated with erectile problems.
Do Treatments for an Enlarged Prostate Cause Erectile Dysfunction?
The quick answer to this question is “yes, but not always.” BPH can be treated with either medications or a variety of medical procedures, including minimally invasive and invasive surgeries. Most of the members in each of these categories can contribute to or cause erectile dysfunction to some degree.
Which Medications for an Enlarged Prostate Cause Erectile Dysfunction?
The five categories of medications used for an enlarged prostate include alpha-blockers, 5-alpha reductase inhibitors, combination medication (Jalyn), anticholinergics, and the phosphodiesterase 5 inhibitor tadalafil. The latter drug, tadalafil, was originally developed to treat erectile dysfunction, therefore it’s one drug you can check off your list as a cause of impotence.
Here’s how the rest of the medications fare with erectile function:
Alpha-blockers. Alpha-blockers generally are not one of the causes of erectile dysfunction. In fact, some studies suggest use of alpha-blockers may actually improve erectile function. For example, in one small study, some of the men reported a 100 percent improvement in erectile dysfunction after taking the alpha-blocker Cardura for two years. In another study, 53 men with BPH took the alpha-blocker doxazosin for six weeks. Some men had erectile dysfunction and others did not. The men who had erectile dysfunction had improved urinary tract symptoms and erectile function, while the men who did not have erectile dysfunction experienced even better improvement in urinary symptoms.
However, at least one study has shown that use of tamsulosin (Flomax) may cause erectile dysfunction. In a 12-week study, 177 men who had benign prostatic hyperplasia with lower urinary tract symptoms were given tamsulosin. Although the incidence of erectile dysfunction was small, it was not negligible and was more apt to occur in men who had a smaller prostate and fewer lower urinary tract symptoms.
5-alpha reductase inhibitors. The two main drugs in this category are dutasteride (Avodart) and finasteride (Proscar). Men who take these drugs typically do not notice any improvement in BPH symptoms for several months, so the impact of side effects also occurs later. A literature review published in the Journal of Sexual Medicine explored the effect of 5-alpha reductase inhibitors on erectile dysfunction. The investigators reported that sexual side effects were found in 2.1 percent to 38 percent of clinical trials and that erectile dysfunction was the most common side effect. The authors attributed the development of erectile dysfunction to a decrease in nitric oxide activity related to a decline in dihydrotestosterone (DHT) levels.
On April 11, 2012, the Food and Drug Administration (FDA) announced that because research suggested use of finasteride was linked to various sexual side effects, manufacturers of finasteride 5 mg (Proscar) and finasteride 1 mg (Propecia, for hair loss) had to add warnings to their labels.
The new changes were in addition to another modification made in 2011, when makers of finasteride added a warning that the drug might cause erectile dysfunction after men stopped using it. The additional warnings include libido disorders, ejaculation disorders, and orgasms disorders after discontinuing Propecia; reduced libido after stopping Proscar; and male infertility and/or poor semen quality that improved after stopping either drug.
Subsequent to the FDA announcement, a study from George Washington University reported in July 2012 that finasteride caused sexual side effects, including erectile dysfunction, changes in genital sensation, and quality of ejaculate. In fact, in the study 96% of men who took finasteride still suffered sexual side effects as long as 14 months after they stopped taking the drug.
Combination medication. The only FDA-approved combination medication for an enlarged prostate is Jalyn, which is composed of the alpha-blocker tamsulosin and the 5-alpha reductase inhibitor dutasteride. One of the common side effects of Jalyn is erectile dysfunction.
Anticholinergics. Anticholinergics block the action of acetylcholine, a chemical that sends messages to the bladder that trigger contractions, which can make you want to urinate even when your bladder is not full. Thus anticholinergics can delay the urge to urinate. Use of anticholinergics increases the risk of erectile dysfunction, as reported by the Merck Manual and several other sources, including a study published in the International Journal of Impotence Research, although no statistics are provided.
Which Nonsurgical and Surgical Procedures Can Cause Erectile Dysfunction?
In addition to drugs, some other BPH treatments can impact erectile function. The risk of experiencing erectile dysfunction following one of the minimally invasive nonsurgical or surgical procedures for an enlarged prostate can vary considerably, so be sure to discuss this question with your healthcare provider if this side effect is of particular concern to you.
Generally, the minimally invasive surgical procedures are not associated with erectile dysfunction. They include transurethral microwave thermotherapy (TUMT), photoselective vaporization of the prostate (PVP), interstitial laser therapy, prostatic urethral lift, stent, and prostatic arterial embolization.
Three procedures do have some risk: Transurethral needle ablation (TUNA), high-intensity focused ultrasound (HIFU), and transurethral microwave thermotherapy (TUMT). For HIFU, the rate is 30 to 70 percent, which is associated with its use in prostate cancer patients. Information on erectile dysfunction when HIFU is used for an enlarged prostate is scarce but believed to be similar to that for prostate cancer.
In the latter case, the risk of erectile dysfunction appears to be related to the dose administered, with lower-energy TUMT procedures resulting in a lower incidence of erectile dysfunction compared with higher-energy procedures. One study found no change in erectile function after low-energy TUMT, while another reported an 18.2 percent rate of erectile dysfunction after a high-energy TUMT procedure.
Among the surgical procedures for BPH, the risk of erectile dysfunction is mixed:
- Transurethral resection of the prostate (TURP), 3 to 35 percent of men
- Transurethral incision of the prostate (TUIP), 4 to 25 percent of men (Fitzpatrick)
- Transurethral vaporization of the prostate (TVP), varying results
- Prostatectomy, varying results. Within one year of surgery, about 40 to 50 percent of men who had nerve-sparing prostatectomy should return to their pre-treatment erectile function, with that number increasing to 30 to 60 percent after two years