Sunday June 24, 2012
Problems of a large prostate
By Assoc Prof Dr CHRISTOPHER C.K. HO
Aside from urinary problems, benign prostate hyperplasia can also affect a man’s sex life.
BENIGN prostate hyperplasia (BPH) is a common condition seen in middle-aged and elderly men. It is an enlargement of the prostate gland, which — although not cancerous — may cause problems, as it may impede the flow of urine out of the bladder.
It may also cause bleeding during urination, and predispose to infection of the urine.
If urine is totally obstructed from passing out of the bladder, it will cause a build-up of pressure and urine in the bladder, which when severe, may cause back-pressure, as well as reflux of urine into the kidney. This will eventually cause renal failure.
BPH and sex
Aside from all the problems described above, BPH may also affect a man’s sexual life.
Multiple studies have shown that BPH and sexual dysfunction are inter-related.
Sexual dysfunction refers to sexual problems, such as erectile dysfunction (unable to maintain satisfactory erection of the penis for sexual intercourse), ejaculatory dysfunction (failure to expel semen), and low sexual desire.
BPH has been found to be a risk factor for erectile dysfunction, independent of age.
BPH has also been found to be a stronger predictor of sexual dysfunction compared to diabetes, heart disease or hypertension. In fact, erectile function has been shown to deteriorate in tandem with worsening symptoms of BPH.
How does BPH cause worsening of sexual function?
There are a few theories, which include the nitric oxide/cyclic guanosine monophosphate pathway, rhokinase, overactivity of the autonomic pathway, and pelvic organ atherosclerosis.
All these theories have one thing in common — failure of relaxation of the smooth muscle.
Relaxation of the smooth muscle in the erectile tissue of the penis is needed for engorgement of the penis with blood.
Similarly, relaxation of the smooth muscle in the prostate and bladder neck is needed for urine to pass out of the bladder through the penis.
When there is failure of relaxation of the smooth muscle in the penis, this leads to erection difficulties; while in the prostate and bladder neck, urination difficulties occur.
Treatment of BPH consists of medical, as well as surgical interventions.
So, does treating BPH improve the symptoms of BPH?
It depends on the medication given. There are basically two groups of medication for BPH, ie alpha blockers and the 5α reductase inhibitors.
Examples of alpha blockers include terazosin, doxazosin, alfuzosin, tamsulosin and silodosin.
There are only two types of 5α reductase inhibitor in the market, ie finasteride and dutasteride.
Alpha blockers have been shown to improve erectile function. Those with worse erectile function had better improvement with alpha blockers.
However, not all the alpha blocker drugs have similar effects on ejaculation. Alpha blockers that act more specifically on the prostate (uroselective), like silodosin, have been shown to have detrimental effects on ejaculation. There is no effect on sexual desire.
The 5α reductase inhibitors act by inhibiting the conversion of testosterone to dihydrotestosterone.
Dihydrotestosterone is the potent hormone that causes growth of the prostate. It is also commonly known as the male hormone responsible for male characteristics.
Therefore, it is no surprise that 5α reductase inhibitors are associated with a decrease in sexual desire and erectile dysfunction. It is also detrimental to ejaculatory function as well.
However, these sexual dysfunctions are seen mainly during the first year of treatment. The incidence of these problems decreases with longer duration of therapy.
Sometimes, both the alpha blockers and 5α reductase inhibitors are used in combination to treat BPH.
Although symptoms of BPH show better improvement with combination therapy, the incidence of sexual dysfunction increases as well. In fact, the incidence of sexual dysfunction is much worse compared to using either medication alone.
What about surgical treatment?
The gold standard for treatment of BPH is still transurethral resection of the prostate (TURP).
The evidence for sexual dysfunction after TURP is debatable. There are studies which show that it worsens sexual function, but conversely, there are also other studies that show otherwise.
However, what is consistent is the evidence that minimally-invasive treatment of BPH like transurethral microwave therapy (TUMT) and transurethral needle ablation (TUNA), is less detrimental to sexual function compared to TURP.
Unfortunately, the long-term success rate for treatment of BPH symptoms with these minimally-invasive therapies are not well established, and may be lower than TURP.
Restoring sexual ability
All is not lost if sexual dysfunction occurs as a result of BPH or its treatment.
If erectile dysfunction occurs, phosphodiestaerase-5 inhibitor medications like vardenafil, tadalafil and sildenafil, can be used.
However, there is a higher risk of postural hypotension (drop in blood pressure) when it is taken together with alpha blockers.
In this situation, the alpha blocker used should be a more uroselective drug (like tamsulosin), which has less complications of hypotension.
Other treatments include intracavernosal prostaglandin injections (injecting a medication known as prostaglandin into the penis), vacuum pump devices, as well as penile prostheses (implanting a medical device into the penis).
If ejaculation is a problem, the alpha blocker can be switched to one that has been proven to have less ejaculatory side effects (like alfuzosin).
There are also other modalities of treatment. However, all these problems are best managed by urologists.
BPH may cause sex-related problems. Similarly, its treatment may also cause sexual dysfunction.
There are treatments available to help alleviate these sexual problems. Consultation with a urologist would be the best step to take.
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This article is contributed by The Star Health & Ageing Panel, which comprises a group of panellists who are not just opinion leaders in their respective fields of medical expertise, but have wide experience in medical health education for the public. The members of the panel include: Datuk Prof Dr Tan Hui Meng, consultant urologist; Dr Yap Piang Kian, consultant endocrinologist; Datuk Dr Azhari Rosman, consultant cardiologist; A/Prof Dr Philip Poi, consultant geriatrician; Dr Hew Fen Lee, consultant endocrinologist; Prof Dr Low Wah Yun, psychologist; Datuk Dr Nor Ashikin Mokhtar, consultant obstetrician and gynaecologist; Dr Lee Moon Keen, consultant neurologist; Dr Ting Hoon Chin, consultant dermatologist; Prof Khoo Ee Ming, primary care physician; Dr Ng Soo Chin, consultant haematologist. For more information, e-mail firstname.lastname@example.org. The Star Health & Ageing Advisory Panel provides this information for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star Health & Ageing Advisory Panel disclaims any and all liability for injury or other damages that could result from use of the information obtained from this article.