Читать книгу Saving Your Sex Life: A Guide for Men With Prostate Cancer - John P. Mulhall - Страница 17

Most patients who have BPH and LUTS are encouraged to limit their caffeine intakes as well as their alcohol intakes. Alcohol is a diuretic, and caffeine is a well recognized bladder-irritant. The first line treatment for BPH/LUTS is medication. There are two classes of drugs that are used for the treatment of BPH; the first is known as alpha-blockers (also known as alpha-adrenergic antagonists), and the second is known as 5–alpha reductase inhibitors. Alpha-blockers (Table 2) are drugs that have been around for many decades, but in their most current form are very effective treatments for BPH and LUTS. Drugs in this class include doxazosin (Cardura), terazosin (Hytrin), tamsulosin (Flomax) and alfuzosin (Uroxatral). These medications have a dual action in that they can reduce LUTS as well as treat a man’s blood pressure.The newer prostate drugs,such as Flomax and Uroxatal,have very little effect on blood pressure and are more specific to the prostate. The belief is that these medications work through reducing muscle tone in the prostate, bladder neck, and urethra. Interestingly, there are many men who have relatively small prostate glands who have tremendous symptoms, and it is proposed that this is not a mechanical obstruction in the sense that the prostate is not large enough to compress the urethra; however, the muscle tone inside the prostate is very high. These are patients who are generally highly sensitive to alpha-blocker therapy.

Another difference between the older (Hytrin, Cardura) and newer alpha-blockers (Flomax, Uroxatral) is that the older ones needed titration, that is, a tweaking of the dose in a sequential fashion to find the correct dose. This is not true for Flomax or Uroxatal. Approximately 60% of men with LUTS will have significant improvement in their symptoms with the use of alpha-blockers. These drugs typically act rapidly (in contrast to 5–alpha reductase inhibitors), but are associated with some side effects. These side effects include lethargy, nasal congestion and, with the older agents, blood pressure drop when the patient moves from a lying or sitting to a standing position (known as postural hypotension).

Another side effect that is worth noting is that they can cause retrograde ejaculation. As I mentioned in Chapter 1, semen is deposited through the ejaculatory ducts and prostate ducts into the urethra as it runs through the prostate. At the same time, the bladder neck closes and the external sphincter below the prostate closes also. This causes the development of a high-pressure zone within the prostate. The external sphincter then opens and the semen is propelled out of the urethra through the penis by rhythmic contractions of the muscles surrounding the urethra. However, in men who have a bladder neck that does not close properly, such as those men who are on alpha blockers, there is a propensity for the semen to travel in a retrograde fashion back into the bladder rather than out through the urethra. This is not a dangerous situation, but it does result in the presence of a dry orgasm, which is alarming for some men.

5–alpha reductase inhibitors (Table 2) are a fairly new drug class available to physicians. They were first introduced to the US in 1996. There are two drugs that are currently available in the United States: finasteride (Proscar) and dutasteride (Avodart). These work in an entirely different fashion to alpha-blockers.They actually shrink the prostate by blocking the production of 5–alpha reductase. Remember that 5–alpha reductase is that enzyme that degrades testosterone to DHT, the latter being the primary hormone that causes prostate growth. These agents can take between three to six months to effect any significant reduction in prostate size and usually, at best, men have a 30 to 50% reduction in their prostate size. It is also important to understand that 5–alpha reductase inhibitors will reduce the PSA level by approximately 50%, and therefore, it is critical that a man have his PSA level checked before starting one of these drugs. 5–alpha reductase inhibitors are also used for male pattern baldness. In fact, the first commercially available male baldness drug, Propecia, is low-dose finasteride.

Table 2 • Medications for LUTS

Alpha-Blocking Agents

Doxazosin (Cardura)

Terazosin (Hytrin)

Tamsulosin (Flomax)

Alfuzosin (Uroxatral)

5–Alpha Reductase Inhibitors

Finasteride (Proscar)

Dutasteride (Avodart)

Most urologists tend to reserve the use of 5–alpha reductase inhibitors as a first-line treatment for men with very large prostates. For men with small to medium prostates, alpha-blockers are typically first-line. However, there is recent evidence that the combination of both may, in fact, be even more effective than the single agent alone.

There is great interest in the concept that 5–alpha reductase inhibitors might prevent prostate cancer. There is a single trial which was conducted, known as the Prostate Cancer Prevention Trial (PCPT). This was published a few years ago and demonstrated that the regular use of finasteride reduced the incidence of prostate cancer, but when prostate cancer was present, the Gleason grade (the assessment of the aggressiveness of the tumor) was increased. There remains confusion regarding this data and at this point in time most authorities suggest that 5–alpha reductase inhibitors should not be used as a prostate cancer prevention strategy.

Table 3 • Surgical Options for BPH

Open

Suprapubic (simple) prostatectomy

Transurethral

Transurethral resection of the prostate (TURP)

Transurethral incision of the prostate (TUIP)

Minimally Invasive

Laser prostatectomy

Laser vaporization (TUVAP)

Transurethral microwave therapy (TUMT)

Transurethral needle aspiration (TUNA)

The side effects of 5–alpha reductase inhibitors are not very common. Approximately 5% of men will complain of loss of libido, and approximately 1% of men will have some problems with erectile function. It is not uncommon for men to note some change in the volume of ejaculate. While beyond the scope of this book, there is a lot of interest in the use of herbal supplements (phytotherapy) for the treatment of benign prostate enlargement, and there are some, in particular saw palmetto, which have been shown in controlled trials to result in some improvement in urinary symptoms in men with BPH/LUTS.