New prostate treatments reflect expanding patient demographic as population ages

Key Points

The aging of the population means there are more men in their 50s and 60s experiencing benign prostatic hyperplasia (BPH) symptoms and seeking treatment. BPH affects approximately 37 million men over 50 and is the fourth most-commonly diagnosed disorder in this age group. The prostatic hyperplasticity that characterizes the disease is diagnosed in approximately half of men over 60 and in up to 90 percent of those reaching age 85.

With more evolved BPH medications already available and several in the pipeline, what does a pharmacist need to know, and what are the answers to the most frequent questions BPH patients are likely to ask?

Cost, side effects, and proper administration are the most frequently asked questions, according to Jack Rosenberg, PharmD, PhD, professor of pharmacy practice and pharmacology, Arnold and Marie Schwartz College of Pharmacy, Brooklyn, N.Y., and a Drug Topics editorial advisory board member.

The urethral compression caused by BPH leads to lower urinary tract symptoms (LUTS), which can be obstructive (causing hesitancy, weak urine stream, straining, prolonged voiding, intermittency, incomplete voiding, and incontinence) or irritative (causing nocturia, frequency, urgency, urge incontinence). Studies have shown that there is no well-defined correlation between the extent of prostate disease and the degree of symptoms, and that the incidence of serious BPH-related complications such as retention incontinence is low in untreated patients.

Therefore, current BPH treatment guidelines from the American Urological Association (AUA) advocate a "watchful waiting" approach for men with symptoms that do not alter their quality of life. For patients with moderate to severe BPH who are bothered by symptoms (AUA Symptom Score ≥ 8 on a scale of 0 to 35), treatment with medication, minimally invasive procedures, or surgery can be considered.

Treatment guidelines: monotherapy

According to the AUA treatment guidelines, treatment preferences can vary. BPH patients often opt for medical therapy because it is less costly and involves less risk than minimally invasive procedures or surgery. Alpha-adrenergic receptor antagonists and 5 alpha-reductase inhibitors can be used as monotherapy or in combination for BPH treatment.

"The most frequently asked question is whether they need to take these medications permanently," said Dr. Edward M. Messing, chair of the department of urology, University of Rochester Medical Center, Rochester, N.Y. "Assuming they are working, the answer for 5 alpha-reductase inhibitors is that they will be taken permanently unless the side effects are very unpleasant, or if they stop working. But the alpha blockers may be able to be stopped after a while if the prostate gets small enough."

Selective alpha-adrenergic receptor antagonists

The agents in this class approved to treat LUTS related to BPH include alfuzosin, doxazosin, tamsulosin, terazosin, and the newly approved silodosin, expected to be available in early 2009. Alpha blockers inhibit the alpha1-adrenergic-mediated contraction of prostatic smooth muscle, allowing muscles at the bladder neck to loosen and permit more complete voiding. Patients can expect an average 4- to 6-point improvement in AUA Symptom Score with these agents.

The most common side effects of these agents are orthostatic hypotension, dizziness, tiredness, retrograde ejaculation, and nasal congestion. Alfuzosin is associated with fewer ejaculatory problems, but it has been linked to a dose-dependent, mild QT-interval prolongation, which increases the risk of the condition known as torsade de pointes (an uncommon variant of ventricular tachycardia). Therefore, alfuzosin should not be administered to patients taking potent CYP3A4 inhibitors including ketoconazole, itraconazole, or ritonavir in order to minimize the risk of increased alfuzosin blood levels.