Currently, there are two classes of drugs that are used to treat BPH.
Alpha-adrenergic receptor blockers (Hytrin®, Cardura®, Flomax®)
Originally used to treat high blood pressure, Cardura and Hytrin relax smooth muscle around blood vessels and within the prostate and bladder. By doing so, they may help increase urinary flow and relieve symptoms of urinary frequency and nocturia. Use of all three drugs has been shown to significantly decrease AUA symptoms scores and increase urinary flow rates when compared to placebo (sugar-pill) treated control patients. They tend to work immediately. Side effects include orthostatic hypotension (fall in blood pressure upon standing, causing dizziness), fatigue, and headaches. To minimize these side effects, the dose of medication is gradually increased (e.g., for Hytin, the dose is increased from 1 mg/day to 2 mg/day up to 5 mg/day). The first dose is usually given at night to minimize side effects.
Flomax is an alpha-adrenergic receptor blocker that is more specific to the prostate and tends to have fewer side effects than Hytrin or Cardura, as it has less effect on blood vessels and blood pressure. Flomax has also been less effective in some studies than Cardura or Hytrin. An advantage of this medication is the ability to start off with the most effective dose (0.8 mg per day) rather than gradually increasing the dose to avoid side effects.
5-alpha reductase inhibitors (Proscar)
Finasteride (Proscar) blocks the conversion of testosterone to dihydrotestosterone, the major male sex hormone found within cells of the prostate. By doing so, it may help to actually shrink the size of the prostate and, in some people, decrease BPH symptoms and increase urinary flow rates. This benefit of finasteride over placebo in the treatment of BPH has been demonstrated in randomized, placebo-controlled trials. Approximately one-third to one-half of patients have clinically significant improvements, while modest benefits were seen in the study population. It must be used indefinitely to prevent recurrence of symptoms and may take as long as 6 months to achieve the maximum benefit. Finasteride may be best suited for men with relatively large prostates (those greater than 50 cubic centimeters in size, with normal prostate size being 25 cubic centimeters). Side effects include: impotence and decreased libido in 3% to 4% of patients and decreased volume of ejaculate in 2% to 3% of patients. These side effects resolve with cessation of the drug. Finasteride tends to lower by about 50% PSA (prostate specific antigen) levels produced by benign prostatic tissue. This is important to realize when screening for prostate cancer.
Use of herbal medications has come into vogue recently. These agents, collectively called phytotherapeutics agents, are derived from plants. The most popular one used in the treatment of BPH is Saw palmetto. Another agent, often used with Saw palmetto, is the herbal agent Pygeum. Mechanism of action is unclear but some postulate their action as being anti-inflammatory, therefore reducing prostate swelling. Other assertations include inhibition of hormones controlling the growth of prostate cells. It is currently believed that the effects of Saw palmetto seem to involve relief of some symptoms with no increase in urinary flow rates. However, only limited controlled studies have been performed to date on these agents.