Finasteride harms and benefits compared to alpha-blockers

This study evaluated the benefits and harms of finasteride (Proscar). The effects of finasteride were compared to placebo (sham therapy with no medical effect) and other treatments for benign prostate hyperplasia (BPH).

Finasteride, a five-alpha reductase inhibitor (5ARI), reduces prostate size by blocking the effects of the hormone testosterone. Finasteride, is commonly used to treat urinary symptoms associated with BPH.

Other drug commonly used to treat urinary symptoms in BPH include alpha-blockers, such as doxazosin (Cardura) and terazosin (Hytrin).

Finasteride, compared to placebo, improved urinary symptoms (as reported by patient questioners). Improved urinary function scores persisted during long-term follow-up (more than one year). Finasteride lowered the risk of BPH progression and the need for surgical intervention in long-term follow-up.

Compared to other drugs, finasteride was less effective than alpha-blockers such as doxazosin or terazosin. Finasteride was equally effective compared to the alpha-blocker tamsulosin (Flowmax). Both doxazosin and terazosin were more likely than finasteride to improve urine flow and nocturia (waking up at night to urinate). However, men receiving finasteride were less likely to need surgery, compared to those receiving doxazosin. Finasteride and doxazosin combination improved both short and long-term results compared to finasteride alone.

The combination of finasteride and doxazosin, compared to doxazosin alone, appears to improve long-term urinary symptoms in men with medium (25 to 39 mL) or large prostates (40 mL or more).

Compared to other treatments (or placebo), men receiving finasteride had a greater chance of experiencing erectile dysfunction, decreased libido, and ejaculation disorders. However, compared to alpha-blockers (doxazosin, terazosin), finasteride was less likely to cause side-effects such as dizziness, weakness and low blood pressure.

Finasteride improves long-term urinary symptoms compared to placebo, but is less effective than doxazosin. Long-term combination therapy with alpha blockers (doxazosin, terazosin) improves symptoms better than finasteride therapy alone.