Comparison of Alpha-Blocker and Enzyme-Inhibitor Drugs

Type of Action

• Relaxes the smooth muscles around the urethra, bladder neck, and elsewhere in the prostate

Pros

• Provide quick relief within 1 or 2 weeks
• Satisfactory response in 70% to 80%; symptom score reduced by 25% to 35%; peak flow rates increased by 15% to 25%
• No adverse effect on erectile or urinary function
• Can be used with any size prostate
• Less expensive than finasteride

Cons

• Some (doxazosin and terazosin) need to be titrated (gradually build up dose to adjust to blood pressure lowering effect)
• Side effects:postural hypotension and dizziness (10%–20%, 5% with tamsulosin); fatigue (5%–10%, 3% with tamsulosin); headache (14%, doxazosin, 3% terazosin, <1% tamsulosin) Tamsulosin (Flomax) causes retrograde ejaculation (5%–8%) and nasal congestion (5%)
• Effects beyond 5 years uncertain
• Does not reduce prostate size

Best Candidates

• Men whose symptoms are the result of increased smooth muscle tone in the prostate (frequent urination, nighttime urination, feelings of urgency, and not completely emptying bladder)

Type of Action

• Blocks the conversion of testosterone to DHT, which stimulates the growth of the prostate

Pros

• Reduces size of prostate by about 25%
• Lowers DHT level by 70% to 80%
• Symptom score reduced by an average 30% to 40% in suitable candidates;peak flow rate increased by an average of 15% to 20%
• May reduce the need for prostate surgery and episodes of acute urinary retention
• No cardiovascular side effects (lowering BP or dizziness)

Cons

• Takes longer to produce results than alpha blockers -- up to 1 year for maximum results
• May cause erectile problems in about 8%, reduced sex drive in 6%, and reduced semen volume in 4%
• Not effective in men with smaller prostates

Best Candidates

• Men with obstructive symptoms due to enlarged prostate (weak, interrupted flow with difficulty starting, dribbling at end)