Which class of medication optimizes urinary flow acutely in a patient with BPH?

• A. Alpha-1 blockers
• B. 5-alpha-reductase inhibitors
• C. Anticholinergics
• D. PDE5 inhibitors

Answer: (A)

Relaxation of prostatic and bladder neck smooth muscle to relieve obstruction is what rapidly improves urinary flow in BPH. Alpha-1 blockers do exactly that: they block alpha-1 adrenergic receptors in the prostate and bladder neck, leading to quick relaxation of the outlet tissues and a noticeable increase in urine flow within days. This fast, targeted relief is why they are best for acutely improving flow.

Medications that shrink the prostate (5-alpha-reductase inhibitors) take months to reduce size and improve flow, so they aren’t acute. Anticholinergics don’t address the obstruction and can worsen retention in BPH. PDE5 inhibitors can help with LUTS but don’t produce the same rapid, flow-focused improvement as alpha-1 blockers.