Medical Treatment of BPH
Medical therapy is where most BPH is managed, and choosing the right drug is a matter of matching the mechanism to the patient.
The big picture
Medical therapy is where most BPH is managed, and choosing the right drug is a matter of matching the mechanism to the patient: relax the smooth muscle for fast relief, shrink the gland if it's big, calm the bladder if storage symptoms dominate, and combine when you need to prevent progression. Each class has a signature benefit and a signature side effect — and knowing both is what lets you pick correctly and counsel honestly.
The framework: five drug classes (alpha-blockers, 5-ARIs, antimuscarinics, beta-3 agonists, PDE5 inhibitors, + desmopressin for nocturia), each by mechanism, dose, onset, and adverse effects — then a medication chooser that maps patient profile to drug.
Mechanism pathway
Tap any step to see why it happens.
Diagnostic algorithm
Each step answers one question. Tap to expand.
Drug selector
Alpha-blocker
Fast relief (first-line)- Targets
- Alpha-1 adrenoceptors on prostatic/bladder-neck smooth muscle (dynamic component)
- Onset
- Days–weeks
- Use when
- Predominant voiding symptoms, want fast relief — tamsulosin/alfuzosin/silodosin (prefer uroselective if on cardiovascular meds)
- Side effects
- Orthostatic hypotension/dizziness; retrograde ejaculation (silodosin ~28%); intraoperative floppy iris syndrome (tamsulosin)
Board traps
Alpha-blockers relieve symptoms fast but don't shrink the gland or stop progression.
Silodosin → ~28% retrograde ejaculation; tamsulosin → IFIS (flag cataract surgery).
Non-selective alpha-blockers (terazosin/doxazosin) lower BP → titrate from bedtime (first-dose hypotension).
5-ARIs work only in enlarged glands, take ≥6 months, halve PSA (double it).
Antimuscarinics: caution with high residual/retention risk.
Tadalafil for LUTS + ED — not with nitrates.
Desmopressin for nocturia → watch hyponatraemia.
Combination (alpha-blocker + 5-ARI) for moderate-severe + enlarged gland prevents progression/retention.