Chart — Med-Surg
BPH Medications Comparison Chart
Two drug classes treat BPH from opposite angles: alpha-blockers relax the muscle for fast relief, while 5-alpha-reductase inhibitors shrinkthe gland over months. The suffixes give them away — “-osin” relaxes, “-steride” shrinks.
Educational use only. Drug selection, combination therapy, and monitoring follow provider orders; PSA interpretation on a 5-ARI requires accounting for the medication’s effect. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Class Comparison
| Feature | Alpha-Blockers (“-osin”) | 5-Alpha-Reductase Inhibitors (“-steride”) |
|---|---|---|
| Examples | Tamsulosin, alfuzosin, doxazosin, terazosin ("-osin") | Finasteride, dutasteride ("-steride") |
| Mechanism | Relax smooth muscle in the prostate and bladder neck | Block conversion of testosterone to DHT, shrinking the gland |
| Onset | Fast — days to a couple of weeks | Slow — 3–6 months for full effect |
| Effect on gland size | None — relieves symptoms only | Actually shrinks the prostate (disease-modifying) |
| Effect on PSA | No significant change | Lowers PSA (roughly by half) — note this when interpreting screening |
| Key side effects | Orthostatic hypotension, dizziness (fall risk); intraoperative floppy iris syndrome (tell the eye surgeon); retrograde ejaculation | Decreased libido, erectile dysfunction; teratogenic — pregnant women must not handle the tablets |
| Best for | Quick symptom relief; smaller glands | Larger glands; long-term size reduction (often combined with an alpha-blocker) |
| Top teaching point | Take at bedtime, rise slowly; report dizziness | Takes months; don't let pregnant partners handle pills; expect lower PSA |
Exam Traps
- ✦"-osin" = alpha-blocker, fast relief, orthostatic hypotension (bedtime dosing, rise slowly).
- ✦"-steride" = shrinks the gland over months and LOWERS PSA — factor that into cancer screening.
- ✦Finasteride is teratogenic by skin contact — pregnant women must not handle the tablets.
- ✦Tamsulosin causes intraoperative floppy iris syndrome — patients must tell the cataract surgeon.
- ✦Combination therapy (both classes) is common for larger glands — fast relief now, size reduction later.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with Academy of Medical-Surgical Nurses (AMSN) · Current medical-surgical nursing standards. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →