STEPTRACKERREPRODUCTIVE | PATHOLOGY + PHARMACOLOGY + ANATOMY | HIGH-YIELD REVIEW

Prostate — Benign

Benign prostatic hyperplasia, the drugs that relax or shrink it, and the forms of prostatitis.

FOCUS ON
BPH: DHT-driven hyperplasia of the transition (periurethral) zone → hesitancy, weak stream, nocturia, retention, UTIs, hydronephrosis; not premalignant. Drugs: α₁-blockers relax smooth muscle (fast; orthostasis); 5α-reductase inhibitors shrink gland (slow; ↓ PSA). Acute prostatitis: fever, tender boggy prostate — don't massage.
DISORDER · TOPIC
MECHANISM
FEATURES
CLUE · TREATMENT
Prostate zones
Anatomic regions with different diseases
Transition zone → BPH · peripheral zone (posterior) → carcinoma, palpable on DRE · central zone → few lesions
Know which zone does what
Benign prostatic hyperplasia
DHT (5α-reductase type 2 in stromal cells) + estrogen sensitization → stromal and glandular nodules
Older men: frequency, nocturia, urgency, hesitancy, weak stream, dribbling, incomplete emptying
Smooth, rubbery, symmetrically enlarged prostate · not precancerous
BPH — complications
Bladder outlet obstruction
Bladder wall hypertrophy (trabeculation), diverticula, stones, UTIs, acute retention, bilateral hydronephrosis → postrenal AKI
Retention after anticholinergics, decongestants, opioids
PSA in BPH
Larger gland makes more PSA
Mild ↑ PSA; higher free PSA fraction than cancer
5α-reductase inhibitors halve PSA
α₁-blockers
Relax prostatic and bladder neck smooth muscle (α₁A)
Tamsulosin (α₁A-selective), terazosin, doxazosin, prazosin; work in days
Orthostatic hypotension, dizziness · floppy iris (cataract surgery)
5α-reductase inhibitors
Block testosterone → DHT
Finasteride, dutasteride; shrink gland over months; also treat male-pattern baldness
↓ libido, ED, gynecomastia · ↓ PSA ~50%
Other BPH treatment
Smooth-muscle relaxation; tissue removal
Tadalafil (PDE5 inhibitor); TURP for refractory disease or complications
TURP → retrograde ejaculation
Acute bacterial prostatitis
Ascending infection: E coli (older men), N gonorrhoeae/C trachomatis (young men)
Fever, chills, dysuria, perineal/low back pain; tender, boggy prostate
No vigorous massage (bacteremia) · fluoroquinolone or TMP-SMX
Chronic bacterial prostatitis
Persistent focus in the prostate
Recurrent UTIs with the same organism; few symptoms between episodes
Culture of prostatic secretions · long antibiotic course
Chronic pelvic pain syndrome
Nonbacterial; most common chronic form
Pelvic/perineal pain, voiding symptoms, painful ejaculation; cultures negative
Diagnosis of exclusion
Granulomatous prostatitis
Intravesical BCG for bladder cancer, TB, after biopsy
Hard nodular prostate mimicking carcinoma
Biopsy shows granulomas

Mechanism — BPH and its two drug targets

Testosterone
→
5α-reductaseStromal cells
→
DHTGrowth factors
→
Static componentBigger gland → finasteride
Sympathetic tone
→
α₁A receptorsProstate smooth muscle
→
Dynamic componentTight urethra → tamsulosin

Combination therapy treats both: relax now (α-blocker), shrink over months (5α-reductase inhibitor).

BPH vs prostate cancer

FEATURE
BPH
CARCINOMA
Zone
Transition (periurethral)
Peripheral (posterior)
Symptoms
Early obstruction
Late, often none
DRE
Smooth, rubbery, symmetric
Hard, irregular nodule
PSA
Mild ↑, ↑ free fraction
↑, ↓ free fraction
Premalignant
No
From high-grade PIN

How it's tested

COMMON CONFUSIONFinasteride lowers PSA by about half. A rising PSA in a man on finasteride is more worrying than the number suggests — double it before interpreting.
THE TRAPAn older man with BPH who can't void after starting a cold medicine or an anticholinergic has acute urinary retention — catheterize, then remove the drug.
YOUR APPROACHSymptoms (storage vs voiding) → DRE (smooth vs nodular) → PSA → complications (retention, hydronephrosis, UTI) → drug choice by mechanism.

If you see… think…

70-year-old with nocturia, weak stream, smooth enlarged prostate → BPH
Zone where BPH arises → transition (periurethral) zone
BPH patient can't urinate after taking diphenhydramine → acute urinary retention
BPH with rising creatinine and bilateral hydronephrosis → postrenal AKI
Quick symptom relief for BPH → tamsulosin (α₁A-blocker)
Dizziness on standing after starting terazosin → α₁-blockade orthostasis
Drug that shrinks the prostate and halves PSA → finasteride
Fever, perineal pain, exquisitely tender boggy prostate → acute bacterial prostatitis
Recurrent E coli UTIs in a man → chronic bacterial prostatitis
Hard nodular prostate after intravesical BCG → granulomatous prostatitis