Pathophys:Usually lateral and median lobes around the urethra lead to obstructive sx by a ball valve effect
Common, 30% prevalence by physical exam at age 40-50 yr, 35% of all men eventually will have sx requiring meds or surgery (Prostate suppl 1996;6:67); 50% over age 70 yr, though only 25% have sx
Sx:
Irritative: frequency, urgency, nocturia, +/ urge incontinence
Obstructive: diminished stream/flow, hesitancy, postvoid dribbling, straining, incomplete emptying
Si:Enlarged prostate, median furrow filled in on rectal exam
Obstructive uropathy, chronic cystitis, bladder calculi; no incr risk of prostate cancer except that incurred by age (Ann IM 1997;126:480)
Lab:
Noninv:Bladder scan PVR if sx of incomplete emptying; peak urine flows: >20 cc/sec = WNL, 15-20 cc/sec = mild, 10-15 cc/sec = moderate, <10 cc/sec = severe (Nejm 1995;332:99)
Rx:
Medical: avoid caffeine, opiates, calcium channel blockers, alcohol, and OTC meds w antihistamines and ephedrine. Saw palmetto herbal rx no help (DBCTNejm 2006;354:557)
1st: -Blockers hs:
- Terazosin (Hytrin) (Nejm 1996;335:533, 586), start w 1 mg, go to 5-10 mg po qd; improves flow within 2 wk; adverse effects: runny nose, impaired ejaculation, dizziness, and postural hypotension (Med Let 1994;36:15); $62/mo
- Prazosin 1 mg po b-tid
- Doxazosin (Cardura) 2 mg qd start, incr up to 8 mg po qd; $35/mo
- Tamsulosin (Flomax) (Med Let 1997;39:96) 0.4-0.8 mg 1/2 h pc po qd; less hypotensive effect than others, cataract surgery cmplc even a year after last dose (Jama 2009;301:1991, 2044); $60-120/mo
- Alfuzosin (Uroxatral) (Med Let 2003;46:1) 10 mg po qd; less hypotension than doxazosin and terazosin and less ejaculatory dysfn than tamsulosin; $56/mo
2nd:
- Finasteride (Proscar) 5 mg po qd (Nejm 2003;349:2387, 2449); prevents conversion of testosterone to dihydrotestosterone; slow onset so may want to use w -blockers for 1st q1-2yr; may or may not (Nejm 1996;335:533, 586) be worth a 6-mo trial if moderate or worse sx and large gland; if works continue it since improvement continues over >4 yr; for prevention of acute retention or surgery, NNT-4 = 16 (Nejm 1998;338:612); cmplc: impotence and decreased libido in 6-8% vs half that in controls, better after 1 yr (men w these sx dropped out); lowers PSA and prostate Ca incidence but increases Gleason score? (Nejm 2003;349:213, 215, 297); $63/mo
- Dutasteride (Avodart) (Med Let 2002;44:110) 0.5 mg po qd; similar to finasteride
3rd:
- Nafarelin 400 µgm sc qd suppresses testosterone by blocking LH release; works but requires continuous use, and it medically castrates
Surgical
- TURP, required in 10%, if retention and/or severe sx; cmplc = 4% incontinence, 5% impotence at 1 yr (J. WennbergJama 1988;259:3010, 3018, 3027), but later VA study found incontinence and sexual dysfunction same in watchfully waiting pts as in operated pts and thus operation for pts w moderate sx may make sense although no harm in waiting (Nejm 1995;332:75); and unexplained 2.5× increased death rate after TURP compared to open, mostly MIs (J. WennbergNejm 1989;320:1120 vs 1142).
- Suprapubic prostatectomy for large glands >100 gm
- Laser prostatectomy
- TUNA (transurethral needle ablation), OP procedure, less effective than TURP
- Transurethral microwave thermotherapy much less effective than TUR (Med Let 1996;38:53)
- Stenting occasionally in high-risk pt