BPH

How does testosterone get metabolized to dihydrotestosterone?

by 5 alpha reductase

Drugs that worsen BPH:

centrally acting anticholinergics

drugs with anticholinergic effects

TCAs

caffeine

diuretics

SNRIs

testosterone products

What is used to diagnose BPH?

digital rectal exam (DRE)

prostate specific antigen (PSA)

Signs and symptoms of BPH:

hesitancy, intermittent urine flow, straining, or a wea stream urine

urinary urgency and leaking or dribbling

urinary frequency, especially nocturia

incomplete emptying of bladder

Treatment for mild BPH disease:

watchful waiting and yearly reassessments

1st line treatment for moderate to severe symptoms:

Alpha 1 blockers

MOA od alpha 1 blockers:

inhibit alpha 1 adrenergic receptors causing relaxation of the smooth muscle in the prostate and bladder neck.

this reduces bladder outlet obstruction and improves urinary flow

Non-selective alpha 1 blockers:

terazosin

doxazosin

Selective alpha 1 blockers:

tamsulosin

alfluzosin

silodosin

Doxazosin (Cardura): dosing

IR: start 1 mg at bedtime ; titrate slowly up to 4-8 mg at bedtime

Terazosin: dosing

start 1 mg at bedtime; titrate slowly to a max of 20 mg at bedtime

Tamsulosin: dosing

0.4 mg daily

Warnings for alpha 1 blockers:

orthostatic hypotension/syncope

intraoperative floppy iris syndrome can occur in cataract surgery

Side effects of alpha 1 blockers:

dizziness

fatigue

headache

abnormal ejaculation

How long will it take to see effects of alpha 1 blockers?

LUTs will be improved quickly but overall effects take 4-6 weeks

PSA does not change and prostate does not shrink

Which alpha 1 blocker causes retrograde ejaculation?

silodosin

MOA of 5-alpha reductase inhibitors:

blocks the conversion of testosterone to dihydrotestosterone

5-alpha reductase inhibitors:

finasteride (Proscar)

dutasteride (Avodart)

Contraindications to 5-alpha reductase inhibitors:

women of child bearing potential

pregnancy

children

Side effects of 5-alpha reductase inhibitors:

impotence

decreased libido

ejaculation disturbances

breast enlargement and tenderness

How does it take to see effects from 5-alpha reductase inhibitors?

treat for 6 months may be required for maximal efficacy

shrink prostate and decreases PSA levels

PDE-5 inhibitors used in BPH:

tadalafil