Benign Prostatic Hyperplasia

Aetiology:

Dihydrotestosterone is responsible for the developement of BPH and it is produced through the conversion of testosterone by the enzyme 5 alpha-reductase type 2 in the stromal cells of the prostate.

Even though testosterone level declines with age, dihydrostestosterone level remains constant thoroughout the life.

Symptoms:

Compression of prostatic urethra causes lower urinary tract symptoms which includes -
Storage symptoms: Frequency, urgency, nocturia and urge incontinence.
Voiding symptoms: hesitency, poor flow, intermittency, straining, dysuria, incomplete emptying.

Symptoms Score: The International Prostate Symptom Score (IPSS) questionnaire is recommended.

Physical Examination:

Digital rectal examination (DRE) is important and can access the prostrate size:
Small - size of walnut, no protrusion into rectum
Medium - size of egg, Back of prostrate is protruding 1 - 2 cm into the rectum
Large - size of tangerine, more protrusion into the rectum
Extra-large - size of an orange, difficult to feel the entire posterior of the prostrate

Basic neurological examination
Perianal sensation and sphincter tone
Bladder palpation
Caliber of the urethral meatus

Investigations:

Urine analysis: midstream urine: microscopy, culture and
sensitivity (MC&S)

Prostate specific antigen (PSA) levels: can be used to differentiate with prostrate cancer

Renal function

USS - prostrate size, post void residual volume

Treatment:

Choices include - watchful waiting, medical therapy and surgery.

Watchful waiting: it includes education, life style modification ( reduction in alcohol, caffeine intake and fluid intake ) and behaviour training such as double voiding.

It is useful for patients with mild symptoms of LUTS secondary to BPH (IPSS score less than 8).

Medical therapy:

Alpha Blocker: include - doxazosin, terazosin, alfuzosin and tamsulosin.

It is effective at reducing lower urinary tract symptoms.

However, these medications do not shrink prostate volume or have any effect on PSA levels.

Tamsulosin and alfuzosin are more selective in relaxing prostatic smooth muscle and have no effect on blood pressure. For this reason tamsulosin and alfuzosin do not need to be titrated and can be started directly at therapeutic dosage.

5-Alpha Reductase Inhibitors: includes Dutasteride and Finasteride.

It has been shown to decrease prostate volume resulting in a decrease in the need for BPH surgery by 48% and acute urinary retention by 57% compared to placebo.

It also lead to a significant reduction in PSA levels. If a patient is experiencing an increase in PSA levels after the treatment nadir at 6-12 months after initiation of therapy of 5-alpha reductase inhibitor, adherence should be verified and if this has been confirmed they should be referred to an urologist to rule out prostate cancer.

Combination therapy: α-blocker with 5α-reductase-inhibitor
has been shown to be more beneficial and durable than the
monotherapy of either substance.

Some guidelines advise clinicians to give patients on combination therapy the option to discontinue the alpha blocker after 6-12 months. If symptoms recur, the alpha blocker should be restarted.

However, lifelong use of 5-alpha reductase inhibitors should be considered to prevent BPH progression.

Anticholinergic Agents ( tolterodine ):
Combination therapy with an alpha receptor antagonist and anticholinergic can be helpful for selected patients with bladder outlet obstruction due to BPH and concomitant detrusor overactivity.

Prior to initiation of anticholinergic therapy, baseline PVR urine should be assessed. Anticholinergics should be used with caution in patients with a post-void residual greater than 250 to 300 mL.

Surgery:
Transurethral resection of the prostate (TURP) for prostates 30–80ml
Transurethral incision of the prostate (TUIP) for prostates <30ml
and without middle lobe
Open prostatectomy or TURP for those >80ml
Laser ablation or resection of BPH available in specific surgical
centres.

Specialist referral:

The patient’s symptoms become more serious: their symptom
score moves into the ‘severely symptomatic’ category
The patient’s symptoms significantly interfere with their quality
of life – score of 5 ‘unhappy’ or 6 ‘terrible’ on the IPSS
After an episode of urinary retention, urinary infection, haematuria
No response to treatment
A risk of prostate cancer exists
Post void residual urine on ultrasound assessment more than 100ml

Follow up and Shared-Care:

It is recommended to do follow up every 12 - 18 months but when initiating or changing BPH therapy, consider evaluating the patient at least every 6 months.