Benign Prostatic Hyperplasia Overview

Benign Prostatic Hyperplasia (BPH)

• BPH is a common condition affecting men over 50, marked by non-cancerous prostate enlargement.
• This enlargement surrounds the urethra, the tube carrying urine out of the body, and often causes urinary flow difficulties.
• The prostate has glandular and fibromuscular parts, and different zones may cause different conditions.
• Benign hypertrophic changes frequently happen in the inner zone, while malignancies often originate in the peripheral zone.
• Hormonal activity, particularly the conversion of testosterone to dihydrotestosterone (DHT), plays a crucial role in stimulating prostate growth and enlargement.
• DHT is five times stronger than testosterone, thus is predominantly responsible for growth factor influence on cell division leading to BPH.
• Enlargement compresses the urethra, leading to bladder outflow obstruction (BOO) and lower urinary tract symptoms (LUTSs).

Pathophysiology

• The prostate surrounds the urethra at the base of the bladder, comparable in size to a walnut.
• The inner zone of the prostate is encapsulated by an outer layer.
• Most malignant changes originate in the peripheral zone.
• Prostatic hypertrophy is directly linked to aging and hormonal activity.

Symptoms

• BPH does not necessarily cause symptoms in all men who have it.
• Symptoms, when present, can range from mild to severe, impacting quality of life.
• Lower urinary tract symptoms (LUTSs), often stem from bladder obstruction, and include types of storage and voiding issues.
• Irritative symptoms include frequency, nocturia (frequent urination during the night), and urgency, incontinence.
• Obstructive symptoms involve: difficulty initiating urination (hesitancy), poor urinary flow, post-micturition dribble, sensation of incomplete bladder emptying, and occasionally acute retention (requiring treatment).
• Other causes of LUTSs can be bladder cancer, kidney stones, urinary tract infections (UTIs), or urethral strictures.

Treatment

• Treatment options range from medical therapy to surgery, based on individual symptom severity and the presence of complications.
• Medical therapies include alpha-adrenoceptor blocking drugs (e.g., prazosin, terazosin, doxazosin, alfuzosin), 5α-reductase inhibitors (e.g., finasteride, dutasteride), or a combination of both.
• Surgical interventions are considered for men with BPH experiencing complications like acute urinary retention, renal impairment, hematuria (blood in the urine), or frequent UTIs.
• Alpha-adrenoceptor blocking drugs are useful for managing BPH symptoms but offer no benefit toward preventing complications and progression to surgery.
• 5-alpha reductase inhibitors reduce the prostate size, improve urinary flow, and are more often suited for patients with large prostates.

Alpha-Adrenoceptor Blocking Drugs

• These drugs typically reduce bladder outlet obstruction and may improve symptoms in men with BPH.
• Alpha-1A adrenoceptors are the primary target in the prostate and typically mediate smooth muscle contraction.
• However, subtypes alpha-1B and alpha-1D receptors have also been identified within the prostate.
• While efficacy data suggests alpha-1A is the dominant receptor, further clinical confirmation is still necessary.
• Various drugs like prazosin, terazosin, doxazosin, and alfuzosin are available.

5α-Reductase Inhibitors

• Finasteride and dutasteride effectively block the conversion of testosterone to DHT, a factor key in BPH development.
• They reduce prostate volume and improve urinary flow.
• Effectiveness is primarily assessed by the impact on prostate volume and flow, particularly in men with prostate size larger than 40ml.
• Side effects, though infrequent, should be considered, including decreased libido, impotence, and, less often, gynecomastia (breast growth) and breast tenderness.

Combination Therapy

• Combining alpha-adrenoceptor blockers and 5α-reductase inhibitors might offer additional benefits over using either treatment alone.
• This approach is often used to manage complications and progression toward BPH-related surgery.
• Despite the reduction of acute urinary retention and BPH-related surgery, combination therapy may not lead to a significantly better outcome compared to dutasteride in terms of symptom management.

Surgical Treatments

• Surgical procedures are typically reserved for patients with BPH in the event that medical therapies cannot effectively manage symptoms.
• Surgery is often undertaken for persistent acute retention or other associated complications like recurrent urinary infections, renal impairment, persistent hematuria, or bladder stones.