What therapies reduce an enlarged prostate (benign prostatic hyperplasia) in men over 50?

What Reduces Enlarged Prostate (BPH)

For men over 50 with an enlarged prostate, 5-alpha-reductase inhibitors (finasteride 5 mg daily or dutasteride 0.5 mg daily) are the only medications proven to physically shrink the prostate gland, reducing volume by approximately 20-30% over 6-12 months, while alpha-blockers provide symptom relief without reducing prostate size. 1, 2, 3

Medications That Actually Shrink the Prostate

5-Alpha-Reductase Inhibitors (5-ARIs)

• Finasteride 5 mg daily and dutasteride 0.5 mg daily are FDA-approved to physically reduce prostate volume by blocking the conversion of testosterone to dihydrotestosterone (DHT), the hormone driving prostate growth. 2, 3

• These agents reduce prostate volume, improve symptoms, reduce acute urinary retention risk by 57-79%, and decrease the need for BPH-related surgery by 48-67% over 2-4 years. 1, 2, 3

• Critical timing consideration: 5-ARIs require 3-6 months before noticeable symptom improvement and at least 6-12 months to achieve maximum prostate shrinkage—they should never be used for immediate symptom relief. 4, 1

• Prostate size matters: 5-ARIs are completely ineffective in men without documented prostatic enlargement (prostate volume <30-40cc, PSA <1.5 ng/mL, or no palpable enlargement on digital rectal exam). 4, 1

• Both finasteride and dutasteride have similar efficacy and safety profiles, with the most common side effects being sexual dysfunction (decreased libido, erectile dysfunction, reduced ejaculation volume). 4, 1

• PSA levels decrease by approximately 50% within 6 months of starting 5-ARI therapy; multiply the measured PSA by 2 to estimate the true value for cancer screening purposes. 4

Medications That Relieve Symptoms Without Shrinking the Prostate

Alpha-Blockers (First-Line for Symptom Relief)

• Alpha-blockers (tamsulosin 0.4 mg daily, alfuzosin, doxazosin, terazosin) provide rapid symptom relief within 2-4 weeks by relaxing prostatic smooth muscle and reducing the dynamic component of bladder outlet obstruction—but they do not reduce prostate size. 1, 5

• Alpha-blockers work regardless of prostate size and should be initiated immediately for symptomatic relief in all men with bothersome BPH symptoms. 1

• Tamsulosin requires no dose titration and has minimal cardiovascular effects, making it the preferred alpha-blocker for most patients. 1

Optimal Strategy: Combination Therapy for Enlarged Prostates

• For men with documented prostatic enlargement (>30-40cc) and bothersome symptoms, combination therapy with an alpha-blocker plus a 5-ARI is superior to monotherapy. 1, 2, 3

• Combination therapy reduces overall BPH progression risk by 67% (compared to 39% for alpha-blockers alone and 34% for 5-ARIs alone), reduces acute urinary retention risk by 79%, and reduces need for surgery by 67% over 4 years. 1

• The alpha-blocker provides immediate symptom relief while the 5-ARI works over months to shrink the prostate and prevent long-term disease progression. 1, 6

Non-Pharmacologic Approaches

• Watchful waiting is appropriate for men with mild-to-moderate symptoms that are not bothersome, particularly those with smaller prostates (<30cc) and lower PSA (<1.5 ng/mL), as many will have minimal symptom progression over time. 4

• Lifestyle modifications include fluid restriction before bedtime to reduce nocturia, limiting caffeine and alcohol intake, and dietary changes (reducing high-calorie bakery products, processed meats, sugar-sweetened beverages while increasing fiber through whole grains, fruits, and vegetables). 1

Surgical Options for Definitive Prostate Reduction

• Transurethral resection of the prostate (TURP) remains the gold standard surgical treatment, physically removing prostatic tissue and providing the most dramatic and immediate reduction in prostate size and obstruction. 5, 7

• Surgery is indicated for men with absolute indications (recurrent urinary retention, recurrent urinary tract infections, bladder stones, renal insufficiency from obstruction, or upper tract dilatation) or those with severe symptoms despite optimal medical therapy. 4, 1, 8

Critical Pitfalls to Avoid

• Never prescribe 5-ARIs without documented prostate enlargement—they expose patients to unnecessary sexual side effects without benefit in men with small prostates. 1

• Never use 5-ARIs as monotherapy for immediate symptom relief—they take 6-12 months to work and patients will remain symptomatic during this period. 1

• Never delay alpha-blocker therapy while waiting for 5-ARI effects—always start the alpha-blocker first or use combination therapy from the outset. 1

• Do not assume all "prostate medications" shrink the prostate—only 5-ARIs physically reduce prostate volume; alpha-blockers only relieve symptoms by relaxing smooth muscle. 1, 5

Monitoring and Follow-Up

• Reassess patients at 2-4 weeks after initiating alpha-blocker therapy to evaluate symptom response using the International Prostate Symptom Score (IPSS). 1, 8

• For patients on 5-ARIs, re-evaluate at 3-6 months with repeat IPSS to gauge symptomatic response, as maximal benefit requires at least 6 months of therapy. 4, 1

• Measure post-void residual volume if initially elevated to monitor for progression of obstruction. 1, 8