Who typically prescribes finasteride (a 5-alpha-reductase inhibitor) for adult males with benign prostatic hyperplasia (BPH) or androgenetic alopecia?

Who Prescribes Finasteride

Finasteride is prescribed by urologists, primary care physicians, and dermatologists, depending on the indication—urologists and primary care physicians primarily prescribe it for benign prostatic hyperplasia (BPH), while dermatologists prescribe the lower dose for androgenetic alopecia. 1

Prescribing by Indication

For Benign Prostatic Hyperplasia (BPH)

Urologists and primary care physicians are the primary prescribers for BPH treatment. The FDA-approved indication is for symptomatic BPH in men with an enlarged prostate to improve symptoms, reduce the risk of acute urinary retention, and reduce the need for surgery 1.

• The AUA guidelines establish that finasteride (5 mg daily) is appropriate for men with LUTS secondary to BPH who have demonstrable prostatic enlargement 2
• Finasteride is not appropriate for men with LUTS who do not have evidence of prostatic enlargement 2
• The clinical trials establishing efficacy enrolled men through urology and primary care settings, with mean ages ranging from 62-77 years 2
• Combination therapy with alpha-blockers (prescribed by the same specialties) is indicated to reduce risk of symptomatic BPH progression 1

For Androgenetic Alopecia

Dermatologists are the primary prescribers for male pattern hair loss. Finasteride 1 mg daily was FDA-approved in 1997 specifically for this indication after initial approval at 5 mg for BPH in 1992 3, 4.

• The lower 1 mg dose is optimal for hair loss treatment, demonstrating efficacy in preventing further hair loss in 91% of patients and producing visible hair growth in up to 66% of men with mild to moderate alopecia 5
• Dermatologists may be deterred from prescribing due to concerns about sexual dysfunction, though large placebo-controlled studies show no clear evidence of negative effects on erectile function beyond what occurs in the general population 6

Prescribing Considerations Across Specialties

Patient Selection Criteria

The prescribing physician must confirm prostatic enlargement before initiating finasteride for BPH. 2

• For BPH: Men should have symptomatic LUTS with prostate volume typically >40 mL or elevated PSA, as the absolute benefit increases with rising prostate volume 2, 7
• For alopecia: Early prescription is indicated before significant hair loss occurs, as finasteride's preservative effect is most valuable when scalp coverage remains 5

Age-Related Prescribing

Finasteride can be prescribed across a wide age range, with clinical trial data supporting use in men up to age 89 years. 7

• Studies included men with mean ages of 62-77 years for BPH, demonstrating maintained efficacy in elderly populations 2, 7
• No dosage adjustments are necessary for elderly patients despite higher terminal elimination half-lives 8
• Life expectancy considerations should focus on symptom control and quality of life rather than long-term disease progression prevention in advanced age 7

Monitoring Requirements

The prescribing physician must counsel patients about PSA interpretation while on finasteride. 8

• Finasteride reduces serum PSA levels by approximately 50%, requiring adjustment of the baseline for prostate cancer screening 8
• Regular monitoring with symptom scores and assessment for adverse effects is required, particularly sexual dysfunction (decreased libido, erectile dysfunction, reduced ejaculate volume) 1

Contraindications and Cautions

Finasteride is contraindicated in women and children, and prescribers must discuss the increased risk of high-grade prostate cancer. 1

• The PCPT trial showed higher incidence of Gleason score 8-10 prostate cancer in finasteride-treated men (1.8%) versus placebo (1.1%) 1
• Men with PSA ≤3.0 who are regularly screened should have a discussion about this risk before initiating therapy for any indication 2
• Sexual adverse effects (decreased libido 6.4%, impotence 8.1% in year 1) should be discussed, though these decrease with continued therapy 1