What is the role of finasteride or dutasteride in BPH management and what is a notable long-term side effect?

• A. They rapidly reduce prostate size within hours, with no sexual side effects.
• B. They reduce prostate size over months and may cause decreased libido, erectile dysfunction, and breast tenderness.
• C. They increase testosterone production.
• D. They cure BPH with no side effects.

Answer: (B)

Finasteride and dutasteride work by blocking the enzyme 5-alpha-reductase, which converts testosterone to dihydrotestosterone (DHT). DHT drives prostate growth, so lowering DHT gradually reduces prostate size over several months. This slower, long-term effect is why they’re used to shrink the gland and help with BPH symptoms over time rather than providing immediate relief. They may be used alone or with alpha-blockers to improve outcomes and can reduce the need for surgical intervention.

A well-known long-term side effect is hormonal changes that can affect sexual function and breast tissue. Patients may experience decreased libido, erectile dysfunction, and breast tenderness or gynecomastia. These reflect the hormonal shifts from reduced DHT and are the reason this class of medications is associated with sexual and breast-related side effects.