Table 1.

Adverse reactions to 1 mg oral finasteride

Common (frequency between≥1/100 and 1/10)

Sexual dysfunction (finasteride 3.8% vs. 2.1% within first 12 months of treatment, 1% of men withdrew finasteride because of sexual dysfunction within first 12 months of treatment, thereafter frequency decreased to 0.6% during following 4 years of treatment)

Diminished libido (finasteride 1.8% vs. placebo 1.3%)

Erectile dysfunction (finasteride 1, 3% vs. placebo 0, 7%)

Occasional (frequency between (≥1/1000 and<1/100)

Abnormal ejaculation

Decreased ejaculatory volume

Rare (frequency between ≥1/10,000 and <1/1000)

Testicular pain

Breast tenderness

Gynecomastia (may persist for months to years after cessation of finasteride treatment)

Allergic reactions: Rash, itching, hives, swelling of the mouth, face, lips, or tongue (angiedema)

Very rare (frequency between (<1/10,000)

Depression

Male breast cancer

Unknown (frequency cannot be estimated from existing data)

Persistent diminished libido or erectile dysfunction (after cessation of finasteride treatment)

Male infertility (usually in association with preexistent subfertility)

Decrease in quality of semen (there are reports on normalization or improvement of semen quality following withdrawal of drug)

PFS

Cause-relationship unresolved

High Gleason grade tumor (7-10) in the event of prostate carcinoma in men >55 years treated with 5 mg oral finasteride daily for benign prostatic hyperplasia (finasteride 6.4% vs. placebo 5.1%)

PFS: Postfinasteride syndrome