The most common adverse reactions reported in subjects receiving Dutasteride were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), and ejaculation disorders. The most common adverse reactions reported in subjects receiving combination therapy (Dutasteride plus Tamsulosin) were impotence, decreased libido, breast disorders (including breast enlargement and tenderness), ejaculation disorders, and dizziness. Ejaculation disorders occurred significantly more in subjects receiving combination therapy (11%) compared with those receiving Dutasteride (2%) or Tamsulosin (4%) as monotherapy.
The most common adverse reaction leading to trial withdrawal was impotence (1%).