Moderate CYP3A4 inhibitors increase
dutasteride levels by 60 to 80%, which, due to the wide safety margin of
dutasteride, is not thought to be clinically significant. However, potent CYP3A4 inhibitors, such as the
protease inhibitors, would be expected to have a larger effect, which may cause a clinically significant rise in
dutasteride levels.
The manufacturers suggest reducing the dosing frequency if increased
dutasteride adverse effects occur.