Diltiazem HCl Diltiazem Hydrochloride Tamsulosin Hydrochloride + Dutasteride
ModerateIn a population study of a small number of patients, those who were also taking diltiazem (or verapamil) had dutasteride blood levels about 1.6 to 1.8 times higher on average than other patients. Diltiazem is a moderate inhibitor of CYP3A4 and also blocks P-glycoprotein, which is probably why dutasteride builds up more.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.