bazedoxifene/conjugated estrogens

7.3 Atorvastatin Concomitant administration of bazedoxifene (40 mg daily) and atorvastatin (20 mg, single-dose) to healthy postmenopausal women did not affect the pharmacokinetics of bazedoxifene, atorvastatin or its active metabolites.

Mechanism: Studies show that these two medicines do not significantly change how the body processes each drug.

What to do: No special dose changes are typically required when taking these two medications at the same time.

John's Wort (Hypericum perforatum) preparations, phenobarbital, carbamazepine, and rifampin, may reduce plasma concentrations of some estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile. The metabolism of bazedoxifene may be increased by concomitant use of substances known to induce UGTs, such as rifampin, phenobarbital, carbamazepine, and phenytoin.

Mechanism: Carbamazepine causes your body to break down estrogens and bazedoxifene faster than usual. This can lower the amount of medicine in your blood and make it less effective.

What to do: Your doctor may need to adjust your treatment or watch for signs that the medicine is not working, such as changes in uterine bleeding.

John's Wort (Hypericum perforatum) preparations, phenobarbital, carbamazepine, and rifampin, may reduce plasma concentrations of some estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile. The metabolism of bazedoxifene may be increased by concomitant use of substances known to induce UGTs, such as rifampin, phenobarbital, carbamazepine, and phenytoin.

Mechanism: Rifampin speeds up the removal of these medicines from your system, which can lead to lower drug levels in your body. This may cause the treatment to be less effective or lead to changes in bleeding patterns.

What to do: Your healthcare provider should monitor you for a decrease in the drug's effects and may need to adjust your dosage.

Concomitant administration of itraconazole, a strong CYP3A4 inhibitor, with DUAVEE, resulted in increases in bazedoxifene exposure (40%) and, to a lesser extent, conjugated estrogens exposure (9% for baseline-adjusted total estrone, 5% for total equilin), compared to DUAVEE alone [see Pharmacokinetics (12.3) ] .

Mechanism: Itraconazole blocks the enzyme your body uses to break down this medicine, which leads to higher levels of the drug in your system.

What to do: Your doctor may need to monitor you more closely for side effects while you are taking these two drugs together.

The metabolism of bazedoxifene may be increased by concomitant use of substances known to induce UGTs, such as rifampin, phenobarbital, carbamazepine, and phenytoin.

Mechanism: Phenytoin speeds up the process your body uses to clear bazedoxifene, which can make the medication less effective.

What to do: Your doctor may need to adjust your dose or check if the medication is still working as expected.