Tegretol and Toremifene

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

CarBAMazepine may significantly reduce the blood levels of toremifene, which may make the medication less effective in treating your cancer. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

GENERALLY AVOID: Coadministration with potent inducers of CYP450 3A4 may significantly decrease the plasma concentrations of toremifene. According to the product labeling, toremifene is primarily metabolized by CYP450 3A4 to N-demethyltoremifene, an antiestrogenic metabolite with weak in vivo antitumor potency but whose serum concentrations are 2 to 4 times higher than those of toremifene at steady state. When a single 120 mg oral dose of toremifene was administered to 9 healthy volunteers following treatment with the potent CYP450 3A4 inducer rifampin at a dosage of 600 mg once daily for 5 days, toremifene peak plasma concentration (Cmax), systemic exposure (AUC) and elimination half-life decreased by 55%, 87% and 44%, respectively, compared to pretreatment with placebo. In addition, rifampin decreased the AUC of N-demethyltoremifene by 80% and increased its Cmax by 48%, suggesting enhanced presystemic metabolism of toremifene in the intestine. Loss of therapeutic efficacy of toremifene may occur.

MANAGEMENT: Concomitant use of toremifene with potent CYP450 3A4 inducers should generally be avoided. Alternative therapeutic agents with less enzyme induction potential should be considered whenever possible during treatment with toremifene. If coadministration is required, a doubling of the toremifene dosage may be necessary depending on patient tolerability. Close monitoring for toxicities (e.g., QT prolongation, hepatotoxicity, hypercalcemia and tumor flare) is recommended if the dosage of toremifene is increased. The dosage should be reduced to the indicated dosage following discontinuation of the potent CYP450 3A4 inducer.

Tegretol

Generic Name: carbamazepine

Brand name: Carbatrol, Epitol, Equetro, Tegretol, Tegretol XR, Tegretol, Tegretol XR

Synonyms: n.a.

What is Tegretol?

Toremifene

Generic Name: toremifene

Brand name: Fareston

Synonyms: n.a.

What is Toremifene?