Nateran Drug Interactions

The drug is metabolised through cytochrome P450 (CYP) 3A4 and aldo-keto reductases and does not inhibit any of the no major CYP ISOENZYMES. The specific inhibition of CYP 3A4 by ketoconazole showed to significant effects on the pharmacokinetics of exemestane.
Although administration of rifampicin, a potent CYP3A4 inducer, significantly decreased Exemestane systemic exposure (C_max and AUC), the suppression of plasma estrogen levels (estrone sulfate) produced by exemestane was not influenced. Therefore, exemestane can be given concomitantly with inducers of CYP3A4 without dosage adjustment.
Exemestane should not be used cautiously with drugs that are metabolized via CYP3A4 and have a narrow therapeutic window. There is no clinical experience of the concomitant use of Exemestane with other anticancer drugs.
Exemestane should not be co-administered with oestrogen-containing medicines as these would negate its pharmacological action.
An interaction with rifampicin, a potent CYP450 inducer, the AUC was reduced C_max the co-administration of drugs, such as rifampicin, anticonvulsants (e.g. phenytoin and carbamazepine) and herbal preparation containing Hypericum perforatum/(St Johns Wort) known to induce CYP3A4, may reduce the efficacy of Nateran.