Drospirenon + etynyloestradiol i Topiramat: interakcja

Contraceptives: decreased contraceptive efficacy and increased breakthrough bleeding, especially at doses greater than 200 mg per day ( 7.4 )

Contraceptives The possibility of decreased contraceptive efficacy and increased breakthrough bleeding may occur in patients taking contraceptive products with topiramate extended-release.

Patients taking estrogen-containing or progestin-only contraceptives should be asked to report any change in their bleeding patterns.

Contraceptive efficacy can be decreased even in the absence of breakthrough bleeding [see Clinical Pharmacology (12.3) ] .

Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampin, topiramate and products containing St.

Counsel patients to use a back-up or alternative method of contraception when enzyme inducers are used with COCs.

Counsel women to use an alternative method of contraception or a back-up method when enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer to ensure contraceptive reliability.

In vitro , EE is a reversible inhibitor of CYP2C19, CYP1A1 and CYP1A2 as well as a mechanism-based inhibitor of CYP3A4/5, CYP2C8, and CYP2J2.

These results demonstrate that DRSP did not inhibit CYP2C19 and CYP3A4 in vivo .