Interação entre Norelgestromina + etinilestradiol e Fentermina + topiramato

Oral Contraceptives Clinical Impact Co-administration of multiple-dose phentermine and topiramate extended-release capsules 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component), in obese otherwise healthy volunteers, decreased the exposure of ethinyl…

Although this interaction is not anticipated to increase the risk of pregnancy, irregular bleeding (spotting) may occur more frequently due to both the increased exposure to the progestin and lower exposure to the estrogen, which tends to stabilize the endometrium.

Oral Contraceptives : Altered exposure of progestin and estrogen may cause irregular bleeding, but not increased risk of pregnancy.

Intervention Inform patients not to discontinue their combination oral contraceptive if spotting occurs, but to notify their health care provider if the spotting is troubling to them.

Advise patients not to discontinue oral contraceptives if spotting occurs ( 7 ).

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

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

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