ethinyl estradiol/levonorgestrel

7.2 Increase in Plasma Levels of Estradiol Associated with Co-Administered Drugs Co-administration of atorvastatin and certain COCs containing ethinyl estradiol increase AUC values for ethinyl estradiol by approximately 20%.

Mechanism: This cholesterol medicine can increase the amount of estrogen from your birth control that stays in your body. It changes how your body processes the hormone.

What to do: Your doctor may need to adjust your treatment if you have side effects from the higher hormone levels.

7.2 Increase in Plasma Levels of Estradiol Associated with Co-Administered Drugs Co-administration of atorvastatin and certain COCs containing ethinyl estradiol increase AUC values for ethinyl estradiol by approximately 20%. Ascorbic acid and acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. 7.4 Changes in Plasma Levels of Co-Administered Drugs COCs containing some synthetic estrogens (e.g., ethinyl estradiol) may inhibit the metabolism of other compounds.

Mechanism: The estrogen in your birth control can slow down how your body processes other estrogen medicines. This can cause the hormone levels to build up in your system.

What to do: Your doctor should check if you need both medicines and may need to adjust your doses.

COCs have been shown to significantly decrease plasma concentrations of lamotrigine likely due to induction of lamotrigine glucuronidation. This may reduce seizure control; therefore, dosage adjustments of lamotrigine may be necessary.

Mechanism: Birth control pills can make your body get rid of this seizure medicine too quickly. This can lower the amount of medicine in your blood and might cause a seizure.

What to do: Your doctor may need to increase your dose of the seizure medicine.

John's wort topiramate HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors : Significant changes (increase or decrease) in the plasma levels of the estrogen and progestin have been noted in some cases of co-administration of HIV protease inhibitors or with non-nucleoside reverse transcriptase inhibitors.

Mechanism: This medicine can cause the levels of hormones in your birth control to either rise or fall. This might make the birth control less effective at preventing pregnancy.

What to do: You should talk to your doctor about using a backup method of birth control.

Ascorbic acid and acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation.

Mechanism: Acetaminophen stops the body from processing the estrogen in the birth control pill. This leads to higher levels of the hormone in your blood.

What to do: Your doctor may need to monitor you for side effects from higher hormone levels. No immediate change is usually needed for occasional use.