Drug Interactions

Changes in contraceptive effectiveness associated with coadministration of other products

Drugs or herbal products that induce enzymes, including CYP3A4, that metabolize progestins may decrease the plasma concentrations of progestins, and may decrease the effectiveness of NEXPLANON. In women on long-term treatment with hepatic enzyme inducing drugs, it is recommended to remove the implant and to advise a contraceptive method that is unaffected by the interacting drug.

Some of these drugs or herbal products that induce enzymes, including CYP3A4, include:

• barbiturates

• bosentan

• carbamazepine

• felbamate

• griseofulvin

• oxcarbazepine

• phenytoin

• rifampin

• St. John’s wort

• topiramate

HIV Antiretrovirals

Significant changes (increase or decrease) in the plasma levels of progestin have been noted in some cases of co-administration with HOV protease inhibitors or with non-nucleoside reverse transcriptase inhibitors. Consult the labeling of all concurrently-used drugs to obtain further information about interactions with hormonal contraceptives or the potential for enzyme alterations.

Increase in plasma concentrations of etonogestrel associated with coadministered drugs

CPY3A4 inhibitors such as itraconazole or ketoconazole may increase plasma concentrations of etonogestrel.

Changes in plasma concentration of coadministered drugs

Hormonal contraceptives may affect the metabolism of other drugs. Consequently, plasma concentrations may either increase (for example, cyclosporin) or decrease (for example, lamotrigine). Consult the labeling of all concurrently-used drugs to obtain further information about interactions with hormonal contraceptives or the potential for enzyme alterations.