| Interaction Color Code | Clinical Bottom Line | Clinical Effects | Drug 1 effect | Drug 2 dose | Drug 2 effect | Management | |
|---|---|---|---|---|---|---|---|
| Rilpivirine (IM) Ethinyl estradiol / Norethindrone acetate | Green: Administer standard doses | Administer standard doses | |||||
| Ritonavir Ethinyl estradiol / Norethindrone acetate 1084 | Red: Avoid combination | Do not coadminister: Reduced levels of ethinyl estradiol | Decreased oral contraceptive effectiveness |
50 mcg x 2 doses | Ethinyl estradiol Cmax decreased 32%; AUC decreased 41% |
Use alternative contraceptive method |
|
| Darunavir Ethinyl estradiol / Norethindrone acetate 959 | Red: Avoid combination | Do not coadminister: Reduced levels of ethinyl estradiol and norethindrone | Potential decreased ethinyl estradiol and norethindrone effects (e.g. contraceptive failure) |
No significant change |
35 mcg / 1.0 mg once daily | Ethinyl estradiol: Cmax decrease 32%, AUC decrease 44%, Cmin decrease 62%; Norethindrone: Cmax decrease 10%, AUC decrease 14%, Cmin decrease 30% |
Use alternative agents. If coadministering, back-up contraceptive methods are recommended. |
| Atazanavir Ethinyl estradiol / Norethindrone acetate 761 | Yellow: Adjust dosing | Adjust dosing to avoid increased levels of hormonal contraception | Increased norethindrone and ethinyl estradiol effects |
1 tab daily (7 / 7 / 7) | Norethindrone Cmax increased 67%, AUC increased 110%, Cmin increased 262%, Ethinyl estradiol AUC increased 48%, Cmax no significant change, Cmin increased 91% |
For unboosted atazanavir, use an oral contraceptive that contains no more than 30 mcg of ethinyl estradiol or recommend an alternative contraceptive method. Oral contraceptives containing less than 25mcg of ethinyl estradiol or progestins other than norethindrone or norgestimate have not been studied. |
|
| Rilpivirine Ethinyl estradiol / Norethindrone acetate 650 | Green: Administer standard doses | Administer standard doses | No significant change |
0.035 mg daily ethinyl estradiol with 1 mg norethindrone daily | Ethinyl estradiol Cmax increased 17%; Norethindrone: no significant change |
||
| Nevirapine Ethinyl estradiol / Norethindrone acetate 616 | Red: Avoid combination | Do not coadminister: Reduced levels of ethinyl estradiol and progesterone | Possible contraceptive failure |
Ethinyl estradiol 0.035 mg / Norethindrone 1 mg daily x 30 days | Ethinyl estradiol: AUC decreased 23%; half-life: decreased 44%; Norethindrone: AUC decreased 18%; half-life: decreased 15% |
Use alternative contraceptive method |
|
| Nevirapine Ethinyl estradiol / Norethindrone acetate 615 | Red: Avoid combination | Do not coadminister: Reduced levels of ethinyl estradiol and progesterone | Possible contraceptive failure |
Ethinyl estradiol 0.035 mg / Norethindrone 1 mg x 1 dose | Ethinyl estradiol AUC decreased 19%; Cmax no significant change. Norethindrone AUC decreased 18% |
Use alternative contraceptive method |
|
| Etravirine Ethinyl estradiol / Norethindrone acetate 530 | Green: Administer standard doses | Administer standard doses | 0.035 mg EE / 1 mg NE daily | Ethinyl estradiol AUC increased 22%; Cmax increased 33%; Norethindrone Cmin decreased 22% |
|||
| Efavirenz Ethinyl estradiol / Norethindrone acetate 461 | Red: Avoid combination | Do not coadminister: Reduced levels of progestin | No significant change |
Ethinyl estradiol 50 mcg x 1 dose | No significant change |
Use alternative contraceptive method |
|
| Fostemsavir Ethinyl estradiol / Norethindrone acetate 25 | Orange: Minimal data to guide interaction | Minimal data to guide interaction, weigh risks and benefits of using this combination | Increased ethinyl estradiol exposure and increased risk of thromboembolic events |
Not reported |
0.030 / 1.5mg once daily | EE: Cmax increased 39%, AUC increased 40%; NE: Cmax increased 8%, AUC increased 8% |
If co-adminstering, ethinyl estradiol daily dose should not exceed 30 mcg. Further caution advised if patient is at increased risk for thromboembolic events. |
