Antiretroviral Drug |
Effect on Drug Levels |
Dosing Recommendation/ Clinical Comment |
Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI) |
Efavirenz
(EFV)
|
Oral ethinyl estradiol/norgestimate:
No effect on ethinyl estradiol concentrations;
↓ active metabolites of norgestimate (levonorgestrel AUC ↓83%; norelgestromin AUC ↓64%)
|
A reliable method of barrier contraception must be used in addition to hormonal contraceptives. Efavirenz had no effect on ethinyl estradiol concentrations, but progestin levels (norelgestromin and levonorgestrel) were markedly decreased. No effect of ethinyl estradiol/norgestimate on efavirenz plasma concentrations was observed. |
Implant: ↓ etonogestrel |
A reliable method of barrier contraception must be used in addition to hormonal contraceptives. The interaction between etonogestrel and efavirenz has not been studied. Decreased exposure of etonogestrel may be expected. In postmarketing reports, contraceptive failure with etonogestrel has been noted in efavirenz-exposed patients.
|
Levonorgestrel AUC ↓58% |
Effectiveness of emergency postcoital contraception may be diminished. |
Etravirine
(ETR)
|
Ethinyl estradiol AUC ↑22%
Norethindrone: no significant effect |
No dosage adjustment needed. |
Nevirapine
(NVP)
|
Ethinyl estradiol AUC ↓20%
Norethindrone AUC ↓19%
|
Additional methods recommended; alternative methods can be considered.
|
DMPA: no significant change |
No dosage adjustment needed. |
Rilpivirine
(RPV)
|
Ethinyl estradiol AUC ↑14%
Norethindrone: no significant change |
No dosage adjustment needed. |
Ritonavir (RTV)-boosted Protease Inhibitor (PI) |
Atazanavir/ritonavir (ATV/r)
|
↓ Ethinyl estradiol
↑ Norgestimate |
Oral contraceptive should contain ≥35 mcg ethinyl estradiol. Oral contraceptives containing progestins other than norethindrone or norgestimate have not been studied. |
Darunavir/ritonavir (DRV/r)
|
Ethinyl estradiol AUC ↓44%
Norethindrone AUC ↓14% |
Additional methods recommended; alternative methods can be considered. |
Fosamprenavir/ritonavir (FPV/r)
|
Ethinyl estradiol AUC ↓37%
Norethindrone AUC ↓34% |
Alternative methods of nonhormonal contraception are recommended. |
Lopinavir/ritonavir
(LPV/r)
|
Ethinyl estradiol AUC ↓42%
Norethindrone AUC ↓17% |
Additional methods recommended; alternative methods can be considered. |
Saquinavir/ritonavir (SQV/r)
|
↓Ethinyl estradiol |
Additional methods recommended; alternative methods can be considered. |
Tipranavir/ritonavir (TPV/r)
|
Ethinyl estradiol AUC ↓48%
Norethindrone: no significant change |
Additional methods recommended; alternative methods can be considered. |
PI without RTV |
Atazanavir
(ATV)
|
Ethinyl estradiol AUC ↑48%
Norethindrone AUC ↑110% |
Oral contraceptive should contain ≤30 mcg of ethinyl estradiol or use alternative method. Oral contraceptives containing <25 mcg ethinyl estradiol or progestins other than norethindrone or norgestimate have not been studied. |
Fosamprenavir
(FPV)
|
Amprenavir: ↑ Ethinyl estradiol and
↑ norethindrone
Fosamprenavir with ethinyl estradiol/norethindrone:
↓ Amprenavir (AUC 22%, Cmin 20%) |
Use alternative method.
Use of fosamprenavir alone with ethinyl estradiol/norethindrone may lead to loss of virologic response. |
Indinavir
(IDV)
|
Ethinyl estradiol AUC ↑25%
Norethindrone AUC ↑26% |
No dose adjustment needed. |
Nelfinavir
(NFV)
|
Ethinyl estradiol AUC ↓47%
Norethindrone AUC ↓18% |
Additional methods recommended; alternative methods may be considered. |
CCR5 Antagonist |
Maraviroc
(MVC)
|
No significant effect on ethinyl estradiol or levonorgestrel |
No dose adjustment needed. |
Integrase Inhibitor |
Raltegravir
(RAL)
|
No significant effect |
No dose adjustment needed. |