New data show that etravirine (ETR) substantially lowers plasma concentrations of dolutegravir (DTG) (DTG Cmin decreased 88%, AUC decreased 71%). This effect is lessened by coadministration of ritonavir-boosted PIs: the combination of ETR + DTG + darunavir/ritonavir (600/100 mg BID) resulted in a decrease in DTG Cmin and AUC of 37% and 25%, respectively. When ETR + DTG were given with lopinavir/ritonavir, the DTG Cmin and AUC were increased slightly. No data are available for the interaction with atazanavir/ritonavir.
Etravirine also lowers levels of atazanavir (ATV): ATV Cmin was decreased by 47% when unboosted ATV was given with ETR, and AUC was 17% lower. Boosting with ritonavir appears to largely overcome this interaction: ATV Cmin was 18% lower and AUC was 4% lower than when ATV was given alone.
Do not use etravirine with:
Dolutegravir (in the absence of a ritonavir-boosted PI as listed below)
No dosage adjustments are recommended for the following combinations:
Etravirine + dolutegravir + darunavir/ritonavir 600/100 mg BID (but note that no data are available for the interaction with of etravirine with dolutegravir + darunavir/ritonavir 800/100 mg once daily)
Etravirine + dolutegravir + lopinavir/ritonavir
No data are available for the interaction of etravirine with dolutegravir + ritonavir-boosted atazanavir
New labeling information is available at Drugs@FDA.