been observed in patients receiving tenofovir DF with didanosine 400 mg daily.
Lopinavir/ritonavir has been shown to increase tenofovir concentrations. The mechanism of this interaction is unknown. Patients receiving lopinavir/ritonavir with ATRIPLA should be monitored for tenofovir-associated adverse reactions. ATRIPLA should be discontinued in patients who develop tenofovir-associated adverse reactions [See Table 4].
Coadministration of atazanavir with ATRIPLA is not recommended since coadministration of atazanavir with either efavirenz or tenofovir DF has been shown to decrease plasma concentrations of atazanavir. Also, atazanavir has been shown to increase tenofovir concentrations. There are insufficient data to support dosing recommendations for atazanavir or atazanavir/ritonavir in combination with ATRIPLA [See Table 4].
Other important drug interaction information for ATRIPLA is summarized in Table 1 and Table 4. The drug interactions described are based on trials conducted with efavirenz, emtricitabine or tenofovir DF as individual agents or are potential drug interactions; no drug interaction trials have been conducted using ATRIPLA [for pharmacokinetics data see Clinical Pharmacology (12.3), Tables 5–9]. The tables include potentially significant interactions, but are not all inclusve.
Table 4 Established and Other Potentially Significant* Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Trials or Predicted Interaction Concomitant Drug Class: Drug Name Effect Clinical Comment
Antiretroviral agents
Protease inhibitor:
atazanavir ↓atazanavir concentration
↑ tenofovir concentration Coadministration of atazanavir with ATRIPLA is not recommended. Coadministration of atazanavir with either efavirenz or tenofovir DF decreases plasma concentrations of atazanavir. The combined effect of efavirenz plus tenofovir DF on atazanavir plasma concentrations is not known. Also, atazanavir has been shown to increase tenofovir concentrations. There are insufficient data to support dosing recommendations for atazanavir or atazanavir/ritonavir in combination with ATRIPLA.
Protease inhibitor:
fosamprenavir calcium ↓ amprenavir concentration Fosamprenavir (unboosted): Appropriate doses of fosamprenavir and ATRIPLA with respect to safety and efficacy have not been established.
Fosamprenavir/ritonavir: An additional 100 mg/day (300 mg total) of ritonavir is recommended when ATRIPLA is administered with fosamprenavir/ritonavir once daily. No change in the ritonavir dose is required when ATRIPLA is administered with fosamprenavir plus ritonavir twice daily.
Protease inhibitor:
indinavir ↓ indinavir concentration The optimal dose of indinavir, when given in combination with efavirenz, is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased indinavir metabolism due to efavirenz.
Protease inhibitor:
lopinavir/ritonavir ↓ lopinavir concentration
↑ tenofovir concentration A dose increase of lopinavir/ritonavir to 600/150 mg (3 tablets) twice daily may be considered when used in combination with efavirenz in treatment-experienced patients where decreased susceptibility to lopinavir is clinically suspected (by treatment history or laboratory evidence). Patients should be monitored for tenofov |
