Table 4.

Established and potentially significant drug interactions with F/TDF and F/TAF [10, 11]

Concomitant drug classa: drug name	Effect on drug concentration	Clinical comments
F/TDF
Nucleoside reverse transcriptase inhibitors
Didanosine	Increased didanosine	Monitor patients closely for adverse reactions
HIV-1 protease inhibitors
Atazanavir	Decreased atazanavir	Atazanavir 300 mg should be given with ritonavir 100 mg
Lopinavir/ritonavir	Increased TDF	Monitor patients closely for adverse reactions
Atazanavir/ritonavir	Increased TDF
Darunavir/ritonavir	Increased TDF
Hepatitis C antiviral agents
Ledipasvir/sofosbuvir	Increased TDF	Monitor patients closely for adverse reactions. In patients receiving F/TDF concomitantly with ledipasvir/sofosbuvir and an HIV-1 protease inhibitor/ritonavir or an HIV-1 protease inhibitor/cobicistat combination, consider an alternative HCV or antiretroviral therapy
F/TAF
HIV-1 protease inhibitors
Tipranavir/ritonavir	Decreased TAF	Coadministration not recommended
Anticonvulsants
Carbamazepine	Decreased TAF	Consider alternative anticonvulsants
Oxcarbazepine	Decreased TAF
Phenobarbital	Decreased TAF
Phenytoin	Decreased TAF
Antimycobacterials
Rifabutin	Decreased TAF	Coadministration with rifabutin, rifampin, or rifapentine not recommended
Rifampin	Decreased TAF
Rifapentine	Decreased TAF
Herbal products
St John’s wort (Hypericum perforatum)	Decreased TAF	Coadministration not recommended

F/TAF emtricitabine/tenofovir alafenamide, F/TDF emtricitabine/tenofovir disoproxil fumarate, HCV hepatitis C virus, NSAID non-steroidal anti-inflammatory drug

^aCoadministration of TDF or TAF with drugs that are eliminated by active tubular secretion may increase concentrations of emtracitabine, TDF, or TAF, and/or the coadministered drug. Some examples include, but are not limited to, acyclovir, adefovir, dipivoxil, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamycin), and high-dose or multiple NSAIDs