Class: Antiretroviral Agent, Reverse Transcriptase Inhibitor; Antiretroviral Agent, Reverse Transcriptase Inhibitor
Dosage Forms. Tablet: Emtricitabine/Tenofovir 200 mg/300 mg
Common FDA Label Indication, Dosing, and Titration.
1. Treatment of HIV-1 infection in combination with other antiretroviral agents: Adults and children ≥12 y, one tablet po daily
2. Preexposure prophylaxis (PrEP) for prevention of HIV-1 infection in adults who are at high risk for acquiring HIV: One tablet po daily (high risk is defined as inconsistent condom use, incarcerated, drug, and alcohol dependence)
1. Treatment of hepatitis B in patients with antiviral-resistant HBV or coinfection with HIV: One tablet po daily
MOA. Emtricitabine is a cytosine analog while tenofovir is an analog of adenosine 5′-monophosphate. Each drug interferes with HIV viral RNA-dependent DNA polymerase resulting in inhibition of viral replication.
Drug Characteristics: Emtricitabine/Tenofovir
Medication Safety Issues: Emtricitabine/Tenofovir
Drug Interactions: Emtricitabine/Tenofovir
Adverse Reactions: Emtricitabine/Tenofovir
Efficacy Monitoring Parameters. Prior to therapy, HIV resistance testing, HBV testing as acute, and severe exacerbations of HBV have been reported following discontinuation of antiretroviral therapy. HIV viral load, CD4 count, for assessment of efficacy. If using for preexposure prophylaxis, patients must be HIV negative. Patients receiving preexposure prophylaxis who get HIV may be drug resistant at diagnosis. Also test for sexually transmitted diseases and treat as necessary.
Toxicity Monitoring Parameters. Liver function tests, bilirubin, CBC, glucose, renal function, phosphorus, assessment of osteoporosis. Lactic acidosis and severe hepatomegaly and sometimes fatal steatosis have been reported with nucleoside and nucleotide analogues.
Key Patient Counseling Points. Take with or without food.
Clinical Pearls. Not recommended for children less than 12 y of age. Recommended as a component of preferred regimens (in combination with atazanavir/ritonavir or darunavir/ritonavir or efavirenz or raltegravir) in antiretroviral-naive patients.