Emtricitabine is a nucleoside analogue.
Emtricitabine has activity against HIV-1.
Emtricitabine must be converted intracellularly to its triphosphate form, which then competes with deoxycytidine 5'-triphosphate for incorporation into the developing viral DNA strand. This results in chain termination and ceases viral DNA synthesis.
Resistance to NRTIs occurs through two mechanisms; decreased incorporation of NRTIs into the viral DNA and increased excision of NRTIs from the viral DNA
Emtricitabine has 93% bioavailability, minimal plasma protein binding (<4%) and is metabolized via oxidation and conjugation. Emtricitabine is primarily excreted by the kidneys, with 86% being unchanged drug and 13% being metabolites.
The most common adverse effects are headache, diarrhea, nausea, and rash.
Adults (18 years of age and older):
200 mg once daily taken orally
Disease state based dosing:
CrCl ≥ 50ml/min – 200mg once daily
CrCl 30-39 ml/min – 200mg once every 48 hours
CrCl 15-29 ml/min – 200mg once every 72 hours
CrCl < 15 ml/min – 200mg once every 96 hours
No dose adjustment necessary
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of NRTIs.
Emtricitabine does not inhibit the CYP450 enzymes or the enzymes responsible for glucuronidation.
Category B: No evidence of risk in humans but studies inadequate.
Emtriva®/Gilead Sciences Inc