Last Updated June 10, 2016
Nucleotide reverse transcriptase inhibitor antiretroviral
Indication: treatment of HIV infection in combination with other antiretrovirals. Taken together with emtricitabine or lamivudine for treatment of HIV/hepatitis B coinfection. In combination with emtricitabine for pre-exposure prophylaxis in HIV-negative, high-risk individuals. Off label use includes reduction of perinatal transmission of HIV and postexposure prophylaxis in combination with other antiretrovirals.
Mechanism of action*: an adenosine 5’-monophosphate analogue that is intracellularly converted to tenofovir, then phosphorylated to active tenofovir diphosphate, which interferes with HIV viral RNA–dependent DNA polymerase inhibiting viral replication.
Pharmacokinetics: renal excretion 70% to 80%.* Half-life*: serum = 17 hours; intracellular = > 60 hours. Oral bioavailability increased with high-fat meal.
Adult Dose: 300 mg once daily.
Take without regard to meals.*
Use in Renal or Hepatic Insufficiency: No dose adjustment required for patients with hepatic impairment.*
Dosage for patients with chronic kidney disease or end-stage renal disease†:
If using coformulated tenofovir/emtricitabine:
Use in Pregnancy and Breastfeeding: Category B. Excreted into breast milk.*
Use in Children: Safety and efficacy not established.
US Prescribing Information Boxed Warning*: lactic acidosis/hepatomegaly with steatosis has been reported with nucleoside analogues with fatal cases reported. Use with caution in patients with risk factors for liver disease and suspend treatment if a patient develops signs and symptoms.
US Prescribing Information Boxed Warning*: acute, severe exacerbations of hepatitis B virus have been reported following discontinuation of antiretroviral therapy in patients with HIV and hepatitis B virus coinfection. Hepatitis B virus testing should be done prior to initiation of tenofovir and caution used in coinfected patients.
Patients at risk of with history of renal dysfunction and patients received concomitant nephrotoxic agents should be carefully monitored for changes in serum creatinine and phosphate. Creatinine clearance should be calculated at initiation of tenofovir therapy and at 6 monthly intervals thereafter.
Drug interactions between tenofovir and other antiretrovirals:
Additional interactions to consider:
See above for pregnancy and lactation.
Renal insufficiency/Fanconi syndrome, osteomalacia/decrease in bone mineral density, asthenia, headache, diarrhoea, nausea, vomiting, flatulence.*
*Information from US prescribing information.
†Recommendation from South African Renal Society, 2008.