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Tenofovir Disoproxil

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Tenofovir Disoproxil, Tenofovir disoproxil Fumarate, Tenofovir, TDF, Viread

  • See Also
  1. Tenofovir Alafenamide
  2. Anti-Retroviral Therapy
  3. Nucleoside Reverse Transcriptase Inhibitor
  • Indications
  1. HIV Infection (combination therapy)
  2. Chronic Hepatitis B Infection (compensated liver disease)
    1. HIghly potent against HBV and among preferred agents
    2. Maintains activity in HBV despite Lamivudine resistance
  • Preparations
  1. Tenofovir disoproxil Fumarate (TDF, Viread)
    1. Covered on this page
    2. Original Tenofovir formulation and used in Stribild, Truvada and Complera
    3. Associated with nephrotoxicity and decreased Bone Mineral Density
    4. Preparations
      1. Tablets: 150, 200, 250 and 300 mg
      2. Oral powder for solution: 40 mg per 1 gram scoop
        1. Mix with 2 to 4 ounces of non-liquid soft food (e.g. applesauce, pureed food, yogurt)
  2. Tenofovir Alafenamide Fumarate (TAF, Vemlidy)
    1. See Tenofovir Alafenamide
    2. Tenofovir formulation released in 2016 and used in Genvoya, Descovy, Odefsey
    3. TAF appears to have less adverse Renal Function and Bone Mineral Density effects than the original TDF
    4. TAF is associated with greater weight gain and dyslipidemia than TDF
  • Mechanism
  1. Nucleoside Reverse Transcriptase Inhibitor (nRTI)
  2. Prodrug hydrolyzed in vivo to Tenofovir
    1. Tenofovir is a Nucleotide analog of Adenosine 5-Monophosphate
  • Precautions
  1. Risk of severe HBV exacerbation on discontinuation
    1. Monitor for at least 2 months after discontinuation
  2. Risk of induced HIV resistance in undiagnosed HIV coinfection
    1. HIV Test before use
    2. Do NOT use in monotherapy in HBV/HIV infected patients
  • Dosing
  1. General
    1. Must be used in combination with other agents when treating HIV Infection (e.g. with Lamivudine or Emtricitibine)
  2. Adult
    1. Tenofovir Disoproxil 300 mg orally daily
  3. Child (age >= 2 years, weight >=10 kg)
    1. Tenofovir Disoproxil 8 mg/kg once daily
  4. Renal Dosing (Adults)
    1. Consider alternative agents if eGFR <60 ml/min AND Drug Interactions that raise TDF levels (see below)
    2. eGFR 30 to 49 ml/min: Tenofovir Disoproxil 300 mg every 48 hours
    3. eGFR 10 to 29 ml/min: Tenofovir Disoproxil 300 mg twice weekly
    4. Hemodialysis: 300 mg once weekly after Hemodialysis
  • Adverse Effects
  1. See nRTI for adverse effects attributed to the class
  2. Renal dysfunction
    1. Increased Serum Creatinine
    2. Proteinuria
    3. Electrolyte abnormalities
      1. Glycosuria
      2. Hypophosphatemia
    4. Nephrotoxicity with Acute Renal Failure (1% risk)
      1. Associated with longer duration of therapy, advanced HIV or pre-existing renal disease
      2. Fanconi Syndrome like-reaction
      3. Avoid with Nephrotoxic Drugs
  3. Gastrointestinal
    1. Diarrhea
    2. Nausea or Vomiting
    3. Abdominal Pain
    4. Flatulence
  4. Miscellaneous
    1. Headache
    2. Hepatitis B flares on withdrawal of medication
    3. Fatigue
    4. Rash
    5. Decrease Bone Mineral Density
  • Safety
  1. Avoid in Lactation
  2. Pregnancy Category B
    1. Tenofovir is the preferred nRTI in pregnancy
  • Drug Interactions
  1. Avoid Tenofovir Disoproxil in combination with the following
    1. Adefovir
    2. Didanosine
    3. Unboosted Atazanavir
  2. Agents that raise Tenofovir Disoproxil levels (monitor for toxicity including Renal Function)
    1. Ledipasvir
    2. Velpatasvir
    3. Ritonavir
    4. Cobicistat
  • Monitoring
  1. Obtain baseline Renal Function, Phosphorus and Urine Protein, then at 2-8 weeks, and then every 3-6 months
  • Resources
  1. Tenofovir Disoproxil (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=33fd6418-fbdc-42ca-a50d-ce2a476a5418
  • References
  1. (2016) Presc Lett 23(9)
  2. (2009) Treat Guidel Med Lett 7(78): 11-22 [PubMed]
  3. (2013) Med Lett Drugs Ther 11(127): 19-30 [PubMed]
  4. Reust (2011) Am Fam Physician 83(12): 1443-51 [PubMed]