Pharm

Tenofovir Alafenamide

search

Tenofovir Alafenamide, Tenofovir Alafenamide Fumarate, TAF, Vemlidy

  • See Also
  1. Tenofovir Disoproxil
  2. Anti-Retroviral Therapy
  3. Nucleoside Reverse Transcriptase Inhibitor
  • Indications
  1. Chronic Hepatitis B Infection (compensated liver disease)
  2. HIV Infection (combination therapy)
  • Contraindications
  1. eGFR <15 ml/min without Hemodialysis
  2. Decompensated Cirrhosis (Child-Pugh B or C)
  • Mechanism
  1. See Tenofovir Disoproxil
  2. Nucleoside Reverse Transcriptase Inhibitor
  • 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 HIV infected patients (must be used in combined regimens)
  • Medications
  1. Tenofovir disoproxil Fumarate (TDF, Viread)
    1. See Tenofovir Disoproxil
    2. Original Tenofovir formulation and used in Stribild, Truvada and Complera
    3. Associated with nephrotoxicity and decreased Bone Mineral Density
  2. Tenofovir Alafenamide Fumarate (TAF, Vemlidy)
    1. Covered on this page
    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
  • Dosing
  1. Adults with Chronic Hepatitis B Infection
    1. Tenofovir Alafenamide (TAF) 25 mg orally daily with food
  2. Adults with HIV Infection
    1. Tenofovir Alafenamide (TAF) 25 mg orally daily with food AND
    2. Take with Emtricitibine 200 mg orally daily
  3. Renal
    1. Contraindicated in eGFR <15 ml/min without Hemodialysis
    2. No renal dose adjustments needed if on Hemodialysis OR eGFR >15 ml/min
  • Adverse Effects
  1. See nRTI for adverse effects attributed to the class
  2. See Tenofovir Disoproxil
  3. Serious (potentially fatal)
    1. Lactic Acidosis
    2. Hepatic Steatosis
  4. Renal dysfunction
    1. Increased Serum Creatinine
    2. Proteinuria
    3. Electrolyte abnormalities
      1. Glycosuria
      2. Hypophosphatemia
    4. Acute Renal Failure (1% risk)
      1. Associated with longer duration of therapy, advanced HIV or pre-existing renal disease
  5. Gastrointestinal
    1. Diarrhea
    2. Nausea or Vomiting
    3. Flatulence
  6. Miscellaneous
    1. Headache
    2. Hepatitis B flares on withdrawal of medication
  • Safety
  1. Avoid in Lactation
  2. Unknown safety in pregnancy (pregnancy registry exists)
  • Drug Interactions
  1. Carbamazepine
    1. Increase dose to 50 mg orally daily (from 25 mg orally daily)
  2. Avoid Tenofovir Alafenamide Fumarate (TAF, Vemlidy) with the following agents
    1. Oxcarbazepine
    2. Phenytoin
    3. Phenobarbital
    4. Rifabutin
    5. Rifampin
    6. Rifapentine
    7. St Johns Wort
  • Monitoring
  1. Obtain baseline Renal Function, Phosphorus, Urine Protein and then at 2-8 weeks, and then every 3-6 months
  • Resources
  1. Tenofovir Alafenamide (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=72e6b33c-0351-4070-9172-eeaa186c01d2
  • References
  1. (2016) Presc Lett 23(9)
  2. (2009) Treat Guidel Med Lett 7(78): 11-22 [PubMed]
  3. Reust (2011) Am Fam Physician 83(12): 1443-51 [PubMed]