tenofovir disoproxil
tenofovir disoproxil.JPG

CLINICAL USE

Nucleoside reverse transcriptase inhibitor:Treatment of HIV in combination with other antiretroviral drugsTreatment of hepatitis B in compensated liver disease

DOSE IN NORMAL RENAL FUNCTION

245 mg once daily

PHARMACOKINETICS

  • Molecular weight                           :635.5 (as disoproxil fumarate)
  • %Protein binding                           :0.7–7.2
  • %Excreted unchanged in urine     : IV: 70–80; Oral: 32
  • Volume of distribution (L/kg)       :0.8
  • half-life – normal/ESRD (hrs)      :12–18/Increased

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

    30–50 245 mg every 48 hours10–30 245 mg every 72–96 hours
  • <10           : 245 mg every 7 days

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD                :Unknown dialysability. Dose as in GFR <10 mL/min
  • HD                     :Dialysed. Dose as in GFR
  • <10           : mL/min
  • HDF/high flux   :Dialysed. Dose as in GFR
  • <10           : mL/min
  • CAV/VVHD      :Dialysed. Dose as in GFR=10–30 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugs
  • Antivirals: reduces concentration of atazanavir; concentration of both drugs may be increased with cidofovir; increased didanosine concentration resulting in increased toxicity (e.g. pancreatitis and lactic acidosis) – avoid concomitant use; concentration increased by lopinavir and atazanavir; monitor renal function with adefovirCo-administration with other drugs that are actively secreted via the tubular anionic transporter, e.g. cidofovir – increased concentrations of both drugs

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    OTHER INFORMATION

    Lactic acidosis, sometimes fatal, and usually associated with severe hepatomegaly and steatosis, has been reported in patients receiving nucleoside reverse transcriptase inhibitorsFollowing a single 300 mg dose of tenofovir, subjects with a calculated creatinine clearance <50 mL/min, and those with ERF requiring dialysis, had substantial reductions in renal elimination of tenofovir, resulting in high systemic exposures necessitating an adjustment in doseA 4 hour high-flux haemodialysis session was found to remove 10% of tenofovir from plasmaRenal impairment, which may include hypophosphataemia, has been reported with the use of tenofovir. The majority of these cases occurred in patients with underlying systemic or renal disease, or in patients taking nephrotoxic agents – monitor creatinine clearance and phosphate levels



    See how to identify renal failure stages according to GFR calculation

    See how to diagnose irreversible renal disease

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