disodium etidronate

CLINICAL USE


Bisphosphonate:Paget’s disease of bone Vertebral osteoporosis (Didronel PMO)

DOSE IN NORMAL RENAL FUNCTION

Paget’s disease: 5–20 mg/kg daily for 3–6 monthsVertebral osteoporosis: 400 mg daily for 14 days followed by 76 days of calcium carbonate 1.25 g (= 500 mg calcium)

PHARMACOKINETICS

  • Molecular weight &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :250
  • %Protein binding &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Depends on calcium concentration and pH
  • %Excreted unchanged in urine &nbsp &nbsp : 50
  • Volume of distribution (L/kg) &nbsp &nbsp &nbsp :0.3–1.3
  • half-life – normal/ESRD (hrs)&nbsp &nbsp &nbsp :1–6/–

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

  • 20 to 50 &nbsp &nbsp : Maximum dose = 5 mg/kg/day
  • 10 to 20 &nbsp &nbsp : Maximum dose = 5 mg/kg/day – use with caution. (May also use Didronel PMO for osteoporosis.)
  • <10 &nbsp &nbsp &nbsp &nbsp &nbsp : Maximum dose = 5 mg/kg/day – use with caution. (May also use Didronel PMO for osteoporosis)

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp:Unknown dialysability. Dose as in GFR <10 mL/min

  • HD &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp :Unknown dialysability. Dose as in GFR <10 mL/min
  • HDF/high flux &nbsp :Unknown dialysability. Dose as in GFR <10 mL/min
  • CAV/VVHD &nbsp &nbsp &nbsp:Unknown dialysability. Dose as in GFR 10 to 20 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugsDo not give iron and mineral supplements, antacids or phosphate binders within 2 hours of an etidronate

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    Take on an empty stomach. Recommended that patients take with water at the midpoint of a 4 hour fast (i.e. 2 hours before and 2 hours after food)Oral bioavailability is very low; only about 4% of dose is absorbed

    OTHER INFORMATION

    Renal clearance of etidronate is 1.2 mL/ minute/kg, whilst the total body clearance is 2.2 mL/minute/kgElimination is likely to be reduced in patients with renal impairment and elderly with reduced renal function necessitating caution. Uptake of etidronate by bone represents non-renal clearance