dosage adjustment of Captopril in renal failure




Captopril.JPG

Captopril

CLINICAL USE

Angiotensin-converting enzyme inhibitor:
  • Hypertension
  • Heart failure
  • Post myocardial infarction
  • Diabetic nephropathy

    DOSE IN NORMAL RENAL FUNCTION

    6.25–50 mg 2–3 times daily
  • Diabetic nephropathy: 75–100 mg daily in divided doses

    PHARMACOKINETICS

  • Molecular weight                           :217.3
  • %Protein binding                           :25–30
  • %Excreted unchanged in urine     : 40–50
  • Volume of distribution (L/kg)       :2
  • half-life – normal/ESRD (hrs)      :2–3/21–32

    DOSE IN RENAL IMPAIRMENT

    GFR (mL/MIN)

  • 20 to 50     : Start low – adjust according to response
  • 10 to 20     : Start low – adjust according to response
  • <10           : Start low – adjust according to response

    DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

  • CAPD                :Not dialysed. 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=10–20 mL/min

    IMPORTANT DRUG INTERACTIONS

    Potentially hazardous interactions with other drugs
  • Anaesthetics: enhanced hypotensive effect cinAnalgesics: antagonism of hypotensive effect and increased risk of renal impairment with NSAIDs; hyperkalaemia with ketorolac and other NSAIDs
  • Ciclosporin: increased risk of hyperkalaemia and nephrotoxicity
  • Diuretics: enhanced hypotensive effect; hyperkalaemia with potassium-sparing diuretics
  • Epoetin: increased risk of hyperkalaemia; antagonism of hypotensive effect
  • Lithium: reduced excretion, possibility of enhanced lithium toxicity
  • Potassium salts: increased risk of hyperkalaemia.
  • Tacrolimus: increased risk of hyperkalaemia and nephrotoxicity

    ADMINISTRATION

    Reconstition

    Route

    Oral

    Rate of Administration

    Comments

    Tablets may be dispersed in water

    OTHER INFORMATION

    A
  • dverse reactions, especially hyperkalaemia, are more common in patients with renal impairment
  • Effective sub-lingually in emergencies As renal function declines a hepatic elimination route for captopril becomes increasingly more significant
  • Renal failure has been reported in association with ACE inhibitors in patients with renal artery stenosis, post renal transplant, or in those with congestive heart failure
  • A high incidence of anaphylactoid reactions has been reported in patients dialysed with high-flux polyacrylonitrile membranes and treated concomitantly with an ACE inhibitor – this combination should therefore be avoided
  • Close monitoring of renal function during therapy is necessary in those with renal insufficiency.