Acetylcysteine

Acetylcysteine

ADMINISTRATION ROUTES:

  • PO, IV & NG

ALTERNATIVE NAMES:

  • Acetadote, Parvolex

ICU INDICATIONS:

  1. Paracetamol overdose
  2. Non-paracetamol induced fulminant hepatic failure
  3. Prevention of contrast-induced nephropathy

PRESENTATION AND ADMINISTRATION:

  • PO / NG:
    Give IV solution orally (unlicensed section 29 use)
  • IV:
  • Acetadote and Parvolex are supplied as sterile solutions in 10ml vials containing 20% (200 mg/ml) acetylcysteine. Compatible with 5% dextrose. Prepare immediately before use and discard any solution not used within 24 hours.

    Note: Inj is section 29; Oral is section 29

DOSAGE:

  • Prevention of Contrast Induced Nephropathy:
    The preferred dosage regime is 1200mg IV by Slow IV Push prior to taking the patient down for angiography or CT with contrast followed by 1200mg IV BD for 48 hours after the investigation.
  • Paracetamol Overdose:
    150mg/kg over 15 minutes; 50mg/kg over the next 4 hours,100mg per kg over the next 16 hours. Total dose 300mg/kg in 20 hours

    • Initial dose: 150mg/kg in 200ml of D5W over 15 minutes
    • Second dose: 50mg/kg in 500ml of D5W over 4 hours
    • Third dose: 100mg/kg in 1000ml of D5W over 16 hours
Weight (kg) Initial Dose in ml Second Dose (mL) Third Dose (mL) Total (mL)
50 37.5 12.5 25 75
60 45.0 15.0 30 90
70 52.5 17.5 35 105
80 60.0 20.0 40 120
90 67.5 22.5 45 135
‘x’ 0.75x 0.25x 0.5x 1.5x

e.g. 76kg; 0.75 multiplied by 76 = 57ml for the initial infusion dose and 19ml and 38ml for the 2nd and 3rd doses respectively

PAEDIATRIC DOSAGE

  • Prevention of Contrast Induced Nephropathy:
    Dosage for this indication has not been established.
  • Paracetamol Overdose:
    150mg/kg over 15 minutes; 50mg/kg over the next 4 hours, 100mg per kg over the next 16 hours. Total dose 300mg/kg in 20 hours

    Note: In children, N-acetylcysteine should be given intravenously as a 40 mg/mL solution in 5% dextrose in water. This is to prevent possible hyponatremia.

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY

  • No dose adjustment is required.

CLINICAL PHARMACOLOGY

  • Paracetamol Overdose:
    Acetylcysteine likely protects the liver by maintaining or restoring the glutathione levels, or by acting as an alternate substrate for conjugation with, and thus detoxification of, the reactive metabolite.

CONTRAINDICATIONS

  1. Hypersensitivity or previous anaphylactoid reactions to acetylcysteine

WARNINGS

  • Serious anaphylactoid reactions, including death in a patient with asthma, have been reported in patients administered acetylcysteine intravenously.

PRECAUTIONS

  • General:
    The total volume administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction (use paediatric dosage regimen).
  • Laboratory Tests:
    No tests are required in addition to routine ICU blood tests
  • Drug/Laboratory Test Interactions:
    None reported

IMPORTANT DRUG INTERACTIONS FOR THE ICU

  • None known

ADVERSE REACTIONS

  • Body as a Whole:
    Urticaria, vasodilatation, rash and itch
  • Cardiovascular System:
    Hypotension
  • Digestive System:
    Dyspepsia, nausea, vomiting
  • Nervous System:
    Abnormal thinking (dysphoria), Gait disturbances
  • Respiratory System:
    Bronchospasm, coughing, dyspnoea
  • Skin & Appendages:
    Angioedema, facial erythema, palmar erythema, pruritus, pruritus, rash, sweating

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