POISONING: N-ACETYLCYSTEINE

Question 1

N-ACETYLCYSTEINE: INDICATIONS

Answer 1

• Antidote to paracetamol poisoning
• Help prevent renal injury due to radiographic contrast material (CONTRAST NEPHROPATHY)
• Reduce viscosity of respiratory secretions (acting as MUCOLYTIC)

Question 2

N-ACETYLCYSTEINE: MOA

Answer 2

• Acetylcysteine replenishes the body’s supply of GLUTATHIONE
• Antioxidant effects, helps combat effects of CONTRAST NEPHROPATHY
• Patients with tenacious respiratory secretions (eg Bronchiectasis), may aid sputum clearance

Question 3

N-ACETYLCYSTEINE: ADVERSE EFFECTS

Answer 3

• Large doses can cause an ANAPHLACTOID RXN
• Involves histamine release of independent of IgE antibodies
• Once rxn has settled (stop A, and adding a bronchodilator) - safe to restart ACETYLCYSTEINE
• When administered in a nebulised form as a mucolytic, can cause BRONCHOSPASM

Question 4

N-ACETYLCYSTEINE: WARNINGS

Answer 4

• Hx of anaphylactoid rxn to acetylcysteine does not CI its use in future
• Important that rxns are not labelled as allergic -> may lead to ineffective tx in paracetamol poisoning

Question 5

N-ACETYLCYSTEINE: IMPORTANT INTERACTIONS

Answer 5

• No significant interactions

Question 6

N-ACETYLCYSTEINE: EXAMPLES

Answer 6

• Acetylcysteine