Q11

What are the clinical features of acute ethanol consumption?

  • CNS – sedation, disinhibited, impaired judgement, impaired motor skills, ataxia, slurred speech, coma, respiratory depression
  • Heart – depressed myocardial contractility
  • Smooth muscle – vasodilation, hypothermia in OD, uterine smooth muscle contraction

Pass Criteria:

  • Must mention CNS plus one other to pass.

Describe the pharmacokinetics of ethanol.

  • Absorption – rapid from GI tract (water soluble), peak levels within 30 minutes
  • Distribution – rapid, Vd ~TBW (0.5 – 0.7 L/kg)
  • Metabolism – predominantly liver metabolism (zero order kinetics – over 90% is oxidised in the liver to acetaldehyde)
    • Mainly via Alcohol Dehydrogenase (ADH), less by microsomal ethanol oxidising system (MEOS)
  • Excretion – lungs, urine

Pass Criteria:

  • Bold to pass. Must mention ADH.

Name other drugs that have zero order kinetics.

  • Phenytoin
  • Theophylline
  • Warfarin
  • Salicylates
  • Heparin
  • Paracetamol

Pass Criteria:

  • One to pass.