Adverse Drug Reactions

TYPES

Expected

Pharmaceutics

  • compatibility issues
  • effects of associated additives and preservatives

Pharmacokinetics

  • absorption
  • competition for binding sites
  • enzyme induction

Pharmacodynamics

  • side effects
  • toxic effects
  • innocent bystander organs
  • agonism of receptor sites other than target sites (bradycardia with suxamethonium)

Interactions with other drugs

  • prolongation of effect (gentamicin and neuromuscular blockade)
  • enzyme induction or inhibition
  • additive effects (erythromycin, haloperidol, amiodarone and prolong QT syndrome)

Unexpected

  • idiosyncratic reactions (haematological, hepatic, dermatological)
  • allergy (mild -> anaphylaxis/anaphylactoid reactions)

PREVENTION

History

  • good drug history, normal medications, OTC,
  • alcohol intake
  • previous drug reactions
  • clear documentation in notes of alerts and allergies
  • consideration of co-morbid conditions that make adverse effects more likely (respiratory depression and OSA)

Examination

  • looking for conditions that make reactions more likely

Management

  • careful prescribing
  • knowledge of drugs and interactions
  • vigilance in monitoring for adverse effects
  • close liaison with clinical pharmacologist
  • appropriate drug monitoring (drug levels, organ function)

CCC Pharmacology Series

Critical Care

Compendium

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.