Biophase Effect Compartment — FRCA Primary MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: E — A hypothetical compartment representing the site of drug action used to model the delay between plasma concentration and clinical effect
The biophase is not a real anatomical compartment but a mathematical construct representing the drug's site of action (e.g. the brain for anaesthetics). It accounts for the time lag (hysteresis) between peak plasma concentration and peak effect. The rate constant ke0 governs equilibration between plasma and the effect site.
Reference: Peck Hill Williams 2014 Pharmacology for Anaesthesia and Intensive Care