Anaes SAQs · Applied cardiovascular & respiratory physiology
Distribution, clearance and half-life
Primary — Vd (apparent volume, loading dose); CL (maintenance rate); t1/2 (0.693 Vd over CL, steady state 4 to 5 t1/2); protein binding (free fraction, hypoalbuminaemia); hepatic extraction ratio (high flow-limited, low capacity-limited); factors changing Vd/CL/t1/2 (age, obesity, liver, renal).
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Prompt
Define volume of distribution, clearance and elimination half-life. State the equations for loading dose and maintenance infusion rate, and explain the significance of protein binding and the hepatic extraction ratio.
Question
Define volume of distribution, clearance and elimination half-life. State the equations for loading dose and maintenance infusion rate, and explain the significance of protein binding and the hepatic extraction ratio.
[1]References4ShowHide
- [1]Pang KS, et al. After 50 Years of Hepatic Clearance Models, Where Should We Go from Here? Improvements and Implications for Physiologically Based Pharmacokinetic Modeling. Drug Metab Dispos, 2024.PMID 39013583
- [6]Martin-Flores M, et al. Bolus and infusions of metoclopramide: insights on benefits and risks from pharmacokinetic modelling. J Small Anim Pract, 2026.PMID 42178715
- [3]Benet LZ. Are all measures of liver Kp(uu) a function of F(H), as determined following oral dosing, or have we made a critical error in defining hepatic drug clearance? Eur J Pharm Sci, 2024.PMID 38522769
- [2]Kabalka E, et al. Critically Ill Patients with Severe Cirrhosis Receiving Dexmedetomidine at a Higher Risk of Cardiovascular Instability: Application of an Objective Novel Cirrhosis Scoring System. J Intensive Care Med, 2026.PMID 41428649