2.5 - Distribution Flashcards
Drug movement from the central compartment (systemic circulation) going to the peripheral compartments (organs & tissues)
Distribution
Objective:
Drug delivery to the biological site of action
2 PHYSIOLOGIC Factors
- Cardiac Output
* Regional Blood Flow
Volume of the blood pumped out by the ❤️ per minute
Cardiac Output (CO)
Fraction of CO delivered to specific organs/ tissues
Regional Blood Flow
⬆️Regional Blood Flow
- Liver
- Kidneys
- Lungs
- Heart
- Brain
⬇️Regional Blood Flow
- Bones
* Adipose Tissues
2 PHARMACOKINETIC Factors
- Volume of Distribution
* Protein Binding
Volume of Distribution (Vd)
⬆️Vd = ⬆️Distribution
Total Body Fluid
60%
Intracellular Fluid
40%
Extracellular Fluid
20%
Interstitial
15%
Intravascular
5%
Types of Blood Proteins
- Albumin
- a1-acid Glycoprotein
- Globulin
– Dominant
– Non-selective
– for weak ACIDS
Albumin
– for weak BASED
– Non-selective
A1-acid Glycoprotein
– Selective
– For hormones only
Globulin
Consequences of Protein Binding
– Longer DOA
– Limit access to certain body compartments
– Potential for drug displacement interaction
⬆️ Protein Bound
- Warfarin
- Midazolam
- Diazepam
- NSAIDs
- Sulfa drugs
Protein binding
⬆️Protein binding = ⬇️Distribution
