Pharmacology 2060A/B Lecture Notes - Lecture 6: Loading Dose, Pharmacokinetics, Therapeutic Index
4 Jan 2021
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Document Summary
The underlying principle of clinical pharmacokinetics is that the relationship exists between the effects of a drug and the concentration of drug in the body. In clinical pharmacokinetics we try to provide: A quantitative relationship between drug dose and effect. A framework to interpret measurements of drug concentrations in biological fluids to benefit patient drug therapy. The most important parameters determining drug disposition in humans are: Clearance the body"s efficiency in drug elimination. Volume of distribution the apparent space in the body available to contain the drug. Elimination half life (t 1/2 ) a measure of the rate of removal of drug from the body. Bioavailability the fraction of drug that reaches the systemic circulation unchanged. Ideally drug concentrations would be measured from the site of action in reality, this is not feasible. Clearly taking a sample from a patient"s brain to measure drug concentrations is invasive and would do more harm than good.
