Pharmacokinetics Applied to the Treatment of Asthma (PKA)
This problem-solving exercise introduces students to pharmacokinetics, a branch of pharmacology that provides a quantitative description of drug disposition. Pharmacokinetics defines the relationship between the dose of a drug and its concentration in various body compartments over time. In contrast, pharmacodynamics is concerned with the relationship between the dose of a drug and its pharmacologic action(s). Selecting the appropriate dose to achieve and maintain a desired therapeutic concentration in a patient depends on an understanding of these concepts.
Learning Goals for the PKA Workshop
- Distinguish between graded and quantal dose-response curves, and derive desired therapeutic drug concentrations from such curves.
- Explain what is meant by describing the body as a single or a series of multiple kinetic compartments, and distinguish between first-order and zero-order (saturation) kinetics.
- Define the following pharmacokinetic terms: half-life (t1/2), volume of distribution (Vd), and clearance (Cl). Explain how these parameters are related to each other.
- Calculate correct loading and maintenance doses to achieve and maintain drug levels in plasma within the therapeutic range.
- Apply the plateau principle to compute concentrations of drug in plasma during approach to plateau or steady-state.
- Define bioavailability. State the consequences of slow or delayed absorption of a drug on peak and trough concentrations during a dosing interval.