Learning unit: Basics of pharmacokinetics

Impact of the learning unit:

To gain knowledge of pharmacokinetics, together with knowledge of the mechanism of action of drugs,
and to select an appropriate drug administration route, dosage form, and dose of the drug. This
will enable students to predict changes in the effect of the drug due to various factors such as
comorbidities, age, sex or concomitant medications.

Important terms

movement of drug molecules across biological membranes within the body

                diffusion through the phospho-lipid bilayer

                diffusion through membrane pores

                carrier-mediated transport

                               facilitated transport

                               active transporters

binding of drugs to plasma proteins

pharmacokinetic processes

pharmacokinetic parameters

                primary

                secondary

invasion of drug

drug absorption

maximum concentration of drug achieved in plasma (c[max])

time needed to achieve maximum plasma concentration (t[max])

bioavailability (F)

absolute

relative

                bioequivalence

area under the curve (AUC)

absorption rate constant (k[a])

pre-systemic elimination

                first-pass effect

P-glycoprotein

                cytochrome P450

distribution of drugs

rate of distribution

distribution equilibrium

volume of distribution (Vd)

redistribution

drug elimination

clearance (Cl)

elimination rate constant (k[e])

half-life (T[1/2])

1^st order kinetics (linear kinetics)

zero order kinetics (non-linear kinetics, saturation kinetics)

drug metabolism

phase 1 reactions

phase 2 reactions

cytochrome P450

induction of P450

inhibition of P450

genetic polymorphism of biotransformation enzymes

biodegradation and bioactivation of drugs and prodrugs

drug excretion

alteration of excretion

renal excretion

glomerular filtration

tubular secretion


tubular reabsorption

liver excretion

enterohepatic recirculation

factors affecting pharmacokinetic processes

pharmacokinetic interactions


Learning outcomes

Students will know the principles of drug molecule movement across the cell barriers in the body

Students understand individual pharmacokinetic processes and know which pharmacokinetic parameter
they describe

Students know and can explain the principles of linear and non-linear pharmacokinetics

Students can predict basic pharmacokinetic interactions and understand their mechanism.

Students can calculate the dose of a drug based on the required plasma concentration, distribution
volume and bioavailability.

Students can calculate time needed to eliminate the drug based on T[1/2].


Study materials:

Rang & Dale’s pharmacology:  Chapters 8,9,10 (pp. 101-131)

Handouts and lecture No. 3