Pharm 2 Flashcards
Pharmacokinetics
Action of body on the drug via movement of the drug in and out of the body.
Pharmacodynamics
Action of drug within the body via a drug-receptor action
Absorption
Dependent on bioavailability, route of administration, first pass effect
Distribution
Dependent on tissues penetration, volume of distribution, fat/water solubility
Distribution phase: time between administration of dose and its equilibration between central and peripheral compartments
Metabolism
Biotransformation within the body
Excretion
The removal of a drug or its metabolites from the body, primarily by the kidneys and urination.
Loading dose
Given to rapidly establish a therapeutic plasma drug concentration. Can be calculated by multiplying the volume of distribution by the desired plasma drug concentration.
Maintenance dose
Given to establish or maintain the desired steady-state plasma drug concentration.
Volume of distribution (Vd)
Amount of volume necessary to fill the internal and external compartments of the body
Clearance
Clearance (Cl) is the most fundamental expression of drug elimination. It is defined as the volume of body fluid (blood) from which a drug is removed per unit of time.
Elimination half-life (t½)
Is the time required to reduce the plasma drug concentration by 50%.
ED50 (or ED99)
Median effective dose (ED50), which is the dose that produces 50% of the maximal response.
TD50
The median toxic dose (TD50) of a drug or toxin is the dose at which toxicity occurs in 50% of cases.
LD50
Lethal dose (LD50) is the amount of an ingested substance that kills 50 percent of a test sample.
Tmax
The time needed to reach the maximum
Cmax
Maximum concentration
Duration of action/duration of effective concentration
The duration of action of a drug is the length of time that particular drug is effective.
Steady state
Overall intake of a drug is fairly in dynamic equilibrium with its elimination.
Therapeutic window
Range of doses that produces therapeutic response without causing any significant adverse effect in patients.
Therapeutic index
The therapeutic index is a quantitative measurement of the relative safety of a drug.
The larger the therapeutic index (TI), the safer the drug is.
Dose-concentration graph
Plots the drug dose (or concentration) against its effect.
Area under the curve (AUC)
Reflects the actual body exposure to drug after administration of a dose of the drug and is expressed in mg*h/L. This area under the curve is dependent on the rate of elimination of the drug from the body and the dose administered.
