Search results
Results from the WOW.Com Content Network
In practice, the drug concentration is measured at certain discrete points in time and the trapezoidal rule is used to estimate AUC. In pharmacology, the area under the plot of plasma concentration of a drug versus time after dosage (called “area under the curve” or AUC) gives insight into the extent of exposure to a drug and its clearance ...
Central to PK/PD models is the concentration-effect or exposure-response relationship. [4] A variety of PK/PD modeling approaches exist to describe exposure-response relationships . PK/PD relationships can be described by simple equations such as linear model, Emax model or sigmoid Emax model . [ 5 ]
Toxicodynamics (TD) and pharmacodynamics (PD) link a therapeutic agent or toxicant, or toxin (xenobiotic)'s dosage to the features, amount, and time course of its biological action. [11] The mechanism of action is a crucial factor in determining effect and toxicity of the drug, taking in consideration the pharmacokinetic (PK) factors. [ 12 ]
Half maximal effective concentration (EC 50) is a measure of the concentration of a drug, antibody or toxicant which induces a biological response halfway between the baseline and maximum after a specified exposure time. [1] More simply, EC 50 can be defined as the concentration required to obtain a 50% [...] effect [2] and may be also written ...
That is, the closer time points are, the closer the trapezoids reflect the actual shape of the concentration-time curve. The number of time points available in order to perform a successful NCA analysis should be enough to cover the absorption, distribution and elimination phase to accurately characterize the drug.
Time course of drug plasma concentrations over 96 hours following oral administrations every 24 hours (τ). Absorption half-life 1 h, elimination half-life 12 h. Biological half-life ( elimination half-life , pharmacological half-life ) is the time taken for concentration of a biological substance (such as a medication ) to decrease from its ...
There are numerous variables that influence the interpretation of drug concentration data: time, route and dose of drug given, time of blood sampling, handling and storage conditions, precision and accuracy of the analytical method, validity of pharmacokinetic models and assumptions, co-medications and, last but not least, clinical status of ...
The solution of this differential equation is useful in calculating the concentration after the administration of a single dose of drug via IV bolus injection: = C t is concentration after time t; C 0 is the initial concentration (t=0) K is the elimination rate constant