What is Michaelis Menten pharmacokinetics?
Drugs that are metabolized by the cytochrome P-450 enzymes and other enzyme systems may undergo Michaelis-Menten or saturable pharmacokinetics. This is the type of nonlinear pharmacokinetics that occurs when the number of drug molecules overwhelms or saturates the enzyme’s ability to metabolize the drug.
What is Vmax in pharmacokinetics?
Vmax is the reaction rate when the enzyme is fully saturated by substrate, indicating that all the binding sites are being constantly reoccupied. From: Introduction to Biological and Small Molecule Drug Research and Development, 2013.
What is Ka in pharmacokinetics?
The absorption rate constant Ka is a value used in pharmacokinetics to describe the rate at which a drug enters into the system. It is expressed in units of time−1. This is in contrast to parameters like bioavailability and elimination half-life, which can often be found in drug and pharmacology handbooks.
What is pharmacokinetics article?
Pharmacokinetics (PK) is the study of how the body interacts with administered substances for the entire duration of exposure (medications for the sake of this article). This is closely related to but distinctly different from pharmacodynamics, which examines the drug’s effect on the body more closely.
What does linear pharmacokinetics mean?
Linear pharmacokinetics is so-called because the graph of the relationship between the various factors involved (dose, blood plasma concentrations, elimination, etc.) gives a straight line or an approximation to one.
What are pharmacokinetic parameters?
Pharmacokinetic parameters are assessed by monitoring variations in concentration of the drug and/or its metabolites in physiological fluids that are easy to access (i.e., plasma and urine). Plasma concentrations are usually checked, and in addition biopsies can be taken from animals and sometimes from humans.
What is pharmacokinetics definition?
Pharmacokinetics is a branch of pharmacology which studies what the body does to a drug. Pharmacokinetics looks at how a substance enters, moves through and exits the body.