Pharmacokinetics

400px|thumb|right|A graph depicting a typical time course of drug plasma concentration over 96 hours, with oral administrations every 24 hours. The main pharmacokinetic metrics are annotated. Steady state is reached after about 5 × 12 = 60 hours. Pharmacokinetics (from Ancient Greek pharmakon 'drug' and kinetikos 'moving, putting in motion'; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to describing how the body affects a specific substance after administration. The substances of interest include any chemical xenobiotics such as pharmaceutical drug

semipermable membrane that separates blood and the brain

pharmacokinetic parameter; (of a substance) time it takes for a substance to lose half of its pharmacologic, physiologic, or radiologic activity

A prodrug is a pharmacologically inactive medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug is absorbed, distributed, metabolized, and excreted (ADME).

path by which a drug, fluid, poison, or other substance is taken into the body

superfamily of enzymes containing heme as a cofactor that function as monooxygenases

comparison of the amount of a drug that has a therapeutic effect to the amount that is toxic

biochemical modification of drugs or foreign compounds by living organisms

phenomenon of drug metabolism

change in the action or side effects of a drug caused by another drug

theoretical volume that would be necessary to contain the total amount of an administered drug at the same concentration that it is observed in the blood plasma.

completed form of a pharmaceutical preparation in which prescribed doses of medication are included

interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules)

thumb|right|335px|A bioequivalency profile comparison of 150 mg extended-release bupropion as produced by [[Impax Laboratories for Teva and Biovail for GlaxoSmithKline]]

thumb|Processes in pharmacokinetics ADME is the four-letter abbreviation (acronym) for absorption, distribution, metabolism, and excretion, and is mainly used in fields such as pharmacokinetics and pharmacology. The four letters stand for descriptors quantifying how a given drug interacts within body over time. The term ADME was first introduced in the 1960s, and has become a standard term widely used in scientific literature, teaching, drug regulations, and clinical practice.

thumb|Polypharmacy is often defined as taking 5 or more medicines. Polypharmacy (polypragmasia) is an umbrella term to describe the simultaneous use of multiple medicines by a patient for their conditions. The term polypharmacy is often defined as regularly taking five or more medicines but there is no standard definition and the term has also been used in the context of when a person is prescribed 2 or more medications at the same time. Polypharmacy may be the consequence of having multiple long-term conditions, also known as multimorbidity and is more common in the elderly. In some cases, an

administration of a discrete amount of medication within a specific time

pharmacological term

movement of a drug into the bloodstream or lymph

thumb|Polyethylene glycol PEGylation (or pegylation) is the process of both covalent and non-covalent attachment or amalgamation of polyethylene glycol (PEG, in pharmacy called macrogol) polymer chains to molecules and macrostructures, such as a drug, therapeutic protein or vesicle, which is then described as PEGylated. PEGylation affects the resulting derivatives or aggregates interactions, which typically slows down their coalescence and degradation as well as elimination in vivo.

statistical technique, with use of the mathematical integration concept to summarize information from a time series of measurements on one individual

observing, recording, or detecting the effects of a chemical substance administered to an individual

form of a substance after metabolism

amount of drug given to establish desired blood level

Pharmacometrics is a field of study of the methodology and application of models for disease and pharmacological measurement. It uses mathematical models of biology, pharmacology, disease, and physiology to describe and quantify interactions between xenobiotics and patients (human and non-human), including beneficial effects and adverse effects. It is normally applied to quantify drug, disease and trial information to aid efficient drug development, regulatory decisions and rational drug treatment in patients.

tablet coating to delay release of the medication until after the tablet leaves the stomach

Drug interactions with grapefruit juice

any one of a number of processes by which a drug is eliminated (that is, cleared and excreted) from an organism either in an unaltered form (unbound molecules) or modified as a metabolite

Toxicokinetics (often abbreviated as 'TK') is the description of both what rate a chemical will enter the body and what occurs to excrete and metabolize the compound once it is in the body.

Microdosing, or micro-dosing, involves the administration of sub-therapeutic doses of drugs to study their effects in humans, aiming to gather preliminary data on safety, pharmacokinetics, and potential therapeutic benefits without producing significant physiological effects. This is called a "Phase 0 study" and is usually conducted before clinical Phase I to predict whether a drug is viable for the next phase of testing. Human microdosing aims to reduce the resources spent on non-viable drugs and the amount of testing done on animals.

method of delivering medication to a patient, increasing the concentration of the medication in some parts of the body relative to others

Bioanalysis is a sub-discipline of analytical chemistry covering the quantitative measurement of xenobiotics (drugs and their metabolites, and biological molecules in unnatural locations or concentrations) and biotics (macromolecules, proteins, DNA, large molecule drugs, metabolites) in biological systems.

process in which a molecule induces the expression of an enzyme

defined volume of body fluids, typically of the human body

Modeling the body's responses to drugs

mechanism that delivers a drug with a delay or continuously after its administration

drug delivery system

toxicology relationship between the concentration of a poisonous gas and duration breathed