pharmacokinetics
Sign in to save400px|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
Article
17 sectionsContents
- ADME
- Metrics
- Modeling
- Noncompartmental analysis
- Compartmental analysis
- Single-compartment model
- Two-compartment model
- Multi-compartment models
- Bioavailability
- Analysis
- Bioanalytical methods
- Mass spectrometry
- Population pharmacokinetics
- Clinical pharmacokinetics
- Ecotoxicology
- See also
- References
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 drugs, pesticides, food additives, cosmetics, etc. PK attempts to analyze chemical metabolism and discover the fate of a chemical from the moment that it is administered up to the point at which it is completely eliminated from the body. PK is based on mathematical modeling that places great emphasis on the relationship between drug plasma concentration and the time elapsed since the drug's administration. Pharmacokinetics is the study of how an organism affects the drug, whereas pharmacodynamics (PD) is the study of how the drug affects the organism. Both together influence dosing, benefit, and adverse effects, as seen in PK/PD models.
== ADME == A number of phases occur once the drug enters into contact with the organism, these are described using the acronym ADME (or LADME if liberation is included as a separate step from absorption): Liberation – the process of active pharmaceutical ingredients (API) separating from its pharmaceutical formulation. See also IVIVC. Absorption – the process of a drug entering into systemic circulation from the site of administration. Distribution – the dispersion or dissemination of substances throughout the fluids and tissues of the body. Metabolism (or biotransformation, or inactivation) – the chemical reactions of the drug and irreversible breakdown into metabolites (e.g. by metabolic enzymes such as cytochrome P450 or glucuronosyltransferase enzymes). Excretion – the removal of the substance or metabolites from the body. In rare cases, some drugs irreversibly accumulate in body tissue.