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Introduction to Administration and Kinetics of Drugs

By

Jennifer Le

, PharmD, MAS, BCPS-ID, FIDSA, FCCP, FCSHP, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego

Reviewed/Revised Jun 2022 | Modified Sep 2022
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Topic Resources

Drug administration is the giving of a drug by one of several means (routes). Drug kinetics (pharmacokinetics) describes how the body handles a drug and accounts for the processes of absorption, distribution, metabolism, and elimination.

Overview of Drug Absorption, Metabolism, and Excretion
VIDEO

Drug treatment requires getting a drug to its specific target site or sites in tissues where the drug has its action. Typically, the drug is introduced into the body (the process of administration Drug Administration Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space... read more Drug Administration ), sometimes far from this target site. The drug must move into the bloodstream (the process of absorption Drug Absorption Drug absorption is the movement of a drug into the bloodstream after administration. (See also Introduction to Administration and Kinetics of Drugs.) Absorption affects bioavailability—how quickly... read more ) and be transported to the target sites where the drug is needed (the process of distribution Drug Distribution Drug distribution refers to the movement of a drug to and from the blood and various tissues of the body (for example, fat, muscle, and brain tissue) and the relative proportions of drug in... read more ). Some drugs are chemically altered (the process of metabolism Drug Metabolism Drug metabolism is the chemical alteration of a drug by the body. (See also Introduction to Administration and Kinetics of Drugs.) Some drugs are chemically altered by the body (metabolized)... read more ) by the body before they take effect, others are metabolized afterward, and still others are not metabolized at all. The final step is the removal of the drug and its metabolites (byproducts) from the body (the process of elimination Drug Elimination Drug elimination is the removal of drugs from the body. (See also Introduction to Administration and Kinetics of Drugs.) All drugs are eventually eliminated from the body. They may be eliminated... read more ).

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