Search results
Results from the WOW.Com Content Network
The duration of action of a drug is the length of time that particular drug is effective. [5] Duration of action is a function of several parameters including plasma half-life, the time to equilibrate between plasma and target compartments, and the off rate of the drug from its biological target. [6]
Pharmacokinetics 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.
Contrary to what many advertised drug tests might promise, not all substances leave their telltale chemical signature in the body for the same amount of time. The moment we take a drug — whether ...
A few drugs such as alcohol are absorbed by the lining of the stomach, and therefore tend to take effect much more quickly than the vast majority of oral medications which are absorbed in the small intestine. Gastric emptying time can vary from 0 to 3 hours, [2] and therefore plays a major role in onset of action for orally administered drugs ...
Pharmacokinetics studies the manner and speed with which drugs and their metabolites are eliminated by the various excretory organs. This elimination will be proportional to the drug's plasmatic concentrations. In order to model these processes a working definition is required for some of the concepts related to excretion.
Pharmacology can also focus on specific systems comprising the body. Divisions related to bodily systems study the effects of drugs in different systems of the body. These include neuropharmacology, in the central and peripheral nervous systems; immunopharmacology in the immune system.
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. [1] Consumption of drugs can be via inhalation, injection, smoking, ingestion, absorption via a patch on the skin, suppository, or dissolution under the tongue.
Polonium in the body has a biological half-life of about 30 to 50 days. Caesium in the body has a biological half-life of about one to four months. Mercury (as methylmercury) in the body has a half-life of about 65 days. Lead in the blood has a half life of 28–36 days. [29] [30] Lead in bone has a biological half-life of about ten years.