- Potency (pharmacology)
pharmacology, potency is a measure of the concentration of a drug at which it is effective.
To understand potency, you have to understand efficacy first. Efficacy is the relationship between receptor occupancy and the ability to initiate a response at the molecular, cellular, tissue or system level. The response is equal to the effect, or (E). The agonist, the ligand, drug or hormone that binds to the receptor and iniates the response is abbreviated A. Below a certain concentration of agonist ( [A] ), E is too low to measure but at higher concentrations it becomes appreciable and rises with increasing agonist concentration [A] until at sufficiently high concentrations it can no longer be increased by raising [A] and asymptotes to a maximum Emax.
The Emax is the maximum possible effect for the agonist. The concentration of A at which E is 50% of Emax is termed [A] 50. The term "potency" refers to the [A] 50 value. The lower the [A] 50, the less the concentration of a drug is required to produce 50% of maximum effect and the higher the potency.
----Higher Potency does not necessarily mean more side effects.
Potency is also the
THCcontent of different varieties of Cannabis.
* "Integrated pharmacology", third edition by Clive Page, Curtis Walker
Wikimedia Foundation. 2010.
Look at other dictionaries:
Potency — may refer to:*Virility *Potency (pharmacology), a measure of the activity of a drug in a biological system *In biology, potency is a measure of the differentiation potential of stem cells *In seismology, the quotient of seismic moment and… … Wikipedia
Pharmacology — A variety of topics involved with pharmacology, including neuropharmacology, renal pharmacology, human metabolism, intracellular metabolism, and intracellular regulation. Pharmacology (from Greek φάρμακον, pha … Wikipedia
pharmacology — pharmacological /fahr meuh keuh loj i keuhl/, pharmacologic, adj. pharmacologically, adv. pharmacologist, n. /fahr meuh kol euh jee/, n. the science dealing with the preparation, uses, and esp. the effects of drugs. [1715 25; < NL pharmacologia.… … Universalium
Distribution (pharmacology) — Distribution in pharmacology is a branch of pharmacokinetics which describes the reversible transfer of drug from one location to another within the body. The distribution of a drug between tissues is dependent on permeability between tissues… … Wikipedia
White widow — (« veuve blanche » en anglais) est une souche de cannabis créée par le producteur de cannabis australien Scott Shantibaba Blakey … Wikipédia en Français
Neuromuscular-blocking drug — Global view of a neuromuscular junction: 1. Axon 2. Motor end plate 3. Muscle fiber 4. Myofibril … Wikipedia
Receptor antagonist — This article is about the biochemistry term. For other uses, see Antagonist (disambiguation). Antagonists will block the binding of an agonist at a receptor molecule, inhibiting the signal produced by a receptor agonist coupling. A receptor… … Wikipedia
drug — drug1 /drug/, n., v., drugged, drugging. n. 1. Pharm. a chemical substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental well being. 2. (in federal law) a. any substance… … Universalium
Drug — /droog/, n. Zoroastrianism. the cosmic principle of disorder and falsehood. Cf. Asha. [ < Avestan drauga] * * * I Any chemical agent that affects the function of living things. Some, including antibiotics, stimulants, tranquilizers,… … Universalium
Chlorpromazine — Systematic (IUPAC) name … Wikipedia