Principles of Pharmacology
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© Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC manning/Shutterstock © Sofi NOT FOR SALE OR DISTRIBUTION NOT FOR2 SALE OR DISTRIBUTION Principles of Pharmacology © Jones & Bartlett Learning, LLC Laura Williford Owens,© Robin Jones Webb & Corbett, Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONTekoa L. King NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE✜ Chapter OR DISTRIBUTION Glossary NOT FOR SALE OR DISTRIBUTION exchange of drugs between the systemic circulation Absorption Movement of drug particles from the gastro- and the circulation in the central nervous system. intestinal tract to the systemic circulation by passive Chronobiology (chronopharmacology) Use of knowledge of cir- absorption, active transport, or pinocytosis. cadian rhythms to time administration of drugs for © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Affinity Degree of attraction between a drug and a recep- maximum benefi t and minimal harm. tor. Th e greater NOTthe attraction, FOR SALE the greater OR DISTRIBUTIONthe extent Clearance Measure of the body’sNOT ability FOR to SALE eliminate OR a drug.DISTRIBUTION of binding. Competitive antagonist Drug or ligand that reversibly binds Agonist Drug that activates a receptor when bound to that to receptors at the same receptor site that agonists use receptor. (active site) without activating the receptor to initiate Agonist–antagonist© Jones & BartlettDrug that Learning,has agonist properties LLC for one a reaction.© Jones & Bartlett Learning, LLC NOTopioid FOR receptor SALE and antagonist OR DISTRIBUTION properties for a diff erent CytochromeNOT P-450 FOR (CYP450) SALE Generic OR name DISTRIBUTION for the family of type of opioid receptor. enzymes that are responsible for most drug metabolism Allele One of a number of alternative forms of a gene or reactions. DNA sequence that is located at a specifi c position on Dissolution Disintegration of solid drugs (tablets) into small a specifi c chromosome. Each individual inherits two particles in the gastrointestinal tract so that they can © Jones & Bartlettalleles for Learning, each gene. IfLLC the two alleles are the same,© the Jones dissolve& Bartlett into a Learning, liquid. LLC NOT FOR SALEperson OR is DISTRIBUTIONhomozygous. If they are diff erent versionsNOT of FORDistribution SALE Process OR DISTRIBUTION by which a drug becomes available to the gene, the person is heterozygous. Genes can have body fl uids and body tissues. several diff erent forms or diff erent alleles. Dose–response relationship (dose–response curve) Change in Antagonist Drug that prevents a receptor from being acti- the response to a drug caused by diff erent doses of that vated when bound© toJones that receptor. & Bartlett Learning, LLC drug. Dose–response curves© Jones help determine& Bartlett safe Learning, doses LLC Bioavailability PercentageNOT of FOR an administered SALE OR drug DISTRIBUTION that is for drugs. NOT FOR SALE OR DISTRIBUTION available to the target tissues. Drug–drug interaction Altered drug eff ect that occurs when Bioequivalence State in which a product’s bioavailability falls another drug is administered at the same time or in close within 80% to 125% of the bioavailability of the refer- proximity to the original drug’s administration time. ence drug. If two products are bioequivalent, one can Drug–herb interactions Altered drug eff ect that occurs when ©usually Jones be substituted& Bartlett for Learning, the other. LLC certain© herbsJones are & taken Bartlett at the Learning, same time orLLC in close BiotransformationNOT FOR SALE Chemical OR changes DISTRIBUTION a substance undergoes proximityNOT to FOR a drug’s SALE administration OR DISTRIBUTION time. in the body. Drug–nutrient interaction Altered drug eff ect that occurs Blood–brain barrier Characteristics of the capillaries sur- when certain foods or liquids are taken at the same time rounding the brain that create a natural barrier to the or in close proximity to a drug’s administration time. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION 25 © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781284078879_CH02.indd 25 7/23/15 9:02 PM 26 CHAPTER 2 Principles of Pharmacology © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOREfficacy SALE Capacity OR toDISTRIBUTION induce a therapeutic response. As NOTMinimum FOR effective SALE concentration OR DISTRIBUTION Minimum concentration of a opposed to eff ectiveness, which is the ability of a drug to drug in serum required to produce a desired pharma- produce a therapeutic response in real life conditions. cologic eff ect. Elimination Removal of a drug or its metabolites whereby Narrow therapeutic index As defi ned by the Food and Drug the drug or metabolites are changed to a water-soluble Administration, less than a twofold diff erence between form, and thereby removed© Jones via the & kidneys;Bartlett less Learning, com- LLCthe median eff ective dose and© the Jones median & lethal Bartlett dose. Learning, LLC mon elimination routesNOT include FOR liver, SALE bile, feces, OR saliva,DISTRIBUTION Noncompetitive antagonist Drug or ligandNOT thatFOR reversibly SALE binds OR DISTRIBUTION lungs, sweat, and breast milk. to a receptor at a site diff erent from the active site used Enteric coating Drug coating applied to slow the release and by agonists; this binding causes a structural change that absorption of a drug in the stomach. inhibits the agonist from binding to the active site. Non- Excretion ©Elimination Jones & of Bartlett a drug from Learning, the biologic LLC system. competitive© antagonists Jones & do Bartlett not compete Learning, for the active LLC Extended NOTrelease (sustainedFOR SALE release, OR slow DISTRIBUTIONrelease) Drug designed binding siteNOT but they FOR do have SALE an antagonist OR DISTRIBUTION eff ect. to be released over an extended period of time. Partial agonist Drug molecule that elicits a partial pharma- First-pass metabolism (first-pass effect) Drug metabolism that cologic response. occurs as a drug passes through the intestinal lumen, Peak level Highest plasma drug concentration. portal vein, and liver prior to entering the systemic cir- P-glycoprotein Permeability glycoprotein (P-gp); a trans- © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC culation. Also known as hepatic fi rst pass. membrane protein that serves as a drug transporter NOT FORG-protein–coupled SALE OR receptor DISTRIBUTION Type of cell membrane receptor. NOTand FOR moves SALE drugs OR out DISTRIBUTIONof cells. Also known as multidrug Th e drug binds with this receptor, which then binds resistance protein 1 (MDR1) or ATP-binding cassette with guanosine triphosphate (GTP) and activates an subfamily B member 1 (ABCB1). eff ector (enzyme) in the cell. Pharmacodynamics Study of drug concentration and the Half-life Time it takes for ©half Jones of the drug & Bartlett concentration Learning, to LLCrecipient’s response; the study© of Jones a drug’s eff& ects,Bartlett includ- Learning, LLC be eliminated from theNOT body (FORt½). SALE OR DISTRIBUTIONing the duration and the magnitudeNOT FOR of the SALE response OR in DISTRIBUTION Hydrophilic Drug that is water soluble. A drug or drug relationship to the drug dose. metabolite must be hydrophilic to be excreted in urine. Pharmacokinetics Process of drug absorption, distribution, Inducer Drug that stimulates production of one of the metabolism, and elimination. CYP450© Jones enzymes, & which Bartlett in turn Learning, rapidly metabolizes LLC the Phase I reaction ©First Jones half of & enzymatic Bartlett metabolism,Learning, which LLC substrate drug. Th is can results in a decreased thera- makes a drug water soluble so it can be excreted; it includes NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION peutic eff ect of the substrate drug. oxidation, hydrolysis, and/or reduction reactions. Inhibitor Drug that prevents production of a CYP450 Phase II conjugation reaction Second half of the drug metabo- enzyme, which in turn decreases metabolism of the lism process, which makes the drug polar and fi nalizes substrate drug. Th is results in an increased plasma level the changes that make it water soluble. © Jones &of theBartlett substrate Learning, drug and, therefore, LLC an increased thera- © JonesPolymorphism & Bartlett One of two Learning, or more naturally LLC occurring vari- NOT FORpeutic SALE eff ect,OR adverse DISTRIBUTION drug reaction, and/or toxic eff ect. NOTants FOR of aSALE particular OR DNA DISTRIBUTION sequence on a chromosomal Inverse agonist Drug that binds to receptors that have an locus. Th e DNA variant is termed a polymorphism (as intrinsic or basal activity, which results in antagonism opposed to a mutation) when it appears in more than of this basal activity and downregulation of the recep- 1% of a population. Two types of polymorphisms are tor’s eff ect. Antihistamines are inverse agonists. distinguished: insertions/deletions and single-nucleo- © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC Ligand Drug or chemical that binds to a specifi c receptor. tide polymorphisms (SNP) wherein there is a change in Lipophilic Drug that has aNOT high affiFOR nity SALE for fat. ORLipophilic DISTRIBUTION the order of an amino acid base.NOT FOR SALE OR DISTRIBUTION drugs transfer