Question | Answer |
absorption | the process whereby a drug enters the circulatory system |
addiction | a dependence characterized by a perceived need to take a drug to attain the psychological and physical effects of mood altering substances |
affinity | the strength by which a particular chemical messenger binds to its receptor site on a cell |
agonist | drugs that bind to a particular receptor site and trigger the cell's response in a manner similar to the action of the body's own chemical messenger |
allergen | substance that produces an allergic response |
allergic response | an instance in which the immune system overreacts to an otherwise harmless substance |
anaphylactic reaction | a severe allergic response resulting in immediate life-threatening respiratory distress, usually followed by vascular collapse and shock and accompanied by hives |
angioedema | abnormal accumulation of fluid in tissue |
antagonist | drugs that bind to a receptor site and block the action of the endogenous messenger or other drugs |
antigen | a specific molecule that stimulates an immune response |
bioavailability | the degree to which a drug or other substance becomes available to the target tissue after administration |
blood-brain barrier | a barrier that prevents many substances from entering the cerebrospinal fluid from the blood; formed by glial cells that envelope the capillaries in the central nervous system, presenting a barrier to many water-soluble compounds though they are permeable |
ceiling effect | a point at which no clinical response occurs with increased dosage |
clearance | the rate at which a drug is eliminated from a specific volume of blood per unit of time |
contraindication | a disease, condition, or symptom for which a drug will not be beneficial and may do harm |
dependence | a state in which a person's body has adapted physiologically and psychologically to a drug and cannot function without it |
distribution | the process by which a drug moves from the blood into other body fluids and tissues and ultimately to its sites of action |
dose | the quantity of a drug administered at one time |
duration of action | the length of time a drug gives the desired response or is at the therapeutic level |
elimination | removal of a drug or its metabolites from the body by excretion |
first-order | depending directly on the concentration of the drug; elimination of most drugs is a first-order process in which a constant fraction of the drug is eliminated per unit of time |
first-pass effect | the extent to which a drug is metabolized by the liver before reaching systemic circulation |
half-life | the time necessary for the body to eliminate half of the drug in the body at any time; written as T1/2 |
homeostasis | stability of the organism |
idiosyncratic reaction | an unusual or unexpected response to a drug that is unrelated to the dose given |
indication | a disease, symptom, or condition for which a drug is known to be of benefit |
induction | the process whereby a drug increases the concentration of certain enzymes that affect the pharmacologic response to another drug |
inhibition | the process whereby a drug blocks enzyme activity and impairs the metabolism of another drug |
interaction | a change in the action of a drug caused by another drug, a food, or another substance such as alcohol or nicotine |
lipid | a fatty molecule, an important constituent of cell membranes |
local effect | an action of a drug that is confined to a specific part of the body |
loading dose | amount of a drug that will bring the blood concentration rapidly to a therapeutic level |
maintenance dose | amount of a drug administered at regular intervals to keep the blood concentration at a therapeutic level |
metabolic pathway | the sequence of chemical steps that convert a drug into a metabolite |
metabolism | the process by which drugs are chemically converted to other compounds |
metabolite | a substance into which a drug is chemically converted in the body |
peak | the top or upper limit of a drug's concentration in the blood |
pharmacokinetic modeling | a method of describing the process of absorption, distribution, metabolism, and elimination of a drug within the body mathematically |
pharmacokinetics | the activity of a drug within the body over a period of time; includes absorption, distribution, metabolism, and elimination |
prophylaxis | effect of a drug in preventing infection or disease |
pruritus | itching sensation |
receptor | a protein molecule on the surface of or within a cell that recognizes and binds with specific molecules, thereby producing some effect within the cell |
side effect | a secondary response to a drug other than the primary therapeutic effect for which the drug was intended |
solubility | a drug's ability to dissolve in body fluids |
specificity | the property of a receptor site that enables it to bind only with a specific chemical messenger; to bind with a specific cell type, the messenger must have a chemical structure that is complementary to the structure of that cell's receptors |
systemic effect | an action of a drug that has a generalized, all-inclusive effect on the body |
therapeutic effect | the desired action of a drug in the treatment of a particular disease state or symptom |
therapeutic level | the amount of drug in a patient's blood at which beneficial effects occur |
therapeutic range | the optimum dosage, providing the best chance for successful therapy; dosing below this range has little effect on the healing process, while overdosing can lead to toxicity and death |
tolerance | a decrease in response to the effects of a drug as it continues to be administered |
trough | the lowest level of a drug in the blood |
urticaria | hives, itching sensation |
volume of distribution | mathematical relationship between the blood concentration attained and the amount of drug administered |
wheals | slightly elevated, red areas on the body surface |
zero-order | not depending on the concentration of the drug in the body; elimination of alcohol is a zero-order process in which a constant quantity of the drug is removed per unit of time |