chapter 1 vocab Flashcards
absorption
Movement of a drug from the site of administration to the circulatory system.
acute tolerance
Rapid tolerance formed during a single administration of a drug, as is the case with alcohol.
additive effects
Drug interactions characterized by the collective sum of the two individual drug effects.
affinity
Attraction between a molecule and a receptor.
area postrema
Area in the medulla of the brain stem that is not isolated from chemicals in the blood. It is responsible for inducing a vomiting response when a toxic substance is present in the blood.
astrocytes
Star-shaped cells of the nerve tissue that have numerous extensions and that modulate the chemical environment around neurons, metabolically assist neurons, and provide phagocytosis for cellular debris.
behavioral tolerance
The reduced effectiveness of a drug administered chronically that involves learning: either instrumental or classical conditioning.
bioavailability
Concentration of drug present in the blood that is free to bind to specific target sites.
biotransformation
Inactivation of a drug through a chemical change, usually by metabolic processes in the liver.
cerebrospinal fluid (CSF)
Fluid that surrounds the brain and spinal cord, providing cushioning that protects against trauma.
classical conditioning
Repeated pairing of a neutral stimulus with an unconditioned stimulus. Eventually the neutral stimulus becomes a conditioned stimulus and elicits a (conditioned) response that is similar to the original unconditioned response.
competitive antagonist
Drug that binds to a receptor but has little or no efficacy. When it competes with an agonist for receptor sites, it reduces the effect of the agonist.
concentration gradient
Difference in the amount or concentration of a substance on each side of a biological barrier, such as the cell membrane.
cross-tolerance
Tolerance to a specific drug can reduce the effectiveness of a another drug in the same class.
cytochrome P450 (CYP450)
Class of liver enzymes, in the microsomal enzyme group, responsible for both phase 1 and phase 2 biotransformation of psychoactive drugs.
depot binding
Type of drug interaction involving binding to an inactive site, such as to proteins in the plasma, to bone, or to fat.
dose-response curve
Graph used to display the amount of biological change in relation to a given drug dose.
double-blind experiment
Type of experiment in which neither the patient nor the observer knows the treatment received by the patient.
down-regulation
Decrease in the number of receptors, which may be a consequence of chronic agonist treatment.
drug action
Molecular changes associated with a drug binding to a particular target site or receptor.
drug competition
Interaction between two drugs that share a metabolic system and compete for the same metabolic enzymes. Bioavailability of one or both increases.
drug depots
Inactive sites where drugs accumulate. There is no biological effect from drugs binding at these sites, nor can they be metabolized.
drug disposition tolerance
metabolic tolerance
drug effects
Alterations in physiological or psychological functions associated with a specific drug.
efficacy
The extent to which a ligand-receptor binding initiates a biological action (e.g., the ability of an agonist to activate its receptor).
enteral
Drug administration by oral or rectal routes.
enzyme induction
Increase in liver drug-metabolizing enzymes associated with repeated drug use.
enzyme inhibition
Reduction in liver enzyme activity associated with a specific drug.
epidural
Method that involves administration of a drug into the cerebrospinal fluid surrounding the spinal cord.
fenestrations
Large pores in endothelial cells allowing rapid exchange between blood vessels and tissue
first-order kinetics
Term used to describe exponential elimination of drugs from the bloodstream.
first-pass metabolism
Phenomenon in which the liver metabolizes some of a drug before it can circulate through the body, particularly when the drug has been taken orally
gene therapy
Application of DNA that encodes a specific protein to increase or block expression of the gene product to correct a clinical condition.
genetic polymorphisms
Genetic variations in a population resulting in multiple forms of a particular protein
half-life
Time required to remove half of the drug from the blood. It is referred to as t1/2.
infusion pump
Drug delivery via an implanted pump (e.g., subcutaneous) that delivers regular, constant doses to the body or into the cerebral ventricles.
inhalation
Method that involves administration of a drug through the lungs.
intercellular clefts
Small gaps between adjacent cells.
intracerebroventricular
Method that involves administration of a drug into the cerebrospinal fluid of the ventricles.
intracranial
Method that involves administration of a drug into the brain tissue.
intramuscular (IM)
Method that involves administration of a drug into a muscle.
intranasal administration
Topical administration of a drug to the nasal mucosa.
intraperitoneal (IP)
Injection technique that is the most common route of administration for small laboratory animals. The drug is injected through the abdominal wall into the peritoneal cavity—the space that surrounds the abdominal organs.
intravenous (IV)
Method that involves administration of a drug directly into the bloodstream by means of a vein.
inverse agonist
Substance that activates a receptor but produces the opposite effect of a typical agonist at that receptor.
ionization
Process involving the dissociation of an electrically neutral molecule into charged particles (ions).
ligant
Molecule that selectively binds to a receptor.
median eminence
Area in the hypothalamus that is not isolated from chemicals in the blood and where hypothalamic-releasing hormones are secreted for transport to the anterior pituitary gland.
metabolic tolerance
Type of tolerance to a drug that is characterized by a reduced amount of drug available at the target tissue, often as a result of more-rapid drug metabolism. It is sometimes also called drug disposition tolerance.
microsomal enzymes
Enzymes in liver cells responsible for metabolizing exogenous substances such as drugs.
neuropharmacology
Area of pharmacology specializing in drug-induced changes to the function of cells in the nervous system.
neuropsychopharmacology
Area of pharmacology focusing on chemical substances that interact with the nervous system to alter behavior, emotions, and cognition.
noncompetitive antagonist
Drug that reduces the effect of an agonist, but does not compete at the receptor site. The drug may bind to an inactive portion of the receptor, disturb the cell membrane around the receptor, or interrupt the intercellular processes initiated by the agonist–receptor association.
nonspecific drug effects
Physical or behavioral changes not associated with the chemical activity of the drug–receptor interaction but with certain unique characteristics of the individual such as present mood or expectations of drug effects.
operant conditioning
Type of learning in which animals learn to repond to obtain rewards and avoid punishment.
oral administration (PO)
Method that involves administering a drug through the mouth.
parenteral
Methods of drug administration that do not use the gastrointestinal system, such as intravenous, inhalation, intramuscular, transdermal, etc.
partial agonists
Drugs that bind to a receptor but have low efficacy, producing weaker biological effects than a full agonist. Hence they act as agonists at some receptors and antagonists at others, depending on the regional concentration of full agonist. These were previously called mixed agonist-antagonists.
partition coefficient
An experimentally-derived measure of a drug’s lipid solubility used to predict its relative rate of movement across cell membranes.
passive diffusion
Movement of lipid-soluble materials across a biological barrier without assistance based on its concentration gradient, from higher to lower concentration.
Pavlovian
Reflexive and unconscious response to a stimulus.
pharmacodynamic tolerance
Type of tolerance formed by changes in nerve cell functions in response to the continued presence of a drug.
pharmacodynamics
Study of physiological and biochemical interactions of a drug with the target tissue responsible for the drug’s effects
pharmacogenetics
The study of the genetic basis for variability in drug response among individuals (sometimes called pharmacogenomics).
pharmacokinetic
Factors that contribute to bioavailability: the administration, absorption, distribution, binding, inactivation, and excretion of a drug.
pharmacology
Study of the actions of drugs and their effects on living organisms.
phospholipids
Lipid molecules that are major constituents of the cell membrane. They are composed of a polar head and two lipid tails.
physiological antagonism
Drug interaction characterized by two drugs reducing each other’s effectiveness in the body.
pinocytotic vesicles
Type of vesicles that envelop and transport large molecules across the capillary wall.
placebo
Substance that is pharmacologically inert, yet in many instances produces both therapeutic and side effects.
potency
Measure of the amount of drug necessary to produce a specific response.
potentiation
Drug interaction characterized by an increase in effectiveness greater than the collective sum of the individual drugs.
psychoactive drugs
Those drugs that have an effect on thinking, mood, or behavior.
psychopharmacology
Area of pharmacology specializing in drug-induced changes in mood, thinking, and behavior.
receptor agonist
A neurochemical or drug that can bind to a particular receptor protein and alter the shape of the receptor to initiate a cellular response.
receptor antagonist
A molecule that interacts with a receptor protein and produces no cellular effect after binding, and also prevents an “active” ligand from binding.
receptor subtypes
Group of receptors that respond to the same neurotransmitter but that differ from each other to varying degrees with respect to their structure, signaling mechanisms, and pharmacology.
receptors
Proteins located on the surface of or within cells that bind to specific ligands to initiate biological changes within the cell.
rectal administration
Drug delivery method, such as a suppository, used to deliver drugs via the lower intestine.
sensitization
Enhanced response to a particular drug after repeated drug exposure.
side effect
Undesired physical or behavioral change associated with a particular drug.
specific drug effects
Physical or behavioral changes associated with biochemical interactions of a drug with the target site.
state-dependent learning
Condition characterized by better performance of a particular task that was learned in a drugged state in the same drugged state, rather than in a nondrugged state. Tasks learned in a nondrugged state are likewise performed better in a nondrugged state.
steady state plasma level
The desired blood concentration of drug achieved when the absorption/distribution phase is equal to the metabolism/excretion phase.
subcutaneous (SC)
Method that involves injection of a drug just below the skin.
teratogen
Any agent including a virus, drug, or radiation that induces abnormal fetal development, causing birth defects.
therapeutic drug monitoring
Taking multiple blood samples to directly measure plasma levels of a drug after administration, to identify the optimum dosage for maximum therapeutic potential and minimal side effects.
therapeutic effects
Desired physical or behavioral changes associated with a particular drug
therapeutic index
The relationship between the drug dose that results in a toxic response compared to the dose required for the desired biological response. It is represented by the equation TI = TD50/ED50 where TD50 is the dose that is toxic for 50% of the population and ED50 is the effective dose for 50%.
tight junctions
Connection between cells characterized by a fusing of adjoining cell membranes.
tolerance
Decreased response to a drug as a direct result of repeated drug exposure.
topical
Method that involves administration of a drug through a mucous membrane such as the oral cavity, nasal mucosa, or vagina.
transdermal
Method that involves administration of a drug through the skin (e.g., with a patch)
up-regulation
Increase in the number of receptors, which may be a consequence of denervation or of chronic antagonist treatment.
viral vector
Use of a virus as a delivery system (called a vector) to carry a gene into the nuclei of target cells to alter protein synthesis.
zero-order kinetics
Term used to describe a constant rate of drug removal from the body, regardless of drug concentration in the blood.
