Chapter 2 Flashcards
the four aspects of pharmacokinetics
1.absorption
2. distribution
3. metabolism
4. excretion
Additive effects
Drug interactions in which the effect of a combination of two or more drugs with similar actions is equivalent to the sum of the individual effects of the same drugs given alone. For example, 1 + 1 = 2 (compare with synergistic effects).
Adverse drug event
Any undesirable occurrence related to administering or failing to administer a prescribed medication.
Adverse drug reaction
Any unexpected, unintended, undesired, or excessive response to a medication given at therapeutic dosages (as opposed to overdose).
Adverse effects
A general term for any undesirable effects that are a direct response to one or more drugs.
Agonist
A drug that binds to and stimulates the activity of one or more receptors in the body.
Allergic reaction
An immunologic hypersensitivity reaction resulting from the unusual sensitivity of a patient to a particular medication; a type of adverse drug event.
Antagonist
A drug that binds to and inhibits the activity of one or more receptors in the body. Antagonists are also called inhibitors.
Antagonistic effects
Drug interactions in which the effect of a combination of two or more drugs is less than the sum of the individual effects of the same drugs given alone (1 + 1 equals less than 2); it is usually caused by an antagonizing (blocking or reducing) effect of one drug on another.
Bioavailability
A measure of the extent of drug absorption for a given drug and route (from 0% to 100%).
Biotransformation
One or more biochemical reactions involving a parent drug; occurs mainly in the liver and produces a metabolite that is either inactive or active. Also known as metabolism.
Blood-brain barrier
The barrier system that restricts the passage of various chemicals and microscopic entities (e.g., bacteria, viruses) between the bloodstream and the central nervous system. It still allows for the passage of essential substances such as oxygen.
Chemical name of drug
The name that describes the chemical composition and molecular structure of a drug.
Contraindication
Any condition, especially one related to a disease state or patient characteristic, including current or recent drug therapy, which renders a particular form of treatment improper or undesirable.
Cytochrome P-450
The general name for a large class of enzymes that plays a significant role in drug metabolism and drug interactions.
Dependence
A state in which there is a compulsive or chronic need, as for a drug.
Dissolution
The process by which solid forms of drugs disintegrate in the gastrointestinal tract and become soluble before being absorbed into the circulation.
Drug
Any chemical that affects the physiologic processes of a living organism.
Drug actions
The processes involved in the interaction between a drug and body cells (e.g., the action of a drug on a receptor protein); also called mechanism of action.
Drug classification
A method of grouping drugs; may be based on structure or therapeutic use.
Drug effects
The physiologic reactions of the body to a drug. They can be therapeutic or toxic and describe how the body is affected as a whole by the drug.
Drug-induced teratogenesis
The development of congenital anomalies or defects in the developing fetus caused by the toxic effects of drugs.
Drug interaction
Alteration in the pharmacologic or pharmacokinetic activity of a given drug caused by the presence of one or more additional drugs; it is usually related to effects on the enzymes required for metabolism of the involved drugs.
Duration of action
The length of time the concentration of a drug in the blood or tissues is sufficient to elicit a response.
Enzymes
Protein molecules that catalyze one or more of a variety of biochemical reactions, including those related to the body’s physiologic processes, as well as those related to drug metabolism.
First-pass effect
The initial metabolism in the liver of a drug absorbed from the gastrointestinal tract before the drug reaches systemic circulation through the bloodstream.
Generic name
The name given to a drug by the United States Adopted Names Council. Also called the nonproprietary name. The generic name is much shorter and simpler than the chemical name and is not protected by trademark.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
A hereditary condition in which red blood cells break down when the body is exposed to certain drugs.
Half-life
In pharmacokinetics, the time required for half of an administered dose of drug to be eliminated by the body, or the time it takes for the blood level of a drug to be reduced by 50% (also called elimination half-life).
Idiosyncratic reaction
An abnormal and unexpected response to a medication, other than an allergic reaction, that is peculiar to an individual patient.
Incompatibility
The characteristic that causes two parenteral drugs or solutions to undergo a reaction when mixed or given together that results in the chemical deterioration of at least one of the drugs.
Intrathecal
Within a sheath (e.g., the theca of the spinal cord, as in an intrathecal injection into the subarachnoid space).
Medication error
Any preventable adverse drug event (see above) involving inappropriate medication use by a patient or health care professional; it may or may not cause patient harm.
Medication use process
1prescribing
2dispensing
3administering of medications
3monitoring of their effects.
Metabolite
A chemical form of a drug that is the product of one or more biochemical (metabolic) reactions involving the parent drug (see later). Active metabolites are those that have pharmacologic activity of their own, even if the parent drug is inactive (see prodrug). Inactive metabolites lack pharmacologic activity and are simply drug waste products awaiting excretion from the body (e.g., via the urinary, gastrointestinal, or respiratory tract).
Onset of action
The time required for a drug to elicit a therapeutic response after dosing.
P-glycoprotein
A transporter protein that moves drugs out of cells and into the gut, urine, or bile.
Parent drug
The chemical form of a drug that is administered before it is metabolized by the body into its active or inactive metabolites (see metabolite). A parent drug that is not pharmacologically active itself is called a prodrug. A prodrug is then metabolized to pharmacologically active metabolites.
Peak effect
The time required for a drug to reach its maximum therapeutic response in the body.
Peak level
The maximum concentration of a drug in the body after administration, usually measured in a blood sample for therapeutic drug monitoring.
Pharmaceutics
The science of preparing and dispensing drugs, including dosage form design.
Pharmacodynamics
The study of the biochemical and physiologic interactions of drugs at their sites of activity. It examines the effect of the drug on the body.
Pharmacoeconomics
The study of economic factors impacting the cost of drug therapy.
Pharmacogenomics
The study of the influence of genetic factors on drug response that result in the absence, overabundance, or insufficiency of drug-metabolizing enzymes
Pharmacognosy
The study of drugs that are obtained from natural plant and animal sources.
Pharmacokinetics
The study of what happens to a drug from the time it is put into the body until the parent drug and all metabolites have left the body. Pharmacokinetics represent the drug absorption into, distribution and metabolism within, and excretion from the body.
Pharmacology
The broadest term for the study or science of drugs. Pharmacotherapeutics The treatment of pathologic conditions through the use of drugs.
Prodrug
An inactive drug dosage form that is converted to an active metabolite by various biochemical reactions once it is inside the body.
Prototypical drug
The first form of a drug, or first in a class of drugs. Throughout this book, prototypical drugs will be denoted as a “key drug.”
Receptor
A molecular structure within or on the outer surface of a cell. Receptors bind specific substances (e.g., drug molecules), and one or more corresponding cellular effects (drug actions) occur as a result of this drug-receptor interaction.
Steady state
The physiologic state in which the amount of drug removed via elimination is equal to the amount of drug absorbed with each dose.
Substrates
Substances (e.g., drugs or natural biochemicals in the body) on which an enzyme acts.
Synergistic effects
Drug interactions in which the effect of a combination of two or more drugs with similar actions is greater than the sum of the individual effects of the same drugs given alone. For example, 1 + 1 is greater than 2 (compare with additive effects).
Therapeutic drug monitoring
The process of measuring drug levels to identify a patient’s drug exposure and to allow adjustment of dosages with the goals of maximizing therapeutic effects and minimizing toxicity.
Therapeutic effect
The desired or intended effect of a particular medication.
Therapeutic index
The ratio between the toxic and therapeutic concentrations of a drug.
Tolerance
Reduced response to a drug after prolonged use.
Toxic
The quality of being poisonous (i.e., injurious to health or dangerous to life).
Toxicity
The condition of producing adverse bodily effects due to poisonous qualities.
Toxicology
The study of poisons, including toxic drug effects, and applicable treatments.
Trade name
The commercial name given to a drug product by its manufacturer; also called the proprietary name.
