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Chapter 2 pharm
Principles of Drug Action and Drug Interactions
Question | Answer |
---|---|
Cellular protein that binds to a hormone so that a response can be elicited. | Receptors |
The study of interactions between drugs and their receptors and the series of events that result in a pharmacologic response. | Pharmacodynamics |
Drug that attach to a receptor but do not stimulate a response; used to block the receptor from attaching to another substance. | Antagonists |
Drugs that interact with a receptor to stimulate a response | Agonists |
Drugs that attach and elicit a small response but also block other responses. | partial agonists |
Acronym for the 4 stages of the drug cycle: absorption, distribution, metabolism, and excretion. | ADME |
The study of the mathematical relationships among the absorption, distribution, metabolism, and excretion of individual medicines over time. | pharmacokinetics |
Administering a drug directly into the gastrointestinal tract by oral, rectal, or nasogastric routes. | Enteral |
Subcutaneous, intramuscular, or intravenous method of administration; treatment by injection. | Parenteral |
A method of drug administration that includes inhalation, sublingual (under the tongue), or topical (on the skin) administration. | percutaneous |
When a drug moves from its site of administration to the blood. | absorption |
The ways in which drugs are transported by the circulating body fluids to the sites of action (receptors), metabolism, and excretion. | distribution |
An assay to determine the amount of drug present in a blood sample. | drug blood level |
Tissue change; the sum of all the physical and chemical process by which a living creature is produced and maintained; the transformation by which energy is made available for the uses of the organism. | metabolism |
The process by which the body inactivates drugs. Also called metabolism. | Biotransformation |
Elimination of drug metabolites and, in many cases, the active drug itself from the body. | excretion |
The amount of time required to eliminate 50% of the drug from the body. | half-life |
Also, known as the pharmacetic effect, relating to the dosage being used. | liberation |
How do drugs interact with receptor sites in the body? | they form a chemical bonds with specific sites. the drug has to have similar shape and affinity for the receptor. |
Explain the differences among a drug agonist, partial agonist, and antagonist, and give examples of each. | Agonist interact w/a receptor to stimulate a response.Antagonist attach to the receptor w/ no response. Partial Antagonist stimulate a response but inhibits other repsonses. |
How do you calculate a drug’s half-life? | the amount of time required to elminate 50% of the drug to be eleminated from the body. |
What stages does a drug go through in the process of pharmacokinetics? | Liberation, absorbtion, distribution, metabolism, and excretion. |
Discuss the effects of adverse drug reactions (ADRs) on individual patients and on the costs of health care. | any noxious, unintended, and desired effect of a drug, Between 5% and 9% of hospital costs are attributed to ADRs |
Investigate mechanisms used at your clinical site to report adverse drug effects. | |
What effects do body weight, body surface area, metabolic rate, and illness have on drug therapy? | |
Discuss the difference between bound and unbound drugs and the resultant effects on drug action. | only an unbound drug is pharmacologically active. |
For which pharmacokinetic effect does a patient with impaired renal function need particular monitoring? | accumulation;Because most drugs are excreted through the kidneys, patients with impaired renal function are at risk for drug accumulation. |
Which is the best description of a toxic reaction to a drug? | Deleterious adverse effect;A toxic reaction is a severe or deleterious adverse effect. Examples of toxic reactions to drugs include kidney and liver damage. |
Two patients, one thin and one obese, each receive a highly lipid-soluble drug. What difference in pharmacokinetics does the nurse expect in the obese patient as compared with the thin patient? | Drug elimination will be slowed.; Distribution is determined by circulation of body fluids. |
A patient states he is allergic to the medication the nurse is ready to administer to him. What does the nurse do next? | Withholds the medication and notifies the prescriber of the situation;Allergic or hypersensitivity reactions to drugs can be severe and life threatening. Therefore, the drug is held and the prescriber is notified. ible seriousness of a |
A patient takes two medications. Drug A is taken once per day; drug B is taken every 8 hours. Based on this information, what does the nurse conclude about drug A? | It has a longer half-life than drug B;Drug A has a longer half-life than drug B; therefore, it does not have to be given as frequently. Half-life is the measure of time required for elimination of the drug from the body. |
When caring for a patient with abnormal levels of hepatic enzymes, the nurse is most concerned with monitoring for signs of change in which aspect of pharmacokinetics? | Metabolism;If levels of hepatic enzymes are high, drug metabolism may occur more rapidly than normal. Conversely, if hepatic enzyme activity is low, drug metabolism is slowed and there is risk of drug accumulation. |
What is the effect of protein binding on drugs in the bloodstream? | Inactivation of the drug;the large size of the drug-protein complex keeps them in the bloodstream and prevents them from reaching the sites of action, metabolism, and excretion. |
A patient is receiving a medication to increase urine output. The patient’s urinary output increases significantly and the blood pressure decreases slightly. How is the effect of decrease in blood pressure classified? | Common adverse effect;The decrease in blood pressure is a common adverse effect. An increase in urinary output is the desired or therapeutic effect. |
During which period is the risk of damage from a teratogenic drug the greatest? | First trimester of pregnancy; Birth defects caused by exposure to a teratogenic drug are most likely to occur during the first trimester of pregnancy because the major organ systems are forming at this time and are more susceptible to malformation. |
Which is the most common symptom of a hypersensitivity reaction to a medication? | Urticaria;Urticaria, or hives, is the most common type of hypersensitivity reaction to medications. This should be taken as a warning that a second exposure to the drug could result in a life-threatening anaphylactic reaction. |
Genetic makeup is most likely to alter a person’s response to medication through its effect on which factor? | Drug metabolism;or biotransformation is the process by which the body inactivates drugs. Liver enzyme systems are primarily responsible for drug metabolism. These enzyme systems are genetically determined and are subject to individual variation. |
A patient is taking an antacid concurrently with ketoconazole. The antacid inhibits the dissolution of ketoconazole. What is this result known as? | Drug interaction;A drug interaction occurs when the action of one drug is altered by another. |