***An antagonist is a drug that prevents receptor activation. A selective drug has only the desired response but may not activate receptors. An agonist is
... [Show More] a molecule that activates receptors. A potent drug requires a lower dose to achieve its effect. Answer- The nurse prepares to give a drug that will prevent receptor activation. Which term would describe this drug?
A. Potent
B. Agonist
C. Selective
D. Antagonist
C. Pharmacodynamics
***Pharmacodynamics is the study of what drugs do to the body. Pharmacokinetics is the study of drug movement throughout the body. Pharmacotherapeutics is the use of drugs to diagnose, prevent, or treat disease or to prevent pregnancy. Pharmacology is the study of drugs in humans. Answer- What is the term for the study of how drugs influence the body?
A. Pharmacology
B. Pharmacokinetics
C. Pharmacodynamics
D. Pharmacotherapeutics
D. The highest dose needed to produce a therapeutic effect is close to the lethal dose.
***A low therapeutic index indicates that the high doses needed to produce therapeutic effects in some people may be large enough to cause death. A high therapeutic index is more desirable, because the average lethal dose is higher than the therapeutic dose. Low variability of responses to a drug is not the definition of a low therapeutic index. Answer- Why does the nurse monitor the patient closely after administering a drug with a low therapeutic index?
A. There is a low variability of responses to this drug.
B. The average lethal dose of the drug is much higher than the therapeutic dose.
C. The dose required to produce a therapeutic response in 50% of patients is low.
D. The highest dose needed to produce a therapeutic effect is close to the lethal dose.
A. Monitor the patient's plasma drug level periodically.
***The therapeutic range of a drug is the range between the minimum effective concentration of the drug in the plasma to obtain the desired drug action and the minimum toxic concentration. The nurse must monitor the plasma drug level periodically to avoid drug toxicity while caring for a patient receiving a drug with a low therapeutic index, such as digoxin. Some medications, such as diphenhydramine [Benadryl], cause drowsiness as a side effect. In such cases, the nurse instructs patients not to drive after taking the medication. Some drugs bind to the protein molecules in the body. The nurse monitors serum albumin levels in patients receiving those drugs to determine the possibility of drug toxicity. Patients who are prescribed enteric-coated tablets should not eat a high-fat meal before taking the drug, as that will decrease the absorption rate of the drug. Answer- The nurse is caring for a patient who is receiving a drug with a low therapeutic index. Which is the most important nursing intervention for this patient?
A. Monitor the patient's plasma drug level periodically.
B. Monitor the patient's serum albumin levels periodically.
C. Instruct the patient not to drive after taking the medication.
D. Instruct the patient not to take the drug after a high-fat meal.
B. Increased heart rate
***Dobutamine mimics the action of norepinephrine (NE) at receptors on the heart, thereby causing an increase in the heart's rate and force of contraction. Answer- The drug dobutamine acts as an agonist of norepinephrine (NE) receptors. Which effect is the nurse most likely to observe in a patient receiving this medication?
A. Sinus bradycardia
B. Increased heart rate
C. Reduced cardiac output
D. Atrioventricular heart block
B. Antagonist
***An antagonist drug is one that blocks the histamine receptors to prevent excessive gastric secretion. Drugs that produce a response are called agonists. For example, epinephrine [Adrenalin] is an agonist that stimulates beta1 and beta2 receptors. Nonspecific drugs affect various sites in the body. Bethanechol [Urecholine] is a nonspecific cholinergic drug that affects cholinergic receptors located in the eye, heart, blood vessels, stomach, bronchus, and bladder. Nonselective drugs affect various receptors. Chlorpromazine [Thorazine] acts on the norepinephrine, dopamine, acetylcholine, and histamine receptors, and a variety of responses result from action at these receptor sites. Answer- The nurse is caring for a patient who is prescribed a drug to block the histamine receptors to prevent excessive gastric secretion. Which category of drugs does this medication belong to?
A. Agonist
B. Antagonist
C. Nonspecific
D. Nonselective
A. Antacids
***Antacids do not act through receptors. Antacids neutralize gastric activity by direct chemical interaction with stomach acid. Answer- The nursing student learns that not all drugs produce effects by binding to a receptor. Which drugs do not act through receptors?
A. Antacids
B. Analgesics
C. Antihistamines
D. Steroid hormones
A. Bronchial dilation
B. Increased heart rate
F. Increased force of heart contraction [Show Less]