A patient reports becoming “immune” to a medication because it no longer works to alleviate symptoms. The nurse recognizes that this decreased effectiveness is likely caused by:
Synthesis of more receptor sites in response to the medication
Decreased selectivity of receptor sites, resulting in a variety of effects
Desensitization of receptor sites by continual exposure to the drug
Antagonists produced by the body that compete with the drug for receptor sites
The Correct Answer is C
Choice A reason: Synthesis of more receptor sites (upregulation) typically occurs with receptor antagonists, not agonists, as the body compensates for blocked receptors. This would increase drug sensitivity, not decrease effectiveness. For most medications, continuous exposure leads to desensitization, not receptor proliferation, making this choice incorrect for explaining tolerance.
Choice B reason: Decreased receptor selectivity implies a drug binding to unintended receptors, causing varied effects, not reduced efficacy. Tolerance results from receptor desensitization, not altered selectivity. This mechanism doesn’t explain the patient’s “immunity” to the drug’s therapeutic effects, making this choice scientifically inaccurate for the scenario.
Choice C reason: Desensitization occurs when continuous drug exposure reduces receptor responsiveness, leading to tolerance. For example, opioid receptors downregulate or internalize with prolonged agonist exposure, decreasing drug efficacy. This explains the patient’s perception of “immunity” as the drug’s effect diminishes over time, making this the correct choice.
Choice D reason: The body does not produce antagonists to compete with drugs for receptor sites. Tolerance arises from receptor desensitization or metabolic changes (e.g., enzyme induction), not endogenous antagonist production. This mechanism is not a recognized pharmacological process for reduced drug effectiveness, making this choice incorrect.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
Choice A reason: Drugs with a narrow therapeutic range, like digoxin, require plasma level monitoring to ensure concentrations remain within a safe and effective range. This prevents toxicity (e.g., arrhythmias) or subtherapeutic effects, as small dose changes can significantly alter blood levels, making monitoring critical for patient safety and efficacy.
Choice B reason: Intravenous administration does not inherently address the risks of a narrow therapeutic range. While it ensures rapid delivery, it increases toxicity risk due to immediate bioavailability. Monitoring plasma levels is more critical than the route to maintain safe and effective drug concentrations, making this choice less appropriate.
Choice C reason: Administering at intervals longer than the half-life may lead to subtherapeutic levels for drugs with a narrow therapeutic range, reducing efficacy. Consistent dosing and plasma level monitoring are needed to maintain steady-state concentrations within the therapeutic window, making this choice incorrect for managing such drugs.
Choice D reason: Teaching that maximum effects occur quickly is inaccurate for most narrow therapeutic range drugs, which often require steady-state concentrations over time. Without monitoring, toxicity or inefficacy risks increase. Patient education should focus on adherence and monitoring, not rapid effects, making this choice inappropriate.
Correct Answer is B
Explanation
Choice A reason: Hydrochlorothiazide is for chronic hypertension, not acute pulmonary edema. Furosemide acts rapidly to relieve fluid overload, so this is incorrect for emergency use.
Choice B reason: Furosemide is the drug of choice for pulmonary edema, rapidly reducing fluid overload and relieving symptoms like frothy sputum. This is the correct choice.
Choice C reason: Mannitol is used for cerebral edema, not pulmonary edema. Furosemide targets acute fluid overload in the lungs, so this is incorrect for this scenario.
Choice D reason: Spironolactone is for chronic heart failure, not acute pulmonary edema. Furosemide’s rapid diuresis is needed, so this is incorrect for immediate treatment.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.