A patient has been taking naltrexone (ReVia) as part of the treatment for addiction to heroin. The nurse expects that the naltrexone will have which therapeutic effect for this patient?

Correct Answer: D

Rationale: The correct answer is D because naltrexone is an opioid antagonist that blocks the euphoric effects of opioids. Here's the rationale: 1. Naltrexone blocks opioid receptors, preventing the euphoria associated with opioid use. 2. By blocking the euphoric effects, naltrexone reduces the reinforcing properties of opioids. 3. This decreases the likelihood of relapse as the patient does not experience the desired effects of opioids. 4. Choices A, B, and C are incorrect because naltrexone does not prevent cravings, act as a substitute, or cause adverse reactions like flushing and sweating.

Correct Answer: B

Rationale: The correct answer is B: A short-acting beta2 agonist such as albuterol (Proventil). In an acute asthma attack, bronchodilation is crucial for quick relief. Short-acting beta2 agonists like albuterol act rapidly to dilate the airways, providing immediate relief of symptoms. Anticholinergics like ipratropium (A) are also bronchodilators but are not as effective for acute exacerbations. Long-acting beta2 agonists like salmeterol (C) are used for long-term maintenance, not for immediate relief. Corticosteroids like fluticasone (D) are important for reducing airway inflammation but are not the first-line treatment for acute attacks.

Correct Answer: A

Rationale: The correct answer is A: Renal tubules. Biological barriers are structures that prevent the entry of harmful substances into the body. Renal tubules are not considered a biological barrier as they are involved in the filtration and reabsorption of substances within the body, rather than acting as a physical barrier. Cell membranes, capillary walls, and the placenta are all examples of biological barriers as they selectively control the passage of substances into and out of cells, tissues, and organs to maintain homeostasis. Therefore, the renal tubules do not fit the criteria of a biological barrier, making option A the correct answer.

Correct Answer: C

Rationale: The correct answer is C, Abstinence Syndrome. This term refers to the occurrence of psychological and somatic disturbances when a drug is suddenly discontinued after prolonged use. Tachyphylaxis (A) is the rapid development of tolerance to a drug. Sensibilization (B) is the opposite of tolerance, where increased sensitivity to a drug occurs over time. Idiosyncrasy (D) is an unexpected or unusual reaction to a drug. In this scenario, the situation describes the consequences of stopping the drug, aligning with the definition of Abstinence Syndrome.

Correct Answer: C

Rationale: The correct answer is C because cocaine actually causes myocardial stimulation and vasoconstriction, not depression and vasodilatation. Cocaine is a local anesthetic and vasoconstrictor, commonly used in nose and throat procedures (Choice A). Its abuse potential limits its medical use (Choice B). Cocaine causes sympathetically mediated effects such as tachycardia and vasoconstriction (Choice D). Therefore, the incorrect statement is C because cocaine does not cause myocardial depression and peripheral vasodilatation.