Which assessment finding, by the nurse, is a priority concern when a client receives pseudoephedrine (Sudafed)?

Correct Answer: C

Rationale: Pseudoephedrine, an oral decongestant, stimulates alpha-adrenergic receptors, potentially causing cardiovascular effects like dysrhythmias due to its sympathomimetic action. An irregular heart rate of 82 is a priority concern, signaling possible arrhythmia, which could escalate to serious cardiac events, requiring immediate reporting. A mild fever or elevated respiratory rate could relate to the underlying condition (e.g., infection) rather than the drug. Dry mouth is a common, benign side effect. The nurse focuses on the irregular pulse as it aligns with pseudoephedrine's known risk of dysrhythmias, especially in susceptible patients, making choice C the most urgent finding to address.

Correct Answer: B

Rationale: Spironolactone is a potassium-sparing diuretic that works by blocking the effects of aldosterone in the distal tubules of the kidney, leading to increased excretion of sodium and water while retaining potassium. This class of diuretics helps to conserve potassium, making them suitable for patients at risk of hypokalemia. In contrast, furosemide, hydrochlorothiazide, and bumetanide are loop diuretics, thiazide diuretics, and another loop diuretic, respectively, which all promote the loss of potassium along with sodium and water.

Correct Answer: B

Rationale: When converting a patient from IV heparin to oral warfarin (Coumadin) therapy, overlapping therapy of both medications for at least 5 days is typically recommended. This overlap ensures that the patient's blood remains appropriately anticoagulated during the transition period. The effectiveness of warfarin is delayed and it takes time for the INR to reach the therapeutic range; therefore, it is important to continue the IV heparin until the INR is within the desired range. Monitoring the INR is essential to adjust the dosages of warfarin accordingly and to ensure that the patient is receiving adequate anticoagulation therapy.

Correct Answer: D

Rationale: Heparin is an anticoagulant that enhances the activity of antithrombin III, a natural inhibitor of thrombin and factor Xa, to prevent clotting. The statement that it inhibits clotting by decreasing antithrombin III effects is false, as heparin actually potentiates antithrombin III, making this the incorrect option. Its oral bioavailability is negligible (not 20-30%), as it's a large polysaccharide requiring parenteral administration (e.g., IV or subcutaneous), so this is false. Heparin is highly plasma protein-bound, not low, contradicting that option. The correct statement, replaced in the fourth slot, is that heparin binds to antithrombin III, causing a conformational change that accelerates its anticoagulant effect. This mechanism is fundamental to its clinical use in thrombosis prevention, distinguishing it from oral anticoagulants like warfarin.

Correct Answer: C

Rationale: Ondansetron is a medication commonly used to prevent nausea and vomiting, particularly in patients receiving chemotherapy or undergoing surgery. Its mechanism of action involves blocking the effects of serotonin, specifically by antagonizing serotonin 5-HT3 receptors in the chemoreceptor trigger zone of the brain and the gastrointestinal tract. By inhibiting serotonin signaling, ondansetron helps to alleviate nausea and vomiting in affected individuals. This action is distinct from the other options provided, making option C the correct answer for the drug Ondansetron.