Which of the following drugs was most likely included in the therapeutic regimen of this patient?

Correct Answer: C

Rationale: The correct answer is C: Furosemide. Furosemide is a loop diuretic commonly used to treat conditions such as edema and hypertension. In this case, the patient likely required a strong diuretic to manage fluid overload, which is best achieved with a loop diuretic like furosemide. Hydrochlorothiazide (A) is a thiazide diuretic, which is less potent than loop diuretics like furosemide. Mannitol (B) is an osmotic diuretic used for conditions such as cerebral edema and not typically included in routine therapeutic regimens. Fenoldopam (D) is a selective dopamine receptor agonist used for acute hypertension but is not commonly included in routine diuretic regimens like furosemide.

Correct Answer: D

Rationale: In this scenario, the correct answer is D) Lithium. Thiazide diuretics, commonly used in the management of heart failure, reduce the excretion of lithium by the kidneys. This can lead to an increase in lithium levels in the body, potentially resulting in lithium toxicity. Therefore, it is crucial to monitor lithium levels closely when a patient on lithium therapy is started on thiazide diuretics. Now, let's discuss why the other options are incorrect: A) Diazepam: Thiazide diuretics do not significantly affect the excretion of diazepam. B) Fluoxetine: Thiazide diuretics do not impact the excretion of fluoxetine. C) Imipramine: Thiazide diuretics do not alter the excretion of imipramine. Educational Context: Understanding drug interactions is essential in clinical practice, especially when managing patients with multiple comorbidities and medications. Pharmacokinetic principles play a vital role in predicting and managing drug interactions. Healthcare professionals need to be aware of how different drugs can affect each other's metabolism, distribution, and elimination to prevent adverse effects and ensure optimal therapeutic outcomes for patients. In this case, recognizing the potential interaction between thiazide diuretics and lithium is crucial for safe and effective patient care.

Correct Answer: C

Rationale: In the case of acute pain of angina pectoris, the most effective treatment would be to administer Sodium nitrate (Option C). Sodium nitrate is a vasodilator that works by dilating the blood vessels, increasing blood flow and oxygen supply to the heart muscle. This helps to relieve the chest pain associated with angina pectoris by reducing the workload on the heart. Option A, Mannitol hexanitrate, is not commonly used in the treatment of angina pectoris. Erythrityl tetranitrate (Option B) and Pentaerythritol tetranitrate (Option D) are also nitrates like Sodium nitrate, but they are not as commonly used or as effective in managing acute angina pain. In an educational context, understanding the mechanism of action of different cardiovascular drugs is crucial for healthcare professionals in making informed decisions about treatment options for patients with cardiovascular conditions. Knowing the specific indications and effectiveness of different medications can help improve patient outcomes and prevent complications.

Correct Answer: B

Rationale: The correct sequence of conduction of the cardiac action potential is from the SA node to the atria to the AV node to the bundle of His. This sequence is essential for the coordinated contraction of the heart and efficient blood pumping. Option A is incorrect because the atria are activated before the AV node. Option C is incorrect because the AV node is located between the atria and the ventricles, so it should come after the atria in the sequence. Option D is incorrect as it reverses the order of activation of the atria and the AV node. Understanding the sequence of cardiac conduction is crucial in cardiovascular drug therapy. Medications targeting specific parts of this conduction system can have significant effects on heart rate, rhythm, and overall cardiac function. Knowing the correct conduction pathway helps healthcare professionals make informed decisions when prescribing or administering cardiovascular drugs.

Correct Answer: B

Rationale: The correct answer is B) An alpha agonist. In this scenario, tissue necrosis at the IV site is a known side effect of administering drugs that cause vasoconstriction or reduced blood flow to the surrounding tissues. Alpha agonists, which stimulate alpha-adrenergic receptors causing vasoconstriction, can lead to tissue ischemia and subsequent necrosis when administered through an IV. Option A) Digoxin is a cardiac glycoside used to treat heart conditions like heart failure and atrial fibrillation. It does not typically cause tissue necrosis at the IV site. Option C) A beta blocker works by blocking beta-adrenergic receptors, leading to reduced heart rate and blood pressure. It does not directly cause tissue necrosis at the IV site. Option D) A calcium channel blocker inhibits the influx of calcium ions into cardiac and smooth muscle cells, leading to vasodilation and reduced blood pressure. It does not typically cause tissue necrosis at the IV site. Educationally, understanding the side effects of different drug classes is crucial for safe and effective patient care. Recognizing the adverse effects associated with specific medications can help healthcare professionals prevent, identify, and manage complications that may arise during treatment. In this case, identifying the culprit drug causing tissue necrosis can prompt timely intervention to prevent further harm to the patient.