Which of the following drugs was most likely administered to prevent further fibrillatory episodes in the patient?

Correct Answer: D

Rationale: The correct answer is D: Amiodarone. Amiodarone is a class III antiarrhythmic drug commonly used to prevent further fibrillatory episodes, particularly in patients with atrial fibrillation. It has a broad spectrum of antiarrhythmic effects and is effective in controlling various types of arrhythmias. Mexiletine (A) is a class IB antiarrhythmic drug used for ventricular arrhythmias. Sotalol (B) is a non-selective beta-blocker with class III antiarrhythmic properties. Quinidine (C) is a class IA antiarrhythmic drug used for atrial and ventricular arrhythmias, but it has a higher risk of adverse effects compared to amiodarone.

Correct Answer: B

Rationale: In this question, the correct answer is B) Increasing intracellular cyclic GMP. Explanation of why this is the correct answer: Organic nitrates, such as nitroglycerin, work by being converted to nitric oxide (NO) in the body. Nitric oxide activates the enzyme guanylate cyclase in vascular smooth muscle cells, leading to an increase in intracellular cyclic GMP (cGMP). This increase in cGMP results in smooth muscle relaxation, vasodilation, and ultimately helps to reduce blood pressure and improve blood flow to the heart. Explanation of why the other options are incorrect: A) Increasing intracellular cyclic AMP: Organic nitrates do not work by increasing cyclic AMP; they primarily act through the cGMP pathway. C) Decreasing intracellular cyclic AMP: Organic nitrates do not decrease cyclic AMP levels; their main mechanism of action is through the increase in cGMP. D) Both (b) and (c): This option is incorrect as organic nitrates primarily work by increasing cGMP levels and do not have a significant impact on cyclic AMP levels. Educational context: Understanding how organic nitrates work is crucial in the study of cardiovascular drugs. By knowing that they increase intracellular cyclic GMP, healthcare professionals can appreciate their role in vasodilation and the treatment of conditions like angina pectoris. This knowledge is essential for safe and effective prescribing practices and patient education regarding the use of these medications.

Correct Answer: B

Rationale: Reserpine is used in hypertension in low doses because side effects become disproportionately marked. Reserpine is a potent antihypertensive drug that works by depleting catecholamines in the body, leading to decreased sympathetic tone and subsequently reducing blood pressure. However, at higher doses, the side effects of reserpine, such as depression, sedation, gastrointestinal disturbances, and postural hypotension, become more pronounced and can outweigh the benefits of its antihypertensive effects. Option A, "It is a very strong antihypertensive," is incorrect because reserpine's strength as an antihypertensive is not the reason for using it in low doses; rather, it is to minimize side effects. Option C, "High doses on chronic use cause addiction," is incorrect because reserpine is not addictive. Option D, "It has a very long duration of action," is incorrect as the duration of action is not the primary reason for using low doses. In an educational context, understanding the rationale behind using reserpine in low doses is crucial for healthcare professionals prescribing antihypertensive medications. It highlights the importance of balancing therapeutic benefits with potential side effects when managing hypertension. This knowledge can guide clinicians in making informed decisions to optimize patient care and outcomes.

Correct Answer: D

Rationale: In this question, the correct answer is D) Morcizine. Morcizine is a class IC anti-arrhythmic agent, not a class IA drug. A) Quinidine is a class IA anti-arrhythmic agent. It works by blocking sodium channels, prolonging action potential duration. B) Disopyramide is another class IA anti-arrhythmic drug, which acts by blocking potassium channels. C) Procainamide is also a class IA anti-arrhythmic drug, functioning by blocking sodium channels. Educationally, understanding the classification of anti-arrhythmic drugs is crucial for healthcare professionals as it guides treatment decisions. Knowing the mechanisms of action and specific characteristics of each class helps in selecting the most appropriate medication for a patient's condition. This knowledge is vital for patient safety and optimal outcomes in managing cardiovascular disorders.

Correct Answer: B

Rationale: Zetia (ezetimibe) is a commonly prescribed cardiovascular drug that acts as a cholesterol absorption inhibitor. The correct answer, option B, "It inhibits absorption of cholesterol in the small intestines," is accurate because Zetia works by blocking the absorption of cholesterol from the diet in the small intestine. By doing so, it helps lower overall cholesterol levels in the body. Option A, "It prevents cholesterol synthesis by the liver," is incorrect because Zetia does not affect the synthesis of cholesterol in the liver. Instead, it specifically targets the absorption of cholesterol from the diet. Option C, "It increases LDL cholesterol production," is also incorrect as Zetia is known to lower LDL cholesterol levels by preventing its absorption in the intestines. Option D, "It increases the ratio of HDL to LDL cholesterol," is incorrect as Zetia's mechanism of action is not related to altering the ratio of HDL to LDL cholesterol, but rather focuses on reducing overall cholesterol levels by inhibiting absorption. In an educational context, understanding the mechanism of action of Zetia is crucial for healthcare professionals to effectively manage patients with hyperlipidemia and cardiovascular risk. By grasping how Zetia works to lower cholesterol levels, nurses can better educate patients on the importance of medication adherence and lifestyle modifications to improve cardiovascular health.