A 52-year-old woman suffering from hypertension still had a blood pressure of 156/92 mm Hg after 3 months of therapy with hydrochlorothiazide and losartan. Her physician decided to add a third drug that acts by decreasing central sympathetic outflow. Which of the following adverse effects was most likely to occur after a few days of therapy with the new drug?

Correct Answer: A

Rationale: The correct answer is A: Severe postural hypotension. Adding a third drug that decreases central sympathetic outflow (possibly a centrally acting alpha-2 adrenergic agonist) can lead to a sudden drop in blood pressure upon standing, causing postural hypotension. This occurs due to decreased sympathetic tone leading to vasodilation and reduced vascular tone. This effect is more likely to occur shortly after initiating therapy with the new drug. Choice B: Megaloblastic anemia is not a common adverse effect of drugs that decrease sympathetic outflow. Choice C: Palpitations are not typically associated with drugs that decrease sympathetic outflow. Choice D: Pronounced sedation is not a common side effect of centrally acting sympatholytic drugs.

Correct Answer: D

Rationale: Quinidine, a class I antiarrhythmic drug, is primarily used for preventing recurrences of atrial and ventricular extrasystoles and tachycardias. This is because quinidine works by blocking sodium channels in cardiac cells, which helps to stabilize the heart's electrical activity and prevent abnormal rhythms. Option A, converting atrial fibrillation to sinus rhythm, is not the primary use of quinidine. Drugs like amiodarone are more commonly used for this purpose due to their efficacy and safety profile. Option B, controlling ventricular rate in atrial flutter, is typically managed with drugs like beta-blockers or calcium channel blockers, which are more effective in controlling heart rate in atrial flutter. Option C, terminating ventricular tachycardia, is usually handled with antiarrhythmic medications like procainamide or amiodarone, as these are more effective in quickly terminating ventricular tachycardia. In an educational context, understanding the specific indications of each cardiovascular drug is crucial for effective pharmacological management of cardiac arrhythmias. Knowing the primary uses of medications like quinidine helps healthcare professionals make informed decisions in selecting the most appropriate treatment for their patients based on the type of arrhythmia present.

Correct Answer: D

Rationale: The correct answer to the question "Which of the following is the longest-acting nitrate?" is D) Pentaerythritol tetranitrate. This is because pentaerythritol tetranitrate, also known as PETN, has a longer duration of action compared to the other options. Glyceryl trinitrate (option A) is a short-acting nitrate commonly used for the acute relief of angina symptoms. Ethyl tetranitrate (option B) and octyl nitrite (option C) are not commonly used nitrates in clinical practice and do not have the same duration of action as pentaerythritol tetranitrate. In an educational context, understanding the duration of action of different nitrates is crucial for healthcare professionals, especially those working with patients who have cardiovascular conditions like angina. Knowing which nitrate has a longer duration of action can help in selecting the most appropriate medication for a patient based on their specific needs and condition. This knowledge can also aid in preventing potential drug interactions and adverse effects by ensuring the proper timing and dosing of medications.

Correct Answer: D

Rationale: In the context of cardiovascular drugs pharmacology, the correct answer is D) Cardiac arrest. Cardio-selective beta blockers are often administered to patients who have experienced cardiac arrest to prevent future episodes. Beta blockers help reduce the workload on the heart by blocking the effects of adrenaline, which can be beneficial in preventing further cardiac events. Option A) Myocardial infarction is not a primary indication for cardio-selective beta blockers. While beta blockers can be used in the management of myocardial infarction, they are not typically the first-line treatment. Option B) Hypertension can be managed with beta blockers, but cardio-selective beta blockers are not specifically chosen for this purpose. Non-selective beta blockers are more commonly used in the treatment of hypertension. Option C) Dysrhythmias can also be managed with beta blockers, but cardio-selective beta blockers are not the preferred choice for this condition. Non-selective beta blockers or other antiarrhythmic drugs are typically used. Educationally, understanding the rationale behind selecting specific medications for different cardiovascular conditions is crucial for healthcare professionals. It ensures appropriate and effective treatment strategies are implemented, leading to improved patient outcomes and safety. Choosing the right medication for the right indication is a fundamental principle in pharmacology and clinical practice.

Correct Answer: C

Rationale: The correct answer is C) It promotes the conversion of plasminogen to plasmin that breaks down blood clots. Tissue plasminogen activator (TPA) works by activating the conversion of plasminogen to plasmin, which is an enzyme responsible for breaking down fibrin clots. This action helps to dissolve blood clots in conditions like myocardial infarction or ischemic stroke. Option A) is incorrect because TPA is not an antiplatelet drug; it does not affect platelet activation. Option B) is incorrect because TPA does not directly inactivate clotting factors; its mechanism involves the conversion of plasminogen to plasmin. Option D) is incorrect because TPA does not block the synthesis of clotting factors; it works by promoting fibrinolysis. Understanding the mechanism of action of cardiovascular drugs like TPA is crucial for nurses to provide safe and effective care to patients with cardiovascular conditions. Knowing how TPA works helps nurses monitor for potential complications, assess the drug's effectiveness, and educate patients on the importance of adherence to treatment regimens.