Persistent dry cough may occur as a side effect of the following antihypertensive drug

Correct Answer: A

Rationale: In pharmacology, it is essential to understand the side effects of medications to ensure safe and effective patient care. In this scenario, the correct answer is A) Enalapril. Enalapril belongs to the class of drugs known as ACE inhibitors. One of the common side effects of ACE inhibitors is a persistent dry cough. This adverse effect is due to the accumulation of bradykinin, a substance that causes coughing, as ACE inhibitors block its breakdown. Now, let's discuss why the other options are incorrect: - B) Atenolol: Atenolol is a beta-blocker commonly used for hypertension. While it has its own set of side effects like bradycardia and fatigue, it is not associated with causing a dry cough. - C) Diltiazem: Diltiazem is a calcium channel blocker used to treat hypertension and angina. Dry cough is not a typical side effect of this medication. - D) Methyldopa: Methyldopa is a centrally acting alpha-2 adrenergic agonist used as an antihypertensive. It is not known to cause a dry cough as a side effect. Educational context: Understanding the side effects of medications is crucial for healthcare professionals to anticipate and manage potential issues that may arise during treatment. Educating students about the specific side effects of different drug classes helps in making informed decisions while prescribing and monitoring patients. This knowledge also contributes to patient safety and adherence to treatment regimens.

Correct Answer: D

Rationale: In the context of CNS drugs pharmacology, understanding the differences between ethacrynic acid and furosemide is crucial for safe and effective prescribing practices. The correct answer, D) All of the above, is the most appropriate choice because it encapsulates the main reasons why ethacrynic acid is rarely used compared to furosemide. Firstly, ethacrynic acid is more ototoxic compared to furosemide. Ototoxicity refers to the potential of a drug to cause damage to the ear, particularly the auditory system. This side effect can lead to hearing loss, dizziness, and balance disturbances, making ethacrynic acid a less favorable option in clinical practice. Secondly, ethacrynic acid is known to cause diarrhea and gut bleeding. These gastrointestinal side effects can significantly impact a patient's quality of life and may lead to complications such as dehydration, electrolyte imbalances, and gastrointestinal bleeding. Additionally, ethacrynic acid exhibits a steep increase in diuretic response over a narrow dose range. This means that small changes in dosage can result in significant changes in diuretic effect, increasing the risk of dose-related adverse reactions and therapeutic challenges. Conversely, furosemide is preferred over ethacrynic acid in clinical practice due to its relatively lower ototoxicity, milder gastrointestinal side effects, and a broader therapeutic window, allowing for more predictable and manageable dosing. Educationally, this question highlights the importance of understanding the nuances of high-ceiling diuretics in pharmacology. By grasping the specific differences between ethacrynic acid and furosemide, healthcare professionals can make informed decisions when selecting the most appropriate treatment options for patients with conditions requiring diuretic therapy.

Correct Answer: C

Rationale: Potassium-sparing diuretics, such as spironolactone and amiloride, work by promoting diuresis while preventing potassium loss. Captopril is an angiotensin-converting enzyme (ACE) inhibitor used to treat hypertension and heart failure. When coadministered with potassium-sparing diuretics, it can lead to hyperkalemia, a condition of elevated potassium levels in the blood, due to the combined effect of both drugs retaining potassium. Option A, Furosemide, and Option B, Hydrochlorothiazide, are loop and thiazide diuretics, respectively, that promote potassium excretion. Co-administering these with potassium-sparing diuretics can help prevent hypokalemia (low potassium levels) that may result from excessive potassium loss. Option D, Verapamil, is a calcium channel blocker used to treat hypertension and certain heart conditions. Verapamil does not directly impact potassium levels and can be safely coadministered with potassium-sparing diuretics unless there are specific contraindications for the individual patient. In an educational context, understanding the interactions between different classes of drugs is crucial for healthcare professionals to ensure safe and effective patient care. Knowledge of drug interactions helps in making informed decisions when selecting appropriate treatment regimens and preventing potential drug-related complications. Proper education on pharmacology is essential for healthcare providers to optimize patient outcomes.

Correct Answer: A

Rationale: The correct answer is A) Adrenaline. Dale's vasomotor reversal phenomenon refers to the phenomenon where, at low doses, adrenaline causes vasodilation through beta-2 adrenergic receptor activation, instead of vasoconstriction which is typically seen at higher doses through alpha-1 adrenergic receptors. This phenomenon is crucial in understanding the complex effects of catecholamines on the cardiovascular system. Option B) Noradrenaline predominantly acts on alpha-1 adrenergic receptors, leading to vasoconstriction. Option C) Isoprenaline is a non-selective beta-adrenergic receptor agonist, thus it does not exhibit the vasomotor reversal phenomenon seen with adrenaline. Educationally, understanding the vasomotor reversal phenomenon is essential for healthcare professionals, especially when prescribing drugs that manipulate the adrenergic system. It highlights the dose-dependent effects of catecholamines on blood vessels and underscores the importance of receptor selectivity in pharmacological actions. This knowledge is crucial in managing conditions where modulation of vascular tone is necessary, such as in hypertension or shock.

Correct Answer: D

Rationale: The correct answer is D) Redistribution to body tissues outside the CNS. Thiopentone sodium is an ultra-short-acting barbiturate commonly used for induction of anesthesia due to its rapid onset and short duration of action. The reason for the rapid clearance of its sedative effects is its redistribution to body tissues outside the central nervous system (CNS). Option A) Rapid hepatic metabolism is not the primary reason for the ultra-short duration of action of thiopentone sodium. While metabolism does play a role, rapid redistribution is the key factor. Option B) Rapid renal clearance is also not the primary reason for the drug's short duration of action. Thiopentone sodium is mainly eliminated by hepatic metabolism and redistribution. Option C) Extensive binding to plasma proteins would actually prolong the drug's effects rather than contribute to its ultra-short duration of action. In an educational context, understanding the pharmacokinetics of CNS drugs like thiopentone sodium is crucial for healthcare professionals, particularly anesthesiologists. Knowing how drugs are metabolized, cleared, and distributed can help in optimizing dosing regimens, anticipating drug interactions, and managing adverse effects effectively. It is important to grasp the mechanisms underlying drug actions to ensure safe and effective patient care.