Tick the unwanted effects of zidovudine:

Correct Answer: B

Rationale: Step 1: Zidovudine is an antiretroviral medication used to treat HIV. Step 2: Anemia and neutropenia are common unwanted effects of zidovudine due to bone marrow suppression. Step 3: Nausea and insomnia are also common side effects of zidovudine. Step 4: Hallucinations, dizziness, hypertension, vomiting, and peripheral neuropathy are not typically associated with zidovudine. Step 5: Therefore, the correct answer is B as it accurately lists unwanted effects of zidovudine based on its pharmacological profile.

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: The correct answer to the question is B) Lidocaine. Lidocaine is the drug of choice for managing cardiac arrhythmias that occur in digitalis toxicity because it is a class Ib antiarrhythmic medication that works by stabilizing the cell membrane and decreasing automaticity in the heart muscle. This helps to suppress arrhythmias caused by digitalis toxicity effectively. Option A) Amiodarone is an antiarrhythmic drug that is often used for various types of arrhythmias, but it is not specifically indicated for managing arrhythmias in digitalis toxicity. Option C) Propranolol is a beta-blocker that is commonly used for managing hypertension, angina, and certain arrhythmias, but it is not the drug of choice for arrhythmias in digitalis toxicity. Option D) Sotalol is a beta-blocker with class III antiarrhythmic properties, but it is not the preferred medication for managing arrhythmias in digitalis toxicity. In an educational context, understanding the appropriate pharmacological interventions for different types of arrhythmias is crucial for healthcare providers, especially those working in cardiology or emergency medicine. Knowing the specific indications for medications like lidocaine in the context of digitalis toxicity can help healthcare professionals make informed decisions quickly to manage potentially life-threatening situations effectively.

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.