A 55-year-old male with chronic hypertension is prescribed atenolol. Atenolol works primarily by:

Correct Answer: A

Rationale: The correct answer is A: Blocking beta-1 adrenergic receptors in the heart. Atenolol is a beta-blocker that primarily acts on beta-1 receptors in the heart, reducing heart rate and blood pressure. This helps in managing hypertension. Beta-2 receptors are predominantly found in the lungs, so choice B is incorrect. Choice C refers to calcium channel blockers, not atenolol. Choice D is related to diuretics, not beta-blockers like atenolol. Thus, the correct answer is A due to atenolol's specific action on beta-1 receptors in the heart.

Correct Answer: A

Rationale: The correct answer is A: Alprazolam. Alprazolam is a benzodiazepine commonly used for treating acute anxiety due to its fast onset of action. It works by enhancing the effects of GABA neurotransmitters, leading to calming effects. Citalopram and Venlafaxine are antidepressants used for long-term treatment of anxiety disorders, not for acute episodes. Zolpidem is a sedative-hypnotic mainly used for insomnia, not anxiety.

Correct Answer: B

Rationale: The correct answer is B: Propranolol. Propranolol is a beta-blocker commonly prescribed for migraine prevention due to its ability to reduce the frequency and severity of migraine attacks by affecting blood vessels and neurotransmitters. Sumatriptan (A) is used for acute migraine treatment, not prevention. Ibuprofen (C) is an over-the-counter pain reliever for acute relief, not prevention. Lorazepam (D) is a benzodiazepine used for anxiety, not migraine prevention. Propranolol is the most appropriate choice for long-term migraine management.

Correct Answer: B

Rationale: The correct answer is B: Inhibiting HMG-CoA reductase in the liver. Atorvastatin is a statin drug that works by inhibiting the enzyme HMG-CoA reductase, which is involved in the production of cholesterol in the liver. By inhibiting this enzyme, atorvastatin reduces the synthesis of cholesterol in the liver, leading to lower levels of LDL cholesterol in the bloodstream. A: Inhibiting the reabsorption of cholesterol in the intestines - This is incorrect because atorvastatin primarily works in the liver, not in the intestines. C: Increasing HDL cholesterol levels - Atorvastatin is more effective at lowering LDL cholesterol levels rather than increasing HDL cholesterol levels. D: Increasing the excretion of cholesterol in the bile - Atorvastatin does not directly increase the excretion of cholesterol in the bile, it primarily acts in the liver to reduce cholesterol production.

Correct Answer: B

Rationale: The correct answer is B: Vitamin K. Warfarin is an anticoagulant that inhibits Vitamin K-dependent clotting factors. In the case of an overdose, administering Vitamin K helps replenish the depleted Vitamin K levels and restores the clotting factors, reversing the effects of warfarin. Protamine sulfate (A) is used to reverse heparin, not warfarin. Naloxone (C) is used to reverse opioid overdose. Flumazenil (D) is used to reverse benzodiazepine overdose.