A 60-year-old female with hypertension is prescribed enalapril. Enalapril works by:

Correct Answer: B

Rationale: Rationale: 1. Enalapril is an ACE inhibitor. 2. ACE inhibitors block the conversion of angiotensin I to angiotensin II. 3. Angiotensin II is a potent vasoconstrictor. 4. By inhibiting its production, enalapril helps lower blood pressure. 5. Therefore, choice B is correct. Summary: A: Blocking angiotensin II directly is the mechanism of ARBs, not ACE inhibitors. C: Enalapril does not directly affect sodium excretion. D: Enalapril may actually increase potassium levels due to decreased aldosterone production.

Correct Answer: B

Rationale: The correct answer is B: Constipation. Opioid medications slow down the movement of the digestive system, leading to constipation. This is a well-known side effect of opioids due to their action on opioid receptors in the gut. Nausea and vomiting can also occur but are less common than constipation. Diarrhea is actually a less common side effect of opioids. Increased appetite is not a typical side effect of opioid medications.

Correct Answer: A

Rationale: The correct answer is A: Blocking beta-1 adrenergic receptors in the heart. Bisoprolol is a beta-blocker that specifically targets beta-1 adrenergic receptors in the heart, leading to reduced heart rate and blood pressure. This helps in managing hypertension. Choices B, C, and D are incorrect because bisoprolol does not target beta-2 adrenergic receptors in the lungs, does not affect sodium excretion in the kidneys, and does not inhibit the conversion of angiotensin I to angiotensin II. The mechanism of action of bisoprolol primarily involves its selective blockade of beta-1 adrenergic receptors in the heart, making choice A the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Epinephrine. Epinephrine is the first-line treatment for severe allergic reactions like anaphylaxis as it works quickly to reverse symptoms and prevent potentially life-threatening complications. It acts by constricting blood vessels, relaxing smooth muscles, and reducing swelling. Diphenhydramine (A) provides relief for mild allergic reactions but is not as fast-acting or potent as epinephrine. Loratadine (C) is an antihistamine that helps with allergy symptoms but is not suitable for treating anaphylaxis. Albuterol (D) is a bronchodilator used for respiratory conditions like asthma and would not be effective in treating anaphylaxis.

Correct Answer: B

Rationale: The correct answer is B: Inhibiting factor Xa. Apixaban is a factor Xa inhibitor, which prevents the formation of thrombin. Factor Xa is a key enzyme in the coagulation cascade that converts prothrombin to thrombin. By inhibiting factor Xa, apixaban effectively reduces blood clot formation. Thrombin is directly inhibited by other anticoagulants like dabigatran. Vitamin K antagonists (e.g. warfarin) block the action of vitamin K, and antiplatelet agents (e.g. aspirin) inhibit platelet aggregation but do not work by inhibiting factor Xa like apixaban.