A 70-year-old female with a history of hypertension is prescribed hydrochlorothiazide. The mechanism of action of hydrochlorothiazide involves:

Correct Answer: A

Rationale: The correct answer is A: Inhibiting the reabsorption of sodium in the kidneys. Hydrochlorothiazide is a thiazide diuretic that acts on the distal convoluted tubule of the nephron to inhibit the sodium-chloride symporter, leading to increased excretion of sodium and water. This mechanism results in decreased blood volume and subsequently lowers blood pressure, making it an effective treatment for hypertension. Option B is incorrect as hydrochlorothiazide does not block calcium channels. Option C is incorrect as hydrochlorothiazide actually increases the excretion of sodium and water, not potassium. Option D is incorrect as hydrochlorothiazide does not directly inhibit aldosterone secretion.

Correct Answer: B

Rationale: The correct answer is B: Methimazole. Methimazole is an anti-thyroid medication that works by inhibiting the synthesis of thyroid hormones, making it a common treatment for hyperthyroidism. It blocks the enzyme responsible for thyroid hormone production. Levothyroxine (A) is used to treat hypothyroidism by providing thyroid hormone replacement. Amiodarone (C) is an anti-arrhythmic drug that can cause thyroid dysfunction but is not commonly used for hyperthyroidism treatment. Prednisone (D) is a corticosteroid and is not used to inhibit thyroid hormone synthesis.

Correct Answer: A

Rationale: The correct answer is A: Omeprazole. Omeprazole is a proton pump inhibitor that reduces stomach acid production, making it effective in treating acid reflux. It works by blocking the enzyme responsible for acid production in the stomach. Loratadine (B) is an antihistamine used for allergies, Diphenhydramine (C) is also an antihistamine used for allergies and sleep aid, and Ibuprofen (D) is a nonsteroidal anti-inflammatory drug used for pain relief. These medications do not target stomach acid production and are not commonly prescribed for acid reflux.

Correct Answer: C

Rationale: The correct answer is C: Reducing inflammation in the airways. Budesonide is a corticosteroid that works by reducing inflammation in the airways, which is a key mechanism in managing asthma symptoms. Corticosteroids like budesonide inhibit the production of inflammatory mediators and suppress immune response in the airways. This helps to decrease swelling and mucus production, ultimately improving breathing in asthma patients. Choice A is incorrect because budesonide does not block leukotriene receptors. Choice B is incorrect because budesonide does not stimulate beta-2 adrenergic receptors like beta-agonists do. Choice D is incorrect because budesonide does not inhibit the release of histamine from mast cells.

Correct Answer: A

Rationale: Step 1: Amlodipine is a calcium channel blocker that inhibits calcium ion entry into smooth muscle cells. Step 2: By blocking calcium influx, amlodipine relaxes blood vessels, reducing blood pressure. Step 3: Enalapril is an ACE inhibitor, not a calcium channel blocker. Step 4: Clonidine is a centrally acting alpha-2 adrenergic agonist, not a calcium channel blocker. Step 5: Hydrochlorothiazide is a thiazide diuretic, not a calcium channel blocker.