Which of the following is a primary side effect of thiazide diuretics?

Correct Answer: B

Rationale: The correct answer is B: Hypokalemia. Thiazide diuretics increase potassium excretion, leading to low potassium levels (hypokalemia). Thiazides inhibit sodium and chloride reabsorption in the distal tubule, causing diuresis and potassium loss. Hyperkalemia (A) is not a primary side effect of thiazides; weight gain (C) is uncommon with thiazides; hyperglycemia (D) is more associated with other classes of diuretics. In summary, hypokalemia is the primary side effect of thiazide diuretics due to increased potassium excretion.

Correct Answer: A

Rationale: The correct answer is A: Blocking the action of angiotensin II at its receptor. Losartan is an angiotensin II receptor blocker (ARB), which binds to angiotensin II receptors, preventing angiotensin II from exerting its effects such as vasoconstriction and aldosterone release. This action results in vasodilation, decreased blood pressure, and reduced workload on the heart. Choices B, C, and D are incorrect as losartan does not inhibit the conversion of angiotensin I to angiotensin II, increase sodium excretion in the kidneys, or block calcium channels in the blood vessels.

Correct Answer: A

Rationale: The correct answer is A: Inhibiting the absorption of cholesterol in the small intestine. Ezetimibe is a medication that works by blocking the absorption of dietary cholesterol in the small intestine, leading to decreased levels of LDL cholesterol in the blood. This mechanism helps reduce overall cholesterol levels in the body. Choices B, C, and D are incorrect because ezetimibe does not inhibit HMG-CoA reductase in the liver (like statins), increase the excretion of cholesterol in the bile, or increase HDL cholesterol levels.

Correct Answer: D

Rationale: The correct answer is D (All of the above). Atorvastatin, Simvastatin, and Fluvastatin are all examples of statins, a class of medications that inhibit HMG-CoA reductase enzyme to lower cholesterol levels. Statins work by blocking the production of cholesterol in the liver, leading to decreased LDL (bad) cholesterol and increased HDL (good) cholesterol levels. Each of these medications has a slightly different potency and dosing regimen, but they all target the same enzyme and have similar mechanisms of action. Therefore, choosing all of the above as the correct answer is appropriate as they are all commonly prescribed to lower cholesterol levels.

Correct Answer: B

Rationale: The correct answer is B: Binding to calcium channels in the central nervous system. Gabapentin binds to the α2δ subunit of voltage-gated calcium channels in the central nervous system, reducing calcium influx and inhibiting the release of excitatory neurotransmitters. This mechanism helps to reduce neuronal hyperexcitability and alleviate neuropathic pain. Choices A, C, and D are incorrect because gabapentin does not block sodium channels, inhibit serotonin reuptake, or increase dopamine levels.