Potassium-sparing diuretics primarily affect which part of the kidney?

Correct Answer: D

Rationale: The correct answer is D: Distal convoluted tubule. Potassium-sparing diuretics, such as spironolactone, act on the distal convoluted tubule by blocking the aldosterone receptor, which leads to decreased sodium reabsorption and potassium retention. This mechanism helps to promote diuresis while preventing potassium loss. Choices A, B, and C are incorrect because potassium-sparing diuretics do not primarily affect the proximal convoluted tubule, loop of Henle, or collecting duct in the kidney.

Correct Answer: A

Rationale: The correct answer is A: Elevated lipid levels. Isoflurane does not cause elevated lipid levels. Isoflurane is a general anesthetic that primarily affects the central nervous system, leading to effects like decreased respiratory function and increased blood flow to the brain. Nausea can also be a side effect of isoflurane due to its impact on the gastrointestinal system. However, there is no direct link between isoflurane and elevated lipid levels. Thus, choice A is the correct answer.

Correct Answer: A

Rationale: The correct answer is A: COPD. Ephedrine is a sympathomimetic drug that acts on alpha and beta adrenergic receptors, leading to vasoconstriction and increased heart rate. It is used to treat hypotension and congestion by increasing blood pressure and dilating airways, respectively. Incontinence is not typically treated with Ephedrine. However, COPD involves bronchoconstriction, which can worsen with Ephedrine due to its vasoconstrictive effects. Therefore, Ephedrine is not used to treat COPD.

Correct Answer: B

Rationale: The correct answer is B: Liver. Warfarin is primarily metabolized in the liver by the cytochrome P450 enzyme system. The liver is responsible for breaking down and activating many drugs, including Warfarin. It is where the drug's metabolism and effects are most significant. The other choices are incorrect because Warfarin's main site of activity is in the liver, not the kidney, blood, or heart. The kidney mainly excretes the drug, while the blood carries it throughout the body, and the heart is not directly involved in Warfarin's metabolism.

Correct Answer: D

Rationale: Step 1: Ethosuximide is the correct answer as it is a known trigger for Stevens-Johnson syndrome due to its association with hypersensitivity reactions. Step 2: Valproic acid can cause liver toxicity but is not typically linked to Stevens-Johnson syndrome. Step 3: Quinidine is associated with drug-induced lupus but not commonly known to cause Stevens-Johnson syndrome. Step 4: Isoniazid is linked to drug-induced hepatitis but not typically associated with Stevens-Johnson syndrome. In summary, Ethosuximide is the correct choice due to its well-documented association with Stevens-Johnson syndrome, while the other options are linked to different adverse effects.

Correct Answer: C

Rationale: Correct Answer: C (Isoniazid) Rationale: 1. Isoniazid is known to cause drug-induced hepatitis due to its hepatotoxic effects. 2. It can lead to liver inflammation, causing hepatitis as a reaction. 3. Regular monitoring of liver function tests is essential when using isoniazid. Summary of other choices: A. Valproic acid: Can cause hepatotoxicity but not specifically linked to hepatitis. B. Quinidine: Mainly known for cardiac side effects, not commonly associated with hepatitis. D. Ethosuximide: Primarily used for treating absence seizures, not typically associated with hepatitis.

Correct Answer: B

Rationale: The correct answer is B: Tachycardia. Atenolol is a beta-blocker that works by slowing down the heart rate, so tachycardia is not related to its toxicity. A: CHF can be exacerbated by Atenolol due to its negative inotropic effects. C: AV block can occur as Atenolol can further slow down the heart's conduction system. D: Sedative appearance can be a side effect of Atenolol due to its action on the central nervous system. In summary, tachycardia is not related to Atenolol toxicity because it decreases heart rate.

Correct Answer: D

Rationale: The correct answer is D: Sexual dysfunction. Nifedipine is a calcium channel blocker that primarily causes vasodilation by relaxing blood vessels. Sexual dysfunction is not a common side effect associated with Nifedipine use. Nausea, flushed appearance, and vertigo are potential side effects of Nifedipine due to its mechanism of action on the cardiovascular system. Therefore, D is the correct choice as it does not align with the expected side effects of Nifedipine.

Correct Answer: D

Rationale: Rationale: Lansoprazole is a proton pump inhibitor used to treat conditions related to excess stomach acid. Thalamus hypertrophy is not a condition affecting stomach acid production, making it unrelated to Lansoprazole use. A: Gastritis, B: Peptic Ulcers, and C: Zollinger-Ellison syndrome all involve excessive stomach acid secretion, hence Lansoprazole is used in these cases. Thalamus hypertrophy does not involve stomach acid issues, making it the correct answer.