Which of the following is the primary site of activity for the drug Warfarin?

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: 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.

Correct Answer: D

Rationale: The correct answer is D: Muscle wasting. Ibuprofen is primarily associated with gastrointestinal side effects like nausea, renal dysfunction, and anemia due to its effects on the stomach, kidneys, and blood. Muscle wasting is not a known direct effect of Ibuprofen toxicity. Ibuprofen is not typically linked to muscle-related issues, making choice D the correct answer.

Correct Answer: D

Rationale: The correct answer is D: Fluoroquinolones. Fluoroquinolones are known to be associated with tendon dysfunction due to their potential to cause tendinitis and tendon rupture. This adverse effect is thought to be related to the drug's ability to disrupt collagen synthesis and structure in tendons. Digitalis (A) is used to treat heart conditions, niacin (B) for cholesterol, and tetracycline (C) for bacterial infections, none of which are linked to tendon dysfunction.

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: Congestion. ACE Inhibitors like Captopril do not typically cause congestion as a side effect. The main reason is that ACE inhibitors work by dilating blood vessels, which helps reduce blood pressure and improve blood flow. Congestion is more commonly associated with conditions like allergies or upper respiratory infections. A: Rash - Possible side effect of ACE inhibitors, but not specific to Captopril. B: Angioedema - Rare but serious side effect of ACE inhibitors, including Captopril. C: Cough - Common side effect of ACE inhibitors due to increased bradykinin levels.

Correct Answer: B

Rationale: The correct answer is B: Diarrhea. Atropine, a cholinoreceptor blocker, inhibits acetylcholine, causing decreased GI motility leading to constipation. Atropine also increases pulse rate due to reduced vagal tone (A). It causes mydriasis by blocking cholinergic receptors in the eye (D). Diarrhea is not a typical side effect of atropine due to its anticholinergic properties.

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: 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.