Which of the following medications is commonly prescribed for the prevention of blood clots in patients after surgery?

Correct Answer: B

Rationale: The correct answer is B: Enoxaparin. Enoxaparin is a low molecular weight heparin commonly prescribed for post-surgery blood clot prevention due to its effectiveness in inhibiting blood clot formation. Warfarin (A) is primarily used for long-term anticoagulation therapy, not typically for post-surgery prevention. Aspirin (C) is a mild antiplatelet agent and is not as effective as enoxaparin for post-surgery clot prevention. Clopidogrel (D) is also an antiplatelet drug but is not commonly prescribed for post-surgery blood clot prevention.

Correct Answer: A

Rationale: The correct answer is A: Penicillin. Penicillin is a beta-lactam antibiotic that works by inhibiting bacterial cell wall synthesis, leading to bacterial cell death. This mechanism makes penicillin effective against a wide range of bacterial infections. Azithromycin (B) and Ciprofloxacin (C) are antibiotics that work by inhibiting bacterial protein synthesis and DNA replication, respectively, not cell wall synthesis. Amoxicillin (D) is also a beta-lactam antibiotic like penicillin, but it is not the best choice here as penicillin is more commonly used for cell wall synthesis inhibition.

Correct Answer: A

Rationale: The correct answer is A: Methotrexate. Methotrexate is a disease-modifying antirheumatic drug (DMARD) commonly used to reduce inflammation and slow down the progression of rheumatoid arthritis. It works by suppressing the immune system and reducing the inflammation that causes joint damage. Ibuprofen (B) and Celecoxib (D) are nonsteroidal anti-inflammatory drugs (NSAIDs) that can help with pain relief but do not target the underlying inflammation in rheumatoid arthritis. Hydroxychloroquine (C) is another DMARD used in rheumatoid arthritis treatment, but it is primarily used for its immunomodulating effects rather than its anti-inflammatory properties.

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: Replacing deficient thyroid hormone. Levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4). In hypothyroidism, the thyroid gland does not produce enough thyroid hormones, leading to various symptoms. By prescribing levothyroxine, we are supplying the body with the thyroid hormone it lacks, thereby replacing the deficient hormone and restoring normal thyroid function. Explanation of other choices: A: Increasing the production of thyroid-stimulating hormone (TSH) is incorrect because levothyroxine does not directly affect TSH production. C: Inhibiting thyroid hormone synthesis is incorrect because levothyroxine does not inhibit thyroid hormone production. D: Increasing the metabolism of thyroid hormones is incorrect because levothyroxine does not directly increase the metabolism of existing thyroid hormones; it simply replaces the deficient hormone.