The drug has a steroid-like structure which is responsible for its anti-androgenic effect:

Correct Answer: D

Rationale: The correct answer is D: Spironolactone (Aldactone). Spironolactone has a steroid-like structure due to its chemical similarity to aldosterone, allowing it to competitively inhibit aldosterone receptors. This anti-androgenic effect is crucial in conditions like hirsutism and acne. Amiloride (A), Furosemide (B), and Hydrochlorothiazide (C) do not possess a steroid-like structure and do not exhibit anti-androgenic properties.

Correct Answer: B

Rationale: The correct answer is B because isoniazid inhibits the synthesis of mycolic acids, a crucial component of the cell wall of Mycobacterium tuberculosis. By blocking mycolic acid synthesis, isoniazid disrupts the integrity of the bacterial cell wall, leading to cell death. Choices A, C, and D are incorrect because isoniazid does not affect protein synthesis, RNA synthesis, or ADP synthesis. These processes are not targeted by isoniazid in its mechanism of action against tuberculosis.

Correct Answer: D

Rationale: Step-by-step rationale for choosing Pyrantel for nematodosis treatment: 1. Pyrantel is a well-known anthelmintic drug effective against roundworms. 2. It works by causing paralysis in the worms, leading to their expulsion from the body. 3. Pyrantel is commonly used to treat various nematode infections in humans. 4. Niclosamide is more effective against tapeworms, not nematodes. 5. Praziquantel is used for tapeworm and fluke infections, not specifically for nematodes. 6. Bithionol is an older drug with limited use and not commonly used for nematodosis treatment.

Correct Answer: A

Rationale: The correct answer is A: Leuprolide. Leuprolide is a gonadotropin-releasing hormone agonist that works by suppressing the release of gonadotropins, ultimately leading to decreased production of testosterone or estrogen. This is commonly used in the treatment of hormone-sensitive cancers, endometriosis, and certain reproductive disorders. Explanation for incorrect choices: B: Tamoxifen is a selective estrogen receptor modulator, not a gonadotropin-releasing hormone agonist. C: Flutamide is an androgen receptor antagonist used in the treatment of prostate cancer, not a gonadotropin-releasing hormone agonist. D: Anastrozole is an aromatase inhibitor that inhibits estrogen synthesis, not a gonadotropin-releasing hormone agonist.

Correct Answer: B

Rationale: Step 1: Identify the patient at highest risk for cardiovascular disease. Step 2: Assess patient characteristics - Patient 2 has diabetes and hypertension. Step 3: Diabetes and hypertension increase cardiovascular risk. Step 4: Antihyperlipidemic drugs reduce cardiovascular risk in patients with diabetes and hypertension. Step 5: Therefore, it is most important to recommend an antihyperlipidemic drug to Patient 2. Summary: - Patient 1: No specific risk factors mentioned. - Patient 3: No information provided to indicate high cardiovascular risk. - Patient 4: Age and gender alone do not warrant immediate antihyperlipidemic drug recommendation.