The drug of choice for treatment and secondary prophylaxis against cryptococcal meningitis among AIDS patients is:

Correct Answer: C

Rationale: Step-by-step rationale: 1. Fluconazole is preferred due to its efficacy, safety, and tolerability in Cryptococcal meningitis. 2. It has better CNS penetration compared to other azoles. 3. It is less toxic than Amphotericin B and Flucytosine. 4. Ketoconazole is less effective and not recommended for this indication. Summary: - A: Amphotericin B is reserved for severe cases due to its toxicity. - B: Flucytosine is used in combination therapy but not as the primary drug of choice. - D: Ketoconazole is less effective and not preferred for Cryptococcal meningitis in AIDS patients.

Correct Answer: A

Rationale: The correct answer is A: Dapsone. Dapsone is known to cause hemolysis in patients with G6PD deficiency due to oxidative stress. G6PD deficiency leads to reduced ability to protect red blood cells from oxidative damage, which can be exacerbated by drugs like dapsone. Rifampicin and clofazimine are not associated with hemolysis in G6PD deficient patients. Option D is incorrect as dapsone is known to cause hemolysis in this population.

Correct Answer: D

Rationale: The correct answer is D: Clindamycin. Clindamycin is associated with the highest incidence of antibiotic-associated pseudomembranous enterocolitis due to its broad-spectrum activity that disrupts the normal gut flora, leading to overgrowth of Clostridium difficile. Ampicillin, Chloramphenicol, and Vancomycin are also associated with pseudomembranous enterocolitis, but the highest incidence is seen with Clindamycin due to its stronger impact on gut flora imbalance.

Correct Answer: B

Rationale: The correct answer is B. Nevirapine has a higher risk of severe hepatotoxicity in patients with higher CD4 cell counts. Choice B specifies a lower threshold for CD4 cell counts in women compared to men, which aligns with the caution needed for initiating Nevirapine. Choices A, C, and D have higher CD4 cell count thresholds for both women and men, which would increase the risk of hepatotoxicity if Nevirapine is initiated in those patients. Therefore, Choice B is the most appropriate option to minimize the risk of hepatotoxicity when initiating Nevirapine.

Correct Answer: B

Rationale: The correct answer is B: Ciprofloxacin. Ciprofloxacin is a fluoroquinolone antibiotic that interferes with DNA function in bacteria by inhibiting DNA gyrase and topoisomerase IV enzymes. This mechanism of action prevents bacterial DNA replication and repair, leading to bacterial cell death. Ciprofloxacin is effective in treating gonorrhea due to its ability to target and kill Neisseria gonorrhoeae, the bacteria causing gonorrhea. A: Chloramphenicol inhibits bacterial protein synthesis, not DNA function. C: Streptomycin disrupts bacterial protein synthesis by binding to the ribosome, not DNA function. D: Erythromycin inhibits bacterial protein synthesis by binding to the ribosome, not DNA function.