Which of the following is FALSE concerning selective COX 2 inhibitors?:

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Flucloxacillin (D) is the correct answer as it's highly effective against staphylococcal infections, particularly those caused by Staphylococcus aureus, including beta-lactamase-producing strains. Its stability against these enzymes makes it a first-line choice for skin, soft tissue, and bone infections. Ampicillin (A) is less effective against staphylococci due to its susceptibility to beta-lactamases, targeting mainly Gram-negative bacteria. Co-amoxiclav (B), combining amoxicillin with clavulanic acid, is effective against resistant staphylococci, broadening coverage to anaerobes and other pathogens. Fusidic acid (C) is also effective, often used topically or in combination for systemic staphylococcal infections like osteomyelitis. Metronidazole (original E) targets anaerobes, not staphylococci. Flucloxacillin's narrow-spectrum activity and resistance to beta-lactamases make it ideal for MSSA (methicillin-sensitive S. aureus), balancing efficacy with reduced resistance development.

Correct Answer: A

Rationale: Metronidazole is used to treat trichomonal infections (A), caused by Trichomonas vaginalis, as a first-line therapy due to its efficacy against anaerobic protozoa, disrupting DNA synthesis. It's also effective in amoebic dysentery (B) from Entamoeba histolytica, targeting liver abscesses and intestinal disease. It treats giardiasis (C), caused by Giardia lamblia, with high cure rates. It's used in gas gangrene (original E), caused by Clostridium perfringens, often with surgery, but not tetanus (D), where antitoxin and penicillin are standard. Metronidazole's selective toxicity to anaerobes and protozoa, sparing aerobic bacteria, stems from its activation in low-oxygen environments, making it invaluable in mixed infections, though its metallic taste and disulfiram-like reaction with alcohol are notable side effects.

Correct Answer: B

Rationale: Amphotericin is effective in systemic Candida spp. infections (B), such as candidemia or invasive candidiasis, due to its broad-spectrum antifungal activity, binding ergosterol in fungal membranes to cause cell death. It's also effective in local Candida infections (A), like oral thrush, but systemic use is more critical. It's nephrotoxic (C), damaging renal tubules, often dose-limiting, requiring hydration and monitoring. It causes hypokalemia (D), from distal tubule effects, necessitating potassium supplementation. It's effective in cryptococcosis (original E is incorrect), notably meningitis. Amphotericin's efficacy in severe fungal infections is unmatched, but its toxicity profile, mitigated by lipid formulations, demands careful administration, balancing therapeutic benefit with renal and electrolyte disturbances.