Chloramphenicol is usually effective in:

Correct Answer: C

Rationale: Chloramphenicol is usually effective in typhoid (C), caused by Salmonella typhi, due to its broad-spectrum activity and excellent tissue penetration, including intracellular bacteria. It's not used for pulmonary tuberculosis (A), where specific anti-TB drugs like isoniazid are required, as chloramphenicol lacks activity against Mycobacterium tuberculosis. It's effective in epiglottitis (B) caused by Haemophilus influenzae, especially in resource-limited settings, but cephalosporins are preferred. It's also effective in bacterial meningitis (D), penetrating the CSF well to treat H. influenzae, S. pneumoniae, and N. meningitidis infections. Bacterial conjunctivitis (original E) responds to topical chloramphenicol. Its use in typhoid reflects its historical efficacy, though resistance and rare aplastic anemia risk limit its routine use today, favoring fluoroquinolones or ceftriaxone in many regions.

Correct Answer: C

Rationale: Fluconazole penetrates the central nervous system well (C), making it ideal for cryptococcal meningitis and other CNS fungal infections, due to its small size and hydrophilicity ensuring high CSF levels. Oral absorption is excellent regardless of food (A is incorrect), with nearly complete bioavailability. Presystemic metabolism is minimal (B is incorrect), unlike voriconazole, enhancing its systemic availability. It's excreted 80% by the kidney (D), requiring dose adjustment in renal failure. It doesn't cause gynecomastia (original E). Fluconazole's efficacy in Candida infections (e.g., thrush, esophagitis) and its favorable pharmacokinetics, including a long half-life, make it a mainstay antifungal, though resistance in non-albicans species is a growing concern.

Correct Answer: C

Rationale: Interferons are indicated in chronic hepatitis C infection (C), with interferon alfa (often pegylated) combined with ribavirin historically, boosting immune clearance of HCV, though direct-acting antivirals now dominate. They're not used in herpes simplex encephalitis (A); aciclovir is standard. They treat chronic hepatitis B (B), suppressing HBV replication. They're indicated in hairy cell leukemia (D), reducing malignant B-cells. They're not used in CMV retinitis (original E). Interferons' antiviral and anticancer effects via immune stimulation and cell cycle inhibition made them vital, though side effects like fatigue and depression often limit tolerability.

Correct Answer: D

Rationale: Cisplatin (D) is considered highly emetogenic, causing severe nausea and vomiting in most patients due to its action on the chemoreceptor trigger zone and GI tract, requiring aggressive antiemetic prophylaxis (e.g., 5HT3 antagonists, dexamethasone). Cyclophosphamide (A) is moderately to highly emetogenic, depending on dose, but less than cisplatin. Methotrexate (B) is mildly emetogenic at standard doses. 5-Fluorouracil (C) causes moderate nausea. Interleukin-2 (original E) is variably emetogenic, not a cytotoxic drug. Cisplatin's alkylating action on DNA is potent against testicular and ovarian cancers, but its emetic potential, linked to serotonin release, makes premedication critical for patient tolerability.

Correct Answer: C

Rationale: Paclitaxel causes sensory neuropathies (C), a dose-limiting toxicity from microtubule stabilization, affecting peripheral nerves, common in breast and ovarian cancer treatment. It's used alone or in combination for epithelial tumors and lymphomas (A), enhancing efficacy. It doesn't inhibit purine synthesis (B); it prevents microtubule disassembly. Glucocorticoid premedication (D) prevents hypersensitivity from its Cremophor vehicle. It causes myelosuppression (original E is incorrect). Paclitaxel's broad antitumor activity and synergy in regimens like AC make it vital, though neuropathy and alopecia require supportive care.