Chemotherapy MCQs

Pharmacology · 37 free questions with answers & explanations.

1. A 35-year-old HIV-negative patient with newly diagnosed pulmonary tuberculosis is started on first-line DOTS therapy. After 2 months of treatment, he develops bilateral foot drop and paraesthesia in the hands. Which drug is responsible, and what is the mechanism?
2. A 50-year-old man with metastatic colorectal cancer is treated with 5-fluorouracil (5-FU). The oncologist adds leucovorin to the regimen. What is the rationale for this combination?
3. A 22-year-old woman is diagnosed with Plasmodium vivax malaria. She is treated with chloroquine for 3 days followed by primaquine for 14 days. Before starting primaquine, the physician orders a specific enzyme assay. Which enzyme is being checked, and why?
4. A patient with a systemic fungal infection is treated with amphotericin B deoxycholate. After 5 days she develops rising serum creatinine, hypokalaemia, and hypomagnesaemia. Which mechanism best explains these electrolyte abnormalities?
5. A 40-year-old man with drug-sensitive pulmonary TB is being treated with HRZE. At week 6, he notices progressive blurring of vision with difficulty distinguishing red from green colours. Which drug is most likely responsible?
6. A 35-year-old woman with recurrent UTI is prescribed amoxicillin-clavulanate. Clavulanate is added primarily because it:
7. A 60-year-old patient receiving vancomycin for MRSA bacteremia develops sudden flushing, erythema, and pruritus over the face and upper trunk during infusion. The most likely mechanism is:
8. A 25-year-old male is initiated on isoniazid (INH) for pulmonary tuberculosis. After 2 months he develops tingling and numbness in his feet. The underlying mechanism of this adverse effect is:
9. A 70-year-old patient on gentamicin therapy for gram-negative sepsis develops irreversible sensorineural hearing loss. The cochlear toxicity of aminoglycosides is primarily attributed to:
10. A 40-year-old HIV-positive patient with CD4 count of 50 cells/µL is started on fluconazole for cryptococcal meningitis maintenance therapy. Which statement about fluconazole's mechanism is CORRECT?
11. A child is brought with Plasmodium vivax malaria. After chloroquine treatment the fever resolves, but the physician also prescribes primaquine. The primary rationale for adding primaquine is to:
12. A 55-year-old man receiving cisplatin-based chemotherapy for non-small cell lung cancer develops persistent vomiting on day 3 after infusion despite ondansetron. This delayed emesis is predominantly mediated by:
13. A 30-year-old female with lupus nephritis is started on methotrexate for adjunctive therapy. She is also prescribed folic acid supplementation. The primary reason folic acid is given alongside methotrexate in non-oncologic uses is to:
14. A 45-year-old woman on long-term tetracycline for acne develops yellow-brown discoloration of permanent teeth in her 8-year-old child who was inadvertently exposed. This occurs because tetracycline:
15. A patient with multidrug-resistant tuberculosis (MDR-TB) is started on bedaquiline. The unique mechanism of action of bedaquiline that differentiates it from all other anti-TB drugs is:
16. A 50-year-old man with breast cancer is prescribed doxorubicin. He develops dose-dependent dilated cardiomyopathy after completing his regimen. The primary mechanism of doxorubicin cardiotoxicity is:
17. A 28-year-old male presents with Pneumocystis jirovecii pneumonia (PCP). The drug of choice for treatment and the additional agent used when PaO2 < 70 mmHg respectively are:
18. A 65-year-old diabetic patient with chronic osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA) is started on linezolid. Which of the following is a unique characteristic of linezolid's mechanism of action?
19. A 32-year-old woman with Clostridium difficile colitis is prescribed metronidazole. The drug's bactericidal activity depends on:
20. A 55-year-old patient with chronic myeloid leukemia (CML) with t(9;22) translocation is started on imatinib. The target of imatinib is:
21. A 48-year-old woman with HER2-positive breast cancer is treated with trastuzumab (Herceptin). She develops dyspnea and ejection fraction drops from 65% to 40%. This cardiotoxicity differs from anthracycline cardiotoxicity in that it is:
22. A patient receiving ceftriaxone for community-acquired meningitis develops hypoprothrombinemia and bleeding. This adverse effect is attributed to:
23. A 24-year-old patient with genital herpes is prescribed acyclovir. The drug's selectivity for infected cells over normal cells is primarily due to:
24. A 3-year-old child presents with bloody diarrhea following recent deworming. Albendazole had been prescribed for a round-worm infection. The mechanism by which albendazole kills helminths is:
25. A 60-year-old patient with Candida bloodstream infection and renal failure is started on caspofungin. Compared with fluconazole, which statement about echinocandins is MOST accurate?
26. A 28-year-old HIV-positive patient is initiated on a regimen including zidovudine (AZT). The dose-limiting toxicity of zidovudine that often necessitates switching therapy is:
27. A 38-year-old patient presents with influenza symptoms for 36 hours. Oseltamivir is prescribed. Its mechanism of action against influenza virus is:
28. A 45-year-old patient on rifampicin for tuberculosis notices his oral contraceptive pills are failing. The most likely explanation is:
29. A 52-year-old man receiving cyclophosphamide for non-Hodgkin lymphoma develops painless hematuria on day 10. The most effective agent for preventing this complication is:
30. A 35-year-old patient receiving vincristine for ALL develops bilateral foot drop, constipation, and absent deep tendon reflexes. These findings represent:
31. A 62-year-old male undergoing bleomycin-containing ABVD chemotherapy for Hodgkin lymphoma develops progressive dyspnea and bibasilar crackles on examination. CT chest shows ground-glass opacities and subpleural fibrosis. The dose-limiting toxicity of bleomycin is:
32. A 55-year-old male with testicular cancer receiving cisplatin develops high-frequency sensorineural hearing loss and peripheral neuropathy. The nephroprotective strategy routinely employed during cisplatin administration is:
33. A 45-year-old female patient with a urinary tract infection due to an extended-spectrum beta-lactamase (ESBL)-producing E. coli is hospitalized. The antibiotic class of CHOICE for ESBL infections is:
34. A 30-year-old patient with Staphylococcus aureus right-sided endocarditis is started on daptomycin. Which clinical scenario would render daptomycin INEFFECTIVE for this patient?
35. A 15-year-old girl with falciparum malaria fails chloroquine therapy. Artemisinin combination therapy (ACT) is started. The primary mechanism of artemisinins involves:
36. A 10-year-old child is brought with suspected meningococcal meningitis. The physician wants to prescribe a 3rd-generation cephalosporin. Which cephalosporin is PREFERRED for bacterial meningitis, and why?
37. A 50-year-old male on azithromycin for community-acquired pneumonia develops palpitations. ECG shows a prolonged QTc interval of 520 ms. Azithromycin causes QT prolongation primarily by: