Bacterial endocarditis and septicemia: therapy principles MCQs With Answer

Bacterial endocarditis and septicemia: therapy principles MCQs With Answer

Introduction: This quiz set is designed for M.Pharm students studying Pharmacotherapeutics II (MPP 202T) and focuses on therapeutic principles for bacterial endocarditis and septicemia. It highlights pathogen-directed and empiric antibiotic choices, pharmacodynamic targets, combination therapy and synergy, duration and monitoring of therapy, special considerations for prosthetic device infections, and basics of sepsis management including source control and timing of antibiotics. The questions demand application of pharmacotherapy concepts such as bactericidal vs bacteriostatic activity, PK/PD targets, and dose adjustments in organ dysfunction—preparing students for clinical decision-making and exam-style reasoning.

Q1. Which organism is classically associated with subacute native valve infective endocarditis following dental procedures?

• Staphylococcus aureus
• Enterococcus faecalis
• Viridans group streptococci
• Haemophilus parainfluenzae

Correct Answer: Viridans group streptococci

Q2. What is a commonly recommended empiric intravenous antibiotic combination for suspected native valve infective endocarditis prior to culture results?

• Vancomycin plus ceftriaxone
• Ampicillin alone
• Oral amoxicillin-clavulanate
• Doxycycline plus metronidazole

Correct Answer: Vancomycin plus ceftriaxone

Q3. Which property of antibiotics is most desirable for effective treatment of infective endocarditis?

• Bacteriostatic activity
• High oral bioavailability only
• Bactericidal activity
• Restricted tissue penetration

Correct Answer: Bactericidal activity

Q4. What is the standard duration of intravenous therapy for uncomplicated, penicillin-susceptible viridans streptococcal native valve endocarditis?

• 5–7 days
• 2 weeks
• 4 weeks
• 6 months

Correct Answer: 4 weeks

Q5. Why are aminoglycosides (e.g., gentamicin) used in combination with beta-lactams for certain endocarditis cases?

• To reduce beta-lactam nephrotoxicity
• To provide synergistic bactericidal activity against enterococci and some staphylococci
• Because aminoglycosides are effective alone against biofilms
• To facilitate oral step-down therapy

Correct Answer: To provide synergistic bactericidal activity against enterococci and some staphylococci

Q6. Which initial empiric regimen is typically recommended for early prosthetic valve endocarditis (within 1 year of surgery)?

• Vancomycin plus gentamicin plus rifampin
• Cefazolin alone
• Oral linezolid monotherapy
• Amoxicillin-clavulanate with metronidazole

Correct Answer: Vancomycin plus gentamicin plus rifampin

Q7. Which of the following is a major indication for early surgical intervention in infective endocarditis?

• Transient fever despite antibiotics
• Large mobile vegetation with acute severe valvular regurgitation causing heart failure
• Low-grade bacteremia controlled within 48 hours
• Isolated mild splenomegaly

Correct Answer: Large mobile vegetation with acute severe valvular regurgitation causing heart failure

Q8. HACEK organisms causing endocarditis are best treated with which antibiotic class as first-line therapy?

• Aminoglycosides alone
• Ceftriaxone (third-generation cephalosporin)
• Trimethoprim-sulfamethoxazole
• Macrolides

Correct Answer: Ceftriaxone (third-generation cephalosporin)

Q9. What is the recommended blood culture strategy before initiating antibiotics in suspected infective endocarditis?

• One set of cultures immediately, then start antibiotics
• Three sets of blood cultures from separate venipunctures obtained before starting antibiotics
• No cultures are needed if empiric therapy is started
• Only culture the valve tissue after surgery

Correct Answer: Three sets of blood cultures from separate venipunctures obtained before starting antibiotics

Q10. Which statement about daptomycin is true in the context of bloodstream infections and endocarditis?

• Daptomycin is the drug of choice for pneumonia due to MRSA
• Daptomycin is inactivated by pulmonary surfactant and is not used for pneumonia, but it is effective for MRSA bacteremia and right-sided endocarditis
• Daptomycin has no role in MRSA bacteremia
• Daptomycin is exclusively bacteriostatic

Correct Answer: Daptomycin is inactivated by pulmonary surfactant and is not used for pneumonia, but it is effective for MRSA bacteremia and right-sided endocarditis

Q11. What is the primary reason rifampicin is added to regimens for staphylococcal prosthetic valve endocarditis?

• To provide rapid blood sterilization within hours
• Because rifampicin penetrates biofilms on prosthetic material and enhances activity when combined with other agents
• Rifampicin alone is sufficient for prosthetic infections
• To replace aminoglycosides when the isolate is susceptible

Correct Answer: Because rifampicin penetrates biofilms on prosthetic material and enhances activity when combined with other agents

Q12. Which pharmacodynamic target is most appropriate for vancomycin when treating serious MRSA bacteremia or endocarditis?

• Peak/MIC ratio >10
• Time above MIC >50%
• AUC/MIC ≥ 400 (AUC-guided dosing)
• Fixed dose regardless of renal function

Correct Answer: AUC/MIC ≥ 400 (AUC-guided dosing)

Q13. In an ampicillin-susceptible Enterococcus faecalis endocarditis patient with significant renal impairment (to avoid aminoglycoside toxicity), which regimen is an accepted alternative?

• Ampicillin plus gentamicin
• Ampicillin plus ceftriaxone (dual beta-lactam regimen)
• Vancomycin monotherapy
• Doxycycline and rifampicin

Correct Answer: Ampicillin plus ceftriaxone (dual beta-lactam regimen)

Q14. For a critically ill patient with septic shock and suspected Pseudomonas infection, which empiric choice is most appropriate initially?

• Piperacillin-tazobactam (antipseudomonal beta-lactam)
• Oral amoxicillin
• Topical mupirocin
• Azithromycin alone

Correct Answer: Piperacillin-tazobactam (antipseudomonal beta-lactam)

Q15. What is the recommended timing for administration of effective intravenous antibiotics in a patient with sepsis or septic shock?

• Within 1 hour of recognition
• Within 48 hours after culture results
• Only after hemodynamic stabilization at 72 hours
• When fever persists for 5 days

Correct Answer: Within 1 hour of recognition

Q16. In the management of septicemia, which principle is most critical in addition to appropriate antimicrobial therapy?

• Prolonging antibiotic therapy indefinitely
• Source control measures such as drainage or removal of infected devices
• Avoiding any surgical intervention
• Using only oral antibiotics

Correct Answer: Source control measures such as drainage or removal of infected devices

Q17. Which antibiotic is considered first-line therapy for methicillin-resistant Staphylococcus aureus (MRSA) infective endocarditis in many guidelines?

• Nafcillin
• Vancomycin
• Cefazolin
• Amoxicillin

Correct Answer: Vancomycin

Q18. What is the minimum usual duration of intravenous antibiotic therapy recommended for prosthetic valve endocarditis?

• 7–10 days
• 2 weeks
• 6 weeks
• 12 months

Correct Answer: 6 weeks

Q19. For native valve infective endocarditis due to methicillin-sensitive Staphylococcus aureus (MSSA), which antibiotic is preferred when the organism is susceptible?

• Nafcillin (or oxacillin)
• Vancomycin
• Daptomycin only
• Metronidazole

Correct Answer: Nafcillin (or oxacillin)

Q20. Therapeutic drug monitoring is essential for aminoglycoside therapy in endocarditis primarily to prevent which adverse effects?

• Hepatotoxicity and QT prolongation
• Nephrotoxicity and ototoxicity (monitor trough levels to minimize risk)
• Hyperglycemia and weight gain
• Thrombocytopenia only

Correct Answer: Nephrotoxicity and ototoxicity (monitor trough levels to minimize risk)

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