MCQ Quiz: Infective Endocarditis

Infective Endocarditis (IE) is a serious and potentially fatal infection of the endocardial surface of the heart, most commonly affecting the heart valves. Its management is complex, requiring a deep understanding of microbiology, diagnostic criteria, and long-term, high-dose parenteral antimicrobial therapy. For PharmD students, mastering the pharmacotherapy of IE is critical, as pharmacists play a key role in optimizing antibiotic regimens, monitoring for toxicity, and ensuring patient adherence. This quiz focuses on the diagnosis of IE using the Modified Duke Criteria, the treatment of common pathogens like Staphylococcus, Streptococcus, and Enterococcus, and the guidelines for dental and procedural prophylaxis.

1. The formation of an infectious vegetation in infective endocarditis typically begins with damage to what layer of the heart?

• a) Pericardium
• b) Myocardium
• c) Endothelium
• d) Epicardium

Answer: c) Endothelium

2. Which of the following is a major criterion in the Modified Duke Criteria for diagnosing Infective Endocarditis?

• a) Fever > 38°C
• b) Positive blood culture for a typical microorganism consistent with IE.
• c) Presence of Janeway lesions.
• d) A new heart murmur.

Answer: b) Positive blood culture for a typical microorganism consistent with IE.

3. Janeway lesions, a peripheral manifestation of IE, are best described as:

• a) Painful nodules on the fingertips.
• b) Splinter hemorrhages under the nails.
• c) Non-tender, erythematous macules on the palms and soles.
• d) Retinal hemorrhages with pale centers.

Answer: c) Non-tender, erythematous macules on the palms and soles.

4. What is the most common causative organism of IE in patients who use intravenous drugs?

• a) Streptococcus bovis
• b) Staphylococcus aureus
• c) Enterococcus faecalis
• d) HACEK organisms

Answer: b) Staphylococcus aureus

5. A patient with a history of IV drug use presents with IE. Which heart valve is most commonly affected?

• a) Mitral valve
• b) Aortic valve
• c) Tricuspid valve
• d) Pulmonic valve

Answer: c) Tricuspid valve

6. The “HACEK” group of organisms are known for causing which type of IE?

• a) Acute, rapidly progressing IE.
• b) Prosthetic valve endocarditis only.
• c) Subacute, culture-negative endocarditis.
• d) IE associated with gastrointestinal malignancies.

Answer: c) Subacute, culture-negative endocarditis.

7. What is the standard duration of IV antibiotic therapy for uncomplicated native valve IE caused by a highly penicillin-susceptible Viridans group streptococcus?

• a) 2 weeks
• b) 4 weeks
• c) 6 weeks
• d) 8 weeks

Answer: b) 4 weeks

8. For a patient with native valve endocarditis caused by methicillin-susceptible Staphylococcus aureus (MSSA), what is the preferred antibiotic?

• a) Vancomycin
• b) Daptomycin
• c) Nafcillin or Oxacillin
• d) Linezolid

Answer: c) Nafcillin or Oxacillin

9. A patient is being treated for prosthetic valve endocarditis (PVE) caused by MRSA. In addition to vancomycin, which antibiotic is typically added to the regimen for its ability to penetrate biofilm?

• a) Gentamicin
• b) Rifampin
• c) Ciprofloxacin
• d) Clindamycin

Answer: b) Rifampin

10. What is the purpose of adding gentamicin to a beta-lactam regimen for the treatment of enterococcal endocarditis?

• a) To provide coverage against gram-negative bacteria.
• b) To provide synergistic bactericidal activity.
• c) To reduce the risk of nephrotoxicity.
• d) To decrease the duration of therapy.

Answer: b) To provide synergistic bactericidal activity.

11. According to AHA guidelines, which of the following patients requires antibiotic prophylaxis before an invasive dental procedure?

• a) A patient with a history of a heart murmur.
• b) A patient with mitral valve prolapse without regurgitation.
• c) A patient with a prosthetic heart valve.
• d) A patient who had a coronary artery bypass graft (CABG).

Answer: c) A patient with a prosthetic heart valve.

12. What is the standard oral antibiotic regimen for IE prophylaxis in an adult patient with a high-risk cardiac condition and no penicillin allergy?

• a) A single 2-gram dose of amoxicillin 30-60 minutes before the procedure.
• b) A 7-day course of amoxicillin starting on the day of the procedure.
• c) A single 500 mg dose of azithromycin.
• d) A single 1-gram dose of vancomycin.

Answer: a) A single 2-gram dose of amoxicillin 30-60 minutes before the procedure.

13. A patient requiring IE prophylaxis has a history of anaphylaxis to penicillin. Which oral agent is a suitable alternative?

• a) Cephalexin
• b) Amoxicillin/Clavulanate
• c) Clindamycin 600 mg
• d) Cefadroxil

Answer: c) Clindamycin 600 mg

14. What is the primary advantage of a transesophageal echocardiogram (TEE) over a transthoracic echocardiogram (TTE) in diagnosing IE?

• a) It is less invasive.
• b) It does not use sound waves.
• c) It has higher sensitivity for detecting smaller vegetations and valvular complications.
• d) It is significantly cheaper.

Answer: c) It has higher sensitivity for detecting smaller vegetations and valvular complications.

15. Roth spots, a peripheral manifestation of IE, are found during an examination of the:

• a) Skin
• b) Nails
• c) Mouth
• d) Eyes (retina)

Answer: d) Eyes (retina)

16. The initial diagnostic workup for a patient with suspected IE must include:

• a) A CT scan of the chest.
• b) At least three sets of blood cultures drawn from different venipuncture sites.
• c) A stool sample for culture.
• d) A throat swab.

Answer: b) At least three sets of blood cultures drawn from different venipuncture sites.

17. What is the target vancomycin trough concentration for a patient with MRSA endocarditis?

• a) 5-10 mcg/mL
• b) 10-15 mcg/mL
• c) 15-20 mcg/mL
• d) >25 mcg/mL

Answer: c) 15-20 mcg/mL

18. Surgical intervention is often indicated in IE for which of the following reasons?

• a) Mild fever
• b) The presence of a small, stable vegetation.
• c) Severe valvular dysfunction causing heart failure.
• d) A positive blood culture on day one of therapy.

Answer: c) Severe valvular dysfunction causing heart failure.

19. Culture-negative endocarditis can be caused by:

• a) Fastidious organisms like Coxiella burnetii or Bartonella species.
• b) Prior antibiotic administration before blood cultures were drawn.
• c) Non-bacterial pathogens like fungi.
• d) All of the above.

Answer: d) All of the above.

20. A patient being treated for IE develops a new-onset stroke. This is most likely due to:

• a) An adverse reaction to the antibiotic.
• b) An embolic event from a dislodged piece of vegetation.
• c) A hypertensive crisis.
• d) An electrolyte abnormality.

Answer: b) An embolic event from a dislodged piece of vegetation.

21. A patient with IE caused by Streptococcus gallolyticus (formerly S. bovis) should undergo which additional screening?

• a) A chest X-ray for tuberculosis.
• b) A colonoscopy to screen for colorectal cancer.
• c) A liver function panel.
• d) A hearing test.

Answer: b) A colonoscopy to screen for colorectal cancer.

22. What is the primary reason for the extended duration (4-6 weeks) of antibiotic therapy in IE?

• a) To ensure patient compliance.
• b) To allow for slow penetration of antibiotics into the avascular vegetation.
• c) To prevent antibiotic resistance from developing.
• d) Because most patients are treated as outpatients.

Answer: b) To allow for slow penetration of antibiotics into the avascular vegetation.

23. Which of the following is NOT considered a minor criterion in the Modified Duke Criteria?

• a) Fever > 38°C
• b) Vascular phenomena (e.g., Janeway lesions)
• c) Echocardiogram showing a valvular vegetation
• d) Predisposing heart condition or IV drug use

Answer: c) Echocardiogram showing a valvular vegetation

24. The diagnosis of definite IE by the Modified Duke Criteria can be met by the presence of:

• a) One major and one minor criterion.
• b) Three minor criteria.
• c) Two major criteria.
• d) One major and two minor criteria.

Answer: c) Two major criteria.

25. A major toxicity associated with long-term gentamicin therapy that requires careful monitoring is:

• a) Hepatotoxicity
• b) Pulmonary fibrosis
• c) Nephrotoxicity and Ototoxicity
• d) Myelosuppression

Answer: c) Nephrotoxicity and Ototoxicity

26. Treatment for fungal endocarditis typically involves:

• a) A short course of oral fluconazole.
• b) A combination of surgical valve replacement and long-term antifungal therapy.
• c) Topical antifungal creams.
• d) Observation and supportive care.

Answer: b) A combination of surgical valve replacement and long-term antifungal therapy.

27. Osler’s nodes are best described as:

• a) Painless macules on the palms and soles.
• b) Painful, violaceous nodules on the fingers or toes.
• c) Small, linear hemorrhages under the nails.
• d) A new, blowing heart murmur.

Answer: b) Painful, violaceous nodules on the fingers or toes.

28. Why is daptomycin not effective for treating MRSA pneumonia, but can be used for MRSA bacteremia and right-sided IE?

• a) It has poor lung penetration.
• b) It is inactivated by pulmonary surfactant.
• c) It is only effective against gram-negative bacteria in the lungs.
• d) It cannot be administered intravenously.

Answer: b) It is inactivated by pulmonary surfactant.

29. The pharmacist’s role in outpatient parenteral antimicrobial therapy (OPAT) for IE includes:

• a) Ensuring appropriate drug selection, dose, and stability for home infusion.
• b) Educating the patient on sterile technique and IV catheter care.
• c) Coordinating monitoring for efficacy and toxicity.
• d) All of the above.

Answer: d) All of the above.

30. Which of the following procedures does NOT require IE prophylaxis, even in a high-risk patient?

• a) A dental extraction.
• b) Placement of an orthodontic band.
• c) A routine, non-invasive skin biopsy.
• d) Tonsillectomy.

Answer: c) A routine, non-invasive skin biopsy.

31. The primary treatment for endocarditis caused by highly susceptible Viridans Group Streptococci (Penicillin MIC ≤ 0.12 mcg/mL) can be:

• a) Vancomycin for 6 weeks.
• b) Penicillin G or Ceftriaxone for 4 weeks.
• c) Doxycycline for 4 weeks.
• d) A single dose of ceftriaxone.

Answer: b) Penicillin G or Ceftriaxone for 4 weeks.

32. Early prosthetic valve endocarditis (within 1 year of surgery) is most often caused by:

• a) Viridans group streptococci.
• b) HACEK organisms.
• c) Coagulase-negative staphylococci (e.g., S. epidermidis) acquired during surgery.
• d) Enterococcus faecalis.

Answer: c) Coagulase-negative staphylococci (e.g., S. epidermidis) acquired during surgery.

33. What is a key consideration for a patient on warfarin who is started on long-term nafcillin for MSSA endocarditis?

• a) Nafcillin will increase the INR, increasing bleeding risk.
• b) Nafcillin is an enzyme inducer and will likely decrease the INR, requiring higher warfarin doses.
• c) There is no interaction between nafcillin and warfarin.
• d) Warfarin should be discontinued during nafcillin therapy.

Answer: b) Nafcillin is an enzyme inducer and will likely decrease the INR, requiring higher warfarin doses.

34. A patient with IE has blood cultures that remain positive after 7 days of appropriate antibiotic therapy. This is a strong indication for:

• a) Immediately stopping all antibiotics.
• b) Considering surgical intervention to debride the infection source.
• c) Switching to oral antibiotics.
• d) Decreasing the dose of the current antibiotic.

Answer: b) Considering surgical intervention to debride the infection source.

35. A “vegetation” in the context of IE is a complex mass composed of platelets, fibrin, and:

• a) Cholesterol crystals
• b) White blood cells
• c) Microorganisms (bacteria or fungi)
• d) Red blood cells

Answer: c) Microorganisms (bacteria or fungi)

36. For a patient with enterococcal endocarditis and high-level resistance to aminoglycosides, synergy cannot be achieved. What is an alternative dual-therapy regimen?

• a) Ampicillin + Vancomycin
• b) Ampicillin + Ceftriaxone
• c) Vancomycin + Daptomycin
• d) Linezolid + Rifampin

Answer: b) Ampicillin + Ceftriaxone

37. Which of the following is an immunologic phenomenon considered a minor criterion for IE diagnosis?

• a) Myocardial abscess
• b) Janeway lesions
• c) Glomerulonephritis
• d) Systemic emboli

Answer: c) Glomerulonephritis

38. The most common valve involved in non-IV drug use associated IE is the:

• a) Tricuspid valve
• b) Pulmonic valve
• c) Mitral valve
• d) Aortic valve

Answer: c) Mitral valve

39. A patient is diagnosed with IE caused by Candida albicans. What is the most appropriate initial therapy?

• a) Oral fluconazole
• b) Topical nystatin
• c) IV Amphotericin B or a broad-spectrum echinocandin.
• d) IV Acyclovir

Answer: c) IV Amphotericin B or a broad-spectrum echinocandin.

40. A dentist calls the pharmacy to ask about prophylaxis for a high-risk patient undergoing a procedure involving manipulation of gingival tissue. The patient reports a non-anaphylactic rash with amoxicillin. A suitable oral alternative is:

• a) Clindamycin 600 mg
• b) Azithromycin 500 mg
• c) Cephalexin 2 g
• d) Doxycycline 100 mg

Answer: c) Cephalexin 2 g

41. The primary source of bacteria for IE caused by Viridans group streptococci is typically:

• a) The gastrointestinal tract.
• b) The skin.
• c) The oral cavity.
• d) The genitourinary tract.

Answer: c) The oral cavity.

42. Which of the following is NOT a high-risk cardiac condition requiring IE prophylaxis?

• a) Prosthetic cardiac valve.
• b) Previous infective endocarditis.
• c) Repaired ventricular septal defect with no residual defect.
• d) Cardiac transplant recipients who develop cardiac valvulopathy.

Answer: c) Repaired ventricular septal defect with no residual defect.

43. A patient develops a new AV block on their EKG during treatment for IE. This is concerning for:

• a) An allergic reaction to the antibiotic.
• b) A perivalvular abscess extending into the conduction system.
• c) An electrolyte imbalance.
• d) A common, benign finding.

Answer: b) A perivalvular abscess extending into the conduction system.

44. What is the reason for obtaining multiple blood culture sets over time for an IE workup?

• a) To increase the chance of contamination.
• b) To document continuous bacteremia, a hallmark of IE.
• c) To satisfy insurance requirements.
• d) Because one set is usually not enough volume.

Answer: b) To document continuous bacteremia, a hallmark of IE.

45. A patient on vancomycin for MRSA endocarditis develops an elevated serum creatinine. The pharmacist’s recommendation should be to:

• a) Immediately switch to linezolid.
• b) Increase the vancomycin dose.
• c) Re-evaluate the vancomycin dose and frequency, potentially with an AUC/MIC-based monitoring approach, to minimize nephrotoxicity.
• d) Discontinue all antibiotics.

Answer: c) Re-evaluate the vancomycin dose and frequency, potentially with an AUC/MIC-based monitoring approach, to minimize nephrotoxicity.

46. A patient is found to have endocarditis caused by Bartonella quintana. This infection is classically associated with exposure to:

• a) Ticks
• b) Contaminated water
• c) Body lice, often in homeless populations.
• d) Farm animals.

Answer: c) Body lice, often in homeless populations.

47. A key educational point for a patient being discharged on OPAT for IE is:

• a) The importance of strict adherence to the lengthy IV antibiotic course.
• b) That they can switch to oral antibiotics if they feel better.
• c) To flush their IV line with tap water.
• d) That follow-up blood tests are not necessary.

Answer: a) The importance of strict adherence to the lengthy IV antibiotic course.

48. Splinter hemorrhages are best described as:

• a) Painful nodes on the fingers.
• b) Small, linear reddish-brown streaks under the nails.
• c) A rash on the chest.
• d) Swelling in the ankles.

Answer: b) Small, linear reddish-brown streaks under the nails.

49. An afebrile patient presents with signs of heart failure and a new murmur. Blood cultures are repeatedly negative. This clinical picture could be consistent with:

• a) A viral infection.
• b) Culture-negative endocarditis.
• c) An autoimmune disease.
• d) A medication side effect.

Answer: b) Culture-negative endocarditis.

50. The primary difference between early PVE (<1 year post-op) and late PVE (>1 year post-op) is:

• a) The location of the infection.
• b) The typical causative pathogens, with late PVE resembling native valve endocarditis.
• c) The duration of therapy.
• d) The need for surgery.

Answer: b) The typical causative pathogens, with late PVE resembling native valve endocarditis. Sources

Generate Audio Overview