Infective Endocarditis

Question 1

What are the goals of IE therapy?

Answer 1

1) Prompt diagnosis and administering the right anti-microbial therapy

2) Assessing the need to remove and infected implanted devices or atrioventricular shunts

3) Identify patients that need valvular surgery

4) Preventing recurrent infection of IE (by good dental hygiene, prophylaxis, and the closure of shunts if present)

Question 2

What is an empiric treatment, and what is the empiric treatment for IE?

Answer 2

• Treating an infection or disease based on clinical judgment and experience, rather than waiting for specific diagnostic test results to confirm the exact cause of the illness.
• The empiric therapy should cover staphylococci (both MSSA & MRSA), streptococci, and enterococci, usually IV vancomycin is an appropriate choice

Question 3

In the case of S.A IE which side of the heart (and valve) are most susceptible, and what is the main cause?

Answer 3

It is mainly due to drug abuse, and occurs in the right side of the heart, at the tricuspid valve

Question 4

What is the clinical result that identifies the patient is responding to the initial empirical treatment?

Answer 4

1) You will see the fever and toxicity subside, while getting infected with a virulent organism like S.A might take 5-7 for the fibrillation to subside in other organisms it will usually take 3-5 days

Question 5

To which patients should we prescribe antibiotic prophylaxis to prevent IE?

Answer 5

1) Patients with prosthetic materials

2) Patients with previous IE

3) Patients with cyanotic congenital heart disease

Question 6

During which procedures should we prescribe prophylaxis for those patients?

Answer 6

1) Dental procedures

2) Procedures that are done to infected/diseased organ

Question 7

When should we administer the prophylaxis?

Answer 7

A single dose regardless of it being IM, ORAL, or IV

• 30-60 minutes before the procedure

Question 8

What is the appropriate prophylaxis for patients not allergic to penicillin/ampicillin

Answer 8

1) Amoxicillin (Oral, CI “Cell wall Inhibitor”)

2) Ampicillin (IM or IV, CI)

3) Cefalozolin “1st gen”/Ceftriaxone “3rd gen”(cephalosporin, given IM or IV, CI)

Question 9

Which medication should we use as a prophylaxis for patients allergic to penicillin?

Answer 9

1) Cephalexin (oral)

2) Azithromycin or Clarithromycin (Macrolides inhibit the 50s ribosomal subunit inhibiting the protein synthesis, ORAL)

3) Doxycycline (Tetracyclin, inhibits the 30s ribosomal subunit, given ORAL)

4) Cefalozolin “1st gen”/Ceftriaxone “3rd gen”(cephalosporin, given IM or IV, CI)

Question 10

Describe the perfect anti-microbial therapy for IE

Answer 10

1) The anti-biotic must be bactericidal and not static

2) The treatment must be prolonged (4-6 weeks)

3) Generally parenteral administration is preferable

4) Therapy regarding prosthetic valves that are implanted in less than 12 months (because after that it becomes part of the endocardium) and S.A infection IE are longer for about 2 weeks but the same antibiotic is used

• Successful treatment of IE relies on the complete eradication of the microbe, and if surgery is indicated it will only be to remove infected material

Question 11

What is the proper empirical treatment for community-acquired IE in patients with a native valve or prosthetic valves for more than 12 months?

Answer 11

1) Ampicillin (IM or IV, CI)

2) Ceftriaxone “3rd gen”(cephalosporin, given IM or IV, CI) or (Flu)cloxacillin

3) Gentamicin (Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

• Gentamicin should be used cautiously as it is highly nephrotoxic, but it is a good synergistic drug with ampicillin and the two others

Question 12

What is the proper empirical treatment for IE in patients with a prosthetic valve for less than 12 months or health-care-related IE?

Answer 12

1) Vancomycin (Glycopeptide that inhibits cell wall synthesis via its inhibition for the synthesis of peptidoglycan, IV) or Daptomycin (acts on gram + bacteria decreasing the integrity of the cell wall, IV)

2) Gentamicin (Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

3) Rifampin (Inhibits the synthesis of mRNA by inhibiting the RNA Polymerase enzyme, IV or ORAL)

Question 13

What is the proper empirical therapy for patients with community-acquired NVE or late PVE, who are allergic to penicillin?

Answer 13

1) Cefazolin (1st generation cephalosporin, given IM or IV, CI) or Vancomycin (Glycopeptide that inhibits cell wall synthesis via its inhibition for the synthesis of peptidoglycan, IV)

2) Gentamicin (Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

Question 14

What is the importance of aminoglycosides?

Answer 14

They act synergistically with the cell wall inhibitors, useful for shortening the duration of the regimen, however, they are highly nephrotoxic

Question 15

What is the proper antibiotic to use when treating IE caused by E.facealis

Answer 15

1) Ampicillin (IM or IV, CI)

2) Ceftriaxone “3rd gen”(cephalosporin, given IM or IV, CI)

• Aminoglycoside are contraindicated as enterococci can have resistant (High Level Aminoglycoside Resistance HLAR, like gentamicin)

Question 16

What antibiotics should you use in case of strep IE that is sensitive to penicillin (MIC <0.125MG/l)?

Answer 16

1) Penicillin G

2) Amoxicillin (Oral, CI “Cell wall Inhibitor”) or Ceftriaxone “3rd gen”(cephalosporin, given IM or IV, CI)

• 4 weeks in NVE, and 6 weeks in PVE

Question 17

Which antibiotic should you prescribe to patients with NVE who are allergic to penicillin?

Answer 17

Vancomycin or Daptomycin (acts on gram + bacteria decreasing the integrity of the cell wall, IV)

Question 18

What is the clinical significance of adding GENTAMICIN to the antibacterial regimen?

Answer 18

It will shorten the duration of the treatment in the case of NVE from 4-week to 2-weeks, making the patient stay less in the hospital and thus less susceptible to virulent microorganisms

Question 19

What should you prescribe to patients with NVE that are infected with strep strain that is resistant to penicillin?

Answer 19

1) Penicillin G (higher dosage, 4-weeks, IV, Inhibitis the cell wall synthesis by inhibiting the peptidoglycan cross-linking)

2) Amoxicillin (Oral, CI “Cell wall Inhibitor”) or Ceftriaxone (4-weeks)

3) Gentamicin (For 2-weeks, Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

Question 20

Which antibiotic you must administer for patients with staphylococci NVE infection that are MSSA?

Answer 20

1) (Flu)cloxacillin or Cefazolin (1st generation cephalosporin, given IM or IV, CI)

Question 21

Which antibiotic you must administer for patients with staphylococci PVE infection that is MSSA?

Answer 21

6-Weeks:

1) (Flu)cloxacillin or Cefazolin (1st generation cephalosporin, given IM or IV, CI)

2) Rifampin (Inhibits the synthesis of mRNA by inhibiting the RNA Polymerase enzyme, IV or ORAL)

2-Weeks:

1) Gentamicin (Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

Question 22

Which antibiotic you must administer for patients with staphylococci NVE infection that are MRSA?

Answer 22

Vancomycin (Glycopeptide that inhibits cell wall synthesis via its inhibition for the synthesis of peptidoglycan, IV) for 4 weeks

Question 23

Which antibiotic you must administer for patients with staphylococci PVE infection that are MRSA?

Answer 23

6-Weeks:

1) Vancomycin (Glycopeptide that inhibits cell wall synthesis via its inhibition for the synthesis of peptidoglycan, IV)

2) Rifampin (Inhibits the synthesis of mRNA by inhibiting the RNA Polymerase enzyme, IV or ORAL)

2-Weeks:

3) Gentamicin (Aminoglycoside, Inhibits the 30S ribosomal subunit, IV or IM)

Question 24

Describe the therapy route for IE

Answer 24

1) First 10-Days:

• Inpatient treatment with IV
• Cardiac surgery if indicated
• Removal of infected cardiac devices
• Draining any abscess if present

2) After day 10-6th week:

• Perform transesophageal echo before therapy
• Complicated patient’s continuous inpatient IV treatment
• after 10 days post-treatment of 7 post-surgery consider administering Oral antibiotics for the patient