Endocarditis, Infective
Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level, Adults 2019 EditionEndocarditis, Infective
I33.0
GENERAL MEASURES
Bed rest.
Early surgical intervention in acute fulminant and prosthetic valve endocarditis is often indicated. Consider surgery if there is heart failure, embolism, large vegetations on echocardiography, heart block, evidence of persistent infection despite antibiotics or renal impairment. Refer these patients promptly.
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MEDICINE TREATMENT
Treat accompanying complications, e.g. cardiac failure. Such treatment should not delay referral.
Antibiotic therapy
- It is essential to do at least 3 blood cultures, taken by separate venipunctures, before starting antibiotics.
- In patients with subacute presentation and no haemodynamic compromise, wait for the results of blood culture before starting antibiotics.
- Empiric treatment (Table 1) is indicated in patients with a rapidly fulminant course or with severe disease only.
- Aminoglycoside therapy should be monitored with trough levels for safety.
- Duration of therapy listed is the minimum and may be extended based on the response (clinical and laboratory).
- Severe penicillin-allergic patients (Z88.0), or methicillin resistant staphylococcal infections (U80):
- Vancomycin, IV, 15–20 mg/kg 12 hourly, is the antibiotic of choice. It is essential to monitor trough concentrations of vancomycin regularly and adjust doses accordingly, starting after the third dose. (See Appendix II: Prescribing Information for Specific Medicines for guidance on prescribing and therapeutic drug monitoring).
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Empiric therapy
| Native valve |
Ampicillin, IV, 2 g 6 hourly for 4 weeks. ANDGentamicin, IV, 1.5 mg/kg 12 hourly for 2 weeks (See Prescribing Information for Specific Medicines, for guidance on prescribing). LoE:IIIblxxi AND Cloxacillin, IV, 3 g, 6 hourly. OR Cefazolin, IV, 2 g, 8 hourly. |
| Prosthetic valve* |
Vancomycin, IV, 15–20 mg/kg 12 hourly for 6 weeks. (See Appendix II: Prescribing Information for Specific Medicines for guidance on prescribing and therapeutic drug monitoring). ANDRifampicin, oral, 7.5 mg/kg 12 hourly for 6 weeks. ANDGentamicin, IV, 1.5 mg/kg 12 hourly for 2 weeks. (See Prescribing Information for Specific Medicines, for guidance on prescribing). LoE:IIIblxxi |
*All cases of prosthetic valve endocarditis should be referred.
Table 1: Empiric therapy for valve endocarditis
Directed therapy (native valve)
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|
Streptococcal
|
|
|
Fully susceptible to penicillin
MIC: ≤0.12 mg/L |
Ampicillin, IV, 2 g 6 hourly for 4 weeks.
OR
Benzylpenicillin (penicillin G), IV. 5 MU 6 hourly for 4 weeks. |
|
Moderately susceptible
MIC: >0.12–2 mg/L |
Ampicillin, IV, 2 g 6 hourly for 4 weeks.
OR
Benzylpenicillin (penicillin G), IV. 5 MU 6 hourly for 4 weeks.
AND Gentamicin, IV, 3 mg/kg daily for 2 weeks (See Prescribing Information for Specific Medicines, for guidance on prescribing). LoE:IIIblxxiv
|
|
Fully resistant
MIC: ≥4 mg/L |
Vancomycin, IV, 15-20 mg/kg 12 hourly for 6 weeks.
AND Gentamicin, IV, 3 mg/kg 12 daily for 6 weeks (See Prescribing Information for Specific Medicines, for guidance on prescribing). LoE:IIIblxxv
|
|
Enterococcal
|
|
| Susceptible to penicillin |
Ampicillin, IV, 2 g 6 hourly for 4-6 weeks.
OR
Benzylpenicillin (penicillin G), IV, 5 MU 6 hourly for 4-6 weeks.
- 6 weeks of therapy may be required in cases with a history of >3 months, or when the regimen is combined with ceftriaxone.
AND
Gentamicin, IV, 3 mg/kg daily for 2-6 weeks.
- 6 weeks of therapy may be required in cases with a history of >3 months (see Appendix II for guidance on prescribing). Check high level gentamicin susceptibility before prescribing.
OR
Ceftriaxone 2 g 12-hourly for 6 weeks
LoE:IIIblxxvi, LoE:IIIblxxvii
|
| Penicillin-resistant MIC ≥4mg/L or significant β-lactam allergy |
Refer |
| Staphylococcal |
|
| Cloxacillin-susceptible (methicillin-susceptible) |
Cloxacillin, IV, 3 g, 6 hourly for 4 weeks. OR Cefazolin, IV, 2 g, 8 hourly for 4 weeks. LoE:IIIblxxviii |
| Cloxacillin-resistant (methicillin resistant) or methicillin sensitive with significant beta-lactam allergy | Vancomycin, IV, 15–20 mg/kg 12 hourly for 4 weeks |
Table 2: Directed therapy for valve endocarditis
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Directed therapy for prosthetic valve endocarditis
Duration of therapy is usually a minimum of at least 6 weeks.
Seek expert opinion on antibiotic choice and the need for referral for repeat cardiac surgery early in the course of treatment.
Endocarditis prophylaxis
Cardiac conditions
Patients with the following cardiac conditions are at high risk of developing infective endocarditis:
- Acquired valvular heart disease with stenosis or regurgitation.
- Patients with prosthetic heart valves.
- Structural congenital heart disease, including surgically corrected or palliated structural conditions, but excluding isolated atrial septal defect, fully repaired ventricular septal defect or fully repaired patent ductus arteriosus.
- Patients who have suffered previous endocarditis.
Procedures requiring prophylaxis
- Antibiotic prophylaxis is recommended for all dental procedures that involve manipulation of either the gingival tissue or the peri-apical region of the teeth.
- Antibiotic prophylaxis is not recommended for patients who undergo a gastro-intestinal or genito-urinary procedure.
Prophylaxis (Z29.2)
Maintain good dental health.
This is the most important aspect of prophylaxis.
Refer all patients to a dental clinic/dental therapist for assessment and on-going dental care.
- Amoxicillin, oral, 2 g one hour before the procedure.
If patient cannot take oral:
- Ampicillin, IV/IM, 2 g one hour before the procedure.
Severe penicillin allergy: (Z88.0)
- Clindamycin, oral, 600 mg one hour before the procedure.
If patient with severe penicillin allergy cannot take oral:
- Clindamycin, IV, 600 mg one hour before the procedure.
Note:
The NICE review noted the lack of a consistent association between interventional procedures and development of infective endocarditis, and that the efficacy of antibiotic prophylaxis is unproven. It further commented that because the antibiotic is not without risk, there is a potential for a greater mortality from severe hypersensitivity than from withholding antibiotics.
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It is very difficult to extrapolate from these guidelines to a South African situation where good dental hygiene may be lacking and valvular heart disease is common. Practitioners need to weigh the risk of the underlying heart disease (particularly previous successfully treated endocarditis) and the essential need for ongoing antibiotic stewardship.
Standard Treatment Guidelines and Essential Medicines List for South Africa, Adult Hospital Level, 2020-2024_Version 1.0_01 November 2024
Chapter 3: Cardiovascular System_3.5 Endocarditis, Infective