Native valve endocarditis
Clinical definition:
Symptoms may be variable and non-specific. Common etiologies include S. aureusA and streptococcal and enterococcal species.
| Preferred antibiotic choice(s) | |||
| Drug | Formulation | Dosage | Duration |
| Combination therapy with: Benzylpenicillin (penicillin G, IV) PLUS Gentamicin (IV) | Powder for injection: 600 mg; 3 g (sodium or potassium salt) in vial | 5 MU 6 hourly | 28 days |
| Gentamicin- Injection: 10 mg; 40 mg (as sulfate)/mL in 2- mL vial | 3 mg/kg daily | 14 days | |
| Alternative antibiotic choice(s) | |||
| Combination therapy with: Ampicillin (IV) PLUS Gentamicin (IV) | Ampicillin- Powder for injection: 500 mg; 1 g (as sodium salt) in vial | 2 g 4 hourly | 28 days |
| Gentamicin- Injection: 10 mg; 40 mg (as sulfate)/mL in 2mL vial | 3 mg/kg daily | 14 days | |
| In case of confirmed drug allergy or medical contraindication | |||
| Vancomycin (IV) | Powder for injection: 250 mg (as hydrochloride) in vial | 20 mg/kg 12 hourly | 6 weeks |
Prosthetic valve or pacemaker infection
Clinical definition:
Infection associated with insertion or presence of prosthetic valve, pacemaker, or implanted defibrillator. Common etiologies include S. aureus, S. epidermidis, and other staphylococcal species.
| Preferred antibiotic choice(s) | |||
| Drug | Formulation | Dosage | Duration |
| Combination therapy with: Vancomycin (IV) PLUS Gentamicin (IV) PLUS Rifampicin (PO)
| Vancomycin- Powder for injection: 250 mg (as hydrochloride) in vial | Loading dose: 25 – 30 mg/kg followed by maintenance dose: 10 – 15 mg/kg | 6 weeks |
| Gentamicin- Injection: 10 mg; 40 mg (as sulfate)/ mL in 2- mL vial | 3 mg/kg daily | 2 weeks | |
| Rifampicin- Oral liquid: 20 mg/mL; Solid oral dosage form: 150 mg; 300 mg | 7.5 mg/kg 12 hourly | 6 weeks | |
A. If there are risk factors for S. aureus (e.g. patient is an IV drug user, if vegetation is very large, or patient has rapidly accelerating symptoms), add cloxacillin.
Principles of Stewardship:
- For suspected infective endocarditis cases, 3 blood cultures should be obtained in rapid succession from 3 anatomic sites within 6 hours before administration of antibiotic therapy.
- Approximately 10% of endocarditis cases are culture negative. The most common reason for which is receipt of antibiotics prior to the blood cultures. True, culture-negative endocarditis suggests infection by a fastidious organism, and includes Bartonella sp., Coxiella burnetti (Q Fever), and Brucella sp, each of which associate with specific risk factors. Discuss investigation and treatment options with your local pathology laboratory.