Treatment regimens for native valve endocarditis due to Staphylococcus

IV: intravenously; IM: intramuscularly; AUC: area under the concentration-time curve.
* Pediatric doses (should not exceed adult doses): oxacillin, cloxacillin, or flucloxacillin: 200 to 300 mg/kg per 24 hours IV in four or six divided doses; trimethoprim-sulfamethoxazole (cotrimoxazole) 12 mg/kg trimethoprim component per 24 hours IV in two divided doses; clindamycin 40 mg/kg per 24 hours IV in three divided doses; vancomycin 40 mg/kg per 24 hours IV in two or three divided doses; daptomycin 10 mg/kg per 24 hours IV once daily.
¶ Regimens for complicated right-sided and all left-sided infective endocarditis.
Δ Another alternative regimen for S. aureus consists of trimethoprim-sulfamethoxazole (cotrimoxazole) 960 mg trimethoprim/4800 mg sulfamethoxazole per 24 hours IV in four or six divided doses for 1 week followed by 5 weeks of oral trimethoprim-sulfamethoxazole plus clindamycin 1800 mg per 24 hours IV in three divided doses for 1 week.
◊ For use in patients with nonsevere penicillin allergy. Avoid cefazolin in complicating brain abscess; nafcillin is preferred.
§ Consultation with a pediatric infectious disease specialist is recommended in cases of infection due to methicillin-resistant strains.
¥ Vancomycin dosing in the 2015 AHA guidelines^[1] consists of 30 mg/kg per 24 hours IV in two divided doses for 6 weeks, with target trough concentrations of 15 to 20 mcg/mL. Per guidelines issued in 2020^[5], vancomycin dosing consists of a loading dose: 20 to 35 mg/kg based on actual body weight, rounded to the nearest 250 mg increment and not exceeding 3000 mg; within this range, we use a higher dose for critically ill patients. The initial maintenance vancomycin dose and interval are determined by nomogram and typically consists of 15 to 20 mg/kg every 8 to 12 hours for most patients with normal kidney function. The subsequent vancomycin dose and interval adjustments are based on AUC-guided (preferred) or trough-guided serum concentration monitoring. Refer to the UpToDate topic on vancomycin dosing for sample nomogram and discussion of AUC-guided and trough-guided vancomycin dosing.
‡ Daptomycin selection and dosing should be assisted by infectious diseases consultation.
† Daptomycin is superior to vancomycin for S. aureus bacteremia with vancomycin minimum inhibitory concentration >1 mg/L. Some experts recommend adding cloxacillin 12 g per 24 hours IV in six divided doses or fosfomycin 8 g per 24 hours IV in four divided doses to daptomycin in order to increase activity and avoid development of daptomycin resistance.