For patients with complications of IE such as perivalvular abscess ormation and septic metastatic complications, at least 6 weeks of nafcillin is recommended. Currently, defining the optimal therapy for NVE attribut- able to MRSA is challenging. Historically, vancomycin has been used and is recommended. As outlined in the Therapy of MSSA IE in Patients Allergic to or Intolerant of -Lactams section below, daptomycin may be a reasonable alternative to daptomycin for left-sided NVE caused by MRSA on the basis of limited data in a prospective, randomized trial; a multina- tional, prospective cohort investigation of the use of high-dose ( 9 mg/kg per dose) daptomycin; and a multicenter, retro- spective, observational study that included daptomycin at 8 mg/kg per dose.13,155 Selection of daptomycin dosing should be assisted by infectious diseases consultation. At this time, additional study of ceftaroline is needed to define its role, if any, in the treatment of left-sided NVE caused by MRSA. Recommendations 1. Gentamicin should not be used for treatment of NVE caused by MSSA or MRSA (Class III; Level of Evidence B). 2. In cases of brain abscess resulting from MSSA IE, nafcillin should be used instead of cefazolin; vanco- mycin should be given in cases of nafcillin intoler- ance (Class I; Level of Evidence C). 3. The usefulness of empirical combination ther- apy with vancomycin plus an antistaphylococcal -lactam antibiotic in patients with S aureus bac- teremia until oxacillin susceptibility is known is uncertain (Class IIb; Level of Evidence B). 4. IE caused by staphylococci that are penicillin sus- ceptible should be treated with antistaphylococcal -lactam antibiotics rather than aqueous crystalline penicillin G because clinical laboratories are not able to detect penicillin susceptibility (Class I; Level of Evidence B). 5. 