IM indicates intramuscular; IV, intravenous; NVE, native valve infective endocarditis; and VGS, viridans group streptococci. Minimum inhibitory concentration is 0.12 g/mL. The subdivisions differ from Clinical and Laboratory Standards Institute recommended break points that are used to define penicillin susceptibility. *Doses recommended are for patients with normal renal function. Data for once-daily dosing of aminoglycosides for children exist, but no data for treatment of IE exist. Other potentially nephrotoxic drugs (eg, nonsteroidal anti-inflammatory drugs) should be used with caution in patients receiving gentamicin therapy. Although it is preferred that gentamicin (3 mg/kg) be given as a single daily dose to adult patients with endocarditis caused by viridans group streptococci, as a second option, gentamicin can be administered daily in 3 equally divided doses. Vancomycin dosages should be infused during the course of at least 1 hour to reduce the risk of histamine-release red man syndrome. Recommendations 1. It is reasonable to treat patients with IE caused by A defectiva, Granulicatella species, and VGS with a penicillin MIC 0.5 g/mL with a combination of ampicillin or penicillin plus gentamicin as done for enterococcal IE with infectious diseases con- sultation (Class IIa; Level of Evidence C). 2. If vancomycin is used in patients intolerant of ampi- cillin or penicillin, then the addition of gentamicin is not needed (Class III; Level of Evidence C). 3. Ceftriaxone combined with gentamicin may be a reasonable alternative treatment option for VGS isolates with a penicillin MIC 0.5 g/mL that are susceptible to ceftriaxone (Class IIb; Level of Evidence C). 