Liver function abnormalities can be seen with ceftriaxone use and are sometimes associated with sludging of drug in the For patients who are unable to tolerate penicillin or ceftriax- one, vancomycin is a reasonably effective alternative. Prolonged intravenous use of vancomycin may be complicated by throm- bophlebitis, rash, fever, neutropenia, and rarely ototoxic reac- tions. The likelihood of red man syndrome is reduced with an infusion of vancomycin over 1 hour. Desired trough vancomy- cin levels should range between 10 and 15 g/mL. Recommendations 1. Both aqueous crystalline penicillin G and ceftriax- one are reasonable options for a 4-week treatment duration (Class IIa; Level of Evidence B). 2. A 2-week treatment regimen that includes gentami- cin is reasonable in patients with uncomplicated IE, rapid response to therapy, and no underlying renal disease (Class IIa; Level of Evidence B). 3. Vancomycin for a 4-week treatment duration is a reasonable alternative in patients who cannot tol- erate penicillin or ceftriaxone therapy (Class IIa; Level of Evidence B). 4. The desired trough vancomycin level should range between 10 and 15 g/mL (Class I; Level of Evidence C). Relatively Penicillin-Resistant VGS and S gallolyticus (bovis) (MIC >0.12 <0.5 g/mL) Penicillin resistance in vitro occurs among some strains of VGS and S gallolyticus (bovis). To date, however, the num- ber of IE cases that have been reported as a result of VGS or S gallolyticus (bovis) strains that harbor any degree of penicil- lin resistance is small.123 126 Therefore, it is difficult to define the optimal treatment strategies for this group of patients. Baddour et al Infective Endocarditis in Adults 1447 Table 8 shows regimens for treatment of NVE caused by rel- atively penicillin-resistant strains (MIC >0.12 <0.5 g/mL). 