TABLE 4.

R2481 versus cefepime combined with various antimicrobials at various dosing intervals

Antimicrobial agent (regimen)	Activities of drug against MRSA R2481 in combination witha:
	Cefepime (2 g q12h)		Cefepime (2 g q8h)		Cefepime (continuous infusion)
	Δ48-h log10 CFU/ml	Activities	Δ48-h log10 CFU/ml	Activities	Δ48-h log10 CFU/ml	Activities
Gentamicin (5.0 mg/kg q24h)	−2.68**	ENC	−2.58*	ENC	−1.69*	IMP
Gentamicin (2.0 mg/kg q12h)	−1.69	IMP	−1.34	IMP	−1.54	IMP
Gentamicin (1.0 mg/kg q12h)	−3.82**	ENC	−3.14**	ENC	−2.62***	ENC
Arbekacin	−2.23*	ENC	−2.34*	ENC	−2.34***	ENC
Daptomycin	0.04	IND	−0.85	IND	−0.11	IND
Linezolid	−0.39	IND	−0.56	IND	−0.15	IND
Tigecycline	1.75	ANG	−0.03	IND	−1.86	IMP

^aChange in 48-h log₁₀ CFU of R2481/ml with cefepime (2g q12h, 2 g q8h, and continuous infusion) plus gentamicin (1.0 or 2.0 mg/kg q12h or 5.0 mg/kg q24h), arbekacin, linezolid, daptomycin, or tigecycline compared to results with the most potent agent alone. ENC, enhancement; IMP, improvement; ANG, antagonistic; IND, indifferent. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001.