TABLE 5.

R2484 versus cefepime combined with various antimicrobials at various dosing intervals

Antimicrobial agent (regimen)	Activities of drug against MRSA R 2484 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)	−3.85*	ENC	−2.05	ENC	−1.46**	IMP
Gentamicin (2.0 mg/kg q12h)	0.23	IND	−0.93	IND	−0.93	IND
Gentamicin (1.0 mg/kg q12h)	−4.32***	ENC	−2.05	ENC	−1.46**	IMP
Tobramycin (5.0 mg/kg q24h)	−2.81**	ENC	−2.05	ENC	−0.44	IND
Tobramycin (2.0 mg/kg q12h)	−3.03***	ENC	−2.05	ENC	−1.46**	IMP
Tobramycin (1.0 mg/kg q12h)	−3.63***	ENC	−2.05	ENC	−1.46**	IMP
Arbekacin	−2.9**	ENC	−1.24	IMP	−1.46**	IMP
Daptomycin	0.9	IND	0.69	IND	0	IND
Linezolid	−1.32	IMP	−0.43	IND	−0.24	IND
Tigecycline	2.06	ANG	−0.28	IND	−0.66	IND

^aChange in 48-h log₁₀ CFU of R2484/ml with cefepime (2 g q12h, 2 g q8h, and continuous infusion) plus gentamicin (1.0 or 2.0 mg/kg q12h or 5.0 mg/kg q24h), tobramycin (1.0 or 2.0 mg/kg q12h or 5.0 mg/kg q24h), arbekacin, daptomycin, linezolid, 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.