The magnitude and timing of peak plasma concentrations of ceftaroline ( active metabolite ) , ceftaroline fosamil ( prodrug ) , and ceftaroline M-1 ( inactive metabolite ) varied according to the ceftaroline fosamil dosing schedule ( q12h or q8h ) and infusion duration ( 60 minutes or 120 minutes ) , but overall plasma ceftaroline exposures within the respective dosing intervals were broadly similar across cohorts .