Woodcock J. Food and Drug Administration. FDA Letter re: Docket nos. FDA-2005-P-0003, FDA-2006-P-0019, FDA-2006-P-0331, and FDA-2006-P-0391: Determine that the discontinued formulation Zosyn (piperacillin and tazobactam for injection), was not discontinued for safety and efficacy reasons. Rockville, MD; US Food and Drug Administration. From regulations.gov website (www.regulations.gov/#!documentDetail;D=FDA-2012-P-0507-0001). Accessed 2015 Feb 26.