MANAGEMENT OF FLUOROQUINOLONE RESISTANCE IN PSEUDOMONAS-AERUGINOSA - OUTCOME OF MONITORED USE IN A REFERRAL HOSPITAL

We evaluated a strategy designed to improve useful activity of ciprofl oxacin against Pseudomonas aeruginosa. Following changes in antimicrob ial agent use made by the institutional Pharmacy and Therapeutic Drug Committee, monthly drug usage and microbial susceptibility records fro m June 1992 through October 1995 were reviewed. From July 1992 through October 1992 (Period 1), ciprofloxacin and ofloxacin usage represente d 95 and 5% of total quinolone doses; from December 1992 to March 1993 (Period 2), ciprofloxacin represented 19%; from July 1993 to October 1993 (Period 3), ciprofloxacin usage represented 85%; from July 1994 t o October 1994 (Period 4), ciprofloxacin represented 95%; and from Jul y 1995 to October 1995 (Period 5), ciprofloxacin and ofloxacin respect ively represented 98 and 2% of total quinolone doses. Comparison of th e anti-pseudomonal activity of the two fluoroquinolones to ofloxacin u se, ciprofloxacin use and total quinolone use during the entire observ ational period showed the highest (negative) correlation with ofloxaci n use versus ofloxacin activity (y = - 15.04x + 1367.99, r(2) = 0.06, w = 0.126). Increased use of quinolones plus a change to primarily ofl oxacin usage appeared to adversely affect the activity of both ofloxac in and ciprofloxacin against P. aeruginosa. (C) 1998 Elsevier Science B.V. All rights reserved.