A review of the comparative in-vitro activities of 12 antimicrobial agents, with a focus on five new ‘respiratory quinolones’

Abstract

Abstract The efficacies of many antimicrobial agents are being threatened by a global increase in the numbers of resistant bacterial pathogens—microorganisms that were once susceptible to some of these agents. In particular, antimicrobial resistance amongst strains of Haemophilus influenzae,Moraxella catarrhalis and Streptococcus pneumoniae has limited the usefulness of first-line agents in some clinical settings. Quinolones were introduced in the 1980s and represented a significant therapeutic advancement in the treatment of patients with infectious diseases. While these compounds possessed potent in-vitro activities against a wide range of Gram-negative pathogens, their activities against some Gram-positive and ‘ atypical’ pathogens remained borderline. Further advancement in the development of quinolones has overcome some of these problems. The ‘respiratory quinolones’ represent a new generation within this class of molecules and comprise compounds possessing broad spectrum activities against Gram-negative, Gram-positive and atypical pathogens. This review will focus on the in-vitro activities of five new respiratory quinolones (gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin and trovafloxacin), ciprofloxacin and six non-quinolone agents (azithromycin, clarithromycin, amoxycillin, co-amoxiclav, cefuroxime and co-trimoxazole) against a range of bacterial and atypical pathogens, including those that are now resistant to several of these compounds.