New antibiotics for community-acquired lower respiratory tract infections:improved activity at a cost?

Opinions are changing as to the continued validity of traditional beta-lact am and macrolide therapy of community acquired LRTI, partly because of resi stance and partly because of early evidence that suggests that some new age nts may be more effective. Guidelines are altering to reflect this view, al though there is conflicting evidence on their effects on outcome. Fluoroqui nolones are becoming accepted in the treatment of community acquired pneumo nia and are established choices for acute exacerbations of chronic bronchit is. The 8-methoxy fluoroquinolones, moxifloxacin and gatifloxacin, have exc ellent anti-pneumococcal activity and may become drugs of choice for penici llin/macrolide resistant infections. They appear free of the serious idiosy ncratic reaction profiles, possibly related to the immunologically reactive 1-difluorophenyl substituent, which characterised the recently withdrawn t emafloxacin, trovafloxacin and tosufloxacin. All quinolones so far tested a ppear to prolong the QTc interval, but only sparfloxacin and grepafloxacin caused clinical effects. Nevertheless, caution is required until this effec t is fully investigated. (C) 2000 Elsevier Science B.V. and International S ociety of Chemotherapy. All rights reserved.