In the past Cephalosporins have been often used in the treatment of intra-abdominal infections. Cephalosporins except, the second generation subgroup with activity against Bacteroides spp (cefoxitin and cefotetan), do not exhibit anti-anaerobic activity and must always be used in combination with anti-anaerobic agents [118]. Second-generation cephalosporins are widely used in surgical prophylaxis and trauma. They have been used in the treatment of mild-to-moderate community-acquired infections, but limitations in their spectra and microbial resistance restrict their utility in complicated intra-abdominal infections. Among third

generation cephalosporins both subgroups with poor activity against Pseudomonas #HDAC inhibitors list randurls[1|1|,|CHEM1|]# aeruginosa (cefotaxime, ceftriaxone, and ceftizoxime) and with good activity against Pseudomonas aeruginosa (cefoperazone and ceftazidime) have been used in the treatment of intra-abdominal infections in association with metronidazole. Both cephalosporins acquired resistance in enterobacteriaceae [119, 120] and intrinsic resistance in Enterococci [121] may limit cephalosporins use in high risk intra-abdominal infections especially in healt-care infections. Cefepime is a ‘fourth-generation’ cephalosporin. It was introduced into clinical practice in 1994 and is used in association with metronidazole for the treatment of severe infections [122]. Cefepime possesses higher

in vitro activity than other extended-spectrum cephalosporins against common Gram-negative and Gram-positive pathogens and may be effective, in association with metronidazole, in high risk intra-abdominal beta-catenin signaling infections [103, 123]. The results of a meta-analysis by Yahav et al. [124] in 2007 indicated a potential increased mortality in patients treated with cefepime compared with patients treated with other β-lactam drugs. Caution in the use of cefepime should be adopted until new evidence on cefepime safety is available Phosphoglycerate kinase [125]. Fluoroquinolones have been widely used in the last years for the treatment of intra-abdominal infections, because of their excellent activity against

aerobic Gram-negative bacteria and tissue penetration. In addition all the fluoroquinolones are rapidly and almost completely absorbed from the gastrointestinal tract. Peak serum concentrations obtained after oral administration are very near those achieved with intravenous administration [126]. Quinolones do not exhibit potent antianaerobic activity and have been used in combination with other therapeutic antianaerobic agents. Many studies have proved fluoroquinolones in association with metronidazole an effective therapeutic option for the treatment of patients with intra-abdominal infections since their discovery [127]. The combination of ciprofloxacin/metronidazole has been one of the most commonly used regimens for the treatment of patients with severe complicated intra-abdomianl infections in the last years.