The role of newer antibiotics in gastroenterology

The past decade has seen the introduction of a number of new potent antimicrobial agents, including broad-spectrum beta-lactam compounds such as the ureidopenicillins, third-generation cephalosporins, carbapenems, and monobactams; combinations of penicillins with inhibitors of beta-lactamase; and the quinolones. Most of these agents have excellent activity against enteric gram-negative rods and some are active against anaerobic organisms, the two bacterial groups most likely to be encountered in gastrointestinal infections. Despite the potency and wide spectrum of many of these new agents, there are currently relatively few clinical situations in which any of the newer antimicrobials are the first-line agents for therapy or prophylaxis of gastrointestinal diseases. Reluctance to use these agents as first-line therapy is based on concerns about the selection and spread of resistant organisms, superinfection syndromes, and the high cost of many of the newer agents. Specific clinical settings in which these agents may be given preference are as follows: 1. use of a third-generation cephalosporin (cefotaxime or ceftriaxone) in the treatment of spontaneous bacterial peritonitis. 2. use of broad-spectrum beta-lactam compounds to provide gram-negative coverage in patients who should not receive aminoglycosides 3. use of a third-generation cephalosporin (ceftriaxone) in the treatment of central nervous system relapses of Whipple's disease 4. use of quinolones for the empiric treatment of suspected bacterial diarrhea in patients sufficiently ill to require empiric initiation of antibiotics. 5. use of quinolones for the treatment of chronic carriers of Salmonella typhi 6. use of norfloxacin for prophylaxis against SBP. As further experience with these new antimicrobial agents is obtained and as more bacteria develop resistance to current first-line agents, there can be little doubt that these new antibiotics will play an increasing role in the prevention and treatment of gastrointestinal disease.