[Current antibiotics for clinical practice]

During the last decade a large number of novel antimicrobial agents has been developed and marketed. For the practitioner, three groups of oral substances are important, namely cephalosporins, fluoroquinolones and macrolides. The new oral cephalosporins have an improved beta-lactamase stability. Their serum half-life of 2 to 4 h is more than twice as long as that of older substances; however, their oral bioavailability is lower than that of older cephalosporins. They have an excellent activity against gram-negative bacteria, but no or only little activity against staphylococci. They are especially indicated in ENT and UT infections. The fluoroquinolones have an excellent bioavailability and are therefore ideal as oral drugs. Their microbiological spectrum is best against gram negative microorganisms. Pneumococci are not very susceptible to quinolones, with the exception of sparfloxacin. There is an increasing emergency of resistance due to a broad use of these substances. Main indications are UT infections, febrile enterocolitis, and bone and joint infections. New macrolides give less side effects and improved pharmacokinetics. Clarithromycin and azithromycin have high tissue concentrations. The main indications are upper respiratory tract infections and the community-acquired pneumonia. Newer indications for clarithromycin and azithromycin are non-tuberculous mycobacteriosis and in special cases toxoplasmosis in AIDS patients. Despite the different advantages of the new oral antibiotics, older substances such as aminopenicillins and cotrimoxazole are still important agents in the outpatient treatment.