Choosing the right antibacterial agent. Is 'newer' always better?

The newer antibacterials are proving in some situations to be more effective than the older agents, and it is tempting to choose them. In many instances, however, traditional agents remain the treatment of choice. Major drawbacks of using newer antibacterials include their higher cost by weight, compared with older drugs, and the emergence of resistant organisms or superinfection as a result of overuse. The newer drugs are best reserved for use when older agents would be inadequate.