Oral antibiotics: practical prescribing rules for practitioners.

Oral antibiotics are frequently prescribed for older patients for the treatment of such common bacterial infections as upper respiratory and urinary tract infections. Six practical prescribing rules can help control the cost of therapy. 1) Oral antimicrobials used to prevent hospitalization are always cost-effective. 2) Oral antimicrobials are always less expensive than parenteral antimicrobials. 3) Generic antimicrobials are not always less expensive than proprietary antimicrobials. 4) The best drug for the infection is usually the most cost-effective in the long run, regardless of cost. 5) The use of antimicrobials for marginal indications is almost always cost-ineffective. 6) The simplest regimens are often the most cost-effective.