Pharmacoeconomics of antimicrobial therapy.

Switch therapy, sequential therapy, and step-down therapy are discussed in terms of their contribution to reducing antimicrobial expenditures. Pharmacoeconomics is the science used to identify and compare the costs and consequences of drug therapy in terms of efficacy, safety, and overall health care. Pharmacoeconomic studies of antimicrobials for respiratory-tract infections have identified significant cost savings associated with regimens that are optimized for a particular patient on the basis of a drug's pharmacokinetic profile. For fluoroquinolones, optimal therapy has been associated with targeting the specific pharmacodynamic variable known as the ratio of the area under the serum concentration-time curve from 0 to 24 hours (AUC) to the minimum inhibitory concentration, also referred to as the area under the inhibitory curve (AUIC). Several studies have shown that regimens that achieve targeted AUIC values of 125 to 250 against gram-negative aerobic bacteria are cost-effective; cost savings are linked to decreased time to bacterial eradication and higher AUICs. Additional cost-effective measures for hospitals and health care institutions include the implementation of formalized i.v.-to-oral conversions and streamlining programs. Pharmacoeconomic analysis of therapies for respiratory-tract and other infections demonstrates that reducing health care costs may best be achieved by curing the infection in the shortest possible time through dosage optimization individualized to the patient.