The effect of pharmacy intervention on aminoglycoside costs

Antibiotics constitute a large percentage of every hospital's drug budget. In an effort to control the escalating costs of antimicrobial therapy, we focused on the usage of aminoglycosides at our institution. The aminoglycosides, gentamicin and tobramycin, are similar in terms of antimicrobial spectra and toxicities. Since gentamicin is much less expensive, it was felt that significant cost savings would be realized if gentamicin were to be used preferentially over tobramycin. Specific criteria for the use of tobramycin were developed and approved by the Pharmacy and Therapeutics Committee. All patients prescribed parenteral tobramycin during the five week data collection period were entered into the study. We chose to use direct verbal intervention as our method for altering physician's prescribing patterns. An educational program of intervention was set up such that when a physician prescribed tobramycin, the patient's chart was immediately reviewed. If tobramycin was prescribed for a purpose other than those in the approved criteria for tobramycin use, the physician was contacted personally to discuss the cost-effectiveness of gentamicin use. Utilization figures from the previous six months showed that our interventions would save approximately $32,000 over a one year period. Our interventions on aminoglycoside prescribing represents a highly successful, cost-effective and educational method for altering physician's prescribing patterns.