Antibiotic combinations with redundant antimicrobial spectra: clinical epidemiology and pilot intervention of computer-assisted surveillance

Clin Infect Dis. 2003 Jul 1;37(1):59-64. doi: 10.1086/376623. Epub 2003 Jun 23.


Redundant antibiotic combinations are a potentially remediable source of antibiotic overuse. At a public teaching hospital, we determined the incidence, cost, and indications for such combinations and measured the effects of a pharmacist-based intervention. Of 1189 inpatients receiving >or=2 antibiotics, computer-assisted screening identified 192 patients (16.1%) receiving potentially redundant combinations. Chart reviews showed that 137 episodes (71%) were inappropriate. Physician overprescribing errors were found in 77 episodes (56%); most involved redundant coverage for gram-positive or anaerobic organisms. In 76 episodes (55%), lapses in the medication ordering and distribution system led to the persistence in the pharmacy records of regimens no longer active according to the patient charts. The incidence of redundant antibiotic combinations was significantly higher in the intensive care unit and surgery services, compared with medical services. Interventions to discontinue redundant agents were successful in 134 (98%) of the 137 episodes. Potential drug cost savings and reduction in redundant antibiotic combination days were 10,800 dollars and 584 days, respectively; pharmacist time for patient review and intervention cost 2880 dollars. Use of redundant antibiotic combinations was common, and a pharmacist-based intervention was feasible, with a potential annualized cost savings of 48,000 dollars.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anti-Bacterial Agents / economics*
  • Anti-Bacterial Agents / therapeutic use
  • Computers*
  • Costs and Cost Analysis
  • Data Collection
  • Drug Therapy, Combination / economics*
  • Drug Utilization
  • Drug Utilization Review / economics*
  • Drug Utilization Review / methods
  • Humans
  • Pharmacists
  • Prospective Studies


  • Anti-Bacterial Agents