Trends in antimicrobial utilization at a tertiary teaching hospital during a 15-year period (1978-1992).
BACKGROUND
Antimicrobials are a major part of hospital pharmacy budgets and must be considered in resource planning and spending projections. Logically, trends in antimicrobial usage should be linked to trends in resistant pathogens.


OBJECTIVE
To examine long-term trends in antimicrobial use over a 15-year period (1978 to 1992) and contrast them with changes in pathogens causing nosocomial bacteremia.


METHODS
A 900-bed, tertiary care teaching hospital.


METHODS
Pharmacy records were reviewed to identify parenteral antimicrobial agents administered to adult inpatients. Results were expressed in average daily adult doses per 1,000 patient days.


RESULTS
Chloramphenicol use decreased, while use of penicillin G, antistaphylococcal penicillins, first-generation cephalosporins, and aminoglycosides remained relatively stable. In contrast, there was a sharp increase in the use of second- and third-generation cephalosporins (7-fold and 6.5-fold increase, respectively), vancomycin (161-fold increase), metronidazole (32-fold increase) and amphotericin B (35-fold increase). The proportion of nosocomial bacteremias due to methicillin-resistant gram-positive bacteria rose, but gentamicin resistance in gram-negatives remained at low levels. During the past 14 years, the percentage of patients receiving at least one parenteral antimicrobial rose from 23% to 44%. Among patients receiving antimicrobials, the average number of different agents used per patient increased from 1.8 to 2.1.


CONCLUSIONS
If newer agents were available, use of older agents usually declined. If newer alternatives were not available, use of older agents rose sharply. The increased use of antimicrobials in adults was related to the expanded proportion of patients receiving these agents.
Pallares
R
R
Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City 52242.
Dick
R
R
Wenzel
R P
RP
Adams
J R
JR
Nettleman
M D
MD
D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D016470:Bacteremia / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D004352:Drug Resistance, Microbial; D004363:Drug Utilization / Q000639:trends*; D006746:Hospital Bed Capacity, 500 and over; D006785:Hospitals, University; D006801:Humans; D007484:Iowa; D010607:Pharmacy Service, Hospital / Q000706:statistics & numerical data*; D013997:Time Factors
D000900:Anti-Bacterial Agents