Concept of defined daily dose (DDD) applied to the follow-up drug consumptions in an hospital pharmacy unit

The concept of defined daily dose (DDD) has been established by the Nordic countries to evaluate and compare the drug consumptions from the data collected in community pharmacies. The concept and the figures of DDD has been revised and approved by the Regional Bureau of the WHO in Copenhagen. Between 03/01/94 and 02/28/95, the mean prescribed daily dose of antibiotics in two intensive care units (ICU) at Lyon and Paris were measured and compared to the defined daily dose (DDD) defined by the WHO. The defined daily dose for the ICU was proposed for each antibiotic and used to build a tool of drug consumptions : penetration index. This index was defined as the ratio of the number of days where a specific antibiotic was administrated on the number of the days of hospitalisation in the unit during the same period of time. The index was calculated for 1996 in the two units, showing differences in the prescriptions of drug with betalactamase inhibitors, imipenem and the glycopeptides. The aminoglycosides were prescribed at the same rate but one unit prescribed preferentially gentamycin and the other, tobramycin and netilmicin. This index appeared to be a simple, understandable information for the physician as for pharmacist.