Rule-based standardised switching of drugs at the interface between primary and tertiary care.

Introduction: Changes in drug treatment are frequently mandatory with hospital admission and discharge because hospital drug formularies are generally restricted to about 3000 drugs as compared to the many times this number - 62,000 in Germany - that are commercially available. Without computerised support, the process involved with switching drugs to a corresponding generic or a therapeutic equivalent is time-consuming and error-prone.

Methods: We have developed and tested a standardised interchange algorithm for subsequent implementation into a computerised decision support system that switches drugs to the corresponding generic or a therapeutic equivalent if they are not listed on the hospital drug formulary.