Objective: Drug interactions may lead to life-threatening injuries. More often, however, they lead to slow recovery, induce slight symptoms or result only in potential injury. Therefore, clinicians are not always aware of using potentially interacting drug combinations. An on-line alarming system of potential drug interactions was developed in Turku University Central Hospital. In the present study, we utilised the system to find out the incidence and nature of potential drug interactions occurring in a representative hospital patient population.
Methods: Computerised anatomical therapeutic chemical (ATC)-coded patient medication data of 2547 patients, treated in two internal medicine wards, were combined with an ATC-coded rule base of drug interactions. All potential drug interactions in the study population were searched for.
Results: A total of 326 potentially serious drug interactions were detected in the study population. The number of patients in this group was 173, i.e. 6.8% of all patients had one or several drug combinations which might have led to serious clinical consequences. Concomitant use of calcium and fluoroquinolones (decreased absorption) was the most common mistake (66 prescriptions).
Conclusions: Potentially inappropriate drug combinations seem to occur frequently. Structured and coded medication data can be utilised efficiently to detect potential drug interactions in hospital. Computerised online monitoring and automatic alarming of potentially hazardous drug combinations might help clinicians to prescribe more safely, but further development of the system is needed to avoid unnecessary alarms.