Drug-related problems in prescribed medicines in Germany at the time of dispensing

Background Drug-related problems (DRPs) can have an important impact on the effectiveness and safety of pharmacotherapy. In Germany, the frequency of DRPs in prescribed medicines in ambulatory care is not yet known. Objective To quantify DRPs in prescribed medicines identified by community pharmacists (CPs) at the time the medicine is dispensed. Setting German CPs in four different regions. Method We invited CPs to document one hundred consecutive patients presenting prescriptions using a standardized documentation form. For each patient, person- and medication-related as well as identified DRP-related data were documented. Data were transcribed electronically, coded if necessary, checked for validity, and analyzed. Main outcome measure Nature and frequency of DRPs. Results In total, 143 CPs documented 14,231 patients with 24,422 prescribed drugs and identified DRPs in 2,556 patients (18.0 %). Analyses resulted in 0.23 DRPs per patient and 0.13 DRPs per prescribed medicine. Four DRPs were responsible for almost 70 % of all DRPs: Potential drug-drug interaction (22.9 %), dose not known to patient (21.7 %), patient insecure due to generic substitution (13.5 %), and insufficient patient knowledge of correct drug use (10.9 %). If a patient's drug file was kept in the pharmacy, specific types of DRPs were detected more frequently e.g., drug-drug interactions (p < 0.001). Interventions primarily comprised counselling, monitoring, and changing drug or instructions for use. The prescribing physician was contacted in 28 % of DRPs resulting in a change of these prescriptions in 50 % of the cases. Overall and according to the pharmacists, more than 90 % of the DRPs detected were partially (10.4 %) or completely (85.4 %) solved. Conclusion We quantified DRPs in prescribed medicines in daily ambulatory care practice in Germany. When filling a prescription, in nearly 20 % of the patients relevant DRPs were revealed. According to the pharmacists, the majority could be partially or completely solved during the encounter at the pharmacy. Keeping a patient's drug file including patient specific data may facilitate the detection of DRPs and shall, therefore, be offered to patients more often.