Background and Importance Medication errors (MEs) associated with drug therapy pose a direct risk to patient safety and negatively affect therapeutic success. Identifying drug dispensing-related MEs allows for root cause analysis and the implementation of preventive measures. Clinical pharmacy service is one applicable resource of minimising MEs.

Aim and Objectives Prior to extending clinical pharmacy control on daily dose manual drug dispensing (MDD) in new hospital settings, our study aims to assess the accuracy and appropriateness of this method, as well as to communicate findings to relevant departments and to develop strategies to rectify identified errors.

Material and Methods Unannounced point prevalence studies were conducted in September 2023, on two different occasions. Data were collected in eight inpatient care units (30 beds each) using camera-equipped mobile phones. Photographic comparison of MDD boxes has been made visually by clinical pharmacists (CP), comparing box content with relevant medication charts. In departments under clinical pharmacy control (=control group) drug dispensing was performed by pharmacy assistants under CP supervision, while in departments with no clinical pharmacy control (=case group) MDD was accomplished by nurses without double-check or supervision. Classification of MEs (using PCNE categories, Pharmaceutical Care Network Europe, version 9.1.) and prescribed drugs on ATC 7 level were recorded and analysed in an Excel table (MS Office 2021).

Results Drug dispensing errors were frequent in the case group: 38 false boxes out of 95 (40% failure rate). Overall, 59 mistakes were identified. Inappropriate dosing intervals (PCNE C.6.1.) happened in 5.0% of all mistakes, wrong drug was administered (C.6.5.) in 13.6%, deviation from the prescribed dosage (C.6.2. and C.6.3.) occurred in 17.0%, drug administration was missed (C.6.4.) in 64.4%. Omitted medications were mainly drugs acting on the cardiovascular system. In the control group, out of 103 boxes one error (<1%) was identified during the study period.

Conclusion and Relevance Identifying drug dispensing-related MEs enables the introduction of targeted interventions that minimise mistakes, enhance patient safety and promote accuracy in practice. Additive safety controls implemented in units with CP supervision can significantly reduce the occurrence of MEs in daily dose manual drug dispensing systems (failure prevalence approaching zero).

Conflict of Interest No conflict of interest.