Drug information centre queries and responses about drug interactions over 10 years—A descriptive analysis

Abstract

Many people are treated with ≥1 drug, implying that risks of drug interactions need to be considered. The aim of this study was to describe drug interaction queries from healthcare professionals to a drug information centre in Sweden over 10 years focusing on drugs frequently asked about and the advice provided. Advice was recorded in mutually exclusive groups: Avoid, Adjust dose, Separate intake, Vigilance or No problem. For queries with Avoid, Adjust dose or Separate intake advice, alerts were extracted from an interaction database (Janusmed). Of 4335 queries to the centre in 2008‐2017, 589 (14%) concerned interactions. Most were posed by physicians (91%) and concerned a specific patient (83%) before treatment initiation (76%). Sertraline, warfarin and methotrexate were the most frequently asked about, whereas queries about cyclophosphamide and rifampicine occurred most often in relation to the number of exposed patients. Advice provided in 557 (95%) replies comprised Avoid: n = 85 (15%), Adjust dose: n = 57 (10%), Separate intake: n = 17 (3%), Vigilance: n = 235 (42%) or No problem: n = 163 (29%). In all, 113 (71%) of 159 queries with Avoid/Adjust dose/Separate intake advice elicited an action alert on Janusmed, whereas 31 (20%) did not result in any alert at all. Summarized, seven in ten replies from the drug information centre recommended an explicit drug treatment action, regarding either specific prescribing aspects, for instance dose adjustments, or active follow‐up including monitoring potential adverse reactions and/or laboratory results. Readily accessible decision support regarding drug interactions often provides relevant action alerts, but cannot be solely relied on.

Clinical-pharmacological drug information center of Hannover Medical School: experiences and analysis from a tertiary care university hospital

“…In the present study, queries submitted by physicians dominated in comparison with queries from pharmacists (96.1% vs. 0.3%), which is in line with previous reports 9,14,17,22,25 , but in contrast to other studies 13,15,16,28,30 . The comparatively low proportion of queries submitted by pharmacists in our study may be owing to the fact that pharmacists in Germany have the opportunity to consult other institutions for DI, such as the DI services provided by the Chambers of Pharmacists (Landesapothekerkammern).…”

“…Besides, we did not investigate the time spent answering queries and the references used in doing so. These topics have been covered comprehensively by other authors 2 , 9 , 11 , 12 , 15 – 17 , 22 , 25 , 27 , 34 , 45 . However, the most important limitation of the present study is that no information on patient-related outcomes was available.…”

“…While several reports from emerging countries [7][8][9][10][11][13][14][15][16][17] and Scandinavia 5,19,[22][23][24][25] have been published in recent years, there is a considerable lack of studies on DICs from central Europe, in particular from Germany. To the best of our knowledge, the most recent data from Germany on clinical pharmacologist-led DICs which provide DI to other healthcare professionals stem from Tröger and Meyer from 2000 26 and from Schwarz and colleagues from 1999 27 .…”

“…Therefore, updating this knowledge was urgently warranted. A strength of the present analysis is the inclusion of nearly six hundred queries, which represents a case number of similar 2,12,[15][16][17]25,27,28 or higher magnitude compared to other studies in the field [8][9][10][11]14 . Furthermore, the structure of the clinical-pharmacological DIC of Hannover Medical School complies with recommendations such as a mixed staff of clinical pharmacologists and clinical pharmacists as core team 19 and the involvement of physicians from other disciplines (e.g., internists, geriatricians, and psychiatrists) in terms of close professional cooperation and regular interdisciplinary exchange 19,29 .…”

“…Hence, it was not possible to determine if consultation of the clinical-pharmacological DIC by treating physicians benefited their patients. To investigate this aspect, a control group would have been necessary, which was not feasible within the constraints of this study-a limitation our analysis shares with other reports [7][8][9][10][11][12][14][15][16][17]21,[25][26][27]30,34 . Due to the exploratory character of our study, the statistical test results were not adjusted for multiple testing and must therefore be interpreted with circumspection.…”