Medication-related adverse events in health care-what have we learned? A narrative overview of the current knowledge

A newly developed, easy-to-use prehospital drug-derived score compared with three conventional scores: A prospective multicenter study

INTRODUCTION

The use of medications by emergency medical services (EMS) is increasing. Conventional scores are time-consuming and therefore difficult to use in an emergency setting. For early decision-making, an easy-to-use score based on the medications administered by the EMS may have prognostic value. The primary objective of this study was to develop the prehospital drug-derived score (PDDS) for 2-day mortality.

METHODS

A prospective, multicenter, ambulance-based cohort study was conducted in adults with undifferentiated acute diseases treated by EMS and transferred to the emergency department. Demographic data, prehospital diagnosis data, prehospital medication and variables for the calculation of the National Early Warning Score 2 (NEWS2), Rapid Emergency Medicine Score (REMS), and Rapid Acute Physiology Score (RAPS) were collected. The PDDS was developed and validated, establishing three levels of risk of 2-day mortality. The predictive capability of each score was determined by the area under the curve of the receiver operating characteristic curve (AUROC) and compared using the Delong's test (p-value).

RESULTS

A total of 6401 patients were included. The PDDS included age and the use of norepinephrine, analgesics, neuromuscular blocking agents, diuretics, antihypertensive agents, tranexamic acid, and bicarbonate. The AUROC of PDDS was .86 (95% CI: .816-.903) versus NEWS2 .866 (95% CI: .822-.911), p = .828; versus REMS .885 (95% CI: .845-.924), p = .311; versus RAPS .886 (95% CI: .846-.926), p = .335, respectively.

CONCLUSION

The newly developed easy-to-use prehospital drug-derived PDDS score has an excellent predictive value of early mortality. The PDDS score was comparable to the conventional risk scores and therefore might serve as an alternative score in the prehospital emergency setting.

Managing drug therapy-related problems and assessment of chronic diabetic wounds

Type 2 diabetes mellitus (T2DM), responsible for most diabetes cases recorded worldwide, increases the risk of chronic wounds and amputation. Patients with T2DM appear to be more susceptible to delayed wound healing due to their treatment adherence. This review explores the specifics of polypharmacy, side effects, possible drug interactions and the importance of medication adherence for therapeutic efficacy. We discuss the effects of anti-diabetes medications on wound healing as well as the role that biofilms and microbial infections play in diabetic wounds. Inconsistent use of medications can lead to poor glycaemic control, which negatively affects the healing process of diabetic foot ulcers. Managing chronic wounds represents a substantial portion of healthcare expenditures. Biofilm-associated infections are difficult for the immune system to treat and respond inconsistently to antibiotics as these infections are slow growing and persistent. Additionally, we emphasize the critical role pharmacists play in enhancing patient adherence and optimizing diabetes treatment by offering comprehensive coverage of drugs associated with problems related to pharmacological therapy in type 2 diabetes.

Translation and Adaptation of the STOPP/START Criteria Version 3 for Potentially Inappropriate Prescribing in Older People to European Portuguese: A Study Protocol

INTRODUCTION

As the global population ages, managing medication use in older adults becomes increasingly complex due to polypharmacy and the associated risks of adverse drug events. To improve the safety and appropriateness of medication use in the older population, tools like the Screening Tool of Older Persons' Prescriptions (STOPP) and Screening Tool to Alert doctors to Right Treatment (START) criteria have been developed. The availability of updated criteria is crucial to better support healthcare professionals in Portuguese-speaking regions. The aim of this study is to translate and validate the STOPP/START version 3 criteria for Portuguese, providing an updated and useful tool for healthcare professionals.

METHODS AND ANALYSIS

This study will be conducted through four phases: I) translation of the STOPP/START version 3 criteria to European Portuguese; II) collection of sociodemographic, clinical, and medication data; III) intrarater reliability study; and IV) interrater agreement study. This study obtained ethics approval by the Ethics Committee of the Administração Regional de Saúde do Centro, Portugal. The availability of the translated criteria will enable the integration of STOPP/START version 3 into clinical practice in Portugal, facilitating improved medication safety and appropriateness. This integration is expected to lead to better management of polypharmacy and a reduction in adverse drug events, ultimately enhancing patient outcomes and supporting evidence-based prescribing practices.

Deciphering the Intricate Interplay in the Framework of Antibiotic-Drug Interactions: A Narrative Review

Drug interactions are a significant and integral part of the concept of medication-related adverse events, whether referring to potential interactions or those currently observed in real-world conditions. The high global consumption of antibiotics and their pharmacokinetic and pharmacodynamic mechanisms make antibiotic-drug interactions a key element that requires continuous study due to their clinical relevance. In the present work, the current state of knowledge on antibiotic-drug interactions, which are less studied than other drug-drug interactions despite their frequent use in acute settings, has been consolidated and updated. The focus was on the interactions of the commonly used antibiotics in clinical practice, on the characteristics of the geriatric population susceptible to interactions, and on the impact of online drug interaction checkers. Additionally, strategies for optimizing the management of these interactions, including spacing out administrations, monitoring, or avoiding certain combinations, are suggested. Sustained research and careful monitoring are critical for improving antibiotic safety and efficacy, especially in susceptible populations, to enhance precision in managing antibiotic-drug interactions.

Novel perspective of therapeutic modules to overcome motor and nonmotor symptoms in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder that involves the loss of dopaminergic neurons, which leads to motor and non-motor symptoms that have a significant impact. The pathophysiology of PD is complex and involves environmental and genetic factors that contribute to alpha-synuclein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammation. The current treatments of PD primarily focus on symptom management and have limitations in addressing disease progression and non-motor symptoms. Epidemiological data indicates a rise in PD cases worldwide, which highlights the need for effective treatments. Pathophysiological insights point out the involvement of various factors in PD progression, such as dopamine dysregulation, genetic mutations, oxidative stress, mitochondrial damage, alpha-synuclein aggregation, and neuroinflammation. Although current treatments, which include dopamine precursors, monoamine oxidase (MAO) inhibitors, and non-dopaminergic drugs, can alleviate motor symptoms, they are not effective in preventing disease progression or managing non-motor symptoms. Additionally, they can lead to adverse effects and become less effective over time. Novel therapeutic approaches, including cell-based therapies, gene therapies, targeted drug delivery therapies, and magnetic field therapies, are promising in improving symptom management and providing personalized treatment. Additionally, emerging therapies that target alpha-synuclein aggregation, mitochondrial dysfunction, and neuroinflammation may have potential disease-modifying effects. To sum up, for dealing with the multiple aspects of PD, there is a great need to come up with new and creative therapeutic approaches that not only relieve symptoms, but also prevent the progression of disease and non-motor symptoms. The progress made in comprehending the underlying mechanisms of PD provides optimism for developing successful treatments that can enhance the outcomes and quality of life.

Retrospective analysis of adverse drug reaction enquiries to a hospital drug information service: lessons to be learned to increase in-hospital drug safety

OBJECTIVES

Adverse drug reactions (ADRs) are a major drug safety concern and a frequent topic of enquiries to hospital drug information services. Our goal was to analyse these enquiries regarding background, complexity, nature of ADR, and involved drug classes to improve in-hospital drug safety.

METHODS

Retrospectively, ADR enquiries to a German university hospital pharmacy drug information 2018-2022 were analysed regarding enquirer (profession, medical specialty) and enquiry details (drugs, suspected ADR/enquiry prior to drug initiation, ADR system organ class, probable cause identified, and enquiry complexity).

KEY FINDINGS

Of 543 enquiries, 516 (95%) were asked by physicians, 493 (91%) patient-specific, 390 (71%) on suspected ADRs, and 153 (28%) prior to drug initiation. Enquiries originated frequently from internal medicine (74/13.6%), paediatrics (71/13.1%), neurology (70/12.9%), and haemato-oncology (62/11.4%). Most frequent ADRs were haematologic (94/17%) and hepatic (72/13%). The median number of drugs per enquiry was three (range 0-37), 209 (38%) enquiries referred to one specific drug, 165 (30%) concerned ≥11 drugs. A probable cause for suspected ADRs was identified in 75 (36%) enquiries concerning one drug and 155 (94%) with ≥11 drugs. Most frequent drugs were antineoplastic (54/25.8%), nervous-system-drugs (42/20.1%), and anti-infective (40/19.1%). Most enquiries (342/63%) were complex (multiple/specialist resources).

CONCLUSIONS

Enquiries were usually asked by physicians referring to suspected ADRs in specific clinical situations. A probable cause was identified in many cases pointing to a direct positive impact on patient care. Enquiries prior to drug initiation should be encouraged to increase drug safety. Information on main ADR effects and drug classes helps with targeted counselling.

Prehospital point-of-care medication burden as a predictor of poor related outcomes in unselected acute diseases

How prehospital medication predicts patient outcomes is unclear. The aim of this work was to unveil the association between medication burden administration in prehospital care and short, mid, and long-term mortality (2, 30, and 365 day) in unselected acute diseases and to assess the potential of the number of medications administered for short, mid, and long-term mortality prediction. A prospective, multicenter, ambulance-based, cohort study was carried out in adults with unselected acute diseases managed by emergency medical services (EMS). The study was carried out in Spain with 44 ambulances and four hospitals. The principal outcome was cumulative mortality at 2, 30, and 365 days. Epidemiological variables, vital signs, and prehospital medications were collected. Patients were classified into four categories: no medication dispensed in prehospital care, one to two medications, three to four medications, and five or more medications. A total of 6401 patients were selected. The 2-day mortality associated with each group was 0.5%, 1.8%, 6.5%, and 18.8%. The 30-day mortality associated with each group was 3.8%, 6.2%, 13.5%, and 31.9%. The 365-day mortality associated with each group was 11%, 15.3%, 25.2%, and 45.7%. The predictive validity of the number of drugs administered, measured by the area under the curve, was 0.808, 0.720, and 0.660 for 2-, 30-, and 365-day mortality, respectively. Our results showed that prehospital drugs could provide relevant information regarding the mortality prediction of patients. The incorporation of this score could improve the management of high-risk patients by the EMS.

Enhanced Free-Text Search for Aggregated Medication Error Report Analysis and Risk Detection

OBJECTIVES

Detecting medication errors (MEs) and learning from them are the key elements of medication safety management in health care. While the aggregation of the data and learning across the ME reports could help detect and manage organizational risks, the inconsistent and partly missing structural data complicate the analysis. The objective of this study was to examine whether an analysis of free-text data of aggregated ME reports could contribute to the detection of organizational risks.

METHODS

A retrospective, cross-sectional analysis of ME reports from a patient safety incident reporting system in a tertiary hospital 2017-2021. Clustering of characteristics and variables of ME reports with an enhanced free-text search of the 10 most frequent active substances (TOP10) related to ME reports using Microsoft Excel. Validity analysis of the four most frequent active substances of the search results (TOP4). Evaluation of the possible impact of the enhanced free-text search method on ME report analysis and risk detection.

RESULTS

The enhanced free-text search increased significantly the number of relevant ME reports of TOP10 active substances from 698 reports to 1578 reports. The validity of the enhanced free-text search results in TOP4 active substances was more than 74%. The enhanced free-text search revealed also new ME findings.

CONCLUSIONS

Enhanced free-text search can contribute to the aggregate analysis of clustered ME reports and to the improvement of ME risk detection. The enhanced free-text search method enables more comprehensive analysis of the free-text data with commonly available software and provides new insights into medication safety improvement.

[INTERPOLAR-prospective, interventional studies as part of the Medical Informatics Initiative to improve medication therapy safety in healthcare]

Medication analyses by ward pharmacists are an important measure of drug therapy safety (DTS). Medication-related problems (MRPs) are identified and resolved with the attending clinicians. However, staff resources for extended medication analyses and complete documentation are often limited. Until now, data required for the identification of risk patients and for an extended medication analysis often had to be collected from various parts of the institution's internal electronic medical record (EMR). This error-prone and time-consuming process is to be improved in the INTERPOLAR (INTERventional POLypharmacy-Drug interActions-Risks) project using an IT tool provided by the data integration centers (DIC).INTERPOLAR is a use case of the Medical Informatics Initiative (MII) that focuses on the topic of DTS. The planning phase took place in 2023, with routine implementation planned from 2024. DTS-relevant data from the EMR is to be presented and the documentation of MRPs in routine care is to be facilitated. The prospective multicenter, cluster-randomized INTERPOLAR‑1 study serves to evaluate the benefits of IT support in routine care. The aim is to show that more MRPs can be detected and resolved with the help of IT support. For this purpose, six normal wards will be selected at each of eight university hospitals, so that 48 clusters (with a total of at least 70,000 cases) are available for randomization.

Medication review and deprescribing in different healthcare settings: a position statement from an Italian scientific consortium

Recent medical advancements have increased life expectancy, leading to a surge in patients affected by multiple chronic diseases and consequent polypharmacy, especially among older adults. This scenario increases the risk of drug interactions and adverse drug reactions, highlighting the need for medication review and deprescribing to reduce inappropriate medications and optimize therapeutic regimens, with the ultimate goal to improving patients' health and quality of life. This position statement from the Italian Scientific Consortium on medication review and deprescribing aims to describe key elements, strategies, tools, timing, and healthcare professionals to be involved, for the implementation of medication review and deprescribing in different healthcare settings (i.e., primary care, hospital, long-term care facilities, and palliative care). Challenges and potential solutions for the implementation of medication review and deprescribing are also discussed.

Screening of Multitarget Compounds against Acetaminophen Hepatic Toxicity Using In Silico, In Vitro, and In Vivo Approaches

Combination therapy and multitarget drugs have recently attracted much attention as promising tools to fight against many challenging diseases and, thus, represent a new research focus area. The aim of the current project was to screen multitarget compounds and to study their individual and combined effects on acetaminophen-induced liver injury. In this study, 2 of the best hepatoprotective multitargeting compounds were selected from a pool of 40 major compounds present in Curcuma longa and Cinnamomum zeylanicum by using molecular docking, ADMET profiling, and Pfizer's rule of five. The two selected compounds, quercetin and curcumin, showed a high binding affinity for the CYP2E1 enzyme, MAPK, and TLR4 receptors that contribute to liver injury. The candidates caused the decreased viability of cancer cell lines (HepG2 and Huh7) but showed no effect on a normal cell line (Vero). Examination of biochemical parameters (ALT, AST, ALP, and bilirubin) showed the hepatoprotective effect of the candidate drugs in comparison with the control group, which was confirmed by histological findings. Taken together, quercetin and curcumin not only satisfied the drug-like assessment criterion and proved to be multitargeting by preventing liver damage but also showed anticancer activities.

Drug Utilization Research and Predictors of Outcomes in the Intensive Care Unit of a Tertiary Care Hospital: A Prospective Observational Study

BACKGROUND

Multiple drugs are commonly prescribed to intensive care unit (ICU) patients owing to the disease profile, multiple organ dysfunction, prophylaxis, management of stress ulcers, nosocomial infections, etc. This study aimed to evaluate the drug utilization patterns and factors influencing mortality and duration of stay in ICU patients.  Methodology: A prospective observational study was conducted in the ICU of our tertiary care hospital, Postgraduate Institute of Medical Sciences, Rohtak. Data was collected from treatment charts of patients using a structured pretested proforma. World Health Organization Anatomical Therapeutic Chemical/Defined Daily Dose (WHO ATC/DDD) methodology and core prescribing indicators were used to assess drug utilization data. The effect of different variables on mortality and duration of stay in the ICU was evaluated using regression analysis.

RESULTS

An average of 8.78 drugs were prescribed per patient. Among the 922 prescriptions, anti-infectives, anti-inflammatory drugs, and drugs acting on the gastrointestinal tract were the most frequent medication classes prescribed. Polypharmacy and trade name prescribing were common. For most of the drugs, the prescribed daily dose corresponded to the WHO-DDD except ceftriaxone and levofloxacin. Age, presence of cardiac disorders, and Glasgow Coma Scale (GCS) score at admission directly correlated with mortality while the use of diuretics had a negative correlation with the duration of ICU stay.  Conclusions: There is a need to rationalize drug therapy in the ICU with regard to limiting polypharmacy and emphasizing generic drug name prescribing and adherence to the essential drug list. Antibiotic prescription patterns, in particular, deserve a special focus keeping in mind the multitude of factors demanding aggressive antibiotic use in critically ill intensive care patients.

Adverse drug reactions in the ambulatory internal patients at the emergency department: Focus on causality assessment and drug-drug interactions

A non-interventional retrospective study in ambulatory patients was conducted at the emergency department of the Division of internal medicine. In 2 months, 266 suspected adverse drug reactions (ADRs) were identified in 224/3453 patients (6.5 %). In 158/3453 patients (4.6 %), an ADR was the reason for emergency department visit and in 49 patients (1.4 %), ADRs led to hospitalisation. A causality assessment algorithm was developed, which included Naranjo algorithm and levels of ADR recognition by the treating physician and the investigators. Using this algorithm, 63/266 ADRs (23.7 %) were classified as "certain", whereas using solely the Naranjo score calculation, only 19/266 ADRs (7.1 %) were assessed as "probable" or "certain", and the rest of ADRs (namely, 247/266 = 92.9 %) were assessed as "possible". There were 116/266 (43.6 %) ADRs related to potential drug-drug interactions (DDIs), stated in at least one of the literature sources used. Based on the causality relationship, the rate of the clinically expressed DDIs was 19.0 %, or 12/63 "certain" ADR cases. Of these, 10 cases presented serious DDI-related ADRs. In summary, ADR causality assessment based exclusively on Naranjo algorithm demonstrated low sensitivity at an ambulatory emergency setting. Additional clinical judgment, including the opinion of the treating physician, proved necessary to avoid under-rating of the causality relationship, and enabled the determination of clinically expressed DDIs.

Comprehensive Multimorbidity Patterns in Older Patients Are Associated with Quality Indicators of Medication-MoPIM Cohort Study

Multimorbidity is increasing and poses a challenge to the clinical management of patients with multiple conditions and drug prescriptions. The objectives of this work are to evaluate if multimorbidity patterns are associated with quality indicators of medication: potentially inappropriate prescribing (PIP) or adverse drug reactions (ADRs). A multicentre prospective cohort study was conducted including 740 older (≥65 years) patients hospitalised due to chronic pathology exacerbation. Sociodemographic, clinical and medication related variables (polypharmacy, PIP according to STOPP/START criteria, ADRs) were collected. Bivariate analyses were performed comparing previously identified multimorbidity clusters (osteoarticular, psychogeriatric, minor chronic disease, cardiorespiratory) to presence, number or specific types of PIP or ADRs. Significant associations were found in all clusters. The osteoarticular cluster presented the highest prevalence of PIP (94.9%) and ADRs (48.2%), mostly related to anxiolytics and antihypertensives, followed by the minor chronic disease cluster, associated with ADRs caused by antihypertensives and insulin. The psychogeriatric cluster presented PIP and ADRs of neuroleptics and the cardiorespiratory cluster indicators were better overall. In conclusion, the associations that were found reinforce the existence of multimorbidity patterns and support specific medication review actions according to each patient profile. Thus, determining the relationship between multimorbidity profiles and quality indicators of medication could help optimise healthcare processes. Trial registration number: NCT02830425.

Management of Hypertension in the Elderly and Frail Patient

Hypertension is a frequent finding in elderly patients. Hypertension in older age can be both associated with frailty and represent a risk factor for frailty. Hypertension is recognized as a main risk factor for cardiovascular diseases such as heart failure, atrial fibrillation, and stroke and the occurrence of these diseases may provoke a decline in health status and/or worsen the degree of frailty. Blood pressure targets in hypertensive older and frail patients are not completely defined. However, specific evaluations of individual patients and their co-morbidities and assessment of domains and components of frailty, together with weighted consideration of drug use, may help in finding the appropriate therapy.

Prioritisation of Adverse Drug Events Leading to Hospital Admission and Occurring during Hospitalisation: A RAND Survey

(1) Adverse drug events (ADEs) are a common cause of emergency department visits and occur frequently during hospitalisation. Instruments that facilitate the detection of the most relevant ADEs could lead to a more targeted and efficient use of limited resources in research and practice. (2) We conducted two consensus processes based on the RAND/UCLA appropriateness method, in order to prioritise ADEs leading to hospital admission (panel 1) and occurring during hospital stay (panel 2) for inclusion in future ADE measurement instruments. In each panel, the experts were asked to assess the “overall importance” of each ADE on a four-point Likert scale (1 = not important to 4 = very important). ADEs with a median rating of ≥3 without disagreement were defined as “prioritised“. (3) The 13 experts in panel 1 prioritised 38 out of 65 ADEs, while the 12 experts in panel 2 prioritised 34 out of 63 ADEs. The highest rated events were acute kidney injury and hypoglycaemia (both panels), as well as Stevens–Johnson syndrome in panel 1 and rhabdomyolysis in panel 2. (4) The survey led to a set of ADEs for which there was consensus that they were of particular importance as presentations of acute medication-related harm, thereby providing a focus for further medication safety research and clinical practice.

Cost-effectiveness of central automated unit dose dispensing with barcode-assisted medication administration in a hospital setting

BACKGROUND

Central automated unit dose dispensing (cADD) with barcode-assisted medication administration (BCMA) has been shown to reduce medication administration errors (MAEs). Little is known about the cost-effectiveness of this intervention.

OBJECTIVE

To estimate the cost-effectiveness of cADD with BCMA compared to usual care.

METHODS

An economic evaluation was conducted alongside a prospective before-and-after effectiveness study in a Dutch university hospital. The primary effect measure was the difference between the rate of MAEs before and after implementation of cADD with BCMA, obtained by disguised observation in six clinical wards and subsequent extrapolation to the entire hospital. The cost-analysis was conducted from a hospital perspective with a 12-month incremental costing approach. The total costs covered the pharmaceutical service, nurse medication handling, wastage, and materials related to cADD. The primary outcome was the cost-effectiveness ratio expressed as costs per avoided MAE, obtained by dividing the annual incremental costs by the number of avoided MAEs. The secondary outcome was the cost-effectiveness ratio expressed as costs per avoided potentially harmful MAE (i.e. MAEs with the potential to cause harm).

RESULTS

The intervention was associated with an absolute MAE reduction of 4.5% and a reduction of 2.7% for potentially harmful MAEs. Based on 2,260,870 administered medications in the entire hospital annually, a total of 102,210 MAEs and 59,830 potentially harmful MAEs were estimated to be avoided. The intervention was associated with an increased incremental cost of €1,808,600 annually. The cost-effectiveness ratio was €17.69 per avoided MAE and €30.23 per avoided potentially harmful MAE.

CONCLUSIONS

The implementation of cADD with BCMA was associated with a reduced rate of medication errors, including harmful ones, at higher overall costs. The costs per avoided error are relatively low, and therefore, this intervention could be an important strategy to improve patient safety in hospitals.

Prevalence of potential drug - drug interactions in the cardiothoracic intensive care unit patients in a Chinese tertiary care teaching hospital

Background

With an increasing number of reviews describing clinically significant drug–drug interactions (DDIs), the scope and severity of interactions involving commonly used drugs in cardiothoracic intensive care units (CCUs) remain unclear. This study aims to identify risk factors and determine the incidence of potential DDIs in intensive care units.

Methods

DDIs were identified based on the profile of the prescribed drug and classified according to the Micromedex drug interaction database. Potential risk factors associated with DDIs have been identified.

Results

A total of 3193 medication episodes were evaluated, and 680 DDIs (21.3%) were found. A total of 203 patients were recruited into the study, with an average of 3.4 DDIs per patient [95% confidence interval (3.2 − 3.6)]. A total of 84.2% of the patients experienced at least one DDI. Anticoagulant and antiplatelet agents were involved in 33.5% (228/680) of the potential drug − drug interactions in the CCU. Univariate analysis and multiple logistic regression analysis showed that the age of the patient and the number of medications prescribed were significantly correlated with the occurrence of DDIs. In multiple linear regression analysis, the number of DDIs had a significant correlation only with the number of prescription drugs.

Conclusions

A high prevalence of DDIs was observed, especially in intensive care units without pharmacist intervention and computerized drug monitoring systems, highlighting the need for active surveillance to prevent potential adverse events.

Drug-Related Hospital Admissions via the Department of Emergency Medicine: A Cross-Sectional Study From the Czech Republic

Background: Drug-related hospital admissions (DRAs) represent a significant problem affecting all countries worldwide. This study aimed to determine the prevalence and preventability of DRAs, identify the most common medications involved in DRAs, the most common clinical manifestations of DRAs and describe the preventability aspects of DRAs.

Methods: This cross-sectional study examined unplanned hospital admissions to the University Hospital Hradec Králové via the department of emergency medicine in August–November 2018. Data were obtained from electronic medical records. The methodology of DRA identification was adapted from the OPERAM DRA adjudication guide.

Results: Out of 1252 hospital admissions, 195 DRAs have been identified (145 related to treatment safety, 50 related to treatment effectiveness). The prevalence of DRAs was 15.6% (95% CI 13.6–17.6). The most common medication classes involved in DRAs related to treatment safety were Antithrombotic agents, Antineoplastic agents, Diuretics, Corticosteroids for systemic use, and Beta blocking agents. The most common medication classes involved in DRAs related to treatment effectiveness included Diuretics, Antithrombotic agents, Drugs used in diabetes, Agents acting on the renin-angiotensin system, and Lipid modifying agents. Gastrointestinal disorders were the leading causes of DRAs related to treatment safety, while Cardiac disorders were the leading causes of DRAs related to treatment effectiveness. The potential preventability of DRAs was 51%. The highest share of potential preventability in medication classes repeatedly involved in DRAs related to treatment safety was observed for Anti-inflammatory and antirheumatic products, Psycholeptics, and Drugs used in diabetes. Potentially preventable DRAs related to treatment safety were most commonly associated with inappropriate drug selection, inappropriate monitoring, inappropriate dose selection, and inappropriate lifestyle measures. On the contrary, DRAs related to treatment effectiveness were more commonly associated with medication nonadherence.

Conclusion: It should be emphasized that in most DRAs, medications were only a contributory reason of hospital admissions and that benefits and risks have to be carefully balanced. It is highlighted by the finding that the same medication classes (Antithrombotic agents and Diuretics) were among the most common medication classes involved in DRAs related to treatment safety and simultaneously in DRAs related to treatment effectiveness. The study highlighted that apart from problems related to prescribing, problems related to monitoring and patient-related problems represent significant preventability aspects.