[Pharmacological knowledge bases in Sweden: successes and future in a time of information overflow]

Skewed information about medicines in social media influence the healthcare-patient contact. Healthcare staff need situation adapted evidence that can be linked to patient data. For 20 years Sweden has provided praised Pharmacological Knowledge Bases (PKB). They include »Janusmed drug-drug interactions«, »Janusmed drugs and birth defects« and »e-Ped (electronic pediatric) instructions and drug dosage control«. PKBs need to be better integrated into digital tools adhering to a national guide for optimal interface presentation of information. They should be produced by medical editors and delivered through a national digital highway. Experts need to adhere to a policy for handling conflicts of interest and evaluate that information is appreciated and used. PKBs should be accessible as a public good for healthcare staff, students and the public to support personalized medical care.

An Adverse Drug Reaction Database for Clinical Use - Potential of and Difficulties with the Summary of Product Characteristics

Adverse drug reactions (ADRs) for all drugs in Europe are described in the legally approved Summary of Product Characteristics (SmPC). An overview of all ADRs of the patients' drug list can support healthcare staff to link patient symptoms to possible ADRs. We review the possibilities and challenges to extract ADR information from SmPCs and present the development of our semi-automated procedure for extraction of ADRs from the tabulated section of the SmPCs to create a database, named Bikt, which is regularly updated and used at point of care in Sweden. The existence of five major table formats for ADRs used in the SmPCs required the development of different parsing scripts. Manual checks for correctness for all content has to be performed. The quality of extraction was investigated for all SmPCs by measuring precision, recall and F1 scores (i.e. the weighted harmonic mean of precision and recall) and compared with other methods published. We conclude that it is possible to semi-automatically extract ADR information from SmPCs. However, clear technical and content guidelines and standards for ADR tables and terms from drug registration authorities would lead to improved extraction and usability of ADR information at point of care.

ADR databases for on-site clinical use: Potentials of summary of products characteristics

Adverse drug reactions (ADRs) for all drugs in Europe are described in the legally approved Summary of Product Characteristics (SmPC). An overview of all ADRs of the patients' drug list can support healthcare staff to link patient symptoms to possible ADRs. We review the possibilities and challenges to extract ADR information from SmPCs or American Structured Product Labels and present the development of our semi-automated procedure for extraction of ADRs from the tabulated section in the SmPCs to create a database, named Bikt, which is regularly updated and used at point of care in Sweden. The existence of five major table formats for ADRs used in the SmPCs required the development of different parsing scripts. Manual checks for correctness for all content have to be performed. The quality of extraction was investigated for all SmPCs by measuring precision, recall and F1 scores and compared with other methods published. We conclude that it is possible to semi-automatically extract ADR information from SmPCs. However, clear technical and content guidelines and standards for ADR tables and terms from drug registration authorities would lead to improved extraction and usability of ADR information at point of care.

Model-Informed Precision Dosing: Background, Requirements, Validation, Implementation, and Forward Trajectory of Individualizing Drug Therapy

Model-informed precision dosing (MIPD) has become synonymous with modern approaches for individualizing drug therapy, in which the characteristics of each patient are considered as opposed to applying a one-size-fits-all alternative. This review provides a brief account of the current knowledge, practices, and opinions on MIPD while defining an achievable vision for MIPD in clinical care based on available evidence. We begin with a historical perspective on variability in dose requirements and then discuss technical aspects of MIPD, including the need for clinical decision support tools, practical validation, and implementation of MIPD in health care. We also discuss novel ways to characterize patient variability beyond the common perceptions of genetic control. Finally, we address current debates on MIPD from the perspectives of the new drug development, health economics, and drug regulations.

Prevalence of potential drug-drug interactions in Swedish pediatric outpatients

PURPOSE

To describe the occurrence of potential drug-drug interactions (DDIs) in prescribed drugs, dispensed to pediatric outpatients in Sweden.

METHODS

A cross sectional study was conducted based on data from a national register of prescribed drugs, dispensed at pharmacies, to children 0-17 years old. The study period was January 1 to April 30, 2010. Drug dispensing data was linked to the DDI database SFINX. Prevalence and frequencies of potential interactions were investigated, and drugs commonly involved in interactions were identified. The study focused on clinically relevant potential interactions, class D (should be avoided), and class C (can be handled, e.g. by dose adjustment).

RESULTS

In the Swedish pediatric population, 0 to 17 years of age, 12% (n = 231 078) of children had at least two dispensed drugs. In this group of patients, 0.14% had potential D-interactions and 1,3% had potential C-interactions. The number of D- and C-interactions that may lead to reduced effects were 181 (52%), and 1224 (32%) respectively. The ten most frequent drugs were involved in 78% and 65% of all potential D-, and C-interactions respectively. Furthermore, 80%, and 58% of the D-, and C-interactions respectively occurred in patients aged 12 to 17.

CONCLUSIONS

We identified a limited number of drugs that were represented in the majority of potential interactions. Interactions that can lead to a reduced treatment effect constituted approximately half of D-interactions, and a third of C-interactions. The frequency of potential interactions was higher in older children. The results may contribute to increased prescriber awareness of important potential drug interactions among pediatric outpatients.

Potential drug-related problems detected by electronic expert support system: physicians' views on clinical relevance

BACKGROUND

Drug-related problems cause suffering for patients and substantial costs. Multi-dose drug dispensing is a service in which patients receive their medication packed in bags with one unit for each dose occasion. The electronic expert support system (EES) is a clinical decision support system that provides alerts if potential drug-related problems are detected among a patients' current prescriptions, including drug-drug interactions, therapy duplications, high doses, drug-disease interactions, drug gender warnings, and inappropriate drugs and doses for geriatric or pediatric patients.

OBJECTIVE

The aim of the study was to explore physicians' views on the clinical relevance of alerts provided by EES. Furthermore we investigated if physicians performed any changes in drug treatment following the alerts and if there were any differences in perceived relevance and performed changes between different types of alerts and drugs.

SETTING

Two geriatric clinics and three primary care units in Sweden.

METHOD

Prescribed medications for patients (n = 254) with multi-dose drug dispensing were analyzed for potential drug-related problems using EES. For each alert, a physician assessed clinical relevance and indicated any intended action. A total of 15 physicians took part in the study. Changes in drug treatment following the alerts were later measured. The relationship between variables was analyzed using Chi square test.

MAIN OUTCOME MEASURE

Physicians' perceived clinical relevance of each alert, and changes in drug treatment following the alerts.

RESULTS

Physicians perceived 68% (502/740) of EES alerts as clinically relevant and 11% of all alerts were followed by a change in drug treatment. Clinical relevance and likelihood to make changes in drug treatment was related to the alert category and substances involved in the alert.

CONCLUSION

In most patients with multi-dose drug dispensing, EES detected potential drug-related problems, with the majority of the alerts regarded as clinically relevant and some followed by measurable changes in drug treatment.

[Few drugs dominate among clinically important interactions. Swedish register study lists problem drugs]

In a recent Swedish register study, a limited number of specific drugs explained a large part of clinically relevant, potential drug-drug interactions (DDI), as defined and detected by the DDI database SFINX. Regarding interactions that should be avoided according to the definition in the database (class D), 15 drug combinations accounted for as much as 80 % of the prevalence in the Swedish population. Ten specific drugs were involved in 94 % of all detected class D interactions. About half of the clinically relevant interactions detected during the four-month study period were associated with an increased risk of adverse drug reactions, whereas the other half has a potential to cause therapeutic failure. An increased awareness among prescribers of these interacting drugs could contribute to safer and more effective drug use.

Evaluation of usage patterns and user perception of the drug-drug interaction database SFINX

PURPOSE

The aim of the present study was to investigate how prescribers and pharmacists use and perceive the drug-drug interaction database SFINX in their clinical work.

METHODS

A questionnaire was developed with questions aimed at the usage of SFINX, and the perceptions of the database. The questionnaire was sent out to all registered users of the web application of SFINX. The anonymous answers from the target users, prescribers and pharmacists were summarized using descriptive statistics. Statistical analysis was performed on age and gender differences for some questions regarding different usage patterns.

RESULTS

The questionnaire was sent to 11,763 registered SFINX users. The response rate was 23%, including 1871 answers from prescribers or pharmacists. SFINX was reported to be used at least weekly or more often by 45% of the prescribers and 51% of the pharmacists. Many prescribers reported using the database during the patient consultation (60%) or directly before or after (56%). Among the prescribers, 74% reported that the information received made them change their action at least sometimes. About 20% of the prescribers and 25% of the pharmacists considered the information as irrelevant sometimes or more often.

CONCLUSION

Most prescribers and pharmacists reported using SFINX in direct association with a patient consultation. Information received by using SFINX makes prescribers and pharmacists change their handling of patients. DDI databases with relevant information about patient handling might improve drug treatment outcome.

On the alert: future priorities for alerts in clinical decision support for computerized physician order entry identified from a European workshop

BACKGROUND

Clinical decision support (CDS) for electronic prescribing systems (computerized physician order entry) should help prescribers in the safe and rational use of medicines. However, the best ways to alert users to unsafe or irrational prescribing are uncertain. Specifically, CDS systems may generate too many alerts, producing unwelcome distractions for prescribers, or too few alerts running the risk of overlooking possible harms. Obtaining the right balance of alerting to adequately improve patient safety should be a priority.

METHODS

A workshop funded through the European Regional Development Fund was convened by the University Hospitals Birmingham NHS Foundation Trust to assess current knowledge on alerts in CDS and to reach a consensus on a future research agenda on this topic. Leading European researchers in CDS and alerts in electronic prescribing systems were invited to the workshop.

RESULTS

We identified important knowledge gaps and suggest research priorities including (1) the need to determine the optimal sensitivity and specificity of alerts; (2) whether adaptation to the environment or characteristics of the user may improve alerts; and (3) whether modifying the timing and number of alerts will lead to improvements. We have also discussed the challenges and benefits of using naturalistic or experimental studies in the evaluation of alerts and suggested appropriate outcome measures.

CONCLUSIONS

We have identified critical problems in CDS, which should help to guide priorities in research to evaluate alerts. It is hoped that this will spark the next generation of novel research from which practical steps can be taken to implement changes to CDS systems that will ultimately reduce alert fatigue and improve the design of future systems.

Physicians' reported needs of drug information at point of care in Sweden

AIMS

Relevant and easily accessible drug information at point-of-care is essential for physicians' decision making when prescribing. However, the information available by using Clinical Decision Support Systems (CDSSs) often does not meet physicians' requirements. The Summary of Product Characteristics (SmPC) is statutory information about drugs. However, the current structure, content and format of SmPCs make it difficult to incorporate them into CDSSs and link them to relevant patient information from the Electronic Health Records. The aim of the study was to evaluate the perceived needs for drug information among physicians in Sweden.

METHODS

We recruited three focus group discussions with 18 physicians covering different specialities. The information from the groups was combined with a questionnaire administered at the beginning of the group discussions.

RESULTS

Physicians reported their needs for knowledge databases at the point of drug prescribing. This included more consistent information about existing and new drugs. They also wished to receive automatically generated alerts for severe drug-drug interactions and adverse effects, and to have functions for calculating glomerular filtration rate to enable appropriate dose adjustments to be made for elderly patients and those with impaired renal function. Additionally, features enhancing electronic communication with colleagues and making drug information more searchable were suggested.

CONCLUSIONS

The results from the current study showed the need for knowledge databases which provide consistent information about new and existing drugs. Most of the required information from physicians appeared to be possible to transfer from current SmPCs to CDSSs. However, inconsistencies in the SmPC information have to be reduced to enhance their utility.

SFINX-a drug-drug interaction database designed for clinical decision support systems

OBJECTIVE

The aim was to develop a drug-drug interaction database (SFINX) to be integrated into decision support systems or to be used in website solutions for clinical evaluation of interactions.

METHODS

Key elements such as substance properties and names, drug formulations, text structures and references were defined before development of the database. Standard operating procedures for literature searches, text writing rules and a classification system for clinical relevance and documentation level were determined. ATC codes, CAS numbers and country-specific codes for substances were identified and quality assured to ensure safe integration of SFINX into other data systems. Much effort was put into giving short and practical advice regarding clinically relevant drug-drug interactions.

RESULTS

SFINX includes over 8,000 interaction pairs and is integrated into Swedish and Finnish computerised decision support systems. Over 31,000 physicians and pharmacists are receiving interaction alerts through SFINX. User feedback is collected for continuous improvement of the content.

CONCLUSION

SFINX is a potentially valuable tool delivering instant information on drug interactions during prescribing and dispensing.

Design and implementation of a point-of-care computerized system for drug therapy in Stockholm metropolitan health region--Bridging the gap between knowledge and practice

INTRODUCTION

Stockholm County Council is the largest health care provider in Sweden with an annual budget of US$ 5 billion and catering the needs of a metropolitan population of 2 million people. About 10% of health care costs are used on drugs. In 1996 Stockholm County Council decided to address the main problems associated with the process and the quality of drug prescribing.

METHODS

A multiyear strategy was designed, including the establishment of a strong evidence-based organisation, Drug and Therapeutics Committees and editorial resources to adapt information to the IT-media and the development of the IT-architecture. The development and implementation of computerized tools such as a physician drug order entry system including decision support, a drug information website and electronic transmission of prescriptions were started in 1996.

RESULTS

The implementation was slow at the point-of-care units. It took about 6 years before the implementation process gained speed. In September 2005 almost 1000 doctors could use the decision support system for prescribing drugs and more than 70% of all prescriptions were transmitted electronically in our region.

CONCLUSIONS

The work with the strategy has shown that improvements in drug use can be accomplished by providing access to simple, rapid and safe electronic tools, but the information provided has to be associated with well-recognized regional and national expert organisations.

Nonlinear self-trapping of matter waves in periodic potentials

We report the first experimental observation of nonlinear self-trapping of Bose-condensed 87Rb atoms in a one-dimensional waveguide with a superimposed deep periodic potential . The trapping effect is confirmed directly by imaging the atomic spatial distribution. Increasing the nonlinearity we move the system from the diffusive regime, characterized by an expansion of the condensate, to the nonlinearity dominated self-trapping regime, where the initial expansion stops and the width remains finite. The data are in quantitative agreement with the solutions of the corresponding discrete nonlinear equation. Our results reveal that the effect of nonlinear self-trapping is of local nature, and is closely related to the macroscopic self-trapping phenomenon already predicted for double-well systems.

Bright Bose-Einstein gap solitons of atoms with repulsive interaction

We report on the first experimental observation of bright matter wave solitons for 87Rb atoms with repulsive atom-atom interaction. This counterintuitive situation arises inside a weak periodic potential, where anomalous dispersion can be realized at the Brillouin zone boundary. If the coherent atomic wave packet is prepared at the corresponding band edge, a bright soliton is formed inside the gap. The strength of our system is the precise control of preparation and real time manipulation, allowing the systematic investigation of gap solitons.

Linear and nonlinear dynamics of matter wave packets in periodic potentials

We investigate experimentally and theoretically the nonlinear propagation of 87Rb Bose Einstein condensates in a trap with cylindrical symmetry. An additional weak periodic potential which encloses an angle with the symmetry axis of the waveguide is applied. The observed complex wave packet dynamics results from the coupling of transverse and longitudinal motion. We show that the experimental observations can be understood applying the concept of effective mass, which also allows to model numerically the three dimensional problem with a one dimensional equation. Within this framework the observed slowly spreading wave packets are a consequence of the continuous change of dispersion. The observed splitting of wave packets is very well described by the developed model and results from the nonlinear effect of transient solitonic propagation.

Dispersion management for atomic matter waves

We demonstrate the control of the dispersion of matter wave packets utilizing periodic potentials. This is analogous to the technique of dispersion management known in photon optics. Matter wave packets are realized by Bose-Einstein condensates of 87Rb in an optical dipole potential acting as a one-dimensional waveguide. A weak optical lattice is used to control the dispersion relation of the matter waves during the propagation of the wave packets. The dynamics are observed in position space and interpreted using the concept of effective mass. By switching from positive to negative effective mass, the dynamics can be reversed. The breakdown of the approximation of constant, as well as experimental signatures of an infinite effective mass are studied.

A single molecule as a probe of optical intensity distribution

Single terrylene molecules embedded in microscopic p-terphenyl crystals are identified with the technique of fluorescence excitation spectroscopy. By use of the architecture of a scanning-probe microscope at T = 1.4 K , a single molecule is scanned through an excitation laser beam while the fluorescence signal is recorded. In this manner we have mapped the intensity distribution in a one-dimensional optical standing wave, demonstrating the potential of a single molecule as a nanometric probe. We discuss future experiments aimed at combining the high spatial and spectral sensitivity of a single molecule.

1- and 3-hydroxylations, in addition to 4-hydroxylation, of debrisoquine are catalyzed by cytochrome P450 2D6 in humans

Twenty-one healthy Swedish Caucasian volunteers, representing different groups with 0-13 functional cytochrome P450 (CYP) 2D6 genes, were given a single oral dose of 20 mg of debrisoquine. The hypothesis of further oxidation of the main metabolite, (S)-4-hydroxydebrisoquine, in subjects with multiple CYP2D6 genes was tested by screening the 0-8-hr urine samples for dihydroxylated metabolites of debrisoquine with protonated molecular ions at m/z 208, using LC/MS. Three peaks were detected in a subject with 13 functional CYP2D6 genes. One compound was identified as dihydroxylated debrisoquine (presumably with hydroxylation at position 4 plus one of the positions in the aromatic ring). This metabolite had not been previously demonstrated in humans and was detected only in this subject. The other two compounds, which were measurable in various amounts in all subjects investigated, were identified as 2-(guanidinomethyl)phenylacetic acid and 2-(guanidinoethyl)benzoic acid. They had been previously detected in the urine of humans, dogs, and rats. They were distinguished by acid-catalyzed deuterium exchange of the hydrogens at the alpha-position, with respect to the carboxylic acid group, of the former but not the latter acid. The acids are formed by 3- and 1-hydroxylation of debrisoquine, respectively, followed by ring opening to aldehydes, which are further oxidized to acids. Strong Spearman rank correlations between debrisoquine products of 1- or 3-hydroxydebrisoquine and debrisoquine/4-hydroxydebrisoquine ratios (rS = 0.97 and rS = 0.96, respectively), using the intensity of the peaks of the reconstructed ion-current chromatograms, clearly showed that both hydroxylation steps are catalyzed by CYP2D6. Because reference compounds for the two acids were not available, the absolute quantities could not be determined.

The involvement of CYP1A2 and CYP3A4 in the metabolism of clozapine

AIMS

Clozapine (CLZ), an atypical neuroleptic with a high risk of causing agranulocytosis, is metabolized in the liver to desmethylclozapine (DCLZ) and clozapine N-oxide (CLZ-NO). This study investigated the involvement of different CYP isoforms in the formation of these two metabolites.

METHODS

Human liver microsomal incubations, chemical inhibitors, specific antibodies, and different cytochrome P450 expression systems were used.

RESULTS

Km and Vmax values determined in human liver microsomes were lower for the demethylation (61 +/- 21 microM, 159 +/- 42 pmol min(-1) mg protein(-1) mean +/- s.d.; n = 4), than for the N-oxidation of CLZ (308 +/- 1.5 microM, 456 +/- 167 pmol min(-1) mg protein(-1); n = 3). Formation of DCLZ was inhibited by fluvoxamine (53 +/- 28% at 10 microM), triacetyloleandomycin (33 +/- 15% at 10 microM), and ketoconazole (51 +/- 28% at 2 microM) and by antibodies against CYP1A2 and CYP3A4. CLZ-NO formation was inhibited by triacetyloleandomycin (34 +/- 16% at 10 microM) and ketoconazole (51 +/- 13% at 2 microM), and by antibodies against CYP3A4. There was a significant correlation between CYP3A content and DCLZ formation in microsomes from 15 human livers (r=0.67; P=0.04). A high but not significant correlation coefficient was found for CYP3A content and CLZ-NO formation (r=0.59; P=0.09). Using expression systems it was shown that CYP1A2 and CYP3A4 formed DCLZ and CLZ-NO. Km and Vmax values were lower in the CYP1A2 expression system compared to CYP3A4 for both metabolic reactions.

CONCLUSIONS

It is concluded that CYP1A2 and CYP3A4 are involved in the demethylation of CLZ and CYP3A4 in the N-oxidation of CLZ. Close monitoring of CLZ plasma levels is recommended in patients treated at the same time with other drugs affecting these two enzymes.

Renal clearance of pyridostigmine in myasthenic patients and volunteers under the influence of ranitidine and pirenzepine

1. To assess the contribution of tubular secretion to the renal excretion of pyridostigmine, and its modification by other cationic drugs, six volunteers were given single oral doses of 60-mg pyridostigmine bromide with and without co-administration of ranitidine or pirenzepine. Renal clearances were determined by h.p.l.c. analysis of pyridostigmine and enzymic measurement of endogenous creatinine in plasma and urine. 2. In patients with myasthenia receiving continuous pyridostigmine therapy, renal clearance values were obtained in the same manner with and without ranitidine (10 patients) or pirenzepine (nine patients) co-medication. 3. Pyridostigmine was not bound to plasma proteins. Its renal clearance averaged 6.65 ml/min per kg (350% of the creatinine clearance) in all subjects, 74% being due to net tubular secretion. 4. Mean values for pyridostigmine renal clearance and for clearance by secretion were decreased in the presence of pirenzepine, but plasma concentrations were not affected significantly. Ranitidine caused a small non-significant decrease of the pyridostigmine clearance in patients. 5. Pyridostigmine had a higher elimination (2 h-1) than the absorption rate constant (0.23 h-1) when administered orally as a non-retarded preparation. 6. The renal clearance of creatinine was slightly increased by pyridostigmine in volunteers and slightly decreased by pirenzepine in the total group of subjects.