Adverse drug reactions

Human leukocyte antigen genetic risk factors of drug-induced liver toxicology

INTRODUCTION

Drug-induced liver injury (DILI) is a rare adverse drug reaction, which impacts significantly on patients. Human leukocyte antigen (HLA) risk alleles have been found to be associated with DILI supporting an immunological basis to DILI pathogenesis.

AREAS COVERED

HLA alleles associated with risk of liver injury induced by specific therapeutic drugs are described. The evidence for a role of the adaptive immune system in DILI is presented; case-control studies showing an association between DILI and HLA alleles are reviewed. Clinical applications of pharmacogenomics are considered.

EXPERT OPINION

Increasing evidence points to a crucial role for the adaptive immune system in the pathogenesis of DILI. Identification of specific HLA alleles as risk factors through large genome-wide association studies has been instrumental in this and in vitro analyses have facilitated improved understanding of the molecular mechanisms. This provides the basis for developing clinical pharmacogenomic applications. Already, genotyping for hypersensitivity HLA risk alleles has been implemented and opportunities for pre-prescription testing in DILI identified. However, although associations are strong, the rarity of DILI means routine testing has not been formally evaluated. Nevertheless, enhanced understanding of how HLA alleles contribute to injury risk is valuable for drug development. Translation of this research into effective pre-emption and primary prevention remains the goal.

A Review of Pharmacovigilance

Pharmacovigilance supports safe and appropriate use of drugs. Spontaneous reporting of adverse drug reactions (ADRs) is an essential component of pharmacovigilance. However, there is significant underreporting of ADRs. Adverse drug reactions have become a major problem in developing countries. Knowledge of pharmacovigilance could form the basis for interventions aimed at improving reporting rates and decreasing ADRs.

Recognition and reporting of suspected adverse drug reactions by surveyed healthcare professionals in Uganda: key determinants

OBJECTIVE

To assess extent and determinants of past-month recognition of suspected adverse drug reactions (ADR) and past-year ADR reporting among healthcare professionals (HCPs) in Uganda.

SETTING

Geographically diverse health facilities (public, private for-profit, private not-for-profit).

PARTICIPANTS

Of 2000 questionnaires distributed, 1345 were completed: return rate of 67%.

PRIMARY AND SECONDARY OUTCOME MEASURES

Per cent HCPs who suspected ADR in the past month; reported ADR in the past year.

RESULTS

Nurses were the majority (59%, 792/1345). Only half the respondents had heard about pharmacovigilance: 39% of nurses (295/763; 95% CI 35% to 42%), 70% otherwise (383/547; 95% CI 66% to 74%). One fifth (268/1289 or 21%; 95% CI 19% to 23%) had suspected an ADR in the previous 4 weeks, 111 of them were nurses; 15% (190/1296) had reported a suspected ADR in the past year, 103 of them were nurses. Past-month ADR suspicion was more likely by non-nurses (OR=1.7, 95% CI 1.16 to 2.40) and with medical research involvement (OR=1.5, 95% CI 1.05 to 2.15) but past-month receipt of patient ADR-complaint predominated (OR=19, 95% CI 14 to 28). Past-year ADR reporting was higher by hospital staff (OR=1.9, 95% CI 1.18 to 3.10), especially in medicine (OR=2.3, 95% CI 1.08 to 4.73); but lower from private for-profit health facilities (OR=0.5, 95% CI 0.28 to 0.77) and by older staff (OR=0.6, 95% CI 0.43 to 0.91); more likely by HCPs who had ever encountered a fatal ADR (OR=2.9, 95% CI 1.94 to 4.25), knew to whom to report (OR=1.7, 95% CI 1.18 to 2.46), or suggested how to improve ADR reporting (OR=1.6, 95% CI 1.04 to 2.49). Two attitudinal factors were important: diffidence and lethargy.

CONCLUSIONS

One in five HCPs suspected an ADR in the past-month and one in seven reported ADR in the previous year. Empowering patients could strengthen ADR detection and reporting in Africa.

A prospective study on Adverse Drug Reactions of antibiotics in a tertiary care hospital

Adverse reactions are the recognized hazards of drug therapy and they can occur with any class of drugs and many studies revealed that the incidence is more in case of antibiotics. The main aim of this study was to detect and analyze Adverse Drug Reactions of antibiotics in inpatients of a tertiary care hospital. A prospective spontaneous reporting study by active and passive methods was carried out for a period of six months. A total of 49 ADRs were reported during the study period with male predominance (53.06%) and geriatric age group. More number of ADRs was from General Medicine and Pediatric departments in which the most affected organ systems were the GIT (38.77%) and the skin (30.61%). The antibiotic classes mostly accounted were cephalosporins (34.69%) followed by fluoroquinolones and others in which type A reactions were more compared to type B and 59.18% of them were predictable. The severity assessment revealed that most of them were moderate (63.26%) followed by mild and severe reactions. Of the reported reactions, 55.10% were definitely preventable and causality assessment was done which showed that 71.42% of the reactions were probable, possible (18.36%), definite (10.20%) and no reactions were unlikely. The study concluded that Adverse Drug Reactions to antibiotics are common and some of them resulted in increased healthcare cost due to the need of some interventions and increased length of hospital stay. The health system should promote the spontaneous reporting of Adverse Drug Reactions to antibiotics, proper documentation and periodic reporting to regional pharmacovigilance centers to ensure drug safety.

Community pharmacists' knowledge and perceptions about adverse drug reactions and barriers towards their reporting in Eastern region, Alahsa, Saudi Arabia

OBJECTIVE

The present study aims to analyze community pharmacists' current knowledge and perceived barriers to adverse drug reaction (ADR) reporting systems in the Eastern region, Alahsa, Saudi Arabia.

METHOD

A cross-sectional study was planned from 1 June 2012 to 15 July 2012 among the community pharmacies in the Eastern region, Alahsa. A total of 70 community pharmacists were approached using a cluster sampling method. A self-administered, 28-item questionnaire was used to attain the objectives of the study. Data analysis was done using Statistical Package for Social Science version 13. Relative index ranking was used to identify the top five barriers to the ADR reporting process.

RESULTS

Response to the survey was 71.43%. In terms of knowledge about ADRs, very few (four, 8.0%) pharmacists were unable to differentiate between the right and wrong definition of ADRs. About 42 (84.0%) pharmacists mentioned that patients often report adverse events. However, 45 (90.0%) were not aware of the ADR reporting system in Saudi Arabia. A deficient professional environment was the main barrier to the ADR reporting process. In addition, unavailability of the reporting forms and poor understanding of the reporting process were common barriers to the reporting process.

CONCLUSION

Most of the community pharmacists were unaware of the ADR reporting system in Saudi Arabia. Logistic issues were the main barriers to the ADR reporting process.

Glucuronidation of drugs and drug-induced toxicity in humanized UDP-glucuronosyltransferase 1 mice

UDP-glucuronosyltransferases (UGTs) are phase II drug-metabolizing enzymes that catalyze glucuronidation of various drugs. Although experimental rodents are used in preclinical studies to predict glucuronidation and toxicity of drugs in humans, species differences in glucuronidation and drug-induced toxicity have been reported. Humanized UGT1 mice in which the original Ugt1 locus was disrupted and replaced with the human UGT1 locus (hUGT1 mice) were recently developed. In this study, acyl-glucuronidations of etodolac, diclofenac, and ibuprofen in liver microsomes of hUGT1 mice were examined and compared with those of humans and regular mice. The kinetics of etodolac, diclofenac, and ibuprofen acyl-glucuronidation in hUGT1 mice were almost comparable to those in humans, rather than in mice. We further investigated the hepatotoxicity of ibuprofen in hUGT1 mice and regular mice by measuring serum alanine amino transferase (ALT) levels. Because ALT levels were increased at 6 hours after dosing in hUGT1 mice and at 24 hours after dosing in regular mice, the onset pattern of ibuprofen-induced liver toxicity in hUGT1 mice was different from that in regular mice. These data suggest that hUGT1 mice can be valuable tools for understanding glucuronidations of drugs and drug-induced toxicity in humans.

Paediatric pharmacovigilance: use of pharmacovigilance data mining algorithms for signal detection in a safety dataset of a paediatric clinical study conducted in seven African countries

Background

Pharmacovigilance programmes monitor and help ensuring the safe use of medicines which is critical to the success of public health programmes. The commonest method used for discovering previously unknown safety risks is spontaneous notifications. In this study we examine the use of data mining algorithms to identify signals from adverse events reported in a phase IIIb/IV clinical trial evaluating the efficacy and safety of several Artemisinin-based combination therapies (ACTs) for treatment of uncomplicated malaria in African children.

Methods

We used paediatric safety data from a multi-site, multi-country clinical study conducted in seven African countries (Burkina Faso, Gabon, Nigeria, Rwanda, Uganda, Zambia, and Mozambique). Each site compared three out of four ACTs, namely amodiaquine-artesunate (ASAQ), dihydroartemisinin-piperaquine (DHAPQ), artemether-lumefantrine (AL) or chlorproguanil/dapsone and artesunate (CD+A). We examine two pharmacovigilance signal detection methods, namely proportional reporting ratio and Bayesian Confidence Propagation Neural Network on the clinical safety dataset.

Results

Among the 4,116 children (6–59 months old) enrolled and followed up for 28 days post treatment, a total of 6,238 adverse events were reported resulting into 346 drug-event combinations. Nine signals were generated both by proportional reporting ratio and Bayesian Confidence Propagation Neural Network. A review of the manufacturer package leaflets, an online Multi-Drug Symptom/Interaction Checker (DoubleCheckMD) and further by therapeutic area experts reduced the number of signals to five. The ranking of some drug-adverse reaction pairs on the basis of their signal index differed between the two methods.

Conclusions

Our two data mining methods were equally able to generate suspected signals using the pooled safety data from a phase IIIb/IV clinical trial. This analysis demonstrated the possibility of utilising clinical studies safety data for key pharmacovigilance activities like signal detection and evaluation. This approach can be applied to complement the spontaneous reporting systems which are limited by under reporting.

Clinical perspectives in drug safety and adverse drug reactions

Adverse drug reactions (ADRs) remain a common clinical problem since they can mimic many diseases and cause significant morbidity and mortality. Judicious prescribing is important to minimize their occurrence. Apart from the recent identification of a few pharmacogenomic biomarkers for serious reactions, many remain unpredictable. Spontaneous reporting continues to play an important role in pharmacovigilance and the value of astute clinical observation and well-documented reports of suspicions of a causal link cannot be underestimated. Many national reporting schemes have developed considerable experience and expertise over many years and have large ADR databases, which are national assets. Despite advances in pharmacovigilance, numerous deficiencies have been identified; postmarketing surveillance remains the weakest link in the regulatory process. Regulatory authorities have tended to act later rather than sooner in response to safety signals, and this, when combined with under-reporting, may have led to exposure of a large number of patients to drug-related harm before restriction or withdrawal. In an attempt to improve vigilance, international surveillance may benefit by moving from its current passive/reactive mode toward active surveillance systems with a prospective, comprehensive and systematic approach to monitoring, collecting, analyzing and reporting data on ADRs. This will include increased pressure on pharmaceutical companies to conduct postmarketing studies. Such an active/proactive approach, while maintaining focus on ADR detection, could also aim to extend knowledge of safety, such that emerging changes in risk-benefit during a drug's marketed life are effectively communicated to clinicians and patients. Drug safety monitoring and its regulation are now undergoing an overhaul and it is hoped that vigilance, public safety and trust will improve as a result.

Evaluating the safety of COPD medications: an evidence-based review

The goals of management of COPD include reducing exposure to risk factors; improving lung function, exercise tolerance, and quality of life; and decreasing exacerbations and mortality. Pharmacologic treatments, such as inhaled β2-agonists, anticholinergics, and inhaled corticosteroids, are widely used to help achieve these goals. In addition to efficacy, medication safety is an important consideration in selecting COPD treatments. Clinical trials conducted in support of the regulatory review and approval process establish the general efficacy and tolerability of pharmacologic treatments for COPD, and these data are reflected in product labeling. Following approval, further research continues to provide more data with longer follow-up and in broader settings than feasible in clinical trials. These data add to our knowledge of the efficacy of medications. Understanding medication safety requires assessment of the quality and appropriateness of study design, as well as knowledge of study findings, and is of paramount importance in making sound clinical judgments in the treatment of patients with COPD. In recent years, a wealth of data on COPD medications has been published from different sources, including randomized clinical trials, meta-analyses, systematic reviews, and observational studies. This review discusses important considerations in interpreting data from different types of studies, summarizes the tolerability profile of COPD medications established in preapproval studies, and discusses new findings from more recent postapproval data.

Pediatric Pharmacovigilance: Enhancing Adverse Drug Reaction Reporting in a Tertiary Care Children's Hospital

BACKGROUND

Adverse drug reactions (ADRs) are notoriously underreported within health care facilities. In 2009-2010, ADRs were detected in only 0.5% of patients at the authors' institution, a pediatric hospital in the Midwestern United States. Additionally, historical ADRs were often inaccurately or incompletely documented in the medical record. An integrative Drug Safety Service (DSS) was implemented to improve the detection and accurate documentation of ADRs.

METHODS

The DSS incorporated standardized ADR terminology, computerized triggers to identify ADRs, and a simplified voluntary reporting system within the facility. The DSS staff provided extensive hospital staff education on ADR reporting and the role of the DSS. The primary aim of this report was to assess the impact of the DSS on the number of ADRs reported at the authors' institution. The secondary aims were to evaluate the mechanisms by which patients with ADRs were identified and to assess the accuracy of ADR documentation after implementation of the DSS.

RESULTS

A significant increase was observed (slope, 6.01; P < .001) in ADR detection after implementation of the DSS, with a greater than 4-fold increase from 10 cases per 10,000 admissions before initiation to 41 cases per 10,000 admissions after DSS implementation. Computerized triggers, International Classification of Diseases, 9th Edition (ICD-9) codes associated with ADRs, and the DSS identified 33%, 33%, and 24% of ADRs, respectively, while voluntary reporting only detected 9% of ADRs.

CONCLUSIONS

Implementation of a multifaceted, interdisciplinary DSS was more effective in detecting ADRs than voluntary reporting alone. A proactive approach to ADR detection resulted in a significant increase in the identification and evaluation of ADRs.

Implementation and evaluation of adverse drug reaction monitoring system in a tertiary care teaching hospital in Mumbai, India

Adverse drug reactions (ADR) are a significant cause of morbidity and mortality, often identified only post-marketingly. Improvement in current ADR reporting, including utility of underused or innovative methods, is crucial to improve patient safety and public health. Hospital-based monitoring is one of the methods used to collect data about drug prescriptions and adverse events. The aims of this study were to identify the most frequent ADRs recognized by the attending physicians, study their nature, and to target these ADRs in order to take future preventive measures. A prospective study was conducted over a 7-month period in an internal medicine department using stimulated spontaneous reporting for identifying ADRs. Out of the 254 admissions, 32 ADRs in 37 patients (14.56%) were validated from the total of 36 suspected ADRs in 41 patients. Female predominance was noted over males in case of ADRs. Fifty percent of total ADRs occurred due to multiple drug therapy. Dermatological ADRs were found to be the most frequent (68.75%), followed by respiratory, central nervous system and gastrointestinal ADRs. The drugs most frequently involved were antibiotics, anti-tubercular agents, antigout agents, and NSAIDs. The most commonly reported reactions were itching and rashes. Out of the 32 reported ADRs, 50% of the reactions were probable, 46.87% of the reactions were possible and 3.12% of the reactions were definite. The severity assessment done by using the Hartwig and Seigel scale indicated that the majority of ADRs were ‘Mild’ followed by ‘Moderate’ and ‘Severe’ reactions, respectively. Out of all, 75% of ADRs were recovered. The most potent management of ADRs was found to be drug withdrawal. Our study indicated that hospital based monitoring was a good method to detect links between drug exposure and adverse drug reactions. Adequate training regarding pharmacology and optimization of drug therapy might be helpful to reduce ADR morbidity and mortality.

Large-scale prediction of adverse drug reactions using chemical, biological, and phenotypic properties of drugs

Objective

Adverse drug reaction (ADR) is one of the major causes of failure in drug development. Severe ADRs that go undetected until the post-marketing phase of a drug often lead to patient morbidity. Accurate prediction of potential ADRs is required in the entire life cycle of a drug, including early stages of drug design, different phases of clinical trials, and post-marketing surveillance.

Methods

Many studies have utilized either chemical structures or molecular pathways of the drugs to predict ADRs. Here, the authors propose a machine-learning-based approach for ADR prediction by integrating the phenotypic characteristics of a drug, including indications and other known ADRs, with the drug's chemical structures and biological properties, including protein targets and pathway information. A large-scale study was conducted to predict 1385 known ADRs of 832 approved drugs, and five machine-learning algorithms for this task were compared.

Results

This evaluation, based on a fivefold cross-validation, showed that the support vector machine algorithm outperformed the others. Of the three types of information, phenotypic data were the most informative for ADR prediction. When biological and phenotypic features were added to the baseline chemical information, the ADR prediction model achieved significant improvements in area under the curve (from 0.9054 to 0.9524), precision (from 43.37% to 66.17%), and recall (from 49.25% to 63.06%). Most importantly, the proposed model successfully predicted the ADRs associated with withdrawal of rofecoxib and cerivastatin.

Conclusion

The results suggest that phenotypic information on drugs is valuable for ADR prediction. Moreover, they demonstrate that different models that combine chemical, biological, or phenotypic information can be built from approved drugs, and they have the potential to detect clinically important ADRs in both preclinical and post-marketing phases.

Pharmacogenomics of severe cutaneous adverse reactions and drug-induced liver injury

Rare but severe adverse drug reactions (ADRs) are an important issue in drug development and in the proper usage of drugs during the post-approval phase. The ability to predict patient susceptibility to severe ADRs would prevent drug administration to high-risk patients. This would save lives and ensure the quality of life for these patients, but occurrence of idiosyncratic severe ADRs had been very difficult to predict for a long time. However, in this decade, genetic markers have been found for several ADRs, especially for severe cutaneous adverse reactions (SCARs) and drug-induced liver injury (DILI). In this review, we summarize recent progress in identifying genetic markers for SCARS and DILI, and discuss issues that remain unresolved. As for SCARs, associations of HLA-B*15:02 or HLA-A*31:01 and HLA-B*58:01 have been revealed for carbamazepine- and allopurinol-related Stevens-Johnson syndrome and toxic epidermal neclolysis, respectively. HLA-B*57:01 is strongly associated with abacavir-induced hypersensitivity syndrome. Several HLA alleles also demonstrate drug-specific associations with DILI, such as HLA-A*33:03 for ticlopidine, HLA-B*57:01 for flucloxacillin and HLA-DQA1*02:01 for lapatinib. Efforts should be continued to find other genetic markers to achieve high predictability for ADRs, with the goal being development of genetic tests for use in clinical settings.

Pharmacovigilance

Any substance that is capable of producing a therapeutic effect can also produce unwanted or adverse effects. It is important to understand the basic concepts related to Adverse Drug Reactions (ADRs): epidemiology, classification, predisposing factors, evaluation parameters, and surveillance methods. Pharmacovigilance is defined as the science and activities relating to the detection, evaluation, understanding, and prevention of ADRs or any other drug-related problems. It involves patients, medical professionals, the pharmaceutical industry, drug regulatory agencies, and academic scientists. Pharmacoinformatics, the application of information technology with regard to the drug design, development, and drug use has played a major role in the appropriate implementation of pharmacovigilance at industry, regulatory, and hospital levels. The functioning of international regulatory agencies and drug safety departments of pharmaceutical industries has been greatly influenced by pharmacoinformatics. Pharmacoinformatics has changed the way in which health care is practiced. Modern information technology can be used by health care professionals for various purposes and, thereby, make a substantial contribution to optimize the quality of medication use in institutions with due importance of safety. Pharmacoinformatics has a major influence in the development of pharmacogenetics and its individual applications including improving drug safety. Pharmacoinformatics will play a major role in the future development and practice of pharmacovigilance. The present chapter is aimed at providing the readers an insight into the importance and basic concepts of pharmacovigilance, and the process involved in it. Application of pharmacoinformatics in improving drug safety at various levels from an industry, regulatory and hospital perspective is discussed.

Prevalence and assessment of factors contributing to adverse drug reactions in wards of a tertiary care hospital, India

BACKGROUND

Adverse drug reactions account for the highest proportion among the causes of morbidity and mortality in clinical wards and are posing a considerable challenge. Hence, the objective of this study was to find out the prevalence of adverse drug reactions and the factors which contribute to their prevalence.

METHODS

A prospective patient record review was carried out at a tertiary care hospital in North India from August 2010-May 2011. A total of 1033 subjects admitted to hospital for any kind of treatment were included while patients admitted in the ward because of adverse drug reactions were excluded. The ward where we collected the data includes multispecialty and cardiovascular wards. The causality, severity, and preventability of adverse drug reactions were assessed using Naranjo, modified Hartwig, and Schumock and Thornton criteria, respectively. Kolmogorov-Smyrnov, chi -square and multiple logistic regression tests were used to determine adverse drug reactions ascribed to drugs.

RESULTS

Out of 1033 patients whose records were assessed, 167(16.2%) experienced one or more adverse drug reactions. The metabolic systems, which accounted for 49(24.6%) were most frequently affected by adverse drug reactions, followed by gastrointestinal, 45(22.6%); hematological, 28(14.1%) and cutaneous, 21(10.6%) systems. The drug classes most frequently associated with the reactions were antibiotics 40(20.1%), diuretics 35(17.6%) and anticoagulants 30(15.1%). According to the selected preventability scale, 72(36.2%) adverse drug reactions were classified as probably or definitely preventable. About 165(83%) of the reactions were type A, which represents augmentation of the pharmacological action of a drug. Number of drugs, length of hospitalization and number of diagnosis were identified as significant predisposing factors for ADRs.

CONCLUSION

The result of this study suggested that adverse drug reactions were significant causes of superimposed health problems that occur following hospitalization. The major risk factors associated with ADR include number of drugs, length of hospitalization and number of diagnosis. Based on the findings a rigorous study is recommended to determine the burden and identify the risk factors of adverse drug reactions to target interventions.

Monitoring medicines use: the role of the clinical pharmacologist

Appreciation of the potential of newly marketed medicines to produce both benefit and harm has increased the role of the clinical pharmacologist. Pharmacoepidemiology applies epidemiological reasoning, methods and knowledge to the study of the uses and effects of drugs in human populations. Pharmacovigilence identifies and then responds to safety issues about marketed drugs. Whilst adverse drug reaction (ADR) reporting systems can identify potential problems with drugs, determination of causation requires population-based studies of adverse events (including information from large clinical trials), which attempt to link unequivocally the adverse outcome to the drug in question. Pharmacovigilance is closely linked to postmarketing surveillance and is important for determining issues such as the long-term effects of drugs, identification of low-frequency ADRs, the effectiveness of drugs for their licensed indications or in new indications and other factors which may modify the efficacy and effectiveness of the drug in question. The related field of drug utilization developed in parallel with the study of adverse drug reactions, in recognition of the dramatic increase in the marketing of new drugs, the wide variations in the patterns and extent of drug prescribing, the growing concern about ADRs and the increasing costs of drugs. With the ever increasing number of recognized adverse effects of drugs, prescribing errors, patients' expectations concerning drug safety and the need for appropriate new drug appraisal, the clinical pharmacologist will play an important role both in the introduction of new drugs and in improving the safe and effective use of established drugs.

Pharmacogenomics of adverse drug reactions

Considerable progress has been made in identifying genetic risk factors for idiosyncratic adverse drug reactions in the past 30 years. These reactions can affect various tissues and organs, including liver, skin, muscle and heart, in a drug-dependent manner. Using both candidate gene and genome-wide association studies, various genes that make contributions of varying extents to each of these forms of reactions have been identified. Many of the associations identified for reactions affecting the liver and skin involve human leukocyte antigen (HLA) genes and for reactions relating to the drugs abacavir and carbamazepine, HLA genotyping is now in routine use prior to drug prescription. Other HLA associations are not sufficiently specific for translation but are still of interest in relation to underlying mechanisms for the reactions. Progress on non-HLA genes affecting adverse drug reactions has been less, but some important associations, such as those of SLCO1B1 and statin myopathy, KCNE1 and drug-induced QT prolongation and NAT2 and isoniazid-induced liver injury, are considered. Future prospects for identification of additional genetic risk factors for the various adverse drug reactions are discussed.

Intensive monitoring of adverse drug reactions in hospitalized patients of two medical units at a tertiary care teaching hospital

Objective:

To detect incidence of adverse drug reactions (ADRs) in hospitalized patients and to assess their causality, seriousness, preventability, and the possible economic impact.

Materials and Methods:

This was a prospective study carried out in two medical units at a tertiary care, teaching hospital, for about 18 months. All the admitted patients who developed an ADR after admission (group A) or who were admitted primarily for the treatment of an ADR (group B) were included. Descriptive statistics with 95% CI, χ², χ² for the trend and kappa test were used.

Results:

Out of 6601 patients, 140 patients developed 154 ADRs with an incidence of 2.12%. Causality of the majority of the ADRs in group A was ‘possible’ while those in group B was ‘probable’. Among 109 ADRs (34 serious) in group A, 38 were preventable. On the other hand, out of 45 serious ADRs in group B, 19 were preventable. The total cost of 154 ADRs in 140 patients was Rs. 1,49,803 with an average of Rs. 1070 per patient. The preventable cost for 57/154 ADR was Rs. 96,310.

Conclusion:

Around 2% of the hospital patients develop ADRs. A large number of these ADRs were preventable. A substantial saving can be made if adequate caution is exerted.

Data mining methodologies for pharmacovigilance

Medicines are designed to cure, treat, or prevent diseases; however, there are also risks in taking any medicine - particularly short term or long term adverse drug reactions (ADRs) can cause serious harm to patients. Adverse drug events have been estimated to cause over 700,000 emergency department visits each year in the United States. Thus, for medication safety, ADR monitoring is required for each drug throughout its life cycle, including early stages of drug design, different phases of clinical trials, and postmarketing surveillance. Pharmacovigilance (PhV) is the science that concerns with the detection, assessment, understanding and prevention of ADRs. In the pre-marketing stages of a drug, PhV primarily focuses on predicting potential ADRs using preclinical characteristics of the compounds (e.g., drug targets, chemical structure) or screening data (e.g., bioassay data). In the postmarketing stage, PhV has traditionally involved in mining spontaneous reports submitted to national surveillance systems. The research focus is currently shifting toward the use of data generated from platforms outside the conventional framework such as electronic medical records (EMRs), biomedical literature, and patient-reported data in online health forums. The emerging trend of PhV is to link preclinical data from the experimental platform with human safety information observed in the postmarketing phase. This article provides a general overview of the current computational methodologies applied for PhV at different stages of drug development and concludes with future directions and challenges.

Mitigating the inhibition of human bile salt export pump by drugs: opportunities provided by physicochemical property modulation, in silico modeling, and structural modification

The human bile salt export pump (BSEP) is a membrane protein expressed on the canalicular plasma membrane domain of hepatocytes, which mediates active transport of unconjugated and conjugated bile salts from liver cells into bile. BSEP activity therefore plays an important role in bile flow. In humans, genetically inherited defects in BSEP expression or activity cause cholestatic liver injury, and many drugs that cause cholestatic drug-induced liver injury (DILI) in humans have been shown to inhibit BSEP activity in vitro and in vivo. These findings suggest that inhibition of BSEP activity by drugs could be one of the mechanisms that initiate human DILI. To gain insight into the chemical features responsible for BSEP inhibition, we have used a recently described in vitro membrane vesicle BSEP inhibition assay to quantify transporter inhibition for a set of 624 compounds. The relationship between BSEP inhibition and molecular physicochemical properties was investigated, and our results show that lipophilicity and molecular size are significantly correlated with BSEP inhibition. This data set was further used to build predictive BSEP classification models through multiple quantitative structure-activity relationship modeling approaches. The highest level of predictive accuracy was provided by a support vector machine model (accuracy = 0.87, κ = 0.74). These analyses highlight the potential value that can be gained by combining computational methods with experimental efforts in early stages of drug discovery projects to minimize the propensity of drug candidates to inhibit BSEP.

Comparative analysis of pharmacovigilance methods in the detection of adverse drug reactions using electronic medical records

OBJECTIVE

Medication  safety requires that each drug be monitored throughout its market life as early detection of adverse drug reactions (ADRs) can lead to alerts that prevent patient harm. Recently, electronic medical records (EMRs) have emerged as a valuable resource for pharmacovigilance. This study examines the use of retrospective medication orders and inpatient laboratory results documented in the EMR to identify ADRs.

METHODS

Using 12 years of EMR data from Vanderbilt University Medical Center (VUMC), we designed a study to correlate abnormal laboratory results with specific drug administrations by comparing the outcomes of a drug-exposed group and a matched unexposed group. We assessed the relative merits of six pharmacovigilance measures used in spontaneous reporting systems (SRSs): proportional reporting ratio (PRR), reporting OR (ROR), Yule's Q (YULE), the χ(2) test (CHI), Bayesian confidence propagation neural networks (BCPNN), and a gamma Poisson shrinker (GPS).

RESULTS

We systematically evaluated the methods on two independently constructed reference standard datasets of drug-event pairs. The dataset of Yoon et al contained 470 drug-event pairs (10 drugs and 47 laboratory abnormalities). Using VUMC's EMR, we created another dataset of 378 drug-event pairs (nine drugs and 42 laboratory abnormalities). Evaluation on our reference standard showed that CHI, ROR, PRR, and YULE all had the same F score (62%). When the reference standard of Yoon et al was used, ROR had the best F score of 68%, with 77% precision and 61% recall.

CONCLUSIONS

Results suggest that EMR-derived laboratory measurements and medication orders can help to validate previously reported ADRs, and detect new ADRs.

Aripiprazole induced severe and extensive skin reaction: A case report

Adverse cutaneous reactions are one of the most frequent types of adverse drug reactions, and have been reported with a wide range of psychotropics including typical and atypical antipsychotics. However the majority of adverse cutaneous reactions are relatively minor, and severe reactions are relatively rare. Aripiprazole is a third-generation atypical antipsychotic that has been available in the UK for over seven years. Here the author reports the first reported case of a lichenoid drug reaction to aripiprazole, a severe and potentially life-threatening adverse cutaneous reaction that required medical and surgical intervention.

Costs of adverse drug events in German hospitals--a microcosting study

OBJECTIVE

In Germany, only limited data are available to quantify the attributable resource utilization associated with adverse drug events (ADEs). The aim of this study was twofold: first, to calculate the direct treatment costs associated with ADEs leading to hospitalization and, second, to derive the excess costs and extra hospital days attributable to ADEs of inpatient treatments in selected German hospitals.

METHODS

This was a retrospective and medical record-based study performed from the hospitals' perspective based on administrative accounting data from three hospitals (49,462 patients) in Germany. Total treatment costs ("analysis 1") and excess costs (i.e., incremental resource utilization) between patients suffering from an ADE and those without ADEs were calculated by means of a propensity score-based matching algorithm ("analysis 2").

RESULTS

Mean treatment costs ("analysis 1") of ADEs leading to hospitalization (n = 564) were €1,978 ± 2,036 (range €191-18,147; median €1,446; €843-2,480 [Q1-Q3]). In analysis 2, the mean costs of inpatients suffering from an ADE (n = 1,891) as a concomitant disease or complication (€5,113 ± 10,059; range €179-246,288; median €2,701; €1,636-5,111 [Q1-Q3]) were significantly higher (€970; P < 0.0001) than those of non-ADE inpatients (€4,143 ± 6,968; range €154-148,479; median €2,387; €1,432-4,701 [Q1-Q3]). Mean inpatient length of stay of ADE patients (12.7 ± 17.2 days) and non-ADE patients (9.8 ± 11.6 days) differed by 2.9 days (P < 0.0001). A nationwide extrapolation resulted in annual total treatment costs of €1.058 billion.

CONCLUSIONS

This is one of the first administrative data-based analyses calculating the economic consequences of ADEs in Germany. Further efforts are necessary to improve pharmacotherapy and relieve health care payers of preventable treatment costs.

Attitudes of Portuguese health professionals toward adverse drug reaction reporting

BACKGROUND

Adverse drug reactions are a major public health problem. Underreporting is an important limitation of all reporting systems, partially due to attitudes of health professionals.

OBJECTIVE

This study sought: (1) to evaluate the reproducibility of a questionnaire on attitudes to and knowledge of adverse drug reaction (ADR) reporting among physicians, nurses and pharmacists: and (2) to compare the attitudes and knowledge of these three groups of health professionals.

METHODS

This study targeted a sample of physicians (n = 30), nurses (n = 30) and pharmacists (n = 20) in the central region of Portugal. A structured questionnaire was administered to each health professional twice, at an interval of 2-4 weeks. Most attitudes were based on Inman's 'seven deadly sins' and measured using a continuous visual analog scale (VAS), with answers scored from 0 (total disagreement) to 10 (total agreement). Questionnaire reproducibility was determined using the intraclass correlation coefficient (ICC).

RESULTS

The response rate was 100 %. Attitudes that registered the highest ICCs were Complacency (the belief that really serious ADRs are well documented by the time a drug is marketed) (physicians, ICC 0.84; nurses, ICC 0.70; pharmacists, ICC 0.99), and Diffidence (the belief that one would only report an ADR if one were sure that it was related to the use of a particular drug) (physicians, ICC 0.73; nurses, ICC 0.65; pharmacists, ICC 0.98). In most cases, there were no differences among the three groups of professionals in terms of attitudes and knowledge.

CONCLUSIONS

The Horizontal continuous VAS is reliable to detect the knowledge and attitudes about ADRs.

Drug allergy: causes and desensitization

Allergic drug reactions occur when a drug, usually a low molecular weight molecule, has the ability to stimulate an immune response. This can be done in one of two ways. The first is by binding covalently to a self-protein, to produce a haptenated molecule that can be processed and presented to the adaptive immune system to induce an immune response. Sometimes the drug itself cannot do this but a reactive breakdown product of the drug is able to bind covalently to the requisite self-protein or peptide. The second way in which drugs can stimulate an immune response is by binding non-covalently to antigen presenting or antigen recognition molecules such as the major histocompatibility complex (MHC) or the T cell receptor. This is known as the p-I or pharmacological interaction hypothesis. The drug binding in this situation is reversible and stimulation of the response may occur on first exposure, not requiring previous sensitization. There is probably a dependence on the presence of certain MHC alleles and T cell receptor structures for this type of reaction to occur.

[Adverse drug reactions in a paediatric intensive care unit]

OBJECTIVE

To determine ADR frequency and characteristics of ADR in a paediatric intensive care unit between may and june 2009.

METHOD

All of the hospitalised children were under intensive pharmacosurveillance by means of daily analysis of their prescription profiles. The following patient characteristics were analysed: age, sex, drugs involved, affected organs and systems, triggered illness, adverse reaction mechanism, presence of polypharmacy, severity and course of the reaction. The following variables were recorded for adverse reactions: frequency, incidence in hospitalised children, incidence per 100 children/day and percentage of preventable reactions.

RESULTS

Of the 123 hospitalised children, 24 experienced at least one adverse reaction. The total number of identified adverse drug reactions was 45. Average age was 34 months, and 14 patients were male.Frequency was 36.6% (CI 95% 28.4-46.4). Adverse reaction average was calculated at 1.9 reactions per child. The ADR incidence rate per 100 children/day was 10.4. There were 66 drugs involved; the most common drug groups were antiepileptics and diuretics. Drug reactions most frequently affected the metabolic and haematological systems. Of the reactions, 61% were preventable. Twelve reactions were severe and 1 patient died.

CONCLUSIONS

Adverse reactions are a frequent health problem among critically ill children. There is a pressing need to create awareness and prevention strategies to decrease their frequency and severity.

Prevalence, seriousness and effect of previous adverse drug reactions on prescribing during acute medical admission

BACKGROUND

Adverse drug reactions (ADRs) are associated with significant morbidity, mortality and cost. Knowledge of the prevalence of previous ADRs at admission highlights the potential burden of ADR risks to hospital in-patients. However, the proportion of acute medical admissions with previous ADRs and how this affects inpatient prescribing is uncertain.

OBJECTIVES

To determine the prevalence and seriousness of previous ADRs in newly admitted medical patients, and ascertain the effect of previous ADRs on choice of prescribed medications during acute hospitalisation. Also, we compared the seriousness of ADRs as classified by patients and standard definition.

SETTING

Acute admissions within the medical directorate of a district general hospital serving a population of about 280,000 people in the north east of England.

METHOD

Newly admitted medical patients over a period of 8 weeks were prospectively screened to identify those with a previous history of ADR using patient interviews. Reviews of hospital notes and general practice summaries were undertaken for patients we were unable to interview. A structured form was used to collect relevant data from patients identified to have previous ADRs from the aforementioned sources.

MAIN OUTCOME MEASURES

Prevalence and seriousness of previous ADRs, and the proportion of acute medical prescriptions affected by previous ADRs.

RESULTS

A total of 509 acute admissions were screened. Of these, 19.8 % had ADRs to previously prescribed medications. Whereas 62.7 % of patients deemed their ADRs to be serious, only 20.9 % of previous ADRs were so by standard definition. 18.8 % of previous ADRs affected choice of prescribed medications during the present admission but this was not influenced by the seriousness of previous ADRs.

CONCLUSION

The prevalence of previous ADRs at admission is high and significantly affects choice of drugs used during acute hospitalisation. There are clear inconsistencies between patient perspective and standard definition of the seriousness of ADRs which is likely to be due to patients' heightened subjective perception of harm.

Pharmacovigilance teaching in UK undergraduate pharmacy programmes

PURPOSE

Pharmacists in the UK are able to report spontaneous adverse drug reactions (ADRs) to the Medicines and Healthcare Products Regulatory Authority. The level of reporting by UK pharmacists remains low. This could be explained by poor knowledge of ADR reporting. The primary objective of this study was to investigate the level of pharmacovigilance education provided to pharmacy students on undergraduate pharmacy programmes in the UK.

METHODS

A cross-sectional survey was used to obtain data relating to the teaching of pharmacovigilance within schools of pharmacy. The survey was designed to reveal whether core elements pertinent to pharmacovigilance and specifically to spontaneous reporting were taught and to what extent.

RESULTS

All of the respondents taught pharmacovigilance within an assessed compulsory module. A small number (23%) did not include pharmacovigilance law within their syllabus. In 54%, the amount of time devoted to teaching pharmacy students about their role in pharmacovigilance was less than 4 h in the 4-year course; only one respondent spent approximately 20 h, the remaining respondents (38%) spent between 4 and 8 h.

CONCLUSIONS

The amount of time dedicated to the teaching of pharmacovigilance on pharmacy undergraduate degree programmes is low. Considering the importance of spontaneous reporting in drug safety and the shift in the role of the pharmacists, more time may need to be devoted to pharmacovigilance on pharmacy undergraduate courses. By doing so, new pharmacists would be more informed of the important role they play in drug safety and thereby potentially help enhance the level of ADR reporting.

Safety assessment in pediatric studies

It typically takes many years before an association of a drug with a rare, serious adverse reaction is established. As related to pediatric drug use, evidence is even more erratic, as most drugs are used off labels. To enhance child safety, there is an urgent need to develop robust and rapid methods to identify such associations in as timely a manner as possible. In this chapter, several novel methods, both clinically based pharmacoepidemiological approaches and laboratory-based methods, are described.

Monitoring of incidence, severity, and causality of adverse drug reactions in hospitalized patients with cardiovascular disease

Background:

Patients admitted to cardiology department are mostly on polypharmacy. So drug-drug interactions and adverse effects of drugs are quite common. Yet, there is a paucity of data regarding adverse drug reaction (ADR) monitoring in cardiology department in India. The present study is an effort to fill up these lacunae.

Materials and Methods:

A prospective, observational study registering 966 indoor cardiology patients according to predetermined inclusion and exclusion criteria was conducted for one year. ADR profile was noted by spontaneous reporting and intensive monitoring. Naranjo ADR probability scale was used to establish the causality.

Results:

A total of 208 ADRs were reported from 188 patients (19.5%). Of these 188 patients, 62 patients (33%) were hospitalized primarily due to the development of ADRs, while 126 (67%) patients developed ADRs during hospital stay. Nitrates were the most common offender drug group (17.8%).

Conclusion:

Development of ADR in one of every five cardiac patient points toward a grave situation, but a higher incidence of Type A reactions in cardiology department means that these can be avoided.

Pathology of flupirtine-induced liver injury: a histological and clinical study of six cases

Drug-induced liver injury may cause impairment of liver function and is a leading cause of acute liver failure. Identification of the causative substance in patients receiving several drugs is often difficult in clinical practice. Evaluation of liver biopsies in suspected drug-induced injury is a challenging task that requires close clinico-pathological correlation. Recognizing a characteristic morphological pattern of liver injury may contribute to identification of the causative drug. Flupirtine, a non-opioid analgesic, has been reported to cause liver injury of idiosyncratic type in rare instances. We wished to characterize the histopathological features of flupirtine-induced liver injury, which have not been reported so far. Liver biopsies of five patients with severe liver injury and one explanted liver of a patient with flupirtine-induced acute liver failure that required transplantation were assessed. In addition clinical presentation and course were reviewed and clinical follow up was performed. Extensive perivenular necrosis with associated ceroid pigment-laden macrophages and a mild to moderate lymphocytic infiltrate was a common feature in all cases. Histological extent of liver necrosis corresponded well to serum amino-transferase levels. Accidental reexposure of one patient resulted in a plasma cell rich hepatitis with perivenular necrosis. This study provides evidence that flupirtine can cause substantial liver injury of hepatocellular type. Liver damage is associated with a characteristic morphological picture, the recognition of which will aid in causality assessment of drug-induced liver injury. Clinical and histological features raise the possibility of an immune-mediated toxicity.

Adverse drug reaction monitoring by United Kingdom hospital pharmacy departments: impact of the introduction of “yellow card” reporting for pharmacists

Objective

To assess the impact of the introduction of hospital pharmacist “yellow card” adverse drug reaction (ADR) reporting on the operation of local schemes.

Method

Prepiloted postal questionnaire sent to hospitals in 1998 following up a previous survey two years earlier.

Setting

Clinical services managers for 200 hospital pharmacies that had been randomly selected for the previous survey.

Key findings

One hundred and fifty usable questionnaires (75 per cent) were returned. Twenty-eight departments (18.9 per cent), compared with 26 departments (15.1 per cent) in 1996, operated ADR reporting schemes. Of a total of 440 local ADR reports made to participating departments, 70.0 per cent (312) were forwarded to the Committee on Safety of Medicines, a significantly higher percentage than the 14.9 per cent in the previous study (P=0.001). Only eight hospitals (5.4 per cent) had schemes for monitoring newly marketed or “black triangle” drugs. Ninety-four departments (62.3 per cent) had supported education and training activities. Of the hospitals without a scheme, 15 (12.5 per cent) said they had definite plans to introduce one in their hospital, 40 (33.3 per cent) had probable plans to introduce one and 65 (54.2 per cent) had no such plans.

Conclusion

Pharmacists' involvement in the CSM yellow card scheme appears to have had little impact on local initiatives. In areas where these local schemes have been implemented and educational activities provided, drug information pharmacists appear to have a significant role. From the results of this study, even in hospitals with local or in-house schemes, gross under-reporting of ADRs remains a major problem.

Attitudes of hospital pharmacists to adverse drug reactions and the “yellow card” scheme: a qualitative study

Objective

To elicit the views of hospital pharmacists towards adverse drug reaction (ADR) reporting.

Method

Qualitative, semi-structured interviews were conducted on a face to face basis using a prepiloted questionnaire. Analysis was carried out using Winmax Pro, content analysis and comparison of interpretation by two independent reviewers.

Setting

All major hospitals in one Committee on Safety of Medicines/Medicines Control Agency (CSM/MCA) regional monitoring centre in England.

Key findings

It was considered that introduction of reporting had been poorly publicised and promoted. Only 42 per cent of those interviewed had submitted more than one “yellow card” report and a similar percentage had reported none. The CSM/MCA has a poor image in terms of accessibility and its perceived opinion of pharmacists' role in reporting. Feedback from the CSM/MCA was satisfactory and Current Problems in Pharmacovigilance was highly regarded. Several factors appear to be dissuading pharmacists from participation in the scheme, including lack of clinical knowledge, pressure of work and a lack of time. The absence of a fee did not appear to be a deterrent to reporting; in fact, a fee was considered inappropriate. Initial schemes for education and training were perceived as having been successful. However, ongoing training needs had not been fully addressed.

Conclusion

While hospitals pharmacists acknowledge ADR reporting as part of their professional role, it is not yet considered as part of their daily practice and requires more vigorous promotion. Further investigation and quantitative work are required to investigate fully this aspect of pharmacy practice.

Evaluating the safety and effectiveness of new drugs

Prescribers seek to provide their patients with access to the latest innovations in medicine to maximize their health status. When a new drug comes to market, it often has not been as widely tested as other available therapies, and its effectiveness and safety cannot be fully evaluated. To address this problem, physicians can use the STEPS (Safety, Tolerability, Effectiveness, Price, and Simplicity) mnemonic to provide an analytic framework for making better decisions about a new drug's appropriate place in therapy. A key element is to base this evaluation on patient-oriented evidence rather than accept disease-oriented evidence (which may be misleading), while avoiding inappropriate reliance on studies that report only noninferiority results or relative-risk reductions. The primary question to ask for each new drug prescribing decision is, "Is there good evidence that this new drug is likely to make my patient live longer or better compared with the available alternatives?"

The cap'n'collar transcription factor Nrf2 mediates both intrinsic resistance to environmental stressors and an adaptive response elicited by chemopreventive agents that determines susceptibility to electrophilic xenobiotics

Transcription factor Nrf2 regulates genes encoding drug-metabolising enzymes and drug transporters, as well as enzymes involved in the glutathione, thioredoxin and peroxiredoxin antioxidant pathways. Using mouse embryonic fibroblast (MEF) cells from Nrf2(+/+) and Nrf2(-/-) mice, in conjunction with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, we have shown that loss of Nrf2 diminishes the intrinsic resistance of mutant fibroblasts towards isothiocyanates (i.e. sulforaphane), epoxides (i.e. (2S,3S)-(-)-3-phenylglycidol, ethyl 3-phenylglycidate and styrene-7,8-epoxide), peroxides, hydroquinones and quinones (i.e. tert-butylhydroperoxide, tert-butylhydroquinone and 2,3-dimethoxynaphthoquinone), NaAsO(2), and various mutagens, including β-propiolactone, cisplatin, mechlorethamine and methyl methanesulfonate to ∼50% of that observed in equivalent wild-type cells. Exposure of Nrf2(+/+) fibroblasts, but not Nrf2(-/-) fibroblasts, to a non-toxic dose (3μmol/l) of the chemopreventive agent sulforaphane (Sul) stimulated an adaptive response that, 18h after first being subjected to the isothiocyanate, caused an induction of between 2- and 10-fold in the levels of mRNA for glutamate-cysteine ligase catalytic (Gclc) and modifier (Gclm) subunits, glutathione S-transferases and NAD(P)H:quinone oxidoreductase-1 (Nqo1); this was accompanied by an increase in total glutathione of between 1.5- and 1.9-fold. Pre-treatment of Nrf2(+/+) MEF cells with 3μM Sul for 18h prior to challenge with xenobiotics, conferred between 2.0- and 4.0-fold protection against isothiocyanates, reactive carbonyls, peroxides, quinones, NaAsO(2), and the anticancer nitrogen mustard chlorambucil, but pre-treatment with 3μM Sul produced no such increased tolerance in Nrf2(-/-) MEF cells. The inducible resistance towards acrolein, cumene hydroperoxide and chlorambucil, produced by pre-treating wild-type fibroblasts with 3μM Sul, was dependent on glutathione because simultaneous pre-treatment with 5μmol/l buthionine sulfoximine abolished the increased tolerance of these xenobiotics. However, inducible resistance towards menadione that occurred upon pre-treatment with 3μM Sul was independent of glutathione and may be due to upregulation of Nqo1. Thus Nrf2 controls cellular resistance against electrophiles.

Adverse drug reactions in internal medicine units and associated risk factors

OBJECTIVES

This study was designed to assess the prevalence of adverse drug reactions (ADRs) in the internal medicine wards of two teaching hospitals, identify the most common ADRs, the principal medications involved, and determine the risk factors implicated in the occurrence of such ADRs.

METHODS

All admissions over 10 weeks were followed prospectively using an intensive drug surveillance method to identify ADRs. Clinical laboratory data, the drug prescribed, and ADRs were taken into consideration. Status of nutrition, liver and kidney function at admission, and ADR time were determined. In order to assess drug interactions a software package was used.

RESULTS

A total of 405 patients were evaluated, 126 patients (31%) had 128 ADRs, 122 ADRs occurred during hospitalization. Two ADR-related deaths were observed during the study. Reactions affecting the gastrointestinal tract, skin, and hematological system were among the most frequent ADRs. For ADRs observed during admission predictors of its occurrence in a multivariate regression model were: OR (95% CI); more than 12 days' hospitalization: 2.11(1.27-3.47), any drug interaction: 9.33 (5.12-17) and acute change in estimated glomerular filtration rate over admission >20%: 2.46 (1.45-4.2). Worsening of renal function or drug interaction was observed in nine of the ten ADRs. Age, sex, nutrition, and number of drugs used were not related to ADRs.

CONCLUSION

A significant prevalence of ADRs was found among hospitalized patients. Duration of hospital admission, changes in renal status during hospitalization and drug interactions seem to be important risk factors for ADRs.

Pharmacogenetics and human genetic polymorphisms

The term pharmacogenetics was first used in the late 1950s and can be defined as the study of genetic factors affecting drug response. Prior to formal use of this term, there was already clinical data available in relation to variable patient responses to the drugs isoniazid, primaquine and succinylcholine. The subject area developed rapidly, particularly with regard to genetic factors affecting drug disposition. There is now comprehensive understanding of the molecular basis for variable drug metabolism by the cytochromes P450 and also for variable glucuronidation, acetylation and methylation of certain drugs. Some of this knowledge has already been translated to the clinic. The molecular basis of variation in drug targets, such as receptors and enzymes, is generally less well understood, although there is consistent evidence that polymorphisms in the genes encoding the β-adrenergic receptors and the enzyme vitamin K epoxide reductase is of clinical importance. The genetic basis of rare idiosyncratic adverse drug reactions had also been examined. Susceptibility to reactions affecting skin and liver appears to be determined in part by the HLA (human leucocyte antigen) genotype, whereas reactions affecting the heart and muscle may be determined by polymorphisms in genes encoding ion channels and transporters respectively. Genome-wide association studies are increasingly being used to study drug response and susceptibility to adverse drug reactions, resulting in identification of some novel pharmacogenetic associations.

Ten-year trends in hospital admissions for adverse drug reactions in England 1999-2009

OBJECTIVES

Adverse drug reactions (ADR) are an important cause of morbidity and mortality. We analysed trends in hospital admissions associated with ADRs in English hospitals between 1999 and 2008.

DESIGN

Data from the Hospital Episode Statistics database were examined for all English hospital admissions (1999-2008) with a primary or secondary diagnosis of an ADR recorded.

SETTING

All NHS (public) hospitals in England.

MAIN OUTCOME MEASURES

The number of admissions and in-hospital mortality rate with a primary (codes including 'adverse drug reaction', 'drug-induced', 'due to drug', 'due to medicament' or 'drug allergy') or secondary diagnosis of ADR (ICD-10 Y40-59) were obtained and analysed. Further analysis for the year 2008-2009 was performed with regard to age, gender, proportion aged >65 yrs and total bed-days.

RESULTS

Between 1999 and 2008, there were 557,978 ADR-associated admissions, representing 0.9% of total hospital admissions. Over this period the annual number of ADRs increased by 76.8% (from 42,453 to 75,076), and in-hospital mortality rate increased by 10% (from 4.3% to 4.7%). In 2008, there were 6,830,067 emergency admissions of which 75,076 (1.1%) were drug-related. Systemic agents were most commonly implicated (19.2%), followed by analgesics (13.3%) and cardiovascular drugs (12.9%).There has been a near two-fold increase in nephropathy and cardiovascular consequences secondary to drugs and a 6.8% fall in mental and behavioural disorders due to drugs. Conclusions ADRs have a major impact on public health. Our data suggest the number of ADR admissions has increased at a greater rate than the increase in total hospital admissions; some of this may be due to improved diagnostic coding. However, in-hospital mortality due to ADR admissions also increased during the period. Our findings should prompt policymakers to implement further measures to reduce ADR incidence and their associated in-hospital mortality, and methods to improve the recording of ADRs.

Self-reported medication side effects in an older cohort living independently in the community--the Melbourne Longitudinal Study on Healthy Ageing (MELSHA): cross-sectional analysis of prevalence and risk factors

Background

Medication side effects are an important cause of morbidity, mortality and costs in older people. The aim of our study was to examine prevalence and risk factors for self-reported medication side effects in an older cohort living independently in the community.

Methods

The Melbourne Longitudinal Study on Healthy Ageing (MELSHA), collected information on those aged 65 years or older living independently in the community and commenced in 1994. Data on medication side effects was collected from the baseline cohort (n = 1000) in face-to-face baseline interviews in 1994 and analysed as cross-sectional data. Risk factors examined were: socio-demographics, health status and medical conditions; medication use and health service factors. Analysis included univariate logistic regression to estimate unadjusted risk and multivariate logistic regression analysis to assess confounding and estimate adjusted risk.

Results

Self-reported medication side effects were reported by approximately 6.7% (67/1000) of the entire baseline MELSHA cohort, and by 8.5% (65/761) of those on medication. Identified risk factors were increased education level, co-morbidities and health service factors including recency of visiting the pharmacist, attending younger doctors, and their doctor's awareness of their medications. The greatest increase in risk for medication side effects was associated with liver problems and their doctor's awareness of their medications. Aging and gender were not risk factors.

Conclusion

Prevalence of self-reported medication side effects was comparable with that reported in adults attending General Practices in a primary care setting in Australia. The prevalence and identified risk factors provide further insight and opportunity to develop strategies to address the problem of medication side effects in older people living independently in the community setting.