Showing papers in "Drug Safety in 2007"

Drug-Induced Liver Injury

Abstract: Drug-induced liver injury is a frequent cause of hepatic dysfunction Reliably establishing whether the liver disease was caused by a drug requires the exclusion of other plausible causes and the search for a clinical drug signature The drug signature consists of the pattern of liver test abnormality, the duration of latency to symptomatic presentation, the presence or absence of immune-mediated hypersensitivity and the response to drug withdrawal Determination of causality also includes an evaluation of individual susceptibility to drug-induced liver injury This susceptibility is governed by both genetic and environmental factors Components of the drug signature in conjunction with certain risk factors have been incorporated into formal scoring systems that are predictive of the likelihood of drug-induced liver injury The most validated scoring system is the Roussel-Uclaf causality assessment method, which nonetheless retains certain imperfections Mitigating the potential for drug-induced liver injury is achieved by the identification of toxicity signals during clinical trials and the monitoring of liver tests in clinical practice There are three signals of liver toxicity in clinical trials: (i) a statistically significant doubling (or more) in the incidence of serum alanine aminotransferase (ALT) elevation >3 x the upper limit of normal (ULN); (ii) any incidence of serum ALT elevation >8-10 x ULN; and (iii) any incidence of serum ALT elevation >3 x ULN accompanied by a serum bilirubin elevation >2 x ULN Monitoring of liver tests in clinical practice has shown unconvincing efficacy, but where a benefit-risk analysis would favour continued therapy, monthly monitoring may have some benefit compared with no monitoring at all With rare exception, treatment of drug-induced liver injury is principally supportive Drug toxicity is the most common cause of acute liver failure, defined as a prolonged prothrombin time (international normalised ratio > or =15) and any degree of mental alteration occurring <26 weeks after the onset of illness in a patient without pre-existing cirrhosis A patient who meets these criteria must be evaluated for liver transplantation The pathogenesis of drug-induced liver injury can be examined on the basis of the two principal patterns of injury The hepatocellular pattern is characterised by a predominant rise in the level of transaminases and results from the demise of hepatocytes by means of either apoptosis or necrosis The cholestatic pattern is characterised by a predominant rise of the serum alkaline phosphatase level and usually results from injury to the bile ductular cells either directly by the drug or its metabolite, or indirectly by an adaptive immune response

Drug-related problems in hospitals: a review of the recent literature.

Abstract: Problems associated with pharmacotherapy (in particular, medication errors and adverse drug events) are frequent and are associated with increased costs for treatment. Analysis of original publications published between 1990 and 2005 on the topics of medication errors and/or adverse drug events in hospitalised patients, focusing on the frequency of, risk factors for and avoidance of such problems associated with pharmacotherapy, indicated that medication errors occurred in a mean of 5.7% of all episodes of drug administration, but with a high variability among the 35 studies retrieved. This variability was explained by the methods by which medication errors were detected (systematic screening of patients versus chart review or spontaneous reporting) and by the way drugs were administered (intravenously administered drugs are associated with the highest error frequencies). Errors occurred throughout the whole medication process, with administration errors accounting for more than half of all errors. Important risk factors included insufficient pharmacological knowledge of health professionals, errors in the patient charts or documentation by nurses and inadequate pharmacy services. Adverse events or reactions, on the other hand, affected 6.1 patients per 100 hospitalised and also showed a high variability among the 46 studies retrieved. This variability could also be explained by the different methods of assessment of the frequency of adverse drug events or reactions, as well as by the different wards on which the studies were performed. Important risk factors for adverse drug events or reactions included polypharmacy, female sex, drugs with a narrow therapeutic range, renal elimination of drugs, age >65 years and use of anticoagulants or diuretics. Since medication errors are strong risk factors for preventable adverse drug events or reactions, strategies have to be put in place for their reduction. Such strategies include ensuring that all persons involved in the medication process (nurses, pharmacists and physicians) have good pharmacological knowledge, computerisation of the entire medication process, and the engagement of a sufficient number of clinical pharmacists on the wards.

The relationship between number of drugs and potential drug-drug interactions in the elderly: a study of over 600,000 elderly patients from the Swedish Prescribed Drug Register.

Abstract: Background: Drug-drug interactions (DDIs) are of great concern, as they are known to be related to adverse drug reactions and hospitalisations. In addition, many DDIs are regarded as predictable and avoidable; therefore, they may be considered as targets for education and interventions.

Negative effects of antiepileptic drugs on mood in patients with epilepsy.

Abstract: With the introduction of several new antiepileptic drugs into clinical practice, renewed attention has been focussed on treatment-emergent adverse effects, including mood disorders. There are several possible causes of psychiatric disorders in patients with epilepsy, including antiepileptic drugs, and it is often difficult to determine whether psychopathological manifestations, especially depressive symptoms, are due to drug therapy or to multiple other factors. Assessment of the negative effects of antiepileptic drugs on mood should always consider all potential factors. Case series, audits and open observational studies can identify psychopathological features, case-control studies are useful for identifying the endophenotypes of patients at risk of adverse effects on mood, and controlled clinical trials give good estimates of incidence of such effects, adjusted for the spontaneous occurrence of symptoms. The barbiturates, vigabatrin and topiramate show greater associations with the occurrence of depressive symptoms than other antiepileptic drugs, presenting in up to 10% of all patients, but even more so in susceptible patients. Data on zonisamide are scarce but it seems that mood disorders may occur in approximately 7% of patients who are receiving high dosages of this drug. In most cases, the use of monotherapy, with slow titration schedules, can significantly reduce the incidence of mood disorders. Tiagabine, levetiracetam and felbamate present an intermediate risk, with prevalence of depression of about 4% or lower. Phenytoin, ethosuximide, carbamazepine, oxcarbazepine, gabapentin, sodium valproate, pregabalin and lamotrigine are all associated with low risks for depression (<1%), and several of these antiepileptic drugs seem to have a positive effect on mood. Antiepileptic drugs can negatively affect mood and behaviour by different mechanisms: potentiation of GABA neurotransmission, folate deficiency, pharmacodynamic interactions with other antiepileptic drugs in polytherapy regimens, forced normalisation. Individuals with a personal or family history of depression should be carefully followed after initiation of therapy with a new antiepileptic drug, especially if structural brain abnormalities such as hippocampal sclerosis are present.

Psychotropic medications and the risk of fracture: a meta-analysis.

Abstract: Background: Older adults throughout the developed world are at significant risk of osteoporotic fractures. Many studies have examined the relationship between the use of psychotropic medications and the risk of fractures, but these studies have reported conflicting results. Purpose: To resolve discrepancies, we carried out a meta-analysis to assess the risk of fractures among users of several classes of psychotropic drugs. Data sources: We retrieved studies published in any language by systematically searching MEDLINE, LILACS, EMBASE and ISI Proceedings databases and by manually examining the bibliographies of the articles retrieved electronically as well as those of recent reviews. Study selection: We included 98 cohort and case-control studies, published in 46 different articles, that reported relative risk (RR) estimates and confidence intervals (CIs) or sufficient data to calculate these values. Data synthesis: Study-specific RRs were weighted by the inverse of their variance to obtain fixed- and random effects pooled estimates. The random effects RR of fractures was 1.34 (95% CI 1.24, 1.45) for benzodiazepines (23 studies), 1.60 (95% CI 1.38, 1.86) for antidepressants (16 studies), 1.54 (95% CI 1.24, 1.93) for non-barbiturate antiepileptic drugs (13 studies), 2.17 (95% CI 1.35, 3.50) for barbiturate antiepileptic drugs (five studies), 1.59 (1.27, 1.98) for antipsychotics (12 studies), 1.15 (95% CI 0.94, 1.39) for hypnotics (13 studies) and 1.38 (95% CI 1.15, 1.66) for opioids (six studies). For non-specified psychotropic drugs (10 studies), the pooled RR was 1.48 (95% CI 1.41, 1.59). Limitations: Main concerns were the potential for residual confounding and for publication bias. Conclusion: Globally, the increase in the risk of fractures among psychotropic drug users is moderate. Further research is needed, especially to examine high-risk populations and newer medications. Future studies should be prospective and emphasise control of confounding bias.

Impact of safety alerts on measures of disproportionality in spontaneous reporting databases: the notoriety bias.

Abstract: Background: Disproportionality analysis of spontaneous reporting is increasingly used, but it may be influenced in unknown ways by safety alerts (notoriety bias). Objective: To explore the consequences of safety alerts on reporting disproportionality. Methods: Within the French national pharmacovigilance database, disproportionality of reporting was tested, using the reporting odds ratio (ROR) and its 95% confidence interval, before and after four safety alerts: valvulopathies with pergolide; tuberculosis with infliximab; strokes with atypical antipsychotics; and rhabdomyolysis with HMG-CoA reductase inhibitors (statins) [after cerivastatin withdrawal]. Results: No cases of valvulopathy were reported in association with pergolide before the safety alert and 63 cases were reported after the alert, (ROR 9400; 95% CI4300, 20 000), of which five had occurred before the alert. Twenty-five reports mentioned rhabdomyolysis associated with statins (not including cerivastatin) before the safety alert (ROR 5.8; 95% CI 3.8, 9.0), and 63 did so after the alert (ROR 9.4; 95% CI 7.0, 13.0). Approximately 280 cases involving cerivastatin were reported after its withdrawal. There were two reports of tuberculosis associated with infliximab before the alert (ROR 1500; 95% CI 130, 18 000) and seven after the alert (ROR 430; 95% CI 110, 1700). There was one report of a stroke in association with atypical antipsychotic treatment before the safety alert (ROR 0.10; 95% CI 0.01, 0.63) and 16 after the alert (ROR 1.10; 95% CI 0.70, 1.90). After excluding events involving treatment with anticoagulant agents, the RORs for stroke in association with atypical antipsychotic treatment were 0.14 (95% CI 0.02, 1.00) before the alert and 2.0 (95% CI 1.2, 3.4) after the alert. Conclusion: Disproportionality in spontaneous reporting databases increases after a safety alert because of increased reporting of the event of interest, including reports of such events that occurred before the alert. This may overflow to increased reporting of the event in association with other drugs.

Clozapine-associated myocarditis: a review of 116 cases of suspected myocarditis associated with the use of clozapine in Australia during 1993-2003.

Abstract: Background: Clozapine is an antipsychotic medication associated with a lower suicide rate compared with other antipsychotic agents. Clozapine is used specifically in patients for whom previous therapy was inadequate or not tolerated, and is the only antipsychotic agent associated with the development of myocarditis.

Corticosteroid-induced adverse events in adults: frequency, screening and prevention.

Abstract: Corticosteroids represent the most important and frequently used class of anti-inflammatory drugs and are the reference therapy for numerous neoplastic, immunological and allergic diseases. However, their substantial efficacy is often counter-balanced by multiple adverse events. These corticosteroid-induced adverse events represent a broad clinical and biological spectrum from mild irritability to severe and life-threatening adrenal insufficiency or cardiovascular events. The purpose of this article is to provide an overview of the available data regarding the frequency, screening and prevention of the adverse events observed in adults during systemic corticosteroid therapy (topically administered corticosteroids are outside the remit of this review). These include clinical (i.e. adipose tissue redistribution, hypertension, cardiovascular risk, osteoporosis, myopathy, peptic ulcer, adrenal insufficiency, infections, mood disorders, ophthalmological disorders, skin disorders, menstrual disorders, aseptic necrosis, pancreatitis) and biological (i.e. electrolytes homeostasis, diabetogenesis, dyslipidaemia) events. Lastly, data about the prescription of corticosteroids during pregnancy are provided. This review underscores the absence of data on many of these adverse events (e.g. lipodystrophy, dyslipidaemia). Our intent is to present to practitioners data that can be used in a practical way to both screen and prevent most of the adverse events observed during systemic corticosteroid therapy.

Bodyweight Changes Associated with Antihyperglycaemic Agents in Type 2 Diabetes Mellitus

Abstract: The majority of patients with type 2 diabetes mellitus are overweight or obese at the time of diagnosis, and obesity is a recognised risk factor for type 2 diabetes and coronary heart disease (CHD). Conversely, weight loss has been shown to improve glycaemic control in patients with type 2 diabetes, as well as to lower the risk of CHD. The traditional pharmacotherapies for type 2 diabetes can further increase weight and this may undermine the benefits of improved glycaemic control. Furthermore, patients’ desire to avoid weight gain may jeopardise compliance with treatment, thereby limiting treatment success and indirectly increasing the risk of long-term complications. This review evaluates the influences of established and emerging therapies on bodyweight in type 2 diabetes.

Safety and toxicity of sulfadoxine/pyrimethamine: implications for malaria prevention in pregnancy using intermittent preventive treatment.

Abstract: Plasmodium falciparum infection during pregnancy is strongly associated with maternal anaemia and low birth weight, contributing to substantial morbidity and mortality in sub-Saharan Africa. Intermittent preventive treatment in pregnancy with sulfadoxine/pyrimethamine (IPTp-SP) has been one of the most effective approaches to reduce the burden of malaria during pregnancy in Africa. IPTp-SP is based on administering ≥2 treatment doses of sulfadoxine/pyrimethamine to pregnant women at predefined intervals after quickening (around 18–20 weeks). Randomised, controlled trials have demonstrated decreased rates of maternal anaemia and low birth weight with this approach. The WHO currently recommends IPTp-SP in malaria-endemic areas of sub-Saharan Africa. However, implementation has been suboptimal in part because of concerns of potential drug toxicities. This review evaluates the toxicity data of sulfadoxine/pyrimethamine, including severe cutaneous adverse reactions, teratogenicity and alterations in bilirubin metabolism. Weekly sulfadoxine/pyrimethamine prophylaxis is associated with rare but potentially fatal cutaneous reactions. Fortunately, sulfadoxine/pyrimethamine use in IPTp programmes in Africa, with 2–4 treatment doses over 6 months, has been well tolerated in multiple IPTp trials. However, sulfadoxine/pyrimethamine should not be administered concurrently with cotrimoxazole given their redundant mechanisms of action and synergistic worsening of adverse drug reactions. Therefore, HIV-infected pregnant women in malaria endemic areas who are already receiving cotrimoxazole prophylaxis should not also receive IPTp-SP. Although folate antagonist use in the first trimester is associated with neural tube defects, large case-control studies have demonstrated that sulfadoxine/pyrimethamine administered as IPTp (exclusively in the second and third trimesters and after organogenesis) does not result in an increased risk of teratogenesis. Folic acid supplementation is recommended for all pregnant women to reduce the rate of congenital anomalies but high doses of folic acid (5 mg/day) may interfere with the antimalarial efficacy of sulfadoxine/pyrimethamine. However, the recommended standard dose of folic acid supplementation (0.4 mg/day) does not affect antimalarial efficacy and may provide the optimal balance to prevent neural tube defects and maintain the effectiveness of IPTp-SP. No clinical association between sulfadoxine/pyrimethamine use and kernicterus has been reported despite the extensive use of sulfadoxine/pyrimethamine and related compounds to treat maternal malaria and congenital toxoplasmosis in near-term pregnant women and newborns. Although few drugs in pregnancy can be considered completely safe, sulfadoxine/pyrimethamine — when delivered as IPTp — has a favourable safety profile. Improved pharmacovigilance programmes throughout Africa are now needed to confirm its safety as access to IPTp-SP increases. Given the documented benefits of IPTp-SP in malaria endemic areas of Africa, access to this treatment for pregnant women should continue to expand.

Physician response to patient reports of adverse drug effects: implications for patient-targeted adverse effect surveillance.

Abstract: Objective: Using a patient targeted survey, we sought to assess patient representations of how physicians responded when patients presented with possible adverse drug reactions (ADRs). As a demonstration case, we took one widely prescribed drug class, the HMG-CoA reductase inhibitors (‘statins’). This information was used to assess whether a patient-targeted ADR surveillance approach may complement provider reporting, potentially fostering identification of additional patients with possible or probable ADRs.

Impact of restricting paracetamol pack sizes on paracetamol poisoning in the United Kingdom: a review of the literature.

Abstract: Paracetamol (acetaminophen) is the most common drug taken in overdose in the UK, accounting for 48% of poisoning admissions to hospital and being involved in an estimated 100–200 deaths per year. In 1998, the UK government introduced legislation that reduced the maximum pack size of all non-effervescent tablets and capsules containing aspirin (acetylsalicylic acid) or paracetamol that can be sold or supplied from outlets other than registered pharmacies from 25 to 16 tablets or capsules. This article reviews the literature to determine the effectiveness of the legislation, focusing specifically on paracetamol poisoning. Seventeen studies on this subject were identified. Three studies found reductions in mortality rates; one study found an increase in mortality rates, while one found an initial reduction followed by an eventual increase; three found no significant difference in mortality rates before and after introduction of the legislation. Five studies found reductions in admissions to liver units, three of these finding a reduction in liver transplantation rates; two further studies found no change in liver function tests and rates of paracetamol-induced acute liver injury or failure. Four studies found a sustained decrease in hospital admissions, while two found an initial decrease followed by an eventual increase. One study found a decline in admissions for paracetamol poisoning and an increase in admissions for non-paracetamol poisoning. Sales data are conflicting, with two studies finding no significant difference in paracetamol sales before and after the introduction of the legislation and one reporting a decline. The severity of overdose appears to have decreased since the maximum permitted packet size was reduced, with five studies reporting a reduction in the number of severe overdoses (measured by numbers of tablets ingested, serum paracetamol concentrations and usage of antidotes). Only two studies reported an increase in the number of severe overdoses. Paracetamol-associated mortality rates, admissions to liver units/liver transplants, hospital admissions and the severity of paracetamol overdose appear to have been decreasing since 1998. However, one study showed that the reductions in mortality and hospital admissions began in 1997; therefore, the contribution of the 1998 legislation to the observed changes is unclear. Most of the studies are based on short-term follow-up so it is difficult to draw any conclusions regarding long-term trends. Many of the studies were also restricted to relatively small areas of the UK; this, combined with a variety of outcome measures, makes it difficult to distinguish any conclusive trends. The studies also suffer from a lack of comparison and control groups. Some studies do not clearly differentiate between the paracetamol preparations covered by the legislation and those not. The limited number of studies to date, combined with a variety of outcome measures, make it difficult to determine with accuracy whether or not the legislation has been a success. More long-term studies are needed to fully assess the impact of the legislation.

An evaluation of the cardiovascular safety profile of duloxetine: findings from 42 placebo-controlled studies

Abstract: Background and objective: In recent years, new classes of medication, such as the serotonin-noradrenaline reuptake inhibitors (SNRIs), have been developed for use in the treatment of major depressive disorder (MDD). For many years, treatment options were largely limited to the use of monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). However, there have been published reports of orthostatic hypotension, arrhythmias and corrected QT (QTc) interval changes in patients treated with TCAs. As new medications become available, it is important to understand how their cardiovascular safety profile compares with that of more established agents to aid clinicians and patients in choosing the best treatment options. This study was designed to evaluate the cardiovascular safety profile of the SNRI duloxetine through evaluation of cardiovascular-related parameters and adverse events (AEs). Methods: The cardiovascular safety of duloxetine was assessed using all placebocontrolled duloxetine clinical trial data as of December 2005. This consisted of data from 42 placebo-controlled clinical trials of 8504 patients who were treated with duloxetine. Additional information from a high-dose clinical pharmacology study and postmarketing safety surveillance are also presented. Of the placebocontrolled trials included in this analysis, clinical indications under investigation included MDD (15 studies), diabetic peripheral neuropathic pain (3 studies), fibromyalgia (2 studies), generalised anxiety disorder (3 studies) and lower urinary tract disorders (19 studies, all related to incontinence). Cardiovascular safety was evaluated based on vital signs, ECGs and the incidence of treatment-emergent AEs potentially related to cardiovascular safety. These safety parameters were analysed across all indications. To identify both serious and non-serious cardiovascular-related AEs, as well as AEs reported as the reason for discontinuation, a comprehensive list of terms derived from the Medical Dictionary for Regulatory Activities (version 8.0) was generated and used to search the duloxetine databases for cardiovascular-related events. Results: Calculation of change from baseline to maximum in ECG parameters showed significant differences between treatment groups for all parameters, with decreases from baseline in RR, QRS and QT intervals for patients receiving duloxetine and increases from baseline for patients treated with placebo. These shifts were related to small heart rate changes, but the mean differences were not considered clinically relevant. Categorical analyses of shifts from normal to abnormal (or abnormal to normal) for heart rate and QT corrected for heart rate using Fridericia’s formula (QTcF) values showed that most patients did not shift from their baseline category. Patients with MDD who were treated for up to 1 year with duloxetine had blood pressure changes early in treatment that then stabilised. Even in patients with elevated blood pressure at baseline in these clinical trials, no increased risk of sustained blood pressure elevation with duloxetine treatment was found. Conclusion: Overall, the findings presented here support our conclusions that use of duloxetine does not appear to be associated with significant cardiovascular risks in patients with conditions for which the drug has been approved or studied.

Interventions to reduce dosing errors in children: a systematic review of the literature.

Abstract: Children are a particularly challenging group of patients when trying to ensure the safe use of medicines. The increased need for calculations, dilutions and manipulations of paediatric medicines, together with a need to dose on an individual patient basis using age, gestational age, weight and surface area, means that they are more prone to medication errors at each stage of the medicines management process. It is already known that dose calculation errors are the most common type of medication error in neonatal and paediatric patients. Interventions to reduce the risk of dose calculation errors are therefore urgently needed. A systematic literature review was conducted to identify published articles reporting interventions; 28 studies were found to be relevant. The main interventions found were computerised physician order entry (CPOE) and computer-aided prescribing. Most CPOE and computer-aided prescribing studies showed some degree of reduction in medication errors, with some claiming no errors occurring after implementation of the intervention. However, one study showed a significant increase in mortality after the implementation of CPOE. Further research is needed to investigate outcomes such as mortality and economics. Unit dose dispensing systems and educational/risk management programmes were also shown to reduce medication errors in children. Although it is suggested that 'smart' intravenous pumps can potentially reduce infusion errors in children, there is insufficient information to draw a conclusion because of a lack of research. Most interventions identified were US based, and since medicine management processes are currently different in different countries, there is a need to interpret the information carefully when considering implementing interventions elsewhere.

Safety considerations with bisphosphonates for the treatment of osteoporosis

Abstract: ment of osteoporosis. Although evidence supports a good safety profile for these agents, numerous tolerability issues have been associated with their use. This review provides an overview of the safety issues associated with the nitrogencontaining class of bisphosphonates and discusses the potential effect of these issues on adherence. The review specifically considers upper gastrointestinal (UGI) adverse events (AEs), renal toxicity, influenza-like illness, osteonecrosis of the jaw and evidence on how to treat or prevent these events. In clinical trials, UGI AEs, including severe events such as oesophageal ulcer, oesophagitis and erosive oesophagitis, have been reported at similar frequencies in placebo- and active-treatment arms. However, postmarketing studies have highlighted UGI AEs as a concern. These studies show that a significant portion of patients are less compliant with administration instructions outside strict clinical trial supervision, and when oral bisphosphonates are not administered as directed, patients are more likely to experience UGI AEs. Some clinical trials with oral bisphosphonates have suggested that a decrease in the frequency of administration may lead to improvement in gastrointestinal tolerability. In the authors’ experience, the issue of UGI tolerability can be minimised by explaining to the patient and/or caregiver the importance of following administration instructions. Intravenous (IV) bisphosphonates have been recently approved for use in osteoporosis, offering an alternative regimen for patients with osteoporosis.

Drug-induced skin, nail and hair disorders.

Abstract: Drug eruptions are among the most common adverse drug reactions, affecting approximately 3% of hospitalised patients. Although the rate of severe cutaneous adverse reactions to medications is low, these reactions can affect anyone who takes medication, and can result in death or disability. Two general patterns can be distinguished, depending on the type of onset of these cutaneous adverse drug reactions: acute or chronic. Acute-onset events are usually rather specific cutaneous ‘syndromes’ that constitute emergencies and should therefore be promptly recognised and treated, while chronic-onset events often present as dermatological diseases. The challenge is therefore to recognise the drug aetiology in front of a ‘classical’ dermatosis such as acne, lichen or pemphigus. Therefore, clinicians should carefully evaluate the signs or symptoms of all adverse reactions thought to be drug related, and discontinue the offending agent when feasible.

Factors that influence under-reporting of suspected adverse drug reactions among community pharmacists in a Spanish region.

Abstract: Background: The spontaneous reporting system is the most efficient warning system of adverse drug reactions (ADRs). Pharmacists can play an important role in the detection and reporting of ADRs. The factors that affect under-reporting among these professionals are unknown in Spain. Objective: To identify the factors that influence community pharmacists’ ADR under-reporting in Navarra, a Northern Spanish region. Methods: A case-control study was conducted on a population of 802 community pharmacists working in Navarra. Cases were pharmacists who had reported at least two ADRs to the region’s drug surveillance unit between 2003 and 2005 and who agreed to participate in the study (18/20; 90%). A random sample of 60 controls was selected from the 762 pharmacists who had not reported any ADR during the same period of time. Results: Factors positively associated with ADR reporting were age, years of work experience as a pharmacist, participation in educational activities related to the detection and resolution of drug-related problems, the habit of detecting ADRs as part of pharmacists’ duties, having the basic knowledge needed to report ADRs, and disagreement with the common belief among healthcare professionals that ’to report an ADR it is necessary to be sure that the reaction is related to the use of a particular drug’. The most frequently mentioned reasons for not reporting ADRs were the ADR is not serious, the ADR is already known, uncertainty concerning the causal relationship between the ADR and the drug, forgetting to report the ADR and a lack of time. Conclusions: Pharmacists’ knowledge, beliefs, behaviour and motivation play an important role in ADR reporting. Under-reporting might be improved through activities focused on modifying such factors.

Adverse drug reactions in patients with phaeochromocytoma: incidence, prevention and management.

Abstract: The dangers of phaeochromocytomas are mainly due to the capability of these neuroendocrine tumours to secrete large quantities of vasoactive catecholamines, thereby increasing blood pressure and causing other related adverse events or complications. Phaeochromocytomas are often missed, sometimes only becoming apparent during therapeutic interventions that provoke release or interfere with the disposition of catecholamines produced by the tumours. Because phaeochromocytomas are rare, evidence contraindicating use of specific drugs is largely anecdotal or based on case reports. The heterogeneous nature of the tumours also makes adverse reactions highly variable among patients. Some drugs, such as dopamine D2 receptor antagonists (e.g. metoclopramide, veralipride) and β-adrenergic receptor antagonists (β-blockers) clearly carry high potential for adverse reactions, while others such as tricyclic antidepressants seem more inconsistent in producing complications. Other drugs capable of causing adverse reactions include monoamine oxidase inhibitors, sympathomimetics (e.g. ephedrine) and certain peptide and corticosteroid hormones (e.g. corticotropin, glucagon and glucocorticoids). Risks associated with contraindicated medications are easily minimised by adoption of appropriate safeguards (e.g. adrenoceptor blockade). Without such precautions, the state of cardiovascular vulnerability makes some drugs and manipulations employed during surgical anaesthesia particularly dangerous. Problems arise most often when drugs or therapeutic procedures are employed in patients in whom the tumour is not suspected. In such cases, it is extremely important for the clinician to recognise the possibility of an underlying catecholamine-producing tumour and to take the most appropriate steps to manage and treat adverse events and clinical complications.

Incidence and nature of medication errors in neonatal intensive care with strategies to improve safety: a review of the current literature.

Abstract: Neonates are highly vulnerable to medication errors because of their extensive exposure to medications in the neonatal intensive care unit (NICU), the general lack of evidence on pharmacotherapeutic interventions in neonates and the lack of neonate-specific formulations. We searched PubMed and EMBASE to identify relevant original studies published in the English language. Eleven studies were identified on the frequency of medication errors in the NICU. The highest rate was 5.5 medication errors per 100 prescriptions; however, medication error rates varied widely between studies, partly due to differences in the definition of an error and the rigor of the method used to identify medication errors. Furthermore, studies were difficult to compare because medication error rates were calculated differently. Most studies did not assess the potential clinical impact of the errors. The majority of studies identified dose errors as the most common type of error. Computerised physician order entry and interventions by clinical pharmacists (e.g. the participation of pharmacists in ward rounds and review of patients' prescriptions prior to dispensing) were the most common interventions suggested to improve medication safety in the NICU. However, only very limited data were available on evaluation of the effects of such interventions in NICUs. More research is needed to determine the frequency and types of medication errors in NICUs and to develop evidence-based interventions to improve medication safety in the NICU setting. Some of these research efforts need to be directed to the establishment of clear definitions of medication errors and agreement on the methods that should be used to measure medication error rates and their potential clinical impact.

Safety of agents used to prevent mother-to-child transmission of HIV: is there any cause for concern?

Abstract: Antiretroviral drugs have been used routinely to reduce the risk of mother-to-child transmission of HIV infection since 1994, following the AIDS Clinical Trials Group 076 trial, which demonstrated the efficacy of zidovudine in reducing the risk of in utero and intrapartum transmission. The use of antiretroviral drugs in pregnancy varies geographically, with widespread use of highly active antiretroviral therapy (HAART) in resource-rich settings for delaying maternal HIV disease progression as well as the prevention of mother-to-child transmission; however, in low- and middle-income settings, abbreviated prophylactic regimens focus on the perinatal period, with very limited access to HAART to date. The potential risks associated with antiretroviral exposure for pregnant women, fetuses and infants depend on the duration of this exposure as well as the number and type of drugs. As the benefits of HAART regimens in reducing the risk of mother-to-child transmission and in delaying disease progression are so great, their widespread use has been accepted, despite the relative lack of safety data from human pregnancies. Animal studies have suggested an increased risk of malformations associated with exposure to specific antiretroviral drugs, although evidence to support this from human studies is limited. Trials, cohorts and surveillance studies have shown no evidence of an increased risk of congenital malformations associated with in utero exposure to zidovudine, or other commonly used antiretroviral drugs, with an estimated 2-3% prevalence of birth defects (i.e. similar to that seen in the general population). Exposure to prophylactic zidovudine for prevention of mother-to-child transmission is associated with a usually mild and reversible, but rarely severe, anaemia in infants. However, a medium-term impact on haematological parameters of antiretroviral-exposed infants has been reported, with small but persistent reductions in levels of neutrophils, platelets and lymphocytes in children up to 8 years of age; the clinical significance of this remains uncertain. To date, there is no evidence to suggest that exposure to antiretroviral drugs in utero or neonatally is associated with an increased risk of childhood cancer, but the potential for mutagenic and carcinogenic effects at older ages cannot be excluded. Nucleoside analogue-related mitochondrial toxicity is well recognised from studies in non-pregnant individuals, whilst animal studies have provided evidence of mitochondrial toxicity resulting from in utero antiretroviral exposure. Clinically evident mitochondrial disease in children with antiretroviral exposure has only been described in Europe, with an estimated 18-month incidence of 'established' mitochondrial dysfunction of 0.26% among exposed children. Regarding pregnancy-related adverse effects, increased risks of prematurity, pre-eclampsia and gestational diabetes mellitus have been reported by a variety of observational studies with varying strengths of evidence and with conflicting results. Based on current knowledge, the immense benefits of antiretroviral prophylaxis in prevention of mother-to-child transmission far outweigh the potential for adverse effects. However, these potential adverse effects require further and longer term monitoring because they are likely to be rare and to occur later in childhood.

Guidelines for Submitting Adverse Event Reports for Publication

Abstract: Publication of case reports describing suspected adverse effects of drugs and medical products that include herbal and complementary medicines, vaccines, and other biologicals and devices is important for postmarketing surveillance. Publication lends credence to important signals raised in these adverse event reports. Unfortunately, deficiencies in vital information in published cases can often limit the value of such reports by failing to provide enough details for either (i) a differential diagnosis or provisional assessment of cause-effect association, or (ii) a reasonable pharmacological or biological explanation. Properly described, a published report of one or more adverse events can provide a useful signal of possible risks associated with the use of a drug or medical product which might warrant further exploration. A review conducted by the Task Force authors found that many major journals have minimal requirements for publishing adverse event reports, and some have none at all. Based on a literature review and our collective experience in reviewing adverse event case reports in regulatory, academic, and industry settings, we have identified information that we propose should always be considered for inclusion in a report submitted for publication. These guidelines have been endorsed by the International Society for Pharmacoepidemiology (ISPE) and the International Society of Pharmacovigilance (ISoP) and are freely available on the societies’ websites. Their widespread distribution is encouraged. ISPE and ISoP urge biomedical journals to adopt these guidelines and apply them to case reports submitted for publication. They also encourage schools of medicine, pharmacy, and nursing to incorporate them into the relevant curricula that address the detection, evaluation, and reporting of suspected drug or other medical product adverse events.

Evaluating the postmarketing experience of risperidone use during pregnancy: pregnancy and neonatal outcomes.

Abstract: Background: A significant number of women of childbearing age have schizophrenia or other psychoses. This means that there is a considerable risk of in utero exposure to risperidone due to maternal use.

Surveillance of Prescription Drug-Related Mortality Using Death Certificate Data

Abstract: Background: The prescription drugs or drug classes that are most frequently associated with death in the US might be identifiable from death certificate data. Objective: To identify the drugs/drug classes associated with the greatest numbers of deaths in the US that might be considered as possible targets for prevention. Study design: US vital statistics data were accessed in order to identify International Classification of Diseases (10th Revision) [ICD-10] codes indicating that prescription drugs had caused or contributed to death and diseases with significant drug-related mortality. Main outcome measure: ICD-10 codes for primarily prescription drugs that were listed as the underlying cause or as ‘total mentions’ on death certificates and were implicated in ≥1000 deaths in any one year were selected. The annual number of deaths by ICD-10 code was obtained from the Division of Vital Statistics, National Center for Health Statistics. Codes for diseases with significant drug-related aetiologies and involvement in ≥1000 deaths in any one year were also identified and analysed separately. Results: For the selected ICD-10 codes, a total of 25 031 deaths were listed as having a prescription drug as the underlying cause in 2003, compared with 16 135 in 1999, a 55% increase. Total mentions of these codes increased from 46 523 in 1999 to 72 080 in 2003, also a 55% increase. Most codes involved ‘poisonings’ (overdose or the wrong substance given or taken in error that is accidental, intentional or with undetermined intent). Drugs associated with poisoning deaths had central nervous system effects. Among the codes associated with specified drug classes, poisonings and accidental poisonings involving narcotics, hallucinogens, psychoactive substances and opioids (other than opium and heroin) were associated with the largest numbers of deaths. Drug-related codes associated with the largest percentage increases in deaths between 1999 and 2003 included poisoning due to methadone (275%); poisoning by other and unspecified antidepressants (primarily selective serotonin reuptake inhibitors) [130%]; and poisoning by psychostimulants with potential for abuse (amfetamines and drugs for attention deficit hyperactivity disorder) [117%]. Anticoagulants were associated with the largest numbers of deaths with codes involving “adverse effects in therapeutic use”. Among diseases with significant drug-related aetiologies, Clostridium difficile enterocolitis (associated primarily with antibacterials) had the largest percentage increase in total mentions, with a 203% rise between 1999 and 2003. Conclusions: Deaths due to overdoses are the most prominent cause of drug-related mortality in death certificate data. Certain drugs and drug classes, especially the opioids (e.g. narcotics, methadone), psychoactive drugs (e.g. antidepressants, amfetamines), anticoagulants and antibacterials (which cause or contribute to C. difficile enterocolitis) are associated with large and increasing numbers of deaths and preventive strategies should be considered.

Suicidality and antiepileptic drugs: is there a link?

Abstract: The main purpose of the present article is to review the possible risk factors for suicidal behaviour in epilepsy with a special emphasis on the different antiepileptic drugs (AEDs). Epidemiological data show that, in general, the suicide rate among patients with epilepsy is 5-fold higher than that in the general population, while in temporal lobe epilepsy and complex partial seizures it is approximately 25-fold higher. A certain psychiatric comorbidity may provoke suicidality in patients with epilepsy, and depression and cognitive impairment seem to be the main risk factors for suicidality in epilepsy. In addition, depression and cognitive deterioration in epilepsy may share common neuropsychological mechanisms in terms of hypofrontality. This may cause similar psychopathological signs in both diagnostic categories, including suicidality. Analysis of the literature has shown that serotonin metabolism disturbances are involved in the pathogenesis of suicidal behaviour irrespective of primary diagnosis. Serotonin disturbances also seem to be a common link between depression, suicidality and even epilepsy itself. The various AEDs differ not only in their mechanisms of action, but also in influences on cognition and mood in epileptic patients and suicidality, respectively. Until now, only Ketter's hypothesis has been proposed to explain the psychotropic effects of different AEDs, although it does not explain the positive psychotropic effects of some AEDs, such as carbamazepine and oxcarbazepine. According to this model, all psychotropic effects of AEDs may be the result of effects on the function of two types of receptor functions: gamma-aminobutyric acid (GABA) ergic and antiglutamatergic; other possible mechanisms have not been incorporated. Presumably, other neurochemical mechanisms, and a serotonergic mechanism in particular, should also be taken into account when explaining the psychotropic effects of different AEDs. Based on these data, it has been suggested that AEDs with certain serotonergic properties should reduce the suicidality risk because they exert effects similar to antidepressants (i.e. selective serotonin reuptake inhibitors), whereas AEDs that lack serotonergic mechanisms would not be effective in suicidality prevention. In line with this paradigm, phenobarbital and phenytoin seem to be the only drugs with proven suicidality risk. On the other hand, carbamazepine, oxcarbazepine, valproate and lamotrigine could be regarded as drugs with antisuicidal properties because they all improve cognitive functions and mood in epileptic patients, and possess serotonergic mechanisms of action. The other AEDs, including topiramate, tiagabine, vigabatrin, levetiracetam and zonisamide, all exert negative effects on mood and cognition, although their influence on suicidality has not been proven in evidence-based studies yet. Although zonizamide has serotonergic properties, it exerts negative psychotropic effects, whereas gabapentin is devoid of serotonergic properties but has positive psychotropic effects on mood and cognition. To more fully explain the positive and negative psychotropic effects and influence on suicidality of AEDs, Ketter's paradigm should be supplemented by an understanding of the serotonergic mechanisms of different AEDs. Further trials are required to prove or refute this model.

Emergency department visits caused by adverse drug events: results of a French survey.

Abstract: Background: Adverse drug events (ADEs) are a substantial cause of hospital admissions. However, little is known about the incidence, preventability and severity of ADEs resulting in emergency department visits. To address this issue, we conducted a prospective survey in emergency departments of French public hospitals.

Psychiatric adverse reactions with statins, fibrates and ezetimibe: implications for the use of lipid-lowering agents.

Abstract: The HMG-CoA reductase inhibitors ('statins') have come into widespread use internationally. There has been a long history of their use in New Zealand and this use has increased in recent years. There has also been an increase in the number of reports to the New Zealand Centre for Adverse Reactions Monitoring (CARM) of suspected psychiatric adverse reactions associated with statins. The reactions mentioned in these reports include depression, memory loss, confusion and aggressive reactions. Convincing reports to CARM of recurrence of these reactions upon rechallenge add weight to recent studies reporting serious psychiatric disturbances in association with statin treatment. Aggressive reactions associated with statins are poorly documented in the literature. These observations emphasise the need to be vigilant in looking for these reactions as they can have a significant personal impact on a patient. The observation that other lipid-lowering agents have similar adverse effects supports the hypothesis that decreased brain cell membrane cholesterol may be important in the aetiology of these psychiatric reactions.

Safety profile of meropenem: an updated review of over 6,000 patients treated with meropenem.

Abstract: Meropenem is a broad-spectrum carbapenem antibacterial with potent antimicrobial activity against a broad range of Gram-negative, Gram-positive and anaerobic bacteria. The second parenteral carbapenem to be introduced worldwide, meropenem has been in clinical use since 1994. Two previous safety reviews have established that meropenem has a favourable and acceptable safety profile. This new review was conducted after the approval of meropenem in the US in 2005 for the treatment of patients with complicated skin and skin-structure infections, in addition to the previously approved indications of intra-abdominal infections and paediatric bacterial meningitis. The analysis includes the clinical trial data from the previous safety reviews, updated with expanded experience across a number of serious bacterial infections, including a large international study in patients with skin or skin-structure infections and further experience in patients with intra-abdominal infections and bacterial meningitis. A total of 6154 patients with 6308 meropenem exposures were compared with 4483 patients treated with comparator agents (4593 exposures), and the paediatric population base for which safety data are available has doubled to over 1000 patients. The data presented reinforce the favourable safety profile of meropenem. In general, the incidence and pattern of adverse events occurring with meropenem were similar to those of the first carbapenem, imipenem/cilastatin, and to those of the cephalosporin- and clindamycin-based regimens to which it had been compared. The most common adverse events reported for meropenem were diarrhoea (2.5%), rash (1.4%) and nausea/vomiting (1.2%). No adverse event occurred in more than 3% of patient exposures to meropenem, indicating a low overall frequency of adverse events as well as excellent gastrointestinal tolerability. Furthermore, no unexpected adverse events were identified, and the very low incidence of seizures in patients with meningitis was not considered to be drug related. In infections other than meningitis, the incidence of seizures considered by investigators to be related to meropenem treatment was 0.07%. In the new studies that updated the earlier safety data, no new cases of drug-related seizure were reported for any treatment or patient group (meningitis/non-meningitis infections). In conclusion, meropenem is well tolerated and has good CNS and gastrointestinal tolerability when used for the treatment of serious bacterial infections in a wide range of adult and paediatric patient populations.

Mometasone furoate nasal spray: a review of safety and systemic effects.

Abstract: The development of corticosteroids that are delivered directly to the nasal mucosa has alleviated much of the concern about the systemic adverse effects associated with oral corticosteroid therapy. However, given the high potency of these drugs and their widespread use in the treatment of allergic rhinitis, it is important to ensure that intranasal corticosteroids have a favourable benefit-risk ratio. One agent that typifies the systemic safety found in the majority of intranasal corticosteroids is mometasone furoate nasal spray, a potent and effective treatment for seasonal and perennial allergic rhinitis and nasal polyposis. Mometasone furoate does not reach high systemic concentrations or cause clinically significant adverse effects. Results from pharmacokinetic studies in adults and children suggest that systemic exposure to mometasone furoate after intranasal administration is negligible. This is probably because of the inherently low aqueous solubility of mometasone furoate, which allows only a small fraction of the drug to cross the nasal mucosa and enter the bloodstream, and because a large amount of the administered drug is swallowed and undergoes extensive first-pass metabolism. There is no clinical evidence that mometasone furoate nasal spray suppresses the function of the hypothalamus-pituitary-adrenal axis when the drug is administered at clinically relevant doses (100–200 μg/day); consequently, mometasone furoate nasal spray has not been associated with growth inhibition in children. The safety and tolerability of mometasone furoate nasal spray have been rigorously assessed in clinical trials involving approximately 4500 patients, with epistaxis, headache and pharyngitis being the most common adverse effects associated with treatment in adolescents and adults.

Statins, neuromuscular degenerative disease and an amyotrophic lateral sclerosis-like syndrome: an analysis of individual case safety reports from vigibase.

Abstract: Background: The WHO Foundation Collaborating Centre for International Drug Monitoring (Uppsala Monitoring Centre [UMC]) has received many individual case safety reports (ICSRs) associating HMG-CoA reductase inhibitor drug (statin) use with the occurrence of muscle damage, including rhabdomyolysis, and also peripheral neuropathy. A new signal has now appeared of disproportionally high reporting of upper motor neurone lesions.

Thiazolidinediones and their fluid-related adverse effects : Facts, fiction and putative management strategies

Abstract: Thiazolidinediones (TZDs) or glitazones are agents that are widely used for the treatment of type 2 diabetes mellitus. These drugs have a multitude of therapeutic effects including reduction in insulin resistance and hyperglycaemia, anti-inflammatory effects and amelioration of hypertension, microalbuminuria and hepatic steatosis. The TZD molecular target, peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear transcription factor, is expressed diffusely in humans, including many tissues comprising the cardiovascular and renal systems. This suggests a potential for TZDs to elicit perturbing effects on these systems, which are independent of their effects on glucose and lipid metabolism. One of the most common adverse effects of TZDs is fluid retention, which can result in, or exacerbate, oedema and congestive heart failure (CHF). The frequency of peripheral oedema is approximately 5% when TZDs are used in mono- or combination oral therapy, and about 15% when used with insulin. Patients with type 2 diabetes are at high risk of myriad morbid complications, including CHF. The development of CHF, particularly in the elderly, is a harbinger of premature mortality. TZD-induced oedema is largely peripheral, may have its origins in changes in haemodynamics, with some contribution from molecules, which regulate cell and tissue permeability (e.g. vascular endothelial growth factor and protein kinase Cbeta), and remains the preponderant manifestation of TZD-induced fluid retention even in those with existing heart failure. Preclinical and pilot clinical data attest to the fact that at least part of the fluid retention derives from a direct effect of TZDs on sodium reabsorption via the renal medullary collecting duct, a mechanism that is sensitive to diuretic agents that have this nephron segment as their site of action, in whole or in part (spironolactone, amiloride and hydrochlorothiazide). Our review suggests various potential clinical strategies by which TZD-induced fluid retention might be effectively monitored and addressed.