Torsadogenic risk of antipsychotics: combining adverse event reports with drug utilization data across Europe. PLoS One. 2013;8:e81208. [PMID: 24278396 PMCID: PMC3835678 DOI: 10.1371/journal.pone.0081208]

Investigating the cardiotoxicity of N-n-butyl haloperidol iodide: Inhibition mechanisms on hERG channels

The human Ether-à-go-go-Related Gene (hERG) encodes a protein responsible for forming the alpha subunit of the IKr channel, which plays a crucial role in cardiac repolarization. The proper functioning of hERG channels is paramount in maintaining a normal cardiac rhythm. Inhibition of these channels can result in the prolongation of the QT interval and potentially life-threatening arrhythmias. Cardiotoxicity is a primary concern in the field of drug development. N-n-Butyl haloperidol iodide (F2), a derivative of haloperidol, has been investigated for its therapeutic potential. However, the impact of this compound on cardiac toxicity, specifically on hERG channels, remains uncertain. This study employs computational and experimental methodologies to examine the inhibitory mechanisms of F2 on hERG channels. Molecular docking and molecular dynamics simulations commonly used techniques in computational biology to predict protein-ligand complexes' binding interactions and stability. In the context of the F2-hERG complex, these methods can provide valuable insights into the potential binding modes and strength of interaction between F2 and the hERG protein. On the other hand, electrophysiological assays are experimental techniques used to characterize the extent and nature of hERG channel inhibition caused by various compounds. By measuring the electrical activity of the hERG channel in response to different stimuli, these assays can provide important information about the functional effects of ligand binding to the channel. The study's key findings indicate that F2 interacts with the hERG channel by forming hydrogen bonding, π-cation interactions, and hydrophobic forces. This interaction leads to the inhibition of hERG currents in a concentration-dependent manner, with an IC50 of 3.75 μM. The results presented in this study demonstrate the potential cardiotoxicity of F2 and underscore the significance of considering hERG channel interactions during its clinical development. This study aims to provide comprehensive insights into the interaction between F2 and hERG, which will may guid us in the safe use of F2 and in the development of new derivatives with high efficiency while low toxicity.

Mapping Strategies to Assess and Increase the Validity of Published Disproportionality Signals: A Meta-Research Study

BACKGROUND AND AIM

Disproportionality analysis is traditionally used in spontaneous reporting systems to generate working hypotheses about potential adverse drug reactions: the so-called disproportionality signals. We aim to map the methods used by researchers to assess and increase the validity of their published disproportionality signals.

METHODS

From a systematic literature search of published disproportionality analyses up until 1 January 2020, we randomly selected and analyzed 100 studies. We considered five domains: (1) rationale for the study, (2) design of disproportionality analyses, (3) case-by-case assessment, (4) use of complementary data sources, and (5) contextualization of the results within existing evidence.

RESULTS

Among the articles, multiple strategies were adopted to assess and enhance the results validity. The rationale, in 95 articles, was explicitly referred to the accrued evidence, mostly observational data (n = 46) and regulatory documents (n = 45). A statistical adjustment was performed in 34 studies, and specific strategies to correct for biases were implemented in 33 studies. A case-by-case assessment was complementarily performed in 35 studies, most often by investigating temporal plausibility (n = 26). Complementary data sources were used in 25 articles. In 78 articles, results were contextualized using accrued evidence from the literature and regulatory documents, the most important sources being observational (n = 45), other disproportionalities (n = 37), and case reports (n = 36).

CONCLUSIONS

This meta-research study highlighted the heterogeneity in methods and strategies used by researchers to assess the validity of disproportionality signals. Mapping these strategies is a first step towards testing their utility in different scenarios and developing guidelines for designing future disproportionality analysis.

Neonatal withdrawal syndrome following in utero exposure to antidepressants: a disproportionality analysis of VigiBase, the WHO spontaneous reporting database

BACKGROUND

Evidence on neonatal withdrawal syndrome following antidepressant intrauterine exposure is limited, particularly for antidepressants other than selective serotonin reuptake inhibitor (SSRIs).

METHODS

In our case/non-case pharmacovigilance study, based on VigiBase®, the WHO database of suspected adverse drug reactions, we estimated reporting odds ratio (ROR) and the Bayesian information component (IC) with 95% confidence/credibility intervals (CI) as measures of disproportionate reporting of antidepressant-related neonatal withdrawal syndrome. Antidepressants were first compared to all other medications, then to methadone, and finally within each class of antidepressants: SSRIs, tricyclics (TCA) and other antidepressants. Antidepressants were ranked in terms of clinical priority, based on semiquantitative score ratings. Serious v. non-serious reports were compared.

RESULTS

A total of 406 reports of neonatal withdrawal syndrome in 379 neonates related to 15 antidepressants were included. Disproportionate reporting was detected for antidepressants as a group as compared to all other drugs (ROR: 6.18, 95% CI 5.45-7.01, IC: 2.07, 95% CI 1.92-2.21). Signals were found for TCAs (10.55, 95% CI 8.02-13.88), followed by other antidepressants (ROR: 5.90, 95% CI 4.74-7.36) and SSRIs (ROR: 4.68, 95% CI 4.04-5.42). Significant disproportionality emerged for all individual antidepressants except for bupropion, whereas no disproportionality for any antidepressant was detected v. methadone. Eleven antidepressants had a moderate clinical priority score and four had a weak one. Most frequent symptoms included respiratory symptoms (n = 106), irritability/agitation (n = 75), tremor (n = 52) and feeding problems (n = 40).

CONCLUSIONS

Most antidepressants are associated with moderate signals of disproportionate reporting for neonatal withdrawal syndrome, which should be considered when prescribing an antidepressant during pregnancy, irrespective of class.

Characteristics of adverse reactions among antipsychotic drugs using the Korean Adverse Event Reporting System database from 2010 to 2019

BACKGROUND

Retrospective studies using spontaneous reporting system databases have provided a great understanding of adverse drug reactions (ADRs) in the real world, complementing the data obtained from randomized controlled trials. However, there have been few reports on large-scale epidemiological studies on the adverse effects of antipsychotics in Asia.

AIM

This study aimed to investigate the characteristics of antipsychotic ADRs using a nationwide pharmacovigilance database.

METHODS

Data were collected from the Korea Adverse Event Reporting System database between 2010 and 2019. The study subjects were selected using the International Classification of Disease codes for diseases related to psychosis and Electronic Data Interchange codes for amisulpride, aripiprazole, clozapine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone. The causality assessment of "possible," "probable," or "certain" by the World Health Organization-Uppsala Monitoring Center System causality category was selected. All data were descriptively analyzed.

RESULTS

In total, 5067 adverse events associated with antipsychotic drugs were reported. The antipsychotics that commonly resulted in ADRs were quetiapine (47.7%), olanzapine (11.3%), and clozapine (10.7%). Serious ADRs were most commonly observed with clozapine. Gastrointestinal and central nervous system problems occurred within a month when ADRs were classified according to the time of onset. In contrast, metabolic and bone marrow-related symptoms occurred after long-term use. Sedation and nausea were the most common ADRs in children and adolescents, whereas constipation and dizziness were common in adults and the elderly.

CONCLUSIONS

This study extends our knowledge of antipsychotic ADRs in the Asian population.

Antipsychotics in routine treatment are minor contributors to QT prolongation compared to genetics and age

BACKGROUND

Drug-induced prolongation of cardiac repolarization limits the treatment with many psychotropic drugs. Recently, the contribution of polygenic variation to the individual duration of the QT interval was identified.

AIMS

To explore the interaction between antipsychotic drugs and the individual polygenic influence on the QT interval.

METHODS

Retrospective analysis of clinical and genotype data of 804 psychiatric inpatients diagnosed with a psychotic disorder. The individual polygenic influence on the QT interval was calculated according to the method of Arking et al.

RESULTS

Linear regression modelling showed a significant association of the individual polygenic QT interval score (ß_std = 0.176, p < 0.001) and age (ß_std = 0.139, p < 0.001) with the QTc interval corrected according to Fridericia's formula. Sex showed a nominal trend towards significance (ß_std = 0.064, p = 0.064). No association was observed for the number of QT prolonging drugs according to AZCERT taken. Subsample analysis (n = 588) showed a significant association of potassium serum concentrations with the QTc interval (ß_std = -0.104, p = 0.010). Haloperidol serum concentrations were associated with the QTc interval only in single medication analysis (n = 26, ß_std = 0.101, p = 0.004), but not in multivariate regression analysis. No association was observed for aripiprazole, clozapine, quetiapine and perazine, while olanzapine and the sum of risperidone and its metabolite showed a negative association.

CONCLUSIONS

Individual genetic factors and age are main determinants of the QT interval. Antipsychotic drug serum concentrations within the therapeutic range contribute to QTc prolongation on an individual level.

Characteristics of voluntary reporting of adverse drug events related to antipsychotics in Australia: 14-year analysis

BACKGROUND

Retrospective analyses of large databases of treated patients can provide useful links to the presence of drug misuse or rare and infrequent adverse effects, such as agranulocytosis, diabetic ketoacidosis or neuroleptic malignant syndrome. The aim of this study is to describe the adverse effects to antipsychotics reported in the Australian Database of Adverse Event Notifications (DAEN).

METHODS

Data were collected from the DAEN - a spontaneous reporting database. The database, which covered the period from January 2004 to December 2017, was obtained from the Therapeutic Goods Administration (TGA) website (www.TGA.gov). The drugs selected for this investigation are the following: aripiprazole, clozapine, olanzapine, paliperidone, risperidone, ziprasidone, quetiapine, haloperidol and pimozide. All data were analysed descriptively. Comparison of reporting and management of adverse events between adults (older than 20 years) and children (5-19 years) was undertaken using chi squared test, where p < 0.05 is significant.

RESULTS

A total of 7122 adverse events associated with the antipsychotics aripiprazole, clozapine, haloperidol, olanzapine, paliperidone, pimozide, quetiapine and risperidone were reported to the TGA between January 2004 and December 2017. On average, there were 2.6 adverse events reported for each case. The most common adverse event reported for antipsychotics was neuroleptic malignant syndrome. There were no significant differences in the number of co-medications, formulations, indications, therapeutic dose, hospital admission and overdose among the antipsychotics between paediatric and adult populations. However, there were significant differences between causality, death and the management of adverse events between adult and paediatric populations (5-19 years) (p < 0.05, chi squared test).

CONCLUSION

The antipsychotic drug associated with the highest adverse events in adults was clozapine, followed by olanzapine. The most common adverse event in adults, and reported with a number of antipsychotic drugs, was neuroleptic malignant syndrome. In children, the highest numbers of adverse events reported in the database were associated with risperidone, clozapine and olanzapine.

PLAIN LANGUAGE SUMMARY

Adverse events reported of antipsychoticsBackground: Retrospective analyses of large databases of treated patients can provide useful clues to the presence of drug misuse or rare and infrequent adverse effects associated with antipsychotics. The drugs selected for this investigation are the following: aripiprazole, clozapine, olanzapine, paliperidone, risperidone, ziprasidone, quetiapine, haloperidol and pimozide.Methods: All data were analysed descriptively and investigated for any associations between the variables collected. Comparison of reporting and management of adverse events between adults (older than 20 years) and children (5-19 years) was undertaken using chi squared test, where p < 0.05 is significant.Results: The antipsychotic drug associated with the highest adverse events was clozapine, followed by olanzapine. In children, the highest numbers of adverse events reported in the database were associated with risperidone, clozapine and olanzapine. The most common adverse event in adults, and reported with a number of antipsychotic drugs, was neuroleptic malignant syndrome.Conclusion: There were significant differences between causality, death and the management of adverse events between adult and paediatric populations (5-19 years).Keywords: Antipsychotics, adverse effects, adverse events, safety.

Drug-induced liver injury associated with antiseizure medications from the FDA Adverse Event Reporting System (FAERS)

PURPOSE

Treatment with antiseizure medications (ASMs) confers a risk of drug-induced liver injury (DILI), especially for older ASMs. We sought to quantify recent reports of DILI attributed to both older and newer generation ASMs and survey newly marketed ASMs for hepatotoxicity in a large post-marketing database.

METHODS

We queried over 2.6 million adverse event reports made to the FDA Adverse Event Reporting System (FAERS) database between July 1, 2018 and March 31, 2020 for DILI due to ASMs commonly used in clinical practice. Patient characteristics and outcomes were assessed. We calculated the reporting odds ratio (ROR) of DILI for each individual ASM versus all non-ASM reports.

RESULTS

A total of 2175 DILI cases were attributed to an ASM during the study period. 97.2% of these were designated as serious reactions, which include death, hospitalization, disability, and other life-threatening outcomes. A number of older and newer generation ASMs were associated with DILI, specifically: carbamazepine (ROR 2.92), phenobarbital (ROR 2.91), oxcarbazepine (ROR 2.58), phenytoin (ROR 2.40), valproate (ROR 2.22), lamotrigine (ROR 2.06), clobazam (ROR 1.67), levetiracetam (ROR 1.56), and diazepam (ROR 1.53). However, increased odds of DILI were not seen with zonisamide, perampanel, stiripentol, lacosamide, clonazepam, pregabalin, felbamate, eslicarbazepine, cannabidiol, topiramate, gabapentin, ethosuximide, brivaracetam, or primidone. Vigabatrin, tiagabine, and rufinamide all had zero reports of DILI.

CONCLUSIONS

The majority of newer generation ASMs were not significantly associated with DILI. Future studies utilizing FAERS in conjunction with other data sources will be critical for the ongoing surveillance of DILI, particularly as newly marketed ASMs continue to enter into widespread clinical use.

Drug-drug interactions between COVID-19 treatments and antipsychotics drugs: integrated evidence from 4 databases and a systematic review

RATIONALE

Management of anxiety, delirium, and agitation cannot be neglected in coronavirus disease (COVID-19). Antipsychotics are usually used for the pharmacological management of delirium, and confusion and behavioral disturbances. The concurrent use of treatments for COVID-19 and antipsychotics should consider eventual drug-drug interactions OBJECTIVE: To systematically review evidence-based available on drug-drug interactions between COVID-19 treatments and antipsychotics.

EVIDENCE REVIEW

Three databases were consulted: Lexicomp® Drug Interactions, Micromedex® Solutions Drugs Interactions, and Liverpool© Drug Interaction Group for COVID-19 therapies. To acquire more information on QT prolongation and Torsade de Pointes (TdP), the CredibleMeds® QTDrugs List was searched. The authors made a recommendation agreed to by consensus. Additionally, a systematic review of drug-drug interactions between antipsychotics and COVID-19 treatment was conducted.

RESULTS

The main interactions between COVID-19 drugs and antipsychotics are the risk of QT-prolongation and TdP, and cytochromes P450 interactions. Remdesivir, baricinitib, and anakinra can be used concomitantly with antipsychotics without risk of drug-drug interaction (except for hematological risk with clozapine and baricinitib). Favipiravir only needs caution with chlorpromazine and quetiapine. Tocilizumab is rather safe to use in combination with antipsychotics. The most demanding COVID-19 treatments for coadministration with antipsychotics are chloroquine, hydroxychloroquine, azithromycin, and lopinavir/ritonavir because of the risk of QT prolongation and TdP and cytochromes interactions. The systematic review provides highly probable drug interaction between lopinavir/ritonavir plus quetiapine and ritonavir/indinavir plus risperidone.

CONCLUSIONS

Clinicians prescribing antipsychotics should be aware of the likely risk of drug-drug interaction with COVID-19 medication and may benefit from taking into account present recommendations of use to preserve patient safety.

Inhibitory Effects of Antipsychotics on the Contractile Response to Acetylcholine in Rat Urinary Bladder Smooth Muscles

The clinical applications of antipsychotics for symptoms unrelated to schizophrenia, such as behavioral and psychological symptoms, in patients with Alzheimer's disease, and the likelihood of doctors prescribing antipsychotics for elderly people are increasing. In elderly people, drug-induced and aging-associated urinary disorders are likely to occur. The most significant factor causing drug-induced urinary disorders is a decrease in urinary bladder smooth muscle (UBSM) contraction induced by the anticholinergic action of therapeutics. However, the anticholinergic action-associated inhibitory effects of antipsychotics on UBSM contraction have not been sufficiently assessed. In this study, we examined 26 clinically available antipsychotics to determine the extent to which they inhibit acetylcholine (ACh)-induced contraction in rat UBSM to predict the drugs that should not be used by elderly people to avoid urinary disorders. Of the 26 antipsychotics, six (chlorpromazine, levomepromazine (phenothiazines), zotepine (a thiepine), olanzapine, quetiapine, clozapine (multi-acting receptor targeted antipsychotics (MARTAs))) competitively inhibited ACh-induced contractions at concentrations corresponding to clinically significant doses. Further, 11 antipsychotics (perphenazine, fluphenazine, prochlorperazine (phenothiazines), haloperidol, bromperidol, timiperone, spiperone (butyrophenones), pimozide (a diphenylbutylpiperidine), perospirone, blonanserin (serotonin-dopamine antagonists; SDAs), and asenapine (a MARTA)) significantly suppressed ACh-induced contraction; however, suppression occurred at concentrations substantially exceeding clinically achievable blood levels. The remaining nine antipsychotics (pipamperone (a butyrophenone), sulpiride, sultopride, tiapride, nemonapride (benzamides), risperidone, paliperidone (SDAs), aripiprazole, and brexpiprazole (dopamine partial agonists)) did not inhibit ACh-induced contractions at concentrations up to 10-5 M. These findings suggest that chlorpromazine, levomepromazine, zotepine, olanzapine, quetiapine, and clozapine should be avoided by elderly people with urinary disorders.

A Rational Use of Clozapine Based on Adverse Drug Reactions, Pharmacokinetics, and Clinical Pharmacopsychology

Using Richardson and Davidson's model and the sciences of pharmacokinetics and clinical pharmacopsychology, this article reviewed the: (1) poor life expectancy associated with treatment-resistant schizophrenia (TRS), which may be improved in patients who adhere to clozapine; (2) findings that clozapine is the best treatment for TRS (according to efficacy, effectiveness and well-being); and (3) potential for clozapine to cause vulnerabilities, including potentially lethal adverse drug reactions such as agranulocytosis, pneumonia, and myocarditis. Rational use requires: (1) modification of the clozapine package insert worldwide to include lower doses for Asians and to avoid the lethality associated with pneumonia, (2) the use of clozapine levels for personalizing dosing, and (3) the use of slow and personalized titration. This may make clozapine as safe as possible and contribute to increased life expectancy and well-being. In the absence of data on COVID-19 in clozapine patients, clozapine possibly impairs immunological mechanisms and may increase pneumonia risk in infected patients. Psychiatrists should call their clozapine patients and families and explain to them that if the patient develops fever or flu-like symptoms, the psychiatrist should be called and should consider halving the clozapine dose. If the patient is hospitalized with pneumonia, the treating physician needs to assess for symptoms of clozapine intoxication since halving the dose may not be enough for all patients; consider decreasing it to one-third or even stopping it. Once the signs of inflammation and fever have disappeared, the clozapine dose can be slowly increased to the prior dosage level.

Antipsychotics and cardiovascular risk: A case/non-case study

Severe mental disorders have been reported to be associated with an increased cardiovascular risk. To measure the potential risk excess as compared, not with the baseline cardiovascular risk for the general population, but with the cardiovascular risk associated with drug iatrogenia. 197 reported cases of cardiovascular adverse reaction to antipsychotic drugs as compared to the reported cases of this type of adverse reactions to drugs other than antipsychotics entered in the Spanish Pharmacovigilance System database (FEDRA) (1995-2018) in an observational case/non-case study. Risk estimates of association were reporting odds ratio (ROR), and, chi-square test (χ²). Overall disproportionality for the whole drug class was found [ROR 2.3 (95% CI 2.0-2.7)], χ² = 127.07]. When the two types of antipsychotics (typical and atypical) were analysed separately, we also found statistically significant disproportionality, and this disproportionality is similar between both groups, with disproportionality measures around 2.30, with the confidence intervals not including the 1. The disproportionality observed suggests a risk excess that might be greater than expected, which holds particularly true for torsade de pointes, sudden death and cardiac arrhythmias in patients treated with any of the two types of antipsychotics. There was no significant risk for ischaemic heart disease.

Haloperidol affects coupling between QT and RR intervals in guinea pig isolated heart

Prolonged QT interval is an independent risk factor for development of ventricular arrhythmias. Haloperidol is one of the drugs inducing QT prolongation. Previous studies showed that haloperidol affects not only QT duration but also heart rate (RR interval). The present work focused on relationship between QT and RR and its changes under acute and chronic haloperidol administration. The study included 14 male guinea pigs divided into control and haloperidol-treated group. After 21-days administration of haloperidol or vehiculum, electrograms in isolated hearts were recorded. QT/RR and dQT/dRR coupling were calculated. Chronic haloperidol administration significantly decreases the coupling between QT and RR. Acute haloperidol exposure significantly decreases the dQT/dRR coupling in both treated and untreated guinea pig hearts. Flatter QT/RR relationship reveals a lack of QT adaptation to increased heart rate. It should be emphasized that in such situation ECG recording will not show significant QT prolongation evaluated according to clinical rules. However, if QT interval does not adapt to increased heart rate sufficiently, the risk of ventricular arrhythmias may be increased despite practically normal QT interval length. The results are supported by findings in biochemical analyses, which proved eligibility of the used model.

Cardiovascular Risks of Fluphenazine in a Patient With Schizophrenia

Objective: Patients with psychiatric illnesses are at an increased risk for heart disease, and many antipsychotic medications elicit adverse effects on the heart. This report summarizes conduction abnormalities manifested as chest pain when a patient is treated with fluphenazine decanoate. Case Summary: A 61-year-old male with a history of schizophrenia, coronary artery disease, and atrial fibrillation presented complaining of chest pain and shortness of breath with moderate T-wave abnormality detected on electrocardiogram. The patient recently initiated fluphenazine decanoate intramuscular injection while continuing oral fluphenazine as directed. Discussion: Utilizing the Naranjo algorithm, the cardiac conduction abnormality was determined to be a possible adverse event associated with fluphenazine use. This was based on recent initiation and increasing dose of fluphenazine and documented association of antipsychotics and risk of Torsades de Pointes. Conclusions: While it is known that fluphenazine decanoate can cause extrapyramidal adverse effects, this case demonstrates that it may also play a role in causing or exacerbating cardiovascular adverse events. Continued cardiovascular monitoring after starting fluphenazine decanoate is warranted.

Drug-induced life-threatening arrhythmias and sudden cardiac death: A clinical perspective of long QT, short QT and Brugada syndromes

Sudden cardiac death is a major public health challenge, which can be caused by genetic or acquired structural or electrophysiological abnormalities. These abnormalities include hereditary channelopathies: long QT, short QT and Brugada syndromes. These syndromes are a notable concern, particularly in young people, due to their high propensity for severe ventricular arrhythmias and sudden cardiac death. Current evidence suggests the involvement of an increasing number of drugs in acquired forms of long QT and Brugada syndromes. However, drug-induced short QT syndrome is still a rarely reported condition. Therefore, there has been speculation on its clinical significance, since few fatal arrhythmias and sudden cardiac death cases have been described so far. Drug-induced proarrhythmia is a growing challenge for physicians, regulatory agencies and the pharmaceutical industry. Physicians should weigh the risks of potentially fatal outcomes against the therapeutic benefits, when making decisions about drug prescriptions. Growing concerns about its safety and the need for more accurate predictive models for drug-induced fatal outcomes justify further research in these fields. The aim of this article is to comprehensively and critically review the recently published evidence with regard to drug-induced life-threatening arrhythmias and sudden cardiac death. This article will take into account the provision of data to physicians that are useful in the identification of the culprit drugs, and thus, contribute to the prompt recognition and management of these serious clinical conditions.

Effects of atypical antipsychotic drugs on QT interval in patients with mental disorders

Background

Drug-induced QT prolongation is associated with higher risk of cardiac arrhythmias and cardiovascular mortality. We investigated the effects of atypical antipsychotic drugs on QT interval in children and adults with mental disorders.

Methods

We conducted random-effects direct frequentist meta-analyses of aggregate data from randomized controlled trials (RCT) and appraised the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Our search in PubMed, EMBASE, the Cochrane Library, clinicaltrials.gov, and PharmaPendium up to October 2017 identified studies that examined aripiprazole, quetiapine, risperidone, olanzapine, ziprasidone and brexpiprazole.

Results

Low quality evidence suggests that aripiprazole (four meta-analyses and twelve RCTs), brexpiprazole (one systematic review and four RCTs) or olanzapine (five meta-analyses and twenty RCTs) do not increase QT interval. Low quality evidence suggests that ziprasidone (five meta-analyses and 11 RCTs) increases QT interval and the rates of QT prolongation while risperidone (four meta-analyses, 70 RCTs) and quetiapine (two meta-analyses and seven RCTs) are associated with QT prolongation and greater odds of torsades de pointes ventricular tachycardia especially in cases of drug overdose.

Conclusions

The main conclusion of our study is that in people with mental disorders and under treatment with atypical antipsychotic drugs, in order to avoid QT prolongation and reduce the risk of ventricular tachycardia clinicians may recommend aripiprazole, brexpiprazole or olanzapine in licensed doses. Long-term comparative safety needs to be established.

International trends in antipsychotic use: A study in 16 countries, 2005-2014

The objective of this study was to assess international trends in antipsychotic use, using a standardised methodology. A repeated cross-sectional design was applied to data extracts from the years 2005 to 2014 from 16 countries worldwide. During the study period, the overall prevalence of antipsychotic use increased in 10 of the 16 studied countries. In 2014, the overall prevalence of antipsychotic use was highest in Taiwan (78.2/1000 persons), and lowest in Colombia (3.2/1000). In children and adolescents (0-19 years), antipsychotic use ranged from 0.5/1000 (Lithuania) to 30.8/1000 (Taiwan). In adults (20-64 years), the range was 2.8/1000 (Colombia) to 78.9/1000 (publicly insured US population), and in older adults (65+ years), antipsychotic use ranged from 19.0/1000 (Colombia) to 149.0/1000 (Taiwan). Atypical antipsychotic use increased in all populations (range of atypical/typical ratio: 0.7 (Taiwan) to 6.1 (New Zealand, Australia)). Quetiapine, risperidone, and olanzapine were most frequently prescribed. Prevalence and patterns of antipsychotic use varied markedly between countries. In the majority of populations, antipsychotic utilisation and especially the use of atypical antipsychotics increased over time. The high rates of antipsychotic prescriptions in older adults and in youths in some countries merit further investigation and systematic pharmacoepidemiologic monitoring.

Pharmacokinetic considerations in antipsychotic augmentation strategies: How to combine risperidone with low-potency antipsychotics

OBJECTIVES

To investigate in vivo the effect of low-potency antipsychotics on metabolism of risperidone (RIS).

METHODS

A therapeutic drug monitoring database containing plasma concentrations of RIS and its metabolite 9-OH-RIS of 1584 patients was analyzed. Five groups were compared; a risperidone group (n=842) and four co- medication groups; a group co-medicated with chlorprothixene (n=67), a group with levomepromazine (n=32), a group with melperone (n=46), a group with pipamperone (n=63) and a group with prothipendyl (n=24). Plasma concentrations, dose-adjusted plasma concentrations (C/D) of RIS, 9-OH-RIS and active moiety (RIS+9-OH-RIS; AM) as well as the metabolic ratios (9-OH-RIS/RIS; MR) were computed.

RESULTS

Differences in plasma concentrations were detected for AM and RIS. Pairwise comparisons revealed significant findings; RIS plasma concentrations were higher in co-medication groups than in monotherapy group. Chlorprothixene- and prothipendyl- medicated patients demonstrated no other differences. In the levomepromazine and melperone group plasma and C/D concentrations of AM and RIS were higher, while MRs were lower. For pipamperone, differences included higher C/D values of RIS and lower MRs.

CONCLUSIONS

Alterations of risperidone metabolism suggest pharmacokinetic interactions for levomepromazine and melperone. In the pipamperone-group, lower MRs as well as higher plasma and C/D levels of RIS suggest potential interactions.

The Contribution of National Spontaneous Reporting Systems to Detect Signals of Torsadogenicity: Issues Emerging from the ARITMO Project

Introduction

Spontaneous reporting systems (SRSs) are pivotal for signal detection, especially for rare events with a high drug-attributable component, such as torsade de pointes (TdP). Use of different national SRSs is rarely attempted because of inherent difficulties, but should be considered on the assumption that rare events are diluted in international databases.

Objective

The aim was to describe TdP-related events associated with antipsychotics, H₁-antihistamines and anti-infectives in three national SRSs (in Italy, Germany and France) and highlight potential signals of torsadogenicity through a combined literature evaluation.

Methods

A common search strategy was applied to extract TdP-related events: (1) TdP, (2) QT interval abnormalities, (3) ventricular fibrillation/tachycardia, and (4) sudden cardiac death. Signals of disproportionate reporting (SDRs) were calculated for TdP + QT interval abnormalities and defined by a lower limit of the 95 % confidence interval of the reporting odds ratio (ROR) >1. Among SDRs with at least three cases without concomitant pro-arrhythmic drugs, we defined potential new signal of torsadogenicity as drugs with no published evidence from (a) the crediblemeds^® website (http://www.crediblemeds.com, as of November 1st, 2014); (b) studies on the FDA Adverse Event Reporting System (FAERS); and (c) safety trials or pharmaco-epidemiological studies (as of December 16th, 2014).

Results

Overall, 3505 cases were retrieved (1372, 1468, and 801 for France, Germany and Italy, respectively). Antipsychotics were mainly recorded in Germany (792 cases), whereas antibiotics peaked at 515 and 491 (France and Italy, respectively). Forty-one drugs met criteria for SDRs in at least one single source, of which 31 were detected only from one single SRS: 18, ten and three (French, German and Italian SRS, respectively). By contrast, only five SDRs were detected in all national data sources (amisulpride, aripiprazole, haloperidol, olanzapine, risperidone). Overall, five potential new signals of torsadogenicity were identified: flupentixol, ganciclovir, levocetirizine, oxatomide and tiapride.

Conclusions

We found differences across and within national SRSs in the reporting of drug-induced TdP, which finally resulted in five potential new signals of torsadogenicity. These findings warrant targeted pharmacovigilance studies to formally assess the existence of actual drug–event associations.

Electronic supplementary material

The online version of this article (doi:10.1007/s40264-015-0353-1) contains supplementary material, which is available to authorized users.

Time-to-Onset Analysis of Drug-Induced Long QT Syndrome Based on a Spontaneous Reporting System for Adverse Drug Events

Long QT syndrome (LQTS) is a disorder of the heart’s electrical activity that infrequently causes severe ventricular arrhythmias such as a type of ventricular tachycardia called torsade de pointes (TdP) and ventricular fibrillation, which can be fatal. There have been no previous reports on the time-to-onset for LQTS based on data from spontaneous reporting systems. The aim of this study was to assess the time-to-onset of LQTS according to drug treatment. We analyzed the association between 113 drugs in 37 therapeutic categories and LQTS including TdP using data obtained from the Japanese Adverse Drug Event Report database. For signal detection, we used the reporting odds ratio (ROR). Furthermore, we analyzed the time-to-onset data and assessed the hazard type using the Weibull shape parameter. The RORs (95% confidence interval) for bepridil, amiodarone, pilsicainide, nilotinib, disopyramide, arsenic trioxide, clarithromycin, cibenzoline, donepezil, famotidine, sulpiride, and nifekalant were 174.4 (148.6–204.6), 17.3 (14.7–20.4), 52.0 (43.4–62.4), 13.9 (11.5–16.7), 69.3 (55.3–86.8), 54.2 (43.2–68.0), 4.7 (3.8–5.8), 19.9 (15.9–25.0), 8.1 (6.5–10.1), 3.2 (2.5–4.1), 7.1 (5.5–9.2), and 254.8 (168.5–385.4), respectively. The medians and quartiles of time-to-onset for aprindine (oral) and bepridil were 20.0 (11.0–35.8) and 18.0 (6.0–43.0) days, respectively. The lower 95% confidence interval of the shape parameter β of bepridil was over 1 and the hazard was considered to increase over time.Our study indicated that the pattern of LQTS onset might differ among drugs. Based on these results, careful long-term observation is recommended, especially for specific drugs such as bepridil and aprindine. This information may be useful for the prevention of sudden death following LQTS and for efficient therapeutic planning.

Mortality Rates in Users of Typical and Atypical Antipsychotics: A Database Study in Poland

Background

The role of antipsychotics in influencing mortality of patients with mental disorders is still unexplained.

Objective

The aim of this study was to determine mortality rates of patients treated with atypical and typical antipsychotics and to compare these data with the mortality rates for the general population.

Methods

The study was based on the 2008–2012 prescription drug reimbursement data from the Polish National Health Fund in Gdansk and mortality data from the death registry. Age-standardized death rates (SDRs) and 95 % confidence intervals (CIs) were calculated for individuals prescribed solely atypical or typical antipsychotics, patients prescribed both atypical and typical antipsychotics, and patients prescribed clozapine.

Results

Between 2008 and 2012, typical and/or atypical antipsychotics and clozapine were prescribed to a total of 81,313 patients. The SDR for typical antipsychotic users (69.6 per 1000, 95 % CI 67.64–71.56) was higher than for those treated with both typical and atypical antipsychotics (53.25 per 1000, 95 % CI 50.8–55.69) or clozapine (65.11 per 1000, 95 % CI 58.63–71.58). The lowest mortality was documented in the case of patients treated exclusively with atypical antipsychotics (SDR = 48.38 per 1000, 95 % CI, 44.78–51.98). The SDRs for patients treated with antipsychotics were more than tenfold higher than the respective SDRs for the general population in 2008, but later in 2012, the differences dropped to threefold.

Conclusion

Although the study was based on administrative record linkage and therefore could not be adjusted for potential confounders, its results suggest that mortality in atypical antipsychotic users is lower than in typical antipsychotic users.

Prescribing pattern of antipsychotic drugs during the years 1996-2010: a population-based database study in Europe with a focus on torsadogenic drugs

INTRODUCTION

Antipsychotic drugs (APDs) are used to treat several mental illnesses. Some APDs have long been known to be associated with QT prolongation, potentially leading to torsades de pointes (TdP) and sudden cardiac death (SCD). In 2005, thioridazine was withdrawn because of the risk of SCD, bringing further attention to the arrhythmogenic potential of APDs.

AIM

The aim of the current study was to evaluate the use of APDs in five European countries during the years 1996-2010.

METHODS

A cohort study was conducted using prescription/dispensing data from seven healthcare databases [the AARHUS University Hospital Database (Denmark), the German Pharmacoepidemiological Research Database (GePaRD) (Germany), Health Search Database/Thales (HSD) and Emilia Romagna Regional Database (ERD) (Italy), PHARMO Database Network and Integrated Primary Care Information (IPCI) (the Netherlands) and The Health Improvement Network (THIN) (the UK), covering a population of 27 million individuals. The annual prescription rate of APDs was measured overall and for individual medications. APDs were classified as torsadogenic according to the Arizona-CERT list. All analyses were stratified by age, gender and calendar year.

RESULTS

A total of 559 276 person-years (PYs) of exposure to APDs was captured. The crude annual prescription rate of APD use ranged from 3.0/1000 PYs in ERD to 7.7/1000 PYs in AARHUS. Among APDs with established torsadogenic potential, thioridazine was the most frequently used medication in the UK. Haloperidol was commonly prescribed in Italy and the Netherlands. The use of APDs with torsadogenic potential was much higher in elderly patients.

CONCLUSIONS

Substantial use of APDs with torsadogenic potential has been reported in Europe in recent years, in spite of increasing concerns about their arrhythmogenic potential. This use was even greater in elderly patients, who are at higher risk of SCD.

The cardiac safety of aripiprazole treatment in patients at high risk for torsade: a systematic review with a meta-analytic approach

RATIONALE

Certain antipsychotics increase the risk of heart rate-corrected QT (QTc) prolongation and consequently Torsades de Pointes (TdP) and sudden cardiac death (SCD). Drug-induced Brugada syndrome (BrS) is also associated with SCD. Most SCDs occur in patients with additional cardiac risk factors.

OBJECTIVES

Aripiprazole's cardiac safety has not been assessed in patients at high risk for torsade, where QTc prolongation risk is highly increased.

METHODS

MEDLINE, Embase, and The Cochrane Library were searched for preclinical, clinical, and epidemiological studies. Eligible studies were reviewed and cardiac safety data were extracted. Continuous and dichotomous QTc data were used in the meta-analysis.

RESULTS

Preclinical studies suggested that aripiprazole has limited affinity for the delayed rectifier potassium current. TdP was reported in two case reports and SCD was reported in one case report and one case series. No clinical studies assessing aripiprazole's cardiac safety in patients at high risk for torsade were found. No thorough QT (TQT) study with aripiprazole was found. The meta-analysis revealed that the mean ΔQTc interval was decreased with aripiprazole and QTc prolongation risk was lower compared with placebo and active controls. Epidemiological studies linked aripiprazole to weak/moderate torsadogenicity. No studies were found associating aripiprazole with BrS suggesting low affinity for the fast sodium current.

CONCLUSIONS

Aripiprazole is a low-risk antipsychotic regarding cardiac safety in healthy patients. However, baseline and steady state electrocardiogram is recommended in patients at high risk for torsade due to marked QTc prolongation, absence of a TQT study, and lack of data in this group.

Concomitant use of two or more antipsychotic drugs is common in Sweden

OBJECTIVES

To assess the prevalence of concomitant use of two or more antipsychotic drugs and other psychotropic drugs in the Swedish population.

METHODS

Data for this observational cohort study were collected from the Swedish Prescribed Drug Register including all dispensed drugs to the entire Swedish population (9.4 million inhabitants). We identified all individuals with at least one dispensed prescription of antipsychotic drug during January to June 2008. After 12 months, a second exposure period was chosen. Individuals who were dispensed two or more antipsychotic drugs in both periods were considered long-time users of antipsychotic polypharmacy.

RESULTS

In 2008, 1.5% of the Swedish population was dispensed antipsychotic drugs, the majority (75%) using only one antipsychotic drug. Out of individuals who were dispensed 2 or more antipsychotic drugs during the first period, 62% also was also dispensed at least 2 antipsychotic drugs during the second period. A total of 665 different unique combinations were used in 2008. Individuals prescribed two or more antipsychotic drugs during both periods were more often dispensed anxiolytics and sedatives than those who were dispensed only one antipsychotic drug. Elderly were dispensed antipsychotic drugs much more often than younger persons.

CONCLUSIONS

In Sweden, 25% of patients dispensed antipsychotic drugs receive a combination of two or more antipsychotic drugs. Individuals who are dispensed antipsychotic polypharmacy are more often dispensed anxiolytics and sedatives than those prescribed only one antipsychotic drug. Long-term observational studies are needed to assess the efficacy and safety of such combinations.

Effects of antipsychotics, antidepressants and mood stabilizers on risk for physical diseases in people with schizophrenia, depression and bipolar disorder

People with severe mental illness have a considerably shorter lifespan than the general population. This excess mortality is mainly due to physical illness. Next to mental illness-related factors, unhealthy lifestyle, and disparities in health care access and utilization, psychotropic medications can contribute to the risk of physical morbidity and mortality. We systematically reviewed the effects of antipsychotics, antidepressants and mood stabilizers on physical health outcomes in people with schizophrenia, depression and bipolar disorder. Updating and expanding our prior systematic review published in this journal, we searched MEDLINE (November 2009 - November 2014), combining the MeSH terms of major physical disease categories (and/or relevant diseases within these categories) with schizophrenia, major depressive disorder and bipolar disorder, and the three major psychotropic classes which received regulatory approval for these disorders, i.e., antipsychotics, antidepressants and mood stabilizers. We gave precedence to results from (systematic) reviews and meta-analyses wherever possible. Antipsychotics, and to a more restricted degree antidepressants and mood stabilizers, are associated with an increased risk for several physical diseases, including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, hyponatremia; cardiovascular, respiratory tract, gastrointestinal, haematological, musculoskeletal and renal diseases, as well as movement and seizure disorders. Higher dosages, polypharmacy, and treatment of vulnerable (e.g., old or young) individuals are associated with greater absolute (elderly) and relative (youth) risk for most of these physical diseases. To what degree medication-specific and patient-specific risk factors interact, and how adverse outcomes can be minimized, allowing patients to derive maximum benefits from these medications, requires adequate clinical attention and further research.

Pro-arrhythmic potential of oral antihistamines (H1): combining adverse event reports with drug utilization data across Europe

Background

There is appreciable utilisation of antihistamines (H₁) in European countries, either prescribed by physician and purchased by patients for self-medication. Terfenadine and astemizole underwent regulatory restrictions in ’90 because of their cardiac toxicity, but only scarce clinical data are available on other antihistamines.

Aim

To investigate the pro-arrhythmic potential of antihistamines by combining safety reports of the FDA Adverse Event Reporting System (FAERS) with drug utilization data from 13 European Countries.

Methods

We identified signals of antihistamine arrhythmogenic potential by analyzing FAERS database for all cases of Torsades de Pointes (TdP), QT abnormalities (QTabn), ventricular arrhythmia (VA) and sudden cardiac death/cardiac arrest (SCD/CA). Number of cases ≥3 and disproportionality were used to define alert signals: TdP and QTabn identified stronger signals, whereas SCD/CA identified weaker signals. Drug utilization data from 2005 to 2010 were collected from administrative databases through health authorities and insurance.

Results

Antihistamines were reported in 109 cases of TdP/QT prolongation, 278 VA and 610 SCD/CA. Five agents resulted in stronger signals (cetirizine, desloratadine, diphenhydramine, fexofenadine, loratadine) and 6 in weaker signals (alimemazine, carbinoxamine, cyclizine, cyproeptadine, dexchlorpheniramine and doxylamine). Exposure to antihistamines with stronger signal was markedly different across European countries and was at least 40% in each Country. Cetirizine was >29 Defined Daily Doses per 1000 inhabitants per day (DID) in Norway, desloratadine >11 DID in France and loratadine >9 DID in Sweden and Croatia. Drugs with weaker signals accounted for no more than 10% (in Sweden) and in most European countries their use was negligible.

Conclusions

Some second-generation antihistamines are associated with signal of torsadogenicity and largely used in most European countries. Although confirmation by analytical studies is required, regulators and clinicians should consider risk-minimisation activities. Also antihistamines without signal but with peculiar use in a few Countries (e.g., levocetirizine) or with increasing consumption (e.g., rupatadine) deserve careful surveillance.

Antipsychotic drugs and the risk of ventricular arrhythmia and/or sudden cardiac death: a nation-wide case-crossover study

BACKGROUND

Antipsychotics have been linked to prolongation of the QT interval. However, little is known about the risk of ventricular arrhythmia (VA) and/or sudden cardiac death (SCD) associated with individual antipsychotic drug use. This study was designed to investigate the association between specific antipsychotic drugs and the risk of VA and/or SCD.

METHODS AND RESULTS

We conducted a case-crossover study using a nation-wide population-based sample obtained from Taiwan's National Health Insurance Research Database. A total of 17 718 patients with incident VA and/or SCD were enrolled. Conditional logistic regression models were applied to examine the effects of antipsychotic drug use on the risk of VA/SCD during various case and control time windows of 7, 14, and 28 days. The effect of the potency of a human ether-à-go-go-related gene (hERG) potassium channel blockade was also assessed. Antipsychotic drug use was associated with a 1.53-fold increased risk of VA and/or SCD. Antipsychotic drugs with increased risk included clothiapine, haloperidol, prochlorperazine, thioridazine, olanzapine, quetiapine, risperidone, and sulpiride. The association was significantly higher among those with short-term use. Antipsychotics with a high potency of the hERG potassium channel blockade had the highest risk of VA and/or SCD.

CONCLUSION

Use of antipsychotic drugs is associated with an increased risk of VA and/or SCD. Careful evaluations of the risks and benefits of antipsychotic treatment are highly recommended.

Antipsychotics, mood stabilisers, and risk of violent crime

BACKGROUND

Antipsychotics and mood stabilisers are prescribed widely to patients with psychiatric disorders worldwide. Despite clear evidence for their efficacy in relapse prevention and symptom relief, their effect on some adverse outcomes, including the perpetration of violent crime, is unclear. We aimed to establish the effect of antipsychotics and mood stabilisers on the rate of violent crime committed by patients with psychiatric disorders in Sweden.

METHODS

We used linked Swedish national registers to study 82,647 patients who were prescribed antipsychotics or mood stabilisers, their psychiatric diagnoses, and subsequent criminal convictions in 2006-09. We did within-individual analyses to compare the rate of violent criminality during the time that patients were prescribed these medications versus the rate for the same patients while they were not receiving the drugs to adjust for all confounders that remained constant within each participant during follow-up. The primary outcome was the occurrence of violent crime, according to Sweden's national crime register.

FINDINGS

In 2006-09, 40,937 men in Sweden were prescribed antipsychotics or mood stabilisers, of whom 2657 (6·5%) were convicted of a violent crime during the study period. In the same period, 41,710 women were prescribed these drugs, of whom 604 (1·4 %) had convictions for violent crime. Compared with periods when participants were not on medication, violent crime fell by 45% in patients receiving antipsychotics (hazard ratio [HR] 0·55, 95% CI 0·47-0·64) and by 24% in patients prescribed mood stabilisers (0·76, 0·62-0·93). However, we identified potentially important differences by diagnosis-mood stabilisers were associated with a reduced rate of violent crime only in patients with bipolar disorder. The rate of violence reduction for antipsychotics remained between 22% and 29% in sensitivity analyses that used different outcomes (any crime, drug-related crime, less severe crime, and violent arrest), and was stronger in patients who were prescribed higher drug doses than in those prescribed low doses. Notable reductions in violent crime were also recorded for depot medication (HR adjusted for concomitant oral medications 0·60, 95% CI 0·39-0·92).

INTERPRETATION

In addition to relapse prevention and psychiatric symptom relief, the benefits of antipsychotics and mood stabilisers might also include reductions in the rates of violent crime. The potential effects of these drugs on violence and crime should be taken into account when treatment options for patients with psychiatric disorders are being considered.

FUNDING

The Wellcome Trust, the Swedish Prison and Probation Service, the Swedish Research Council, and the Swedish Research Council for Health, Working Life and Welfare.

Assessing liver injury associated with antimycotics: Concise literature review and clues from data mining of the FAERS database

AIM: To inform clinicians on the level of hepatotoxic risk among antimycotics in the post-marketing setting, following the marketing suspension of oral ketoconazole for drug-induced liver injury (DILI).

METHODS: The publicly available international FAERS database (2004-2011) was used to extract DILI cases (including acute liver failure events), where antimycotics with systemic use or potential systemic absorption were reported as suspect or interacting agents. The reporting pattern was analyzed by calculating the reporting odds ratio and corresponding 95%CI, a measure of disproportionality, with time-trend analysis where appropriate.

RESULTS: From 1687284 reports submitted over the 8-year period, 68115 regarded liver injury. Of these, 2.9% are related to antimycotics (1964 cases, of which 112 of acute liver failure). Eleven systemic antimycotics (including ketoconazole and the newer triazole derivatives voriconazole and posaconazole) and terbinafine (used systemically to treat onychomicosis) generated a significant disproportionality, indicating a post-marketing signal of risk.

CONCLUSION: Virtually all antimycotics with systemic action or absorption are commonly reported in clinically significant cases of DILI. Clinicians must be aware of this aspect and monitor patients in case switch is considered, especially in critical poly-treated patients under chronic treatment.

Assessing liver injury associated with antimycotics: Concise literature review and clues from data mining of the FAERS database

AIM

To inform clinicians on the level of hepatotoxic risk among antimycotics in the post-marketing setting, following the marketing suspension of oral ketoconazole for drug-induced liver injury (DILI).

METHODS

The publicly available international FAERS database (2004-2011) was used to extract DILI cases (including acute liver failure events), where antimycotics with systemic use or potential systemic absorption were reported as suspect or interacting agents. The reporting pattern was analyzed by calculating the reporting odds ratio and corresponding 95%CI, a measure of disproportionality, with time-trend analysis where appropriate.

RESULTS

From 1687284 reports submitted over the 8-year period, 68115 regarded liver injury. Of these, 2.9% are related to antimycotics (1964 cases, of which 112 of acute liver failure). Eleven systemic antimycotics (including ketoconazole and the newer triazole derivatives voriconazole and posaconazole) and terbinafine (used systemically to treat onychomicosis) generated a significant disproportionality, indicating a post-marketing signal of risk.

CONCLUSION

Virtually all antimycotics with systemic action or absorption are commonly reported in clinically significant cases of DILI. Clinicians must be aware of this aspect and monitor patients in case switch is considered, especially in critical poly-treated patients under chronic treatment.

Can authorities appreciably enhance the prescribing of oral generic risperidone to conserve resources? Findings from across Europe and their implications

BACKGROUND

Generic atypical antipsychotic drugs offer health authorities opportunities for considerable savings. However, schizophrenia and bipolar disorders are complex diseases that require tailored treatments. Consequently, generally there have been limited demand-side measures by health authorities to encourage the preferential prescribing of generics. This is unlike the situation with hypertension, hypercholaesterolaemia or acid-related stomach disorders.The objectives of this study were to compare the effect of the limited demand-side measures in Western European countries and regions on the subsequent prescribing of risperidone following generics; to utilise the findings to provide future guidance to health authorities; and where possible, to investigate the utilisation of generic versus originator risperidone and the prices for generic risperidone.

METHODS

Principally, this was a segmented regression analysis of retrospective time-series data of the effect of the various initiatives in Belgium, Ireland, Scotland and Sweden following the introduction of generic risperidone. The study included patients prescribed at least one atypical antipsychotic drug up to 20 months before and up to 20 months after generic risperidone. In addition, retrospective observational studies were carried out in Austria and Spain (Catalonia) from 2005 to 2011 as well as one English primary care organisation (Bury Primary Care Trust (PCT)).

RESULTS

There was a consistent steady reduction in risperidone as a percentage of total selected atypical antipsychotic utilisation following generics. A similar pattern was seen in Austria and Spain, with stable utilisation in one English PCT. However, there was considerable variation in the utilisation of generic risperidone, ranging from 98% of total risperidone in Scotland to only 14% in Ireland. Similarly, the price of generic risperidone varied considerably. In Scotland, generic risperidone was only 16% of pre-patent loss prices versus 72% in Ireland.

CONCLUSION

Consistent findings of no increased prescribing of risperidone post generics with limited specific demand-side measures suggests no 'spillover' effect from one class to another encouraging the preferential prescribing of generic atypical antipsychotic drugs. This is exacerbated by the complexity of the disease area and differences in the side-effects between treatments. There appeared to be no clinical issues with generic risperidone, and prices inversely reflected measures to enhance their utilisation.

Cost-effectiveness of asenapine in the treatment of schizophrenia in Canada

OBJECTIVE

Asenapine is the first tetracyclic antipsychotic approved in Canada for the treatment of schizophrenia (SCZ). Asenapine has shown a comparable efficacy profile to other atypical antipsychotics and it is associated with a favourable metabolic profile and less weight gain. This study aimed to assess the economic impact of asenapine compared to other atypical antipsychotics in the treatment of SCZ in Canada.

METHODS

A decision tree combined with a Markov model was constructed to assess the cost-utility of asenapine compared with other atypical antipsychotics. The decision tree takes into account the occurrence of extrapyramidal symptoms, the probability of switching to a different antipsychotic, and the probability of gaining weight. The Markov model takes into account long-term metabolic complications including diabetes, hypertension, coronary heart diseases, and stroke. In the base-case analysis, asenapine was compared to olanzapine. Asenapine was also compared with other atypical antipsychotics commonly used in Canada in alternative scenarios. Analyses were conducted from both Canadian Ministry of Health (MoH) and societal perspectives over a 5-year time horizon.

RESULTS

In the treatment of SCZ, asenapine is a dominant strategy over olanzapine from both MoH and societal perspectives. Compared to quetiapine, asenapine is also a dominant strategy. Furthermore, asenapine has a favorable economic impact compared to ziprasidone and aripiprazole, as these antipsychotics are not cost-effective compared to asenapine from both MoH and societal perspectives.

CONCLUSION

Despite the short time horizon, the lack of compliance data and the assumptions made, this economic evaluation demonstrates that asenapine is a cost-effective strategy compared to olanzapine and to most of the atypical antipsychotics frequently used in Canada.