Trends in utilization of antiepileptic drugs in Denmark

Indications and prescribing patterns of antiseizure medications in children in New Zealand

AIM

To determine indications and prescribing patterns for antiseizure medications (ASMs) in children by age, sex, and socioeconomic status.

METHOD

This retrospective study searched the New Zealand database of ASM prescriptions dispensed to individuals aged 18 years or under during 2015 in three regions of New Zealand (48% paediatric population). Medical records were reviewed by a paediatric neurologist for indication. ASMs were grouped into old or new (1993 onwards).

RESULTS

In total, 2594 children (0 to 18 years, mean age 11 years 2 months, median 12 years; 51% male) were dispensed 3557 ASMs for seizures (76%), pain (6%), headache (5%), mental health (3%), and movement disorders (2%). After 10 years of age, lamotrigine was more likely and valproate less likely to be prescribed in females than males. No sex difference was observed for valproate prescriptions for non-seizure indications. Topiramate prescriptions increased in adolescent females. Prescriptions for non-seizure indications increased from 7% in children aged 6 years or under to 31% in 16- to 18-year-olds. The proportion of children receiving a new ASM compared to an old ASM was greater in children from higher than lower socioeconomic areas.

INTERPRETATION

Our results highlight a need for focused ASM teratogenicity messaging to clinicians prescribing ASMs for non-seizure indications. In addition, to improve equity of epilepsy care, it is critical for health policies to consider socioeconomic factors that impact on ASM prescribing.

Published population pharmacokinetic models of valproic acid in adult patients: a systematic review and external validation in a Chinese sample of inpatients with bipolar disorder

BACKGROUND

This study reviewed all published valproic acid (VPA) population pharmacokinetic (PPK) models in adult patients and assessed them using external validation methods to determine predictive performance.

METHODS

Thirteen published PPK models (labeled with letters A to M) not restricted to children were identified in PubMed, Embase, and Web of Science databases. They were evaluated in a sample totaling 411 serum concentrations from 146 adult inpatients diagnosed with bipolar disorder in a Chinese hospital. Serum concentrations of VPA were analyzed by validated ultra-performance liquid chromatography-tandem mass spectrometry. Performance was assessed by 4 tests (prediction-based diagnostics, visual predictive checks, normalized prediction distribution error, and Bayesian forecasting).

RESULTS

Models K and L, developed in large samples of Chinese and Thai patients, showed good performance in our Chinese dataset. Models H and J demonstrated good performance in Tests 2 and 3 of the 4 tests, respectively. Another 7 models exhibited intermediate performance. The models with the worst performance, F and M, could not be improved by Bayesian forecasting.

CONCLUSION

In our validation study the most important factors contributing to good performance were absence of children, Asian ethnicity, one-compartment models and inclusion of body weight and VPA dose in previously published models.

Changes in antiepileptic drug prescriptions over a decade in childbearing women in Lombardy region, Italy

AIMS

To describe the antiepileptic drug (AED) prescription pattern in pregnant women and women of childbearing age in the 2010-2019 period in the Lombardy region, Italy.

METHODS

The Lombardy region administrative healthcare databases (2010-2019) were analysed. AEDs were classified as drugs belonging to the N03A subgroup of the Anatomical Therapeutic Chemical Classification System. Women aged 15-49 years were considered as being of childbearing age, while exposure during pregnancy was estimated taking into account the 12 months before delivery (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM codes in the diagnosis record from 650 to 659).

RESULTS

During 2019, 16 605 women of childbearing age (prevalence: 14.8‰) received at least 1 AED prescription. Pregabalin was the most widely used antiepileptic in women of childbearing age (22.3%), followed by valproic acid (20.0%). In 2010, the prevalence of valproic acid prescription to women of childbearing age was 30.2%; in 2019 this was 20.0%. In pregnant women, this prevalence was 24.9% in 2010 and 14.1% in 2019. Starting from 2017, levetiracetam and lamotrigine were the most commonly drugs prescribed to pregnant women.

CONCLUSION

Despite the decrease in valproic acid prescription over time, this drug is still among the most used AEDs, in particular in women of childbearing age. Educational interventions for healthcare professionals and women are needed in order to reduce the risk of unplanned pregnancy.

Social Media Analytics for Pharmacovigilance of Antiepileptic Drugs

Epilepsy is a common neurological disorder worldwide and antiepileptic drug (AED) therapy is the cornerstone of its treatment. It has a laudable aim of achieving seizure freedom with minimal, if any, adverse drug reactions (ADRs). Too often, AED treatment is a long-lasting journey, in which ADRs have a crucial role in its administration. Therefore, from a pharmacovigilance perspective, detecting the ADRs of AEDs is a task of utmost importance. Typically, this task is accomplished by analyzing relevant data from spontaneous reporting systems. Despite their wide adoption for pharmacovigilance activities, the passiveness and high underreporting ratio associated with spontaneous reporting systems have encouraged the consideration of other data sources such as electronic health databases and pharmaceutical databases. Social media is the most recent alternative data source with many promising potentials to overcome the shortcomings of traditional data sources. Although in the literature some attempts have investigated the validity and utility of social media for ADR detection of different groups of drugs, none of them was dedicated to the ADRs of AEDs. Hence, this paper presents a novel investigation of the validity and utility of social media as an alternative data source for the detection of AED ADRs. To this end, a dataset of consumer reviews from two online health communities has been collected. The dataset is preprocessed; the unigram, bigram, and trigram are generated; and the ADRs of each AED are extracted with the aid of consumer health vocabulary and ADR lexicon. Three widely used measures, namely, proportional reporting ratio, reporting odds ratio, and information component, are used to measure the association between each ADR and AED. The resulting list of signaled ADRs for each AED is validated against a widely used ADR database, called Side Effect Resource, in terms of the precision of ADR detection. The validation results indicate the validity of online health community data for the detection of AED ADRs. Furthermore, the lists of signaled AED ADRs are analyzed to answer questions related to the common ADRs of AEDs and the similarities between AEDs in terms of their signaled ADRs. The consistency of the drawn answers with the existing pharmaceutical knowledge suggests the utility of the data from online health communities for AED-related knowledge discovery tasks.

Psychotropic Drug-Associated Pneumonia in Older Adults

The use of psychotropic drugs (antipsychotics, benzodiazepines and benzodiazepine-related drugs, and antidepressants) is common, with a prevalence estimates range of 19-29% among community dwelling older adults. These drugs are often prescribed for off-label use, including neuropsychiatric symptoms. The older adult population also has high rates of pneumonia and some of these cases may be associated with adverse drug events. In this narrative review, we summarize the findings from current observational studies on the association between psychotropic drug use and pneumonia in older adults. In addition to studies assessing the use of psychotropics, we included antiepileptic drugs, as they are also central nervous system-acting drugs, whose use is becoming more common in the aging population. The use of antipsychotics, benzodiazepine, and benzodiazepine-related drugs are associated with increased risk of pneumonia in older adults (≥ 65 years of age), and these findings are not limited to this age group. Minimal and conflicting evidence has been reported on the association between antidepressant drug use and pneumonia, but differences between study populations make it difficult to compare findings. Studies regarding antiepileptic drug use and risk of pneumonia in older persons are lacking, although an increased risk of pneumonia in antiepileptic drug users compared with non-users in persons with Alzheimer's disease has been reported. Tools such as the American Geriatric Society Beers Criteria and the STOPP/START criteria for potentially inappropriate medications aids prescribers to avoid these drugs in order to reduce the risk of adverse drug events. However, risk of pneumonia is not mentioned in the current criteria and more research on this topic is needed, especially in vulnerable populations, such as persons with dementia.

The anti-epileptic drug lamotrigine inhibits the CYP17A1 lyase reaction in vitro

The potential endocrine disrupting effects of the commonly prescribed anti-epileptic drug lamotrigine (LAM) were investigated using the H295R steroidogenic in vitro assay and computational chemistry methods. The H295R cells were exposed to different concentrations of LAM, and a multi-steroid LC-MS/MS method was applied to quantify the amount of secreted steroid hormones. LAM affected several steroid hormones in the steroidogenesis at therapeutic concentrations. All progestagens as well as 11-deoxycorticosterone and corticosterone increased 100-200% with increasing concentrations of LAM suggesting a selective inhibitory effect of LAM on CYP17A1, in particular on the lyase reaction. Recombinant CYP17A1 assay confirmed the competitive inhibition of LAM toward the enzyme with IC50 values of 619 and 764 μM for the lyase and the hydroxylase reaction, respectively. Levels of androstenedione and testosterone decreased at LAM concentrations above the therapeutic concentration range. The ability of LAM to bind to CYP17A1, CYP19A1, and CYP21A2 was investigated using docking and molecular dynamics simulations. This in silico study showed that LAM was able to bind directly to the heme iron in the active site of CYP17A1, but not CYP21A2, thus supporting the results of the in vitro studies. The molecular dynamics simulations also suggested binding of LAM to the heme iron in the CYP19A1 active site. No inhibition of the aromatase enzyme was, however, observed in the H295R assay. This could be due to a sequential effect within the steroidogenesis caused by the inhibition of CYP17A1, which reduced the amounts of androgens available for CYP19A1.

Trends in sodium valproate prescriptions among children aged 0 to 14 years between 2010 and 2016: A study based on the French National Health Insurance Database

PURPOSE

After a huge campaign of information on the teratogenic risk of sodium valproate (VPA) having taken place in France we aimed to evaluate the trend of its prescriptions in young epileptic girls.

METHOD

Using the French National Health Insurance Database we searched for patients aged 0-14 years being supplied an antiepileptic drug (AED) between 2010 and 2016.

RESULTS

113,362 children received at least one AED, 61,259 boys and 52,103 girls. Compared to 2010-2014 years, VPA was less prescribed in 2016 as first AED (29% vs 37.3% respectively). The difference between the two periods was greater for girls (-41%) than for boys (-12%).

CONCLUSION

The changing trend of VPA as first AED prescribed, particularly in girls, reflects published evidence in terms of safety.

Epilepsy Among Elderly Medicare Beneficiaries: A Validated Approach to Identify Prevalent and Incident Epilepsy

BACKGROUND

Uncertain validity of epilepsy diagnoses within health insurance claims and other large datasets have hindered efforts to study and monitor care at the population level.

OBJECTIVES

To develop and validate prediction models using longitudinal Medicare administrative data to identify patients with actual epilepsy among those with the diagnosis.

RESEARCH DESIGN, SUBJECTS, MEASURES

We used linked electronic health records and Medicare administrative data including claims to predict epilepsy status. A neurologist reviewed electronic health record data to assess epilepsy status in a stratified random sample of Medicare beneficiaries aged 65+ years between January 2012 and December 2014. We then reconstructed the full sample using inverse probability sampling weights. We developed prediction models using longitudinal Medicare data, then in a separate sample evaluated the predictive performance of each model, for example, area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity.

RESULTS

Of 20,945 patients in the reconstructed sample, 2.1% had confirmed epilepsy. The best-performing prediction model to identify prevalent epilepsy required epilepsy diagnoses with multiple claims at least 60 days apart, and epilepsy-specific drug claims: AUROC=0.93 [95% confidence interval (CI), 0.90-0.96], and with an 80% diagnostic threshold, sensitivity=87.8% (95% CI, 80.4%-93.2%), specificity=98.4% (95% CI, 98.2%-98.5%). A similar model also performed well in predicting incident epilepsy (k=0.79; 95% CI, 0.66-0.92).

CONCLUSIONS

Prediction models using longitudinal Medicare data perform well in predicting incident and prevalent epilepsy status accurately.

Pharmaceutical residues are widespread in Baltic Sea coastal and offshore waters - Screening for pharmaceuticals and modelling of environmental concentrations of carbamazepine

The consumption of pharmaceuticals worldwide coupled with modest removal efficiencies of sewage treatment plants have resulted in the presence of pharmaceuticals in aquatic systems globally. In this study, we investigated the environmental concentrations of a selection of 93 pharmaceuticals in 43 locations in the Baltic Sea and Skagerrak. The Baltic Sea is vulnerable to anthropogenic activities due to a long turnover time and a sensitive ecosystem in the brackish water. Thirty-nine of 93 pharmaceuticals were detected in at least one sample, with concentrations ranging between 0.01 and 80 ng/L. One of the pharmaceuticals investigated, the anti-epileptic drug carbamazepine, was widespread in coastal and offshore seawaters (present in 37 of 43 samples). In order to predict concentrations of pharmaceuticals in the sub-basins of the Baltic Sea, a mass balance-based grey box model was set up and the persistent, widely used carbamazepine was selected as the model substance. The model was based on hydrological and meteorological sub-basin characteristics, removal data from smaller watersheds and wastewater treatment plants, and statistics relating to population, consumption and excretion rate of carbamazepine in humans. The grey box model predicted average environmental concentrations of carbamazepine in sub-basins with no significant difference from the measured concentrations, amounting to 0.57-3.2 ng/L depending on sub-basin location. In the Baltic Sea, the removal rate of carbamazepine in seawater was estimated to be 6.2 10^-9 s^-1 based on a calculated half-life time of 3.5 years at 10 °C, which demonstrates the long response time of the environment to measures phasing out persistent or slowly degradable substances such as carbamazepine. Sampling, analysis and grey box modelling were all valuable in describing the presence and removal of carbamazepine in the Baltic Sea.

Pharmacokinetics in Plants: Carbamazepine and Its Interactions with Lamotrigine

Carbamazepine and lamotrigine prescribed antiepileptic drugs are highly persistent in the environment and were detected in crops irrigated with reclaimed wastewater. This study reports pharmacokinetics of the two drugs and their metabolites in cucumber plants under hydroponic culture, testing their uptake, translocation, and transformation over 96 h in single and bisolute systems at varying pH. Ruling out root adsorption and transformations in the nutrient solution, we demonstrate that carbamazepine root uptake is largely affected by the concentration gradient across the membrane. Unlike carbamazepine, lamotrigine is adsorbed to the root and undergoes ion trapping in root cells thus its translocation to the shoots is limited. On the basis of that, carbamazepine uptake was not affected by the presence of lamotrigine, while lamotrigine uptake was enhanced in the presence of carbamazepine. Transformation of carbamazepine in the roots was slightly reduced in the presence of lamotrigine. Carbamazepine metabolism was far more pronounced in the shoots than in the roots, indicating that most of the metabolism occurs in the leaves, probably due to higher concentration and longer residence time. This study indicates that the uptake of small nonionic pharmaceuticals is passive and governed by diffusion across the root membrane.

Development of an algorithm to identify pregnancy episodes and related outcomes in health care claims databases: An application to antiepileptic drug use in 4.9 million pregnant women in France

Purpose

Access to claims databases provides an opportunity to study medication use and safety during pregnancy. We developed an algorithm to identify pregnancy episodes in the French health care databases and applied it to study antiepileptic drug (AED) use during pregnancy between 2007 and 2014.

Methods

The algorithm searched the French health care databases for discharge diagnoses and medical procedures indicative of completion of a pregnancy. To differentiate claims associated with separate pregnancies, an interval of at least 28 weeks was required between 2 consecutive pregnancies resulting in a birth and 6 weeks for terminations of pregnancy. Pregnancy outcomes were categorized into live births, stillbirths, elective abortions, therapeutic abortions, spontaneous abortions, and ectopic pregnancies. Outcome dates and gestational ages were used to calculate pregnancy start dates.

Results

According to our algorithm, live birth was the most common pregnancy outcome (73.9%), followed by elective abortion (17.2%), spontaneous abortion (4.2%), ectopic pregnancy (1.1%), therapeutic abortion (1.0%), and stillbirth (0.4%). These results were globally consistent with French official data. Among 7 559 701 pregnancies starting between 2007 and 2014, corresponding to 4 900 139 women, 6.7 per 1000 pregnancies were exposed to an AED. The number of pregnancies exposed to older AEDs, comprising the most teratogenic AEDs, decreased throughout the study period (−69.4%), while the use of newer AEDs increased (+73.4%).

Conclusions

We have developed an algorithm that allows identification of a large number of pregnancies and all types of pregnancy outcomes. Pregnancy outcome and start dates were accurately identified, and maternal data could be linked to neonatal data.

No signal of interactions between influenza vaccines and drugs used for chronic diseases: a case-by-case analysis of the vaccine adverse event reporting system and vigibase

BACKGROUND

An increasing number of reports indicates that vaccines against influenza may interact with specific drugs via drug metabolism. To date, actual impact of vaccine-drug interactions observed in the real world clinical practice has not been investigated.

METHODS

From VAERS and VigiBase, we collected Adverse Event Following Immunization (AEFI) reports for individuals receiving vaccines against influenza recorded as suspect and selected cases where predictable toxicity was recorded with oral anticoagulants, antiepileptics and statins (i.e. hemorrhages, overdosage and rhabdomyolysis, respectively). We applied AEFI and Drug Interaction Probability Scale (DIPS) Algorithms to assess causality of drug-vaccine interactions.

RESULTS

116 AEFI reports submitted to VAERS and 83 from Vigibase were included in our analysis; antiepileptics and statins were related to the highest number of indeterminate/consistent (93.7%; 65.3%) and possible/probable (50%; 57.7%) cases according to the AEFI and DIPS, respectively. The majority of cases occurred within the first week after vaccine administration (5-7 days).

CONCLUSION

The relative paucity of detected interactions does not impact on the benefit of the vaccination against influenza, which remains strongly recommended; this does not exclude that closer monitoring for selected patients exposed to concomitant chronic pharmacological therapies and affected by predisposing factors may be useful.

Accuracy of claims-based algorithms for epilepsy research: Revealing the unseen performance of claims-based studies

OBJECTIVE

To evaluate published algorithms for the identification of epilepsy cases in medical claims data using a unique linked dataset with both clinical and claims data.

METHODS

Using data from a large, regional health delivery system, we identified all patients contributing biologic samples to the health system's Biobank (n = 36K). We identified all subjects with at least one diagnosis potentially consistent with epilepsy, for example, epilepsy, convulsions, syncope, or collapse, between 2014 and 2015, or who were seen at the epilepsy clinic (n = 1,217), plus a random sample of subjects with neither claims nor clinic visits (n = 435); we then performed a medical chart review in a random subsample of 1,377 to assess the epilepsy diagnosis status. Using the chart review as the reference standard, we evaluated the test characteristics of six published algorithms.

RESULTS

The best-performing algorithm used diagnostic and prescription drug data (sensitivity = 70%, 95% confidence interval [CI] 66-73%; specificity = 77%, 95% CI 73-81%; and area under the curve [AUC] = 0.73, 95%CI 0.71-0.76) when applied to patients age 18 years or older. Restricting the sample to adults aged 18-64 years resulted in a mild improvement in accuracy (AUC = 0.75,95%CI 0.73-0.78). Adding information about current antiepileptic drug use to the algorithm increased test performance (AUC = 0.78, 95%CI 0.76-0.80). Other algorithms varied in their included data types and performed worse.

SIGNIFICANCE

Current approaches for identifying patients with epilepsy in insurance claims have important limitations when applied to the general population. Approaches incorporating a range of information, for example, diagnoses, treatments, and site of care/specialty of physician, improve the performance of identification and could be useful in epilepsy studies using large datasets.

Clinical Use of Mood Stabilizers With Antidepressants in Asia: Report From the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) Projects in 2004 and 2013

OBJECTIVE

As most reports concerning treatment with combinations of mood stabilizer (MS) with antidepressant (AD) drugs are based in the West, we surveyed characteristics of such cotreatment in 42 sites caring for the mentally ill in 10 Asian countries.

METHODS

This cross-sectional, pharmacoepidemiologic study used 2004 and 2013 data from the REAP-AD (Research Study on Asian Psychotropic Prescription Patterns for Antidepressants) to evaluate the rates and doses of MSs given with ADs and associated factors in 4164 psychiatric patients, using standard bivariate methods followed by multivariable logistic regression modeling.

RESULTS

Use of MS + AD increased by 104% (5.5% to 11.2%) between 2004 and 2013 and was much more associated with diagnosis of bipolar disorder than major depression or anxiety disorder, as well as with hospitalization > outpatient care, psychiatric > general-medical programs, and young age (all P < 0.001), but not with country, sex, or AD dose.

CONCLUSIONS

The findings provide a broad picture of contemporary use of MSs with ADs in Asia, support predictions that such treatment increased in recent years, and was associated with diagnosis of bipolar disorder, treatment in inpatient and psychiatric settings, and younger age.

Changes in prevalence of psychotropic drug use and alcohol consumption among the elderly in Germany: results of two National Health Interview and Examination Surveys 1997-99 and 2008-11

BACKGROUND

Psychotropic drug use and alcohol consumption among older adults need to be monitored over time as their use or combined use bears risks of harms. Representative data on changes in prevalence, patterns and co-relates of substance use are lacking in Germany.

METHODS

Participants were older adults (60-79 years) from two German National Health Surveys: 1997-99 (GNHIES98, N = 1,606) and 2008-11 (DEGS1, N = 2,501). Included were drugs acting on the nervous system used during the last 7 days. Alcohol consumption was measured by frequency (daily drinking) and quantity (risky drinking: ≥20/10 g/day alcohol for men/women). Changes in prevalence adjusted for potential socio-economic and health-related confounders were calculated by logistic regression models approximated by the SAS LSMEANS statement.

RESULTS

The prevalence of overall psychotropic drug use (20.5% vs. 21.4%) remained constant between the two surveys. Significant changes were observed in the use of some psychotropics (all GNHIES98 vs. DEGS1): Synthetic antidepressants (3.9% vs. 6.9%), St. John's wort (2.9% vs. 1.1%), benzodiazepines (3.7% vs. 2.5%), benzodiazepine related drugs (0.2% vs. 0.8%), narcotic analgesics (3.0% vs. 4.1%), anti-dementia drugs (2.2% vs. 4.2%) and anti-epileptics (1.0% vs. 2.3%). Significant changes were also observed in long-term use of synthetic anti-depressants (3.2% vs. 5.9%), St. John's wort (2.0% vs. 0.6%) and opioid analgesics (1.0% vs. 2.2%). Further, we found significant changes in benzodiazepines use (3.3% vs. 1.4%) among men, opioids use (2.9% vs. 7.3%) among people with a lower social status, and overall psychotropics (26.8% vs. 32.5%) as well as opioids use (4.4% vs. 8.1%) among those with a worse health status. Moderate alcohol consumption increased significantly (58.0% vs. 66.9%). Risky drinking remained unchanged (16.6% vs. 17.0%). In spite of significant increases in daily alcohol drinking (13.2% vs. 18.4%) psychotropic drug use combined with daily drinking remained unchanged (1.8% vs. 2.7%).

CONCLUSIONS

Although prevalence of overall psychotropic drug use remained stable, changes in the use of some psychotropic drug groups and alcohol consumption patterns have been observed. Further studies are required to investigate resulting health consequences and public health relevance of those outcomes.

The anti-convulsants lacosamide, lamotrigine, and rufinamide reduce myotonia in isolated human and rat skeletal muscle

INTRODUCTION

In myotonia congenita, loss of ClC-1 Cl^- channel function results in skeletal muscle hyperexcitability and myotonia. Anti-myotonic treatment has typically targeted the voltage-gated sodium channel in skeletal muscle (Nav1.4). In this study we explored whether 3 sodium channel-modulating anti-epileptics can reduce myotonia in isolated rat and human muscle.

METHODS

Dissected muscles were rendered myotonic by ClC-1 channel inhibition. The ability of the drugs to suppress myotonia was then assessed from subclinical to maximal clinical concentrations. Drug synergy was determined using isobole plots.

RESULTS

All drugs were capable of abolishing myotonia in both rat and human muscles. Lamotrigine and rufinamide completely suppressed myotonia at submaximal clinical concentrations, whereas lacosamide had to be raised above the maximal clinical concentration to suppress myotonia completely. A synergistic effect of lamotrigine and rufinamide was observed.

CONCLUSION

These findings suggest that lamotrigine and rufinamide could be considered for anti-myotonic treatment in myotonia congenita. Muscle Nerve 56: 136-142, 2017.

Impact of varying outcomes and definitions of suicidality on the associations of antiepileptic drugs and suicidality: comparisons from UK Clinical Practice Research Datalink (CPRD) and Danish national registries (DNR)

PURPOSE

The purpose of this study is to quantify the impact of the different outcomes and definitions of suicidality on the association between antiepileptic drugs (AEDs) and suicidality.

METHODS

Retrospective cohort studies of selected AEDs (carbamazepine, gabapentin, lamotrigine, phenytoin, pregabalin, topiramate and valproate) using data from UK Clinical Practice Research Datalink (CPRD) alone and linked to UK Hospital Episode Statistics (HES) and UK Office of National Statistics (ONS), and from Danish national registries (DNR). Follow-up started at initiation of one of the study AEDs, divided into exposure periods, a maximum 90-day post-exposure period, and the reference period starting the day after the 90-day post-exposure period ended. Primary outcomes were completed suicide (SUI)/suicide attempt (SA) for CPRD and SUI/deliberate self-harm (DSH) for DNR. We applied adjusted Cox regression analyses and sensitivity analyses with varying outcome definitions.

RESULTS

We analyzed 84,524 AED users from CPRD-HES-ONS (1188 SUI/SA; 96 SUI) and 258,180 users from DNR (7561 SUI/DSH; 781 SUI). The adjusted hazard ratios (HRs) on SUI/SA ranged between 1.3 (95% confidence interval (CI): 0.84-2.00) for lamotrigine and 2.7 (1.24-5.81) for phenytoin in CPRD-HES-ONS, and between 0.9 (0.78-1.00) for valproate and 1.8 (1.10-3.07) for phenytoin on SUI/DSH in DNR. HRs for the primary outcomes varied consistently across exposure periods and data sources. HRs for SUI were in general lower, more stable and similar for periods of exposure and the 90-day post-exposure period.

CONCLUSION

Applying different outcomes and definitions of suicidality had an impact on the relative risks of suicidality associated with the investigated AEDs with results for SUI being most consistent and reliable.

Patient-reported financial barriers to adherence to treatment in neurology

Objective

Many effective medical therapies are available for treating neurological diseases, but these therapies tend to be expensive and adherence is critical to their effectiveness. We used patient-reported data to examine the frequency and determinants of financial barriers to medication adherence among individuals treated for neurological disorders.

Patients and methods

Patients completed cross-sectional surveys on iPads as part of routine outpatient care in a neurology clinic. Survey responses from a 3-month period were collected and merged with administrative sources of demographic and clinical information (eg, insurance type). We explored the association between patient characteristics and patient-reported failure to refill prescription medication due to cost in the previous 12 months, termed here as “nonadherence”.

Results

The population studied comprised 6075 adults who were presented between July and September 2015 for outpatient neurology appointments. The mean age of participants was 56 (standard deviation: 18) years, and 1613 (54%) were females. The patients who participated in the surveys (2992, 49%) were comparable to nonparticipants with respect to gender and ethnicity but more often identified English as their preferred language (94% vs 6%, p<0.01). Among respondents, 9.8% (n=265) reported nonadherence that varied by condition. These patients were more frequently Hispanic (16.7% vs 9.8% white, p=0.01), living alone (13.9% vs 8.9% cohabitating, p<0.01), and preferred a language other than English (15.3% vs 9.4%, p=0.02).

Conclusion

Overall, the magnitude of financial barriers to medication adherence appears to vary across neurological conditions and demographic characteristics.

Neurologist adherence to clinical practice guidelines and costs in patients with newly diagnosed and chronic epilepsy in Germany

PURPOSE

The aim of this study was to evaluate physician adherence to the German Neurological Society guidelines of 2008 regarding initial monotherapy and to determine the cost-of-illness in epilepsy.

METHODS

This was an observational cohort study using health data routinely collected at 55 outpatient neurology practices throughout Germany (NeuroTransData network). Data on socioeconomic status, course of epilepsy, anticonvulsive treatment, and direct and indirect costs were recorded using practice software-based questionnaires.

RESULTS

One thousand five hundred eighty-four patients with epilepsy (785 male (49.6%); mean age: 51.3±18.1years) were enrolled, of whom 507 were newly diagnosed. Initial monotherapy was started according to authorization status in 85.9%, with nonenzyme-inducing drugs in 94.3% of all AEDs. Drugs of first choice by guideline recommendations were used in 66.5%. Total annual direct costs in the first year amounted to €2194 (SD: €4273; range: €55-43,896) per patient, with hospitalization (59% of total direct costs) and anticonvulsants (30%) as the main cost factors. Annual total direct costs decreased by 29% to €1572 in the second year, mainly because of a 59% decrease in hospitalization costs. The use of first choice AEDs did not influence costs. Chronic epilepsy was present in 1077 patients, and total annual direct costs amounted to €1847 per patient, with anticonvulsants (51.0%) and hospitalization (41.0%) as the main cost factors. Potential cost-driving factors in these patients were active epilepsy and focal epilepsy syndrome.

CONCLUSION

This study shows excellent physician adherence to guidelines regarding initial monotherapy in adults with epilepsy. Newly diagnosed patients show higher total direct and hospital costs in the first year upon diagnosis, but these are not influenced by adherence to treatment guidelines.

Utilization of antiepileptic drugs in Israel

PURPOSE

The aim of the study was to identify trends in utilization of antiepileptic drugs (AEDs) over time in a nation-wide population in Israel.

METHODS

Data on AED utilization (for all indications) for the period 2010-2014 were obtained from pharmaceutical companies that distribute AEDs in Israel. Prevalence of AED utilization was reported as defined daily doses (DDD)/1000 inhabitants/day.

RESULTS

The utilization of most AEDs included in our analysis remained stable over the study period. The greatest increases in utilization of drugs established in Israel were observed for lamotrigine (33%), oxcarbazepine (31%), and primidone (18%). Decreases in use were recorded for carbamazepine (18%) and phenobarbital (15%). Use of older AEDs appeared to be relatively high, compared with the use of newer AEDs.

CONCLUSIONS

During the study period of 2010-2014, conventional AEDs remained a main treatment choice in Israel, in certain cases in contrast to current recommendations and guidelines, for reasons yet to be revealed in further research.

Prevalence of Different Combinations of Antiepileptic Drugs and CNS Drugs in Elderly Home Care Service and Nursing Home Patients in Norway

Introduction. Antiepileptic drugs (AEDs) are used to treat different conditions in elderly patients and are among the drug classes most susceptible to be involved in drug-drug interactions (DDI). The aim of the study was to describe and compare use of AEDs between home care service and nursing home patients, as these patients are not included in nationwide databases of drug utilization. In the combined population, we investigate DDI of AEDs with other central nervous system- (CNS-) active drugs and DDIs involving AEDs in general. Materials and Methods. Point-prevalence study of Norwegian patients in home care services and nursing homes in 2009. At the patient level, we screened for different DDIs involving AEDs. Results. In total, 882 patients (7.8%) of 11,254 patients used AEDs and number of users did not differ between home care services and nursing homes (8.2% versus 7.7%). In the combined population, we identified 436 potential DDIs in 45% of the patients. Conclusions. In a large population of elderly, home care service and nursing home patients do not differ with respect to exposure of AEDs but use more AEDs as compared to the general population of similar age. The risk of DDIs with AEDs and other CNS-active drugs should be taken into consideration and individual clinical evaluations are assessed in this population.

Changes in utilisation of antiepileptic drugs in epilepsy and non-epilepsy disorders-a pharmacoepidemiological study and clinical implications

PURPOSE

The purpose of this study was to investigate changes in utilisation of antiepileptic drugs (AEDs) in epilepsy and non-epilepsy disorders in Norway and furthermore to study the retention rates of the most commonly used AEDs in these indications in long-term use.

METHODS

The data consisted of all prescriptions of AEDs from Norwegian pharmacies in the Norwegian Prescription Database (NorPD) (2004-2012). Variables included anonymous data regarding age, gender, diagnosis specific reimbursement codes and utilisation of AEDs.

RESULTS

In recent years (2008-2012), the utilisation of AEDs in non-epilepsy disorders accounted for 45-53 % of the total use. In epilepsy, the most commonly used AED was lamotrigine, followed by levetiracetam, carbamazepine and valproate. Lamotrigine was also the predominant AED used in psychiatry, while pregabalin and gabapentin were mostly used in neuropathic pain. In migraine, topiramate predominated but accounted for <1 % of the total utilisation of AEDs. The majority of prescriptions were by general practitioners and only 20 % by specialists. Regardless of indication, newer AEDs had higher retention rates (34-48 %) and were used for a longer period before discontinuation.

CONCLUSIONS

The use of AEDs in non-epilepsy disorders is increasing and accounted for 53 % in 2012. Newer AEDs were predominantly used and demonstrated higher retention rates than older AEDs in all indications. This nationwide study demonstrates an increased exposure to AEDs in new patient groups, and details in prescription patterns and clinical and safety considerations should be closely monitored. This contributes to long-term post-marketing data of AED and accordingly improved pharmacovigilance.

The Risk of Specific Congenital Anomalies in Relation to Newer Antiepileptic Drugs: A Literature Review

BACKGROUND

More information is needed about possible associations between the newer anti-epileptic drugs (AEDs) in the first trimester of pregnancy and specific congenital anomalies of the fetus.

OBJECTIVES

We performed a literature review to find signals for potential associations between newer AEDs (lamotrigine, topiramate, levetiracetam, gabapentin, oxcarbazepine, eslicarbazepine, felbamate, lacosamide, pregabalin, retigabine, rufinamide, stiripentol, tiagabine, vigabatrin, and zonisamide) and specific congenital anomalies.

METHODS

We searched PubMed and EMBASE to find observational studies with pregnancies exposed to newer AEDs and detailed information on congenital anomalies. The congenital anomalies in the studies were classified according to the congenital anomaly subgroups of European Surveillance of Congenital Anomalies (EUROCAT). We compared the prevalence of specific congenital anomalies in fetuses exposed to individual AEDs in the combined studies with that of the general population in a reference database. A significantly higher prevalence based on three or more fetuses with anomalies was considered a signal.

RESULTS

Topiramate showed a higher rate of congenital anomalies than the other newer AEDs. Four signals were found. The signals for associations between topiramate and cleft lip with/without cleft palate and hypospadias were considered strong. Associations between lamotrigine and anencephaly and transposition of great vessels were found within one study and were not supported by other studies. No signals were found for the other newer AEDs, or the information was too limited to provide such a signal.

CONCLUSION

In terms of associations between monotherapy with a newer AED in the first trimester of pregnancy and a specific congenital anomaly, the signals for topiramate and cleft lip with/without cleft palate and hypospadias should be investigated further.

Antiepileptic use for epilepsy and nonepilepsy disorders: A population-based study (1998-2013)

OBJECTIVE

To examine the trends in antiepileptic drug (AED) use among individuals living in Manitoba with and without a history of epilepsy.

METHODS

Using data obtained from administrative health databases in Manitoba, we assessed the quarterly prevalence of AED use between 1998 and 2013 among individuals with and without a history of epilepsy using cross-sectional time series analysis.

RESULTS

Over the study period, the number of individuals prescribed AEDs increased more than 3-fold, from 8,883 to 27,246. The prevalence of AED use among patients with epilepsy increased by 3%, from 789.6 per 1,000 in 1998/1999 to 813.9 per 1,000 in 2012/2013 (p < 0.001 after 2006). In contrast, we observed a 210% increase in AED use among patients without epilepsy from 6.8 to 21.1 per 1,000 over the same period (p < 0.001). We observed a 55-fold rise in gabapentin use among patients without a seizure disorder (from 0.2 to 11.1 per 1,000; p < 0.001), while gabapentin use among those with epilepsy increased only 2-fold, from 21.6 to 41.3 per 1,000 (p < 0.001).

CONCLUSIONS

There has been a marked increase in the prevalence of AED users over the last 15 years, with a large shift towards the use of newer antiepileptic agents (primarily gabapentin) among those without epilepsy. Further research on the effect of these trends on health and economic outcomes will be of interest for clinicians and policymakers.

Changing incidence of hyperammonemia in Japan from 2006 to 2013: expansion of new antiepileptic drugs reduces the risk of hyperammonemia

PURPOSE

The purpose of the present study was to examine the relationship between the incidence of hyperammonemia and changes in the prescribing of concomitant antiepileptic drugs (AEDs) in patients receiving valproic acid.

METHODS

We evaluated 40,363 plasma samples from 6009 epilepsy patients obtained from 2006 to 2013. Hyperammonemia was defined as a plasma ammonia level exceeding 100 μg/dL.

RESULTS

In 2006, 32.6 % of the plasma samples were from patients with concomitant use of phenytoin but this decreased to 16.0 % in 2013. Lamotrigine and levetiracetam were approved in 2008 and 2010, respectively, and were prescribed for patients who provided 27.8 and 14.9 % of the plasma samples in 2013. The incidence rate of hyperammonemia (per 100 person years) decreased markedly from 40.8 (95 % confidence interval (CI), 37.7-43.9) in 2006 to 14.2 (95 % CI, 12.5-15.9) in 2013. In any year reviewed, concomitant use of phenytoin, phenobarbital, carbamazepine, or carbonic anhydrase inhibitors was a risk factor for hyperammonemia. Among enzyme-inducing AEDs, concomitant use of phenytoin was associated with the highest risk of hyperammonemia.

CONCLUSION

Drug interactions caused by enzyme-inducing AEDs, especially phenytoin, are closely related to the development of hyperammonemia. This study demonstrated that introduction of new AEDs changed the co-prescribing pattern in patients receiving valproic acid, resulting in a marked decrease of hyperammonemia. Although their higher cost may be problematic, new AEDs are beneficial for reducing the risk of drug interactions.

Antiepileptic drug prescribing before, during and after pregnancy: a study in seven European regions

PURPOSE

The aim of this study was to explore antiepileptic drug (AED) prescribing before, during and after pregnancy as recorded in seven population-based electronic healthcare databases.

METHODS

Databases in Denmark, Norway, the Netherlands, Italy (Emilia Romagna/Tuscany), Wales and the Clinical Practice Research Datalink, representing the rest of the UK, were accessed for the study. Women with a pregnancy starting and ending between 2004 and 2010, which ended in a delivery, were identified. AED prescriptions issued (UK) or dispensed (non-UK) at any time during pregnancy and the 6 months before and after pregnancy were identified in each of the databases. AED prescribing patterns were analysed, and the choice of AEDs and co-prescribing of folic acid were evaluated.

RESULTS

In total, 978 957 women with 1 248 713 deliveries were identified. In all regions, AED prescribing declined during pregnancy and was lowest during the third trimester, before returning to pre-pregnancy levels by 6 months following delivery. For all deliveries, the prevalence of AED prescribing during pregnancy was 51 per 10 000 pregnancies (CI95 49-52%) and was lowest in the Netherlands (43/10 000; CI95 33-54%) and highest in Wales (60/10 000; CI95 54-66%). In Denmark, Norway and the two UK databases lamotrigine was the most commonly prescribed AED; whereas in the Italian and Dutch databases, carbamazepine, valproate and phenobarbital were most frequently prescribed. Few women prescribed with AEDs in the 3 months before pregnancy were co-prescribed with high-dose folic acid: ranging from 1.0% (CI95 0.3-1.8%) in Emilia Romagna to 33.5% (CI95 28.7-38.4%) in Wales.

CONCLUSION

The country's differences in prescribing patterns may suggest different use, knowledge or interpretation of the scientific evidence base. The low co-prescribing of folic acid indicates that more needs to be done to better inform clinicians and women of childbearing age taking AEDs about the need to offer and receive complete preconception care.

Indications of newer and older anti-epileptic drug use: findings from a southern Italian general practice setting from 2005-2011

AIMS

The aim of the study was to analyze the prescribing pattern of both newer and older AEDs.

METHODS

A population of almost 150 000 individuals registered with 123 general practitioners was included in this study. Patients who received at least one AED prescription over 2005-2011 were identified. The 1 year prevalence and cumulative incidence of AED use, by drug class and individual drug, were calculated over the study period. Potential predictors of starting therapy with newer AEDs were also investigated.

RESULTS

The prevalence of use per 1000 inhabitants of older AEDs increased from 10.7 (95% CI10.1, 11.2) in 2005 to 13.0 (95% CI12.4, 13.6) in 2011, while the incidence remained stable. Newer AED incidence decreased from 9.4 (95% CI 8.9, 9.9) in 2005 to 7.0 (95% CI 6.6, 7.5) in 2011, with a peak of 15.5 (95% CI 14.8, 16.1) in 2006. Phenobarbital and valproic acid were the most commonly prescribed AEDs as starting therapy for epilepsy. Gabapentin and pregabalin accounted for most new pain-related prescriptions, while valproic acid and lamotrigine were increasingly used for mood disorders. Female gender (OR 1.36, 95% CI 1.20, 1.53), age ranging between 45-54 years (OR 1.39, 95% CI 1.16, 1.66) and pain as an indication (OR 16.7, 95% CI, 13.1, 21.2) were associated with newer AEDs starting therapy.

CONCLUSIONS

Older AEDs were mainly used for epileptic and mood disorders, while newer drugs were preferred for neuropathic pain. Gender, age, indication of use and year of starting therapy influenced the choice of AED type. The decrease of newer AED use during 2007 is probably related to the restricted reimbursement criteria for gabapentin and pregabalin.

Drug interactions involving antiepileptic drugs: assessment of the consistency among three drug compendia and FDA-approved labels

Interactions of antiepileptic drugs (AEDs) with other substances may lead to adverse effects and treatment failure. To avoid such interactions, clinicians often rely on drug interaction compendia. Our objective was to compare the concordance for twenty-two AEDs among three drug interaction compendia (Micromedex, Lexi-Interact, and Clinical Pharmacology) and the US Food and Drug Administration-approved product labels. For each AED, the overall concordance among data sources regarding existence of interactions and their classification was poor, with less than twenty percent of interactions listed in all four sources. Concordance among the three drug compendia decreased with the fraction of the drug excreted unchanged and was greater for established inducers of hepatic drug-metabolizing enzymes than for the drugs that are not inducers (R-square=0.83, P<0.01). For interactions classified as contraindications, major, and severe, concordance among the four data sources was, in most cases, less than 30%. Prescribers should be aware of the differences between drug interaction sources of information for both older AEDs and newer AEDs, in particular for those AEDs which are not involved in hepatic enzyme-mediated interactions.

Changes in opioid and other analgesic use 1995-2010: repeated cross-sectional analysis of dispensed prescribing for a large geographical population in Scotland

BACKGROUND

Despite recent concerns about increasing rates of analgesic prescribing, detailed epidemiological studies are lacking. We identified and described changes in the pattern of community-dispensed prescriptions to the Tayside population, Scotland, between 31st March 1995 (n = 301,020) and 31st March 2010 (n = 311,881).

METHODS

Repeated cross-sectional analysis of patient-level population data on dispensed analgesics, stratified by sociodemographic variables; logistic regression to identify factors associated with strong opioid dispensing in 2010.

RESULTS

The proportion of people currently dispensed any analgesic increased in 2010 (17.9%) compared with 1995 (15.7%). This increase was not equal across drug classes, with paracetamol, opioids and gabapentin/pregabalin showing an increase, but others showing a decrease. Weak opioids were less commonly dispensed in 2010 (8.2% vs. 8.4%) but dispensing of strong opioids increased 18-fold (3.6% vs. 0.2%), including a five-fold increase of morphine, fentanyl or oxycodone (0.75% vs. 0.15%). People receiving more non-analgesic drugs (odds ratio 20.7 if dispensed >14 non-analgesic medications vs. those dispensed <4) and those living in more deprived areas (OR 1.63 most deprived vs. most affluent) were more likely to receive a strong opioid in 2010.

CONCLUSIONS

Analgesic use rose modestly between 1995 and 2010, but with larger changes within individual classes, only partly reflecting evidence-based guidance. Dispensing of strong opioids increased dramatically, largely driven by tramadol, although other strong opioids tripled. Polypharmacy and socio-economic deprivation were strongly associated with strong opioid use. Research is needed to establish the causes, benefits and harms of the increase in analgesic, and especially strong opioid use.

Concomitant therapy in people with epilepsy: potential drug-drug interactions and patient awareness

People with epilepsy (PWE) may use prescription and over-the-counter (OTC) drugs for the treatment of concomitant diseases. Combinations of these drugs, as well as dietary supplements, with antiepileptic drugs (AEDs) may lead to reduced control of seizures and of coexisting medical conditions and increased risk of adverse drug reactions (ADRs). The aims of this study were to obtain comprehensive lists of medications, dietary supplements, botanicals, and specific food components used by adult PWE and to evaluate the potential for interactions involving AEDs and patients' awareness of such potential interactions. We conducted a prospective, questionnaire-based study of PWE attending the Hadassah-Hebrew University Epilepsy Clinic over a period of 7months. The questionnaire interview included the listing of medications, medicinal herbs, dietary supplements, and specific food components consumed and the knowledge of potential drug-drug interactions (DDIs), and it was conducted by a pharmacist. Drug-drug interactions were analyzed via the Micromedex online database. Out of 179 patients who attended the clinic over the study period, we interviewed 73 PWE, of which 71 were included in our final analysis. The mean number of AEDs consumed per subject was 1.7 (SD: 0.8, range: 1-4). Forty (56%) subjects were also treated with other prescription and/or OTC medications, and thirty-four (48%) took dietary supplements. Drug families most prone to DDIs involving AEDs included antipsychotic agents, selective serotonin reuptake inhibitors, and statins. Two-thirds of study participants (67%) knew that DDIs may lead to ADRs, but only half (56%) were aware of the potential for reduced seizure control. Only 44% always reported treatment with AEDs to medical professionals. This study provides for the first time a comprehensive picture of prescription and OTC drugs and food supplements used by PWE. Despite a considerable potential for DDIs involving AEDs, patient awareness is limited, highlighting the importance of patient and caregiver education.

Multi-indication carbamazepine and the risk of severe cutaneous adverse drug reactions in Korean elderly patients: a Korean health insurance data-based study

Objective

To evaluate the risk of severe cutaneous adverse drug reactions (SCAR) after exposure to multi-indication antiepileptic drugs for in Korean elderly patients.

Methods

We used a nationwide database from the Korean Health Insurance Review and Assessment Service claims constructed for the monitoring of drug utilization among the entire Korean elderly population from January 2005 to June 2006. We identified cases of SCARs among inpatients aged ≥65 years and those newly diagnosed with erythema multiforme according to the International Classification of Diseases, 10th revision code (L51). Each case was matched to four controls for gender, age, and the first hospitalization date as the index date. The use of carbamazepine, gabapentin, lamotrigine, topiramate, phenobarbital, phenytoin, and valproate during a 60-day period before the index date was compared. A conditional logistic regression analysis was performed to calculate the odds ratios (OR) and 95% confidence intervals (CI) of SCARs for antiepileptic drug.

Results

We identified 286 cases of SCAR and 1,144 matched controls. Among the 25 patients who were prescribed antiepileptic drugs within 60 days of the index date. There were 11 cases (3.8%) of severe ocular manifestations, and most elderly patients were first-time or short-term users of antiepileptic drugs. Among the 10 cases of carbamazepine use, only 2 cases were prescribed carbamazepine for seizure. All antiepileptic drugs were associated with an increased SCAR risk (adjusted OR = 3.42, 95% CI: 1.75–6.63). The SCAR risk was highest in patients treated with carbamazepine (adjusted OR = 10.39, 95% CI: 2.64–40.86, for multi-indication; adjusted OR = 6.84, 95% CI: 1.55–30.10, for neuropathic pain).

Conclusion

Carbamazepine use was associated with a nearly 10-fold increase in severe cutaneous drug reactions in Korean elderly patients. This association was consistently high with SCAR patients who received carbamazepine for neuropathic pain.

Drug utilization profile in adult patients with refractory epilepsy at a tertiary referral center

Objective To evaluate the utilization profile of antiepileptic drugs in a population of adult patients with refractory epilepsy attending a tertiary center. Method Descriptive analyses of data were obtained from the medical records of 112 patients. Other clinical and demographic characteristics were also registered. Results Polytherapies with ≥3 antiepileptic drugs were prescribed to 60.7% of patients. Of the old agents, carbamazepine and clobazam were the most commonly prescribed (72.3% and 58.9% of the patients, respectively). Among the new agents, lamotrigine was the most commonly prescribed (36.6% of the patients). At least one old agent was identified in 103 out of the 104 polytherapies, while at least one new agent was prescribed to 70.5% of the population. The most prevalent combination was carbamazepine + clobazam + lamotrigine. The mean AED load found was 3.3 (range 0.4–7.7). Conclusion The pattern of use of individual drugs, although consistent with current treatment guidelines, is strongly influenced by the public health system.

Trends in laboratory test volumes for Medicare Part B reimbursements, 2000-2010

CONTEXT

Changes in reimbursements for clinical laboratory testing may help us assess the effect of various variables, such as testing recommendations, market forces, changes in testing technology, and changes in clinical or laboratory practices, and provide information that can influence health care and public health policy decisions. To date, however, there has been no report, to our knowledge, of longitudinal trends in national laboratory test use.

OBJECTIVE

To evaluate Medicare Part B-reimbursed volumes of selected laboratory tests per 10,000 enrollees from 2000 through 2010.

DESIGN

Laboratory test reimbursement volumes per 10,000 enrollees in Medicare Part B were obtained from the Centers for Medicare & Medicaid Services (Baltimore, Maryland). The ratio of the most recent (2010) reimbursed test volume per 10,000 Medicare enrollees, divided by the oldest data (usually 2000) during this decade, called the volume ratio, was used to measure trends in test reimbursement. Laboratory tests with a reimbursement claim frequency of at least 10 per 10,000 Medicare enrollees in 2010 were selected, provided there was more than a 50% change in test reimbursement volume during the 2000-2010 decade. We combined the reimbursed test volumes for the few tests that were listed under more than one code in the Current Procedural Terminology (American Medical Association, Chicago, Illinois). A 2-sided Poisson regression, adjusted for potential overdispersion, was used to determine P values for the trend; trends were considered significant at P < .05.

RESULTS

Tests with the greatest decrease in reimbursement volumes were electrolytes, digoxin, carbamazepine, phenytoin, and lithium, with volume ratios ranging from 0.27 to 0.64 (P < .001). Tests with the greatest increase in reimbursement volumes were meprobamate, opiates, methadone, phencyclidine, amphetamines, cocaine, and vitamin D, with volume ratios ranging from 83 to 1510 (P < .001).

CONCLUSIONS

Although reimbursement volumes increased for most of the selected tests, other tests exhibited statistically significant downward trends in annual reimbursement volumes. The observed changes in reimbursement volumes may be explained by disease prevalence and severity, patterns of drug use, clinical or laboratory practices, and testing recommendations and guidelines, among others. These data may be useful to policy makers, health systems researchers, laboratory directors, and industry scientists to understand, address, and anticipate trends in laboratory testing in the Medicare population.

Trends in resource utilization and prescription of anticonvulsants for patients with active epilepsy in Germany

This study evaluated trends in the resource use of patients with active epilepsy over a 5-year period at an outpatient clinic of a German epilepsy center. Two cross-sectional cohorts of consecutive adults with active epilepsy were evaluated over a 3-month period in 2003 and 2008. Data on socioeconomic status, course of epilepsy, as well as direct and indirect costs were recorded using validated patient questionnaires. We enrolled 101 patients in 2003 and 151 patients in 2008. In both cohorts, 76% of the patients suffered from focal epilepsy, and the majority was on antiepileptic drug (AED) polytherapy (mean AED number: 1.7 (2003), 1.8 (2008)). We calculated epilepsy-specific costs of € 2955 in 2003 and € 3532 in 2008 per 3 months per patient. Direct medical costs were mainly due to anticonvulsants in 2003 (59.4% of total direct costs, 34.0% in 2008) and to hospitalization in 2008 (46.9% of total direct costs, 27.7% in 2003). The proportion of enzyme-inducing anticonvulsants and 'old' AEDs decreased between 2003 and 2008. Indirect costs of € 1689 and € 1847 were mainly due to early retirement (48.4%; 46.0% of total indirect costs in 2003; 2008), unemployment (26.1%; 24.2%), and days off due to seizures (25.5%; 29.8%). This study showed a shift in distribution of direct cost components with increased hospital costs as well as a cost-neutral increase in the prescription of 'newer' AEDs. The amount and distribution of indirect cost components remained unchanged.

The long-term safety of antiepileptic drugs

Antiepileptic drugs (AEDs) are used by millions of people worldwide for the treatment of epilepsy, as well as in many other neurological and psychiatric conditions. They are frequently associated with adverse effects (AEs), which have an impact on the tolerability and success of treatment. Half the people who develop intolerable AEs discontinue treatment early on after initiation, while the majority of people will continue to be exposed to their effects for long periods of time. The long-term safety of AEDs reflects their potential for chronic, cumulative dose effects; rare, but potentially serious late idiosyncratic effects; late, dose-related effects; and delayed, teratogenic or neurodevelopmental effects. These AEs can affect every body system and are usually insidious. With the exception of delayed effects, most other late or chronic AEs are reversible. To date, there is no clear evidence of a carcinogenic effect of AEDs in humans. While physicians are aware of the long-term AEs of old AEDs (the traditional liver enzyme-inducing AEDs and valproate), information about AEs of new AEDs (such as lamotrigine, levetiracetam, oxcarbazepine, topiramate or zonisamide), particularly of their teratogenic effects, has emerged over the years. Sporadic publications have raised issues about AEs of the newer AEDs eslicarbazepine, retigabine, rufinamide, lacosamide and perampanel but their long-term safety profiles may take years to be fully appreciated. Physicians should not only be aware of the late and chronic AEs of AEDs but should systematically enquire and screen for these according to the individual AED AE profile. Care should be taken for individuals with comorbid conditions that may render them more susceptible to specific AEs. Prevention and appropriate management of long-term AED AEs is expected to improve adherence to treatment, quality of life and control of epilepsy.

How phenobarbital revolutionized epilepsy therapy: the story of phenobarbital therapy in epilepsy in the last 100 years

Phenobarbital (phenobarbitone) was first used as an antiepileptic drug 100 years ago, in 1912. This article tells the story of the discovery of its antiepileptic action, its early development, and the subsequent course of its clinical use over the 100-year period. The side effects, pharmacokinetics, and misuse of barbiturates are considered, along with the more recent clinical trials and the drug's current clinical utilization. The introduction of controlled drug regulations, the comparative cost of phenobarbital, and its inclusion on the World Health Organization (WHO) essential drug list are discussed. It is one of the few drugs on the formulary in 1912 that is still listed today, and remarkably its efficacy in epilepsy has not been significantly bettered. The current recommendation by the WHO is that phenobarbital should be offered as the first option for therapy for convulsive epilepsy in adults and children if availability can be ensured. This is rated as a strong recommendation because of the proven efficacy and low cost of phenobarbital, and despite its perceived side-effect profile and the practical problems of access. Whether this recommendation puts "a hierarchy on the brain," as has been suggested, is arguable. Much still needs to be learned about the drug's effects, and the issues raised by phenobarbital have lessons for all antiepileptic drug therapy.

Trends in the utilisation of psychotropic medications in Australia from 2000 to 2011

OBJECTIVE

This study examined longitudinal trends in the dispensing of psychotropic medications in Australia from January 2000 to December 2011.

METHOD

Dispensing data for the major classes of psychotropic medications (antidepressants, anxiolytics, sedatives, antipsychotics, mood stabilisers and attention-deficit hyperactivity disorder (ADHD) medications) were obtained from the Drug Utilisation Sub-Committee of the Australian Department of Health and Ageing. Results were expressed in terms of defined daily doses/1000 population/day (DDDs/1000/day).

RESULTS

There was a 58.2% increase in the dispensing of psychotropic drugs in Australia from 2000 to 2011, driven by major increases in antidepressants (95.3% increase in DDDs/1000/day), atypical antipsychotics (217.7% increase) and ADHD medications (72.9% increase). Dispensing of anxiolytics remained largely unchanged, while sedatives and typical antipsychotics decreased by 26.4% and 61.2%, respectively. Lithium dispensing remained static while valproate and lamotrigine increased markedly. In 2011, antidepressants accounted for 66.9% of total psychotropic DDDs/1000/day totals, far greater than anxiolytics (11.4%), antipsychotics (7.3%), mood stabilisers (5.8%), sedatives (5.5%), or ADHD medications (3.0%). Sertraline, olanzapine, valproate and methylphenidate were the most frequently dispensed antidepressant, antipsychotic, mood stabiliser and ADHD medication, respectively, while diazepam and temazepam were the most commonly dispensed anxiolytic and sedative.

CONCLUSIONS

Psychotropic utilisation markedly increased in Australia between 2000 and 2011. Some potential concerns include: (1) the continuing high use of benzodiazepines, particularly alprazolam, despite their problematic effects; (2) the rapid increase in serotonin noradrenaline reuptake inhibitor (SNRI) use, given their more complex side-effect profile relative to selective serotonin reuptake inhibitors (SSRIs); and (3) the dramatic increase in antidepressant prescriptions despite questions about the efficacy of these drugs in mild to moderate depression. Finally, some limitations are identified regarding use of the DDDs/1000/day metric, which can distort estimates of utilisation of specific drugs when the defined daily dose is higher or lower than the formulation most commonly dispensed by pharmacies.

Trends in the use of antiepileptic drugs among pregnant women in the US, 2001-2007: a medication exposure in pregnancy risk evaluation program study

BACKGROUND

Little is known about the extent of antiepileptic drug (AED) use in pregnancy, particularly for newer agents. Our objective was to assess whether AED use has increased among pregnant women in the US, 2001-2007.

METHODS

  We analysed data from the Medication Exposure in Pregnancy Risk Evaluation Program (MEPREP) database, 1 January 2001 to 31 December 2007. We identified liveborn deliveries among women, aged 15-45 years on delivery date, who were members of MEPREP health plans (n=585615 deliveries). Pregnancy exposure to AEDs, determined through outpatient pharmacy dispensing files. Older AEDs were available for clinical use before 1993; other agents were considered newer AEDs. Information on sociodemographic and medical/reproductive factors was obtained from linked birth certificate files. Maternal diagnoses were identified based on ICD-9 codes.

RESULTS

  Prevalence of AED use during pregnancy increased between 2001 (15.7 per 1000 deliveries) and 2007 (21.9 per 1000 deliveries), driven primarily by a fivefold increase in the use of newer AEDs. Thirteen per cent of AED-exposed deliveries involved a combination of two or more AEDs. Psychiatric disorders were the most prevalent diagnoses, followed by epileptic and pain disorders, among AED users regardless of AED type, year of conception or gestational period.

CONCLUSIONS

  AED use during pregnancy increased between 2001 and 2007, driven by a fivefold increase in the use of newer AEDs. Nearly one in eight AED-exposed deliveries involved the concomitant use of more than one AED. Additional investigations of the reproductive safety of newer AEDs may be needed.