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

Content and sentiment analysis of gabapentinoid-related tweets: An infodemiology study

INTRODUCTION

The increasing number of gabapentinoid (pregabalin and gabapentin) harms, including deaths observed across countries is concerning to health-care professionals and policy makers. However, it is unclear if the public shares these concerns. This study aimed to describe posts related to gabapentinoids, conduct a content analysis to identify common themes and describe adverse events or symptoms.

METHODS

Keywords of 'pregabalin' or 'Lyrica' or 'gabapentin' or 'Neurontin' were used to search for related tweets posted by people in the community between 8 March and 7 May 2021. Eligible tweets included a keyword in the post. We extracted de-identified data which included descriptive data of the total number of posts over time; and data on individual tweets including date, number of re-tweets and post content. Data were exported separately for pregabalin- and gabapentin-related tweets. A 20% random sample was used for the thematic analysis.

RESULTS

There were 2931 pregabalin-related tweets and 2736 gabapentin-related tweets. Thematic analysis revealed three themes (sharing positive experiences and benefits of taking gabapentinoids, people voicing their negative experiences, and people seeking opinions and sharing information). Positive experiences of gabapentinoids were related to sharing stories and giving advice. This was contrasted to negative experiences including ineffectiveness, withdrawals, side effects and frustration related to cost and insurance coverage. Brain fog was the most common adverse symptom reported. Gabapentinoid-related deaths were only mentioned in three tweets.

DISCUSSION

The increasing public health concern of gabapentinoid-related deaths was not translated to Twitter discussions.

In Vivo and In Vitro Characterization of Close Analogs of Compound KA-11, a New Antiseizure Drug Candidate

Epilepsy is a neurological disorder involving a number of disease syndromes with a complex etiology. A properly matched antiseizure drug (ASD) gives remission in up to 70% of patients. Nevertheless, there is still a group of about 30% of patients suffering from drug-resistant epilepsy. Consequently, the development of new more effective and/or safer ASDs is still an unmet clinical need. Thus, our current studies were focused on the structural optimization/modifications of one of the leading compounds, KA-11, aiming at the improvement of its antiseizure activity. As a result, we designed and synthesized two close analogs with highly pronounced drug-like physicochemical properties according to in silico predictions, namely KA-228 and KA-232, which were subsequently tested in a panel of animal seizure models, i.e., MES, 6 Hz (32 mA), scPTZ and ivPTZ. Among these compounds, KA-232, which was designed as a water-soluble salt, was distinctly more effective than KA-228 and assured similar antiseizure protection as its chemical prototype KA-11. With the aim of a more detailed characterization of both new molecules, in vitro binding tests were performed to evaluate the potential mechanisms of action. Furthermore, KA-232 was also evaluated in several ADME-Tox studies, and the results obtained strongly supported its drug-like potential. The proposed chemical modification of KA-11 enabled the identification of new pharmacologically active chemotypes, particularly water-soluble KA-232, which, despite the lack of better efficacy than the leading compound, may be used as a chemical prototype for the development of new ASDs, as well as substances potentially active in other neurological or neurodegenerative conditions.

Current evidence for adjunct pyridoxine (vitamin B6) for the treatment of behavioral adverse effects associated with levetiracetam: A systematic review

BACKGROUND

Levetiracetam (LVT), while an effective treatment for multiple seizure types, is associated with a high incidence of neuropsychiatric adverse events (NPAEs). In predominantly retrospective studies, supplementation with pyridoxine/vitamin B₆ (PN) was associated with improvement in NPAEs in some people. A previous review highlighted a lack of double-blind, controlled trials of PN for the treatment of NPAEs in individuals treated with LVT. The current paper updates the findings from the previous review to include evidence from studies published since June 2019.

METHODS

An updated systematic review of the published literature was performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Embase, the Cochrane Library, and Google Scholar were searched to identify studies published between June 2019 and 2nd November 2022 in which supplementary PN was initiated for the treatment of LVT-associated NPAEs. All study types were eligible. The risk of bias in randomized trials was assessed using the Cochrane risk-of-bias tool.

RESULTS

Seven additional studies were identified: two double-blind, randomized controlled trials (RCTs), four retrospective studies, and one retrospective case series. One RCT reported significant improvements from baseline in behavioral adverse events (BAEs) in both the intervention (PN) group and the low-dose control group (both p < 0.05), with a significantly greater improvement in the intervention group (p < 0.001). In the second RCT, differences in BAE severity between PN and placebo groups at the endpoint were not statistically significant. In one retrospective study, subjective irritability was reported to have improved from baseline in 9/20 individuals (45%) treated with supplementary PN. Data for systematic assessments (PHQ-9 and GAD-7) were available for 10 individuals. Assessment by PHQ-9 showed that six individuals improved, two worsened and two had no change. Based on the GAD-7, three people improved, two worsened and five had no change. In the second retrospective study, 18/41 individuals (44%) who commenced PN following the emergence of BAEs showed "significant" improvement. In a separate group of individuals with pre-existing behavioral problems in whom PN treatment was initiated at the same time as commencing LVT, 3/18 (16.7%) developed BAEs. This compared with 79/458 people (17.2%) who were initially treated only with LVT. The third retrospective study compared treatment-related irritability in individuals who had been treated with both LVT and perampanel, either sequentially or concomitantly. Two people who developed irritability while receiving LVT monotherapy were able to continue treatment with the addition of PN. The fourth study reported a significantly lower LVT discontinuation rate in individuals taking PN and a higher rate of improved behavior in those who were able to continue LVT. The case series reported improvements in behavioral symptoms in six people within two to three weeks of commencing supplementary PN.

CONCLUSION

Data published within the last three years add to earlier evidence suggesting that PN might be effective in the treatment of NPAEs associated with LVT. However, the quality of evidence remains poor and only a few prospective trials have been published. Data from placebo-controlled trials are still largely lacking. Currently, there is insufficient evidence to justify any firm recommendation for PN supplementation to treat NPAEs associated with LVT. Further well-designed, prospective trials are warranted.

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.

Clinical Application of Pharmacokinetics to Appraise Adherence to Levetiracetam in Portuguese Epileptic Patients

Adherence to antiseizure drug treatment determines its effectiveness and safety, and consequently affects patients’ quality of life. Herein, we assessed adherence to levetiracetam in Portuguese patients with refractory epilepsy (n = 115), with resort to a pharmacokinetic drug monitoring approach. The pharmacokinetic parameters of levetiracetam in each patient were determined in steady-state while admitted to the hospital. Then, adherence was assessed by comparing the plasma concentration of the drug observed on the first day of hospitalization with the predicted plasma concentration, considering previously determined pharmacokinetic parameters. The rate of adherence was assessed according to gender, age, diagnosis, and antiseizure drug regimen. Among 115 enrolled patients, 49 (42.6%) were identified as non-adherent, 30 (26.1%) classified as under-consumers, and 19 (16.5%) as over-consumers. A relationship between adherence, daily dose and plasma concentrations was herein reported for the first time. Adherent patients received higher daily doses of levetiracetam [2500 (2000–3000) mg] than non-adherent over-consumers [1500 (1000–2000) mg] and non-adherent under-consumers [2000 (1500–3000) mg]. Higher average steady-state plasma concentrations of levetiracetam were found in non-adherent under-consumers [27.28 (15.33–36.36) mg/L], followed by adherent patients [22.05 (16.62–29.81) mg/L] and non-adherent over-consumers [17.50 (10.69–24.37) mg/L]. This study demonstrates that adherence (or lack thereof) influences the plasma concentrations of levetiracetam in steady-state and its pharmacological effects. Moreover, it emphasizes the importance of educating patients to encourage adherence to therapy. Otherwise, the risk of developing toxic and subtherapeutic concentrations is undeniable, compromising the therapeutic effect and safety of treatment.

Estimates of epilepsy prevalence, psychiatric co-morbidity and cost

PURPOSE

This study estimated epilepsy prevalence, psychiatric co-morbidity and annual costs associated with epilepsy.

METHODS

We used Danish national health registers to identify persons diagnosed with epilepsy and psychiatric disorders, and persons using antiseizure medication and persons using drugs for psychiatric disorders. We calculated the prevalence of epilepsy and co-morbid psychiatric disorders in Denmark on December 31, 2016, using information on epilepsy and psychiatric disorders based on combinations of hospital contacts and use of antiseizure and psychoactive medication. Further, direct and indirect annual costs associated with epilepsy were calculated using individual-level data from a range of socioeconomic registers.

RESULTS

There were 5,044,367 persons alive and living in Denmark on December 31, 2016, including 33,628 persons with at least one hospital contact with epilepsy in the previous five years (epilepsy prevalence 0.67% (0.69% males; 0.65% females)). Among these persons with epilepsy, we identified 12,562 (37.4%) persons with a psychiatric disorder or use of drugs used for psychiatric disorders as compared with 801,052 (15.9%) persons in the general population. The estimated total annual individual net costs associated with epilepsy was €30,683. Compared with prevalence estimates on December 31, 2006, the prevalence of epilepsy on December 31, 2016, was slightly higher in the older population and slightly lower in children CONCLUSIONS: Population estimates from national registers provide epilepsy prevalence estimates of approximately 0.6-0.7% - similar to previous reviews of epilepsy prevalence. In addition, the national sample allowed idenitfication of high prevalence of psychiatric disorders and high societal costs associated with epielspy.

Antidepressant and anticonvulsant prescription rates in patients with osteoarthritis: a population-based cohort study

Objectives

There are signs that antidepressants and anticonvulsants are being prescribed more often for OA patients, despite limited evidence. Our objectives were to examine prescription rates and time trends for antidepressants and anticonvulsants in OA patients, to assess the percentage of long-term prescriptions, and to determine patient characteristics associated with antidepressant or anticonvulsant prescription.

Methods

A population-based cohort study was conducted using the Integrated Primary Care Information database. First, episodic and prevalent prescription rates for antidepressants (amitriptyline, nortriptyline and duloxetine) and anticonvulsants (gabapentinoids) in OA patients were calculated for the period 2008–17. Logistic regression was used to assess which patient characteristics were associated with prescriptions.

Results

In total, 164 292 OA patients were included. The prescription rates of amitriptyline, gabapentin and pregabalin increased over time. The increase in prescription rates for pregabalin was most pronounced. Episodic prescription rate increased from 7.1 to 13.9 per 1000 person-years between 2008 and 2017. Amitriptyline was prescribed most (15.1 episodic prescriptions per 1000 person-years in 2017). Prescription rates of nortriptyline and duloxetine remained stable at 3.0 and 2.0 episodic prescriptions per 1000 person-years, respectively. For ≤3% of patients with incident OA, medication was prescribed long-term (≥3 months). In general, all medication was prescribed more frequently for older patients (except duloxetine), women, patients with OA in ≥2 joints, patients with spinal OA and patients with musculoskeletal disorders.

Conclusion

Prescription rates of amitriptyline, gabapentin and pregabalin increased over time. Since there is little evidence to support prescription in OA, caution is necessary when prescribing.

A review of antiepileptic drugs: Part 1 occurrence, fate in aquatic environments and removal during different treatment technologies

Antiepileptic drugs (AEDs) are the main treatment for people with epilepsy. However, in recent years, more and more people are using them for other indications such as: migraine, chronic neuropathic pain, and mood disorders. Consequently, the prescriptions and consumption of these drugs are increasing worldwide. In WWTPs, AEDs can resist degradation processes, such as photodegradation, chemical degradation and/or biodegradation. Until now, only constructed wetlands and photocatalysis have shown good removal rates of AEDs from wastewater. However, their effectiveness depends on the specific conditions used during the treatment. Since the consumption of AEDs has increased in the last decade and their degradation in WWTPs is poor, these drugs have been largely introduced into the environment through the discharge of municipal and/or hospital effluents. Once in the environment, AEDs are distributed in the water phase, as suspended particles or in the sediments, suggesting that these drugs have a high potential for groundwater contamination. In this first part of the AEDs review is designed to fill out the current knowledge gap about the occurrence, fate and removal of these drugs in the aquatic environment. This is a review that emphasizes the characteristics of AEDs as emerging contaminants.

Stem Cell Therapy for Modulating Neuroinflammation in Neuropathic Pain

Neuropathic pain (NP) is a complex, debilitating, chronic pain state, heterogeneous in nature and caused by a lesion or disease affecting the somatosensory system. Its pathogenesis involves a wide range of molecular pathways. NP treatment is extremely challenging, due to its complex underlying disease mechanisms. Current pharmacological and nonpharmacological approaches can provide long-lasting pain relief to a limited percentage of patients and lack safe and effective treatment options. Therefore, scientists are focusing on the introduction of novel treatment approaches, such as stem cell therapy. A growing number of reports have highlighted the potential of stem cells for treating NP. In this review, we briefly introduce NP, current pharmacological and nonpharmacological treatments, and preclinical studies of stem cells to treat NP. In addition, we summarize stem cell mechanisms—including neuromodulation in treating NP. Literature searches were conducted using PubMed to provide an overview of the neuroprotective effects of stem cells with particular emphasis on recent translational research regarding stem cell-based treatment of NP, highlighting its potential as a novel therapeutic approach.

Characteristics of adverse drug reactions associated with antiepileptics at a tertiary children's hospital in Japan: A retrospective observational cohort study

OBJECTIVE

The aim of this study was to explore the prescription pattern of antiepileptics and the relationship between antiepileptics and adverse drug reactions (ADRs) in a Japanese population.

METHODS

A retrospective observational cohort study was conducted by reviewing the medical records of patients who visited or were admitted to a single tertiary care center between January 2011 and June 2019, were treated with antiepileptics, and developed allergic ADRs associated with these drugs.

RESULTS

In total, 14,230 unique patients received antiepileptics during the study period. Diazepam was the most frequently used antiepileptic drug (74.8 %), followed by phenobarbital (14.3 %), valproic acid (11.4 %), fosphenytoin (10.0 %), and carbamazepine (7.3 %). Although a trend of increasing prevalence of newer generation antiepileptics was noted, most patients are still treated with older generation antiepileptics. Thirty-two (0.22 %) unique patients experienced ADRs associated with antiepileptics, and the antiepileptic drug most frequently associated with ADRs was carbamazepine, at a rate of 1.4 %. Three patients developed Stevens-Johnson syndrome/toxic epidermal necrolysis, in two of which carbamazepine was implicated. Most patients experienced ADRs associated with aromatic antiepileptics (84.4 %) or older generation antiepileptics (81.3 %).

SIGNIFICANCE

This is the first study to assess the relationship between ADRs and antiepileptics at a tertiary care center in Japan. Based on our results, most patients were prescribed older generation antiepileptics, and most ADR events were linked to the administration of drugs in this category; thus, identification of patients at risk of developing ADRs is critical in order to prevent such events.

Pharmacokinetic Monitoring of Levetiracetam in Portuguese Refractory Epileptic Patients: Effect of Gender, Weight and Concomitant Therapy

Levetiracetam is a second-generation antiepileptic drug, widely used in the treatment of focal and generalized epilepsy due to its pharmacokinetic and safety profiles. Its pharmacokinetic monitoring is ascribed as useful to personalize its dosing regimen. The aim of the present study was to describe, for the first time, the pharmacokinetics of levetiracetam in Portuguese refractory epileptic patients. Therefore, a retrospective study was carried out on 65 Portuguese refractory epileptic patients (pharmacokinetic study: 48; validation study: 17) admitted to the Refractory Epilepsy Centre of the Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal. The pharmacokinetic parameters of levetiracetam were estimated by applying a one-compartment model with first-order absorption and elimination analysis. Male patients showed higher distribution volume (Vd/F) and oral clearance (CL/F) than female patients (median Vd/F: 52.40 L in males and 38.60 L in females, p = 0.011; median CL/F: 4.71 L/h in males and 3.91 L/h in females, p = 0.028). Higher values of Vd/F (p = 0.026) and CL/F (p = 0.003) were also found in overweight patients relative to normal weight and obese patients. Carbamazepine was the co-administered antiepileptic drug that mostly affected the pharmacokinetics of levetiracetam, increasing both Vd/F (61.30 L with carbamazepine and 39.10 L without carbamazepine, p = 0.007) and CL/F (6.71 L/h with carbamazepine and 3.91 L/h without carbamazepine, p < 0.001). The pharmacokinetics of levetiracetam was affected by gender, body mass index, and co-administration of carbamazepine. This study highlights the impact of several factors on the CL/ and Vd/F of levetiracetam when administered to refractory epileptic patients. The importance of its pharmacokinetic monitoring in clinical pharmacy stands out, thereby enabling the optimization of antiepileptic drug therapy.

ALIAmides Update: Palmitoylethanolamide and Its Formulations on Management of Peripheral Neuropathic Pain

Neuropathic pain results from lesions or diseases of the somatosensory nervous system and it remains largely difficult to treat. Peripheral neuropathic pain originates from injury to the peripheral nervous system (PNS) and manifests as a series of symptoms and complications, including allodynia and hyperalgesia. The aim of this review is to discuss a novel approach on neuropathic pain management, which is based on the knowledge of processes that underlie the development of peripheral neuropathic pain; in particular highlights the role of glia and mast cells in pain and neuroinflammation. ALIAmides (autacoid local injury antagonist amides) represent a group of endogenous bioactive lipids, including palmitoylethanolamide (PEA), which play a central role in numerous biological processes, including pain, inflammation, and lipid metabolism. These compounds are emerging thanks to their anti-inflammatory and anti-hyperalgesic effects, due to the down-regulation of activation of mast cells. Collectively, preclinical and clinical studies support the idea that ALIAmides merit further consideration as therapeutic approach for controlling inflammatory responses, pain, and related peripheral neuropathic pain.

Trends in gabapentinoid prescribing, co-prescribing of opioids and benzodiazepines, and associated deaths in Scotland

BACKGROUND

Gabapentinoid drugs (gabapentin and pregabalin) are effective in neuropathic pain, which has a prevalence of ∼7%. Concerns about increased prescribing have implications for patient safety, misuse, and diversion. Drug-related deaths (DRDs) have increased and toxicology often implicates gabapentinoids. We studied national and regional prescribing rates (2006-2016) and identified associated sociodemographic factors, co-prescriptions and mortality, including DRDs.

METHODS

National data from the Information Service Division, NHS Scotland were analysed for prescribing, sociodemographic, and mortality data from the Health Informatics Centre, University of Dundee. DRDs in which gabapentinoids were implicated were identified from National Records of Scotland and Tayside Drug Death Databases.

RESULTS

From 2006 to 2016, the number of gabapentin prescriptions in Scotland increased 4-fold (164 630 to 694 293), and pregabalin 16-fold (27 094 to 435 490). In 2016 'recurrent users' (three or more prescriptions) had mean age 58.1 yr, were mostly females (62.5%), and were more likely to live in deprived areas. Of these, 60% were co-prescribed an opioid, benzodiazepine, or both (opioid 49.9%, benzodiazepine 26.8%, both 17.1%). The age-standardised death rate in those prescribed gabapentinoids was double that in the Scottish population (relative risk 2.16, 95% confidence interval 2.08-2.25). Increases in gabapentinoids contributing to cause of DRDs were reported regionally and nationally (gabapentin 23% vs 15%; pregabalin 21% vs 7%). In Tayside, gabapentinoids were implicated in 22 (39%) of DRDs, 17 (77%) of whom had not received a prescription.

CONCLUSIONS

Gabapentinoid prescribing has increased dramatically since 2006, as have dangerous co-prescribing and death (including DRDs). Older people, women, and those living in deprived areas were particularly likely to receive prescriptions. Their contribution to DRDs may be more related to illegal use with diversion of prescribed medication.

Antiepileptic Drug Treatment Patterns in Women of Childbearing Age With Epilepsy

Importance

Limited population-based data are available on antiepileptic drug (AED) treatment patterns in women of childbearing age with epilepsy; the current population risk is not clear.

Objectives

To examine the AED treatment patterns and identify differences in use of valproate sodium and topiramate by comorbidities among women of childbearing age with epilepsy.

Design, Setting, and Participants

A retrospective cohort study used a nationwide commercial database and supplemental Medicare as well as Medicaid insurance claims data to identify 46 767 women with epilepsy aged 15 to 44 years. The eligible study cohort was enrolled between January 1, 2009, and December 31, 2013. Data analysis was conducted from January 1, 2017, to February 22, 2018.

Exposures

Cases required an International Classification of Diseases, Ninth Revision, Clinical Modification-coded epilepsy diagnosis with continuous medical and pharmacy enrollment. Incident cases required a baseline of 2 or more years without an epilepsy diagnosis or AED prescription before the index date. For both incident and prevalent cases, focal and generalized epilepsy cohorts were matched by age, payer type, and enrollment period and then compared.

Main Outcomes and Measures

Antiepileptic drug treatment pattern according to seizure type and comorbidities.

Results

Of the 46 767 patients identified, there were 8003 incident cases (mean [SD] age, 27.3 [9.4] years) and 38 764 prevalent cases (mean [SD] age, 29.7 [9.0] years). Among 3219 women in the incident epilepsy group who received AEDs for 90 days or more, 3173 (98.6%) received monotherapy as first-line treatment; among 28 239 treated prevalent cases, 18 987 (67.2%) received monotherapy. In 3544 (44.3%) incident cases and 9480 (24.5%) prevalent cases, AED treatment was not documented during 180 days or more of follow-up after diagnosis. Valproate (incident: 35 [5.81%]; prevalent: 514 [13.1%]) and phenytoin (incident: 33 [5.48%]; prevalent: 178 [4.53%]) were more commonly used for generalized epilepsy and oxcarbazepine (incident: 53 [8.03%]; prevalent: 386 [9.89%]) was more often used for focal epilepsy. Levetiracetam (incident: focal, 267 [40.5%]; generalized, 271 [45.0%]; prevalent: focal, 794 [20.3%]; generalized, 871 [22.2%]), lamotrigine (incident: focal, 123 [18.6%]; generalized, 106 [17.6%]; prevalent: focal, 968 [24.8%]; generalized, 871 [22.2%]), and topiramate (incident: focal, 102 [15.5%]; generalized, 64 [10.6%]; prevalent: focal, 499 [12.8%]; generalized, 470 [12.0%]) were leading AEDs prescribed for both focal and generalized epilepsy. Valproate was more commonly prescribed for women with comorbid headache or migraine (incident: 53 of 1251 [4.2%]; prevalent: 839 of 8046 [10.4%]), mood disorder (incident: 63 of 860 [7.3%]; prevalent: 1110 of 6995 [15.9%]), and anxiety and dissociative disorders (incident: 57 of 881 [6.5%]; prevalent: 798 of 5912 [13.5%]). Topiramate was more likely prescribed for those with comorbid headache or migraine (incident: 335 of 1251 [26.8%]; prevalent: 2322 of 8046 [28.9%]).

Conclusions and Relevance

Many women appear to be treated with valproate and topiramate despite known teratogenicity risks. Comorbidities may affect selecting certain AEDs despite their teratogenicity risks.

Pain And The Use Of Gabapentinoids In German Nursing Home Residents - Results From An Analysis Based On Statutory Health Insurance Data

Background

Gabapentinoids (gabapentin and pregabalin) are psychoactive medications that are increasingly used for different conditions. Since there is evidence that psychotropic drugs, in general, are often inappropriately prescribed in elderly patients, we aimed to determine frequency and indications of gabapentinoid prescribing for nursing home residents.

Methods

We analyzed data from a large German statutory health insurance database. Included were records from people ≥65 years-of-age, who were admitted to a nursing home between January 2010 and December 2014. We determined the number and proportion of common indications for on- and off-label prescriptions, the most frequent co-medications, and the characteristics of patients and prescribers.

Results

Of 127,277 residents, 9539 (7.5%) received gabapentinoids and 4852 initiated treatment (4.0%; with 66.3% pregabalin). Median age of gabapentinoid initiators was 84 years (78.5% females). In these users, on-label prescribing was found in 57.4%, predominantly for neuropathic pain. Other painful conditions were also chief causes (84.7%) for off-label prescribing. Gabapentinoids were mainly started by general practitioners (64.5%) while pain specialists contributed <2%. Forty-six percent of users received additional opioids and in 27.5% gabapentinoids were prescribed only once.

Conclusion

Gabapentinoids were frequently used in nursing home residents. Regular co-prescribing with opioids and psychotropic drugs might indicate employment to improve pain or assist treatment of conditions that are frequently associated with disruptive behavior such as dementia. However, more research is needed to better understand decision-making regarding gabapentinoid prescribing, especially in view of aggressive marketing, uncertain analgesic effects, problematic side effects, and uncritical use in the elderly.

Single-tube multiplex real-time PCR assay for rapid and reliable detection of HLA-A*31:01 allele

AIM

HLA-A*31:01 has been associated with carbamazepine-induced hypersensitivity reactions. HLA-A*31:01 genetic testing is recommended before the initiation of carbamazepine therapy.

METHODS

A novel real-time PCR assay was designed for HLA-A*31:01 detection by allele-specific primers and TaqMan minor groove binding probes.

RESULTS

The genotyping results in 100 subjects by the established method who were in 100% agreement with the sequencing-based typing method. The assay presents a sensitivity of 1 (95% CI: 0.69-1.00), a specificity of 1 (95% CI: 0.96-1.00) and a positive and negative predictive value of 1. The carrier rates of HLA-A*31:01 in Tibetan (n = 45), Han Chinese (n = 100), Miaos (n = 48) and Khalkhas (n = 48) were 22.2, 10, 4.2 and 18.8%, respectively.

CONCLUSION

This assay is reliable to detect HLA-A*31:01 and would be useful to prevent carbamazepine-induced hypersensitivity reactions.

Development of EpiRisk: An online clinical tool for estimating the risk of major congenital malformations in pregnant women treated for epilepsy

Antiepileptic drugs (AEDs) are known to associate with an increased risk of major congenital malformations (MCMs) in children born to women who become pregnant while taking them. As the indications for AEDs continue to diversify, novel AEDs emerge, and polytherapy becomes more prevalent, the volume and complexity of the information relating to teratogenic risk can become unmanageable for the clinician. This in turn makes accurate education of pregnant women treated with AEDs regarding the risk of MCMs challenging. To enable clinicians to provide better information regarding the potential teratogenic risk of AEDs, we outline here the method we have employed to underpin a new system of real-time risk analysis, "EpiRisk." When launched, EpiRisk will offer a user-friendly, online clinical tool, compatible with all modern Internet browsers, smart phones, and personal computers. Using the most current published data, as well as "real world" data from the UK and the Australian Pregnancy Registers, EpiRisk will enable clinicians to quickly and accurately assess the teratogenic risk of AEDs in mono- and polytherapy. EpiRisk may thus provide a future-proof central hub for empowering patients, clinicians, and registries by delivering evidence-based information on the teratogenic risk of the AEDs in pregnant women with epilepsy through an easily accessible platform.

Psychiatric comedication in patients with epilepsy

Psychiatric disorders are more common in patients with epilepsy than in the general population. The aims of the study were to assess the frequency and type of psychotropic drug usage in patients with epilepsy, to assess the risk factors for their use, and to assess their proconvulsive potential and the risk of interactions with antiepileptic drugs. This 20-month prospective study included patients treated at the university hospital outpatient clinic. Psychotropic drugs have been classified according to the Anatomical Therapeutic Chemical Classification System. Of the 621 patients (with a mean age of 35.4years), 60% were women, and 37.5% were in remission; 54.8% of the patients used antiepileptic drug monotherapy. The most commonly used antiepileptic drugs were valproate, levetiracetam, lamotrigine, and carbamazepine. Eighty-nine (14.3%) patients received psychiatric comedication. Sertraline, perazine, and hydroxyzine were the predominantly used psychotropic drugs. Independent variables associated with psychotropic drug usage in the logistic regression model included age, active epilepsy, combined focal and generalized epilepsy type, use of somatic comedication, and phenobarbital. Over one-third of the patients simultaneously received antiepileptic drugs and psychotropic drugs, between which clinically significant interactions may occur, 10% of patients used psychotropic drugs to lower the seizure threshold. The results of the study indicate the need for closer cooperation between doctors of various specialties when caring for patients with epilepsy.

The impact of a pain assessment intervention on pain score and analgesic use in older nursing home residents with severe dementia: A cluster randomised controlled trial

BACKGROUND

Pain is highly prevalent in older adults, especially those in institutional settings such as nursing homes. The presence of dementia may increase the risk of underdiagnosed and undertreated pain. Pain assessment tools are not regularly used in clinical practice, however, there are indications that the regular use of pain assessments tools may influence the recognition of pain by nursing staff and thereby affect pain management.

OBJECTIVES

To assess whether regular pain assessment using a pain assessment tool is associated with changes in i) pain scores and ii) analgesic use in nursing home residents with severe dementia.

DESIGN

Cluster-randomised controlled trial.

SETTING

The study was conducted in 16 nursing homes in four counties in Norway.

PARTICIPANTS

A total of 112 nursing home residents aged 65 years and older with dementia who lacked the capacity for self-reporting pain or were non-verbal.

METHODS

The experimental group were regularly assessed pain with a standardised pain scale (the Doloplus-2) twice a week for a 12-week intervention period. The control group received usual care. The primary outcome was pain score measured with the Doloplus-2, and the secondary outcome was analgesic use (oral morphine equivalents and milligram/day paracetamol). Data on the outcomes were collected at baseline and at the end of week 12. The nursing staff in both the experimental and the control groups received training to collect the data. Linear mixed models were used to assess possible between-group difference over time.

RESULTS

No overall effect of regular pain assessment was found on pain score or analgesic use. The mean score of Doloplus-2 and analgesic use remained unchanged and above the established cut-off in both groups.

CONCLUSION

The current intervention did not change analgesic use or pain score compared with the control condition. However, there is not sufficient evidence to conclude that regular pain assessment using a pain assessment tool is not clinically relevant. Furthermore, our results indicated that pain continued to be inadequately treated in nursing home residents with severe dementia. Therefore, further research on how standardised pain assessment can be used to support effective pain management in this population is needed.

Declining trend in valproate use in Finland among females of childbearing age in 2012-2016 - a nationwide registry-based outpatient study

BACKGROUND AND PURPOSE

Documented teratogenic effects of valproate (VPA) prompted restrictions of its use in females of childbearing age in 2014. We investigated possible annual changes in the outpatient use of VPA in Finland during 2008-2016 with a special focus on women.

METHODS

We identified all outpatients with VPA purchases between 2008 and 2016 categorizing users due to epilepsy, bipolar disorder or miscellaneous indications. Temporal trends in the annual prevalence rates of VPA use were estimated using Poisson regression analyses.

RESULTS

Between 2012 and 2016, the prevalence of VPA use among women aged 15-44 years decreased by 19%, from 50/10 000 to 40/10 000 (prevalence rate ratio, 0.81; 95% confidence intervals, 0.77-0.91; P < 0.001). The use of VPA due to epilepsy decreased significantly in females aged 15-24 and 25-34 years and that due to bipolar disorders decreased significantly in females aged 25-34 and 35-44 years. The use of VPA in the miscellaneous indication group decreased by 32% after 2014 in females aged 15-44 years and, most strikingly, by 56% among those aged 15-25 years. In women with epilepsy, the use of VPA increased among those over the age of 44 years.

CONCLUSIONS

The rates of female VPA users with childbearing potential have decreased in all three major indication groups in Finland during recent years, especially after the European Medicines Agency restrictions were published in 2014. However, it still remains open to question as to whether the practice of VPA use follows current guidelines. A special concern is the relatively high prevalence of off-label use of VPA in fertile-aged females.

Observational multicentre study into the use of antiepileptic drugs in Spanish neurology consultations

INTRODUCTION

The study aims to quantify the types of antiepileptic drugs (AED) prescribed in neurology consultations.

MATERIAL AND METHOD

This descriptive, observational study included a sample of 559 patients older than 14 years, diagnosed with epilepsy, and receiving pharmacological treatment. Data were collected at outpatient consultations by 47 Spanish neurologists in May 2016. Epilepsy was defined based on the International League Against Epilepsy classification. According to the year of marketing, AEDs were categorised as classic (before 1990) or new (after 1990). We performed a descriptive analysis of qualitative and quantitative variables.

RESULTS

Female patients accounted for 54.6% of the sample. Mean age was 42.7 years; mean age of onset was 22.4. Regarding epilepsy type, 75.7% of patients experienced partial seizures, 51.5% were symptomatic,32.4% had refractory epilepsy, 35.6% had been seizure-free for the previous year, and 59.2% had associated comorbidities.A total of 1103 AED prescriptions were made; 64.6% of prescriptions were for new AEDs; 85.4% of patients received new AEDs. Patients received a mean of 2 AEDs (range, 1-5). A total of 59.6% of patients received polytherapy.The most frequently prescribed AEDs were levetiracetam (42.6%), valproic acid (25.4%), lamotrigine (19.5%), carbamazepine (17.9%), and lacosamide (17.5%). No AED was employed exclusively as monotherapy. The most frequently prescribed AEDs for generalised and partial seizures were valproic acid (48.2%) and levetiracetam (43.2%), respectively. Valproic acid was less frequently prescribed to female patients. Patients with refractory epilepsy or with associated comorbidities were more frequently prescribed a combination of new and classic AEDs (48.7% and 45.6%, respectively) than only one type of AED.

CONCLUSIONS

The majority of patients received new AEDs. The combination of classic and new AEDs was more frequently prescribed to patients with refractory epilepsy or with associated comorbidities.

Pharmacokinetic variability of valproate during pregnancy - Implications for the use of therapeutic drug monitoring

BACKGROUND AND PURPOSE

Use of valproate (VPA) in women of childbearing age is restricted due to dose-dependent risk of teratogenicity. The purpose of this study was to characterise pharmacokinetic variability of VPA in pregnancy, and discuss use of therapeutic drug monitoring (TDM) as guidance to exposure in women.

METHOD

Measurements of trough total and unbound VPA concentrations before, during and after pregnancy, at assumed steady-state were collected from the TDM-database (2006-2016) at the National Center for Epilepsy in Norway. Additional clinical data were obtained from the Oppland county Perinatal Database (1994-2011).

RESULTS

Data from 51 pregnancies in 33 women aged 19-40 years were included. Each woman underwent 1-4 pregnancies, and 1-7 measurements per pregnancy were performed. The variability in total concentration/dose (C/D)-ratios between women was 13-fold, and intra-patient variability extensive. Total C/D-ratios were reduced by 46% from before pregnancy to third trimester (0.48-0.29 μmol/L/mg). Unbound concentrations of VPA were only requested in 10% of the pregnancies. Repeated measurements from two pregnancies in one women revealed increased unbound concentration of VPA during pregnancy. There were 19 with idiopathic generalized epilepsy and two focal based on clinical data from 21 women and 38 pregnancies; 1 major congenital malformation was noted.

CONCLUSION

There is pronounced pharmacokinetic variability of VPA during pregnancy. Unbound concentrations are rarely requested. TDM should be used by measurements of both total and unbound concentrations since total concentrations may be misleading for efficacy and fetal exposure of VPA.

Reference ranges for antiepileptic drugs revisited: a practical approach to establish national guidelines

BACKGROUND AND OBJECTIVE

Laboratories sometimes use different reference ranges for the same antiepileptic drug (AED), particularly for new and poorly investigated drugs. This may contribute to misunderstandings, concerns or inappropriate dose changes, which in turn may affect therapeutic effect, drug safety or treatment adherence. Therefore, the Norwegian Association of Clinical Pharmacology wished to update and harmonize the reference ranges for AEDs and establish national guidelines for Norway.

METHODS

A working group collected information on the reference ranges used by Norwegian laboratories for all commonly used AEDs. These reference ranges were compared to recent recommendations by the International League Against Epilepsy, current literature, applicable clinical studies, reference ranges used by leading Northern European epilepsy centers outside of Norway, and routine data derived from Norwegian laboratory databases.

RESULTS

Reference ranges varied between laboratories for four of 23 available AEDs (lamotrigine, valproate, eslicarbazepine and oxcarbazepine). For four AEDs (brivaracetam, perampanel, stiripentol and sulthiame), reference ranges had not previously been established. In total, 13 reference ranges were either harmonized, updated or newly established. No changes were applied to the remaining 10 AEDs.

CONCLUSION

Updated and harmonized reference ranges are now available for 22 of the 23 AEDs available in Norway. The exception is vigabatrin (reference range not applicable). Revision of reference ranges is an important part of pharmacovigilance of AEDs and must be a continuous process based on current literature and clinical experience.

Electroconvulsive therapy and subsequent epilepsy in patients with affective disorders: A register-based Danish cohort study

OBJECTIVE

It has been suggested that Electroconvulsive Therapy (ECT) might increase the risk of epilepsy but the few patient studies with retrospective data from medical records do not support the hypothesis. The aim of this study was to examine the relationship between ECT and subsequent incident epilepsy in patients with affective disorder. We also explored whether any association varied with number of ECTs and time since last treatment.

METHODS

All 169,457 patients with first hospital contact for an affective disorder between January 2005 and December 2015 were identified in the Danish National Patient Registry and followed for incident epilepsy from January 2005 until November 2016. The association between ECT and epilepsy was examined using Cox proportional hazard regression with adjustment for gender, age, educational level, comorbid schizophrenia, previous stroke and antidepressant and antipsychotic medication use.

RESULTS

A total of 5875 patients had at least one ECT and 1873 patients developed epilepsy (Incidence rate: 213 pr. 100,000 person years) during the follow-up of mean 5 years. In patients below age 40 years, ECT was associated with a higher rate of epilepsy after adjustment for covariables (Hazard Ratio (HR) = 1.84; 95% Confidence Intervals (CI) = [1.24-2.74]). In patients aged 41-60 years ECT was not associated with epilepsy, while for those above 60 treated with ECT the rate was lower (HR = 0.57; (95% CI = [0.37-0.89]).

CONCLUSION

In patients with affective disorders, we found a weak positive association between ECT and subsequent diagnosis of epilepsy in those younger than 40 years, and a weak negative association in patients older than 60 years. The associations might be subject to residual confounding from risk factors related to ECT.

The HLA-A*31:01 allele: influence on carbamazepine treatment

Carbamazepine (CBZ) is an effective anticonvulsant that can sometimes cause hypersensitivity reactions that vary in frequency and severity. Strong associations have been reported between specific human leukocyte antigen (HLA) alleles and susceptibility to CBZ hypersensitivity reactions. Screening for HLA-B*15:02 is mandated in patients from South East Asia because of a strong association with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). HLA-A*31:01 predisposes to multiple phenotypes of CBZ hypersensitivity including maculopapular exanthema, hypersensitivity syndrome, and SJS/TEN in a range of populations including Europeans, Japanese, South Koreans and Han Chinese, although the effect size varies between the different phenotypes and populations. Between 47 Caucasians and 67 Japanese patients would need to be tested for HLA-A*31:01 in order to avoid a single case of CBZ hypersensitivity. A cost-effectiveness study has demonstrated that HLA-A*31:01 screening would be cost-effective. Patient preference assessment has also revealed that patients prefer pharmacogenetic screening and prescription of alternative anticonvulsants compared to current standard of practice without pharmacogenetic testing. For patients who test positive for HLA-A*31:01, alternative treatments are available. When alternatives have failed or are unavailable, HLA-A*31:01 testing can alert clinicians to 1) patients who are at increased risk of CBZ hypersensitivity who can then be targeted for more intensive monitoring and 2) increase diagnostic certainty in cases where hypersensitivity has already occurred, so patients can be advised to avoid structurally related drugs in the future. On the basis of the current evidence, we would favor screening all patients for HLA-A*31:01 and HLA-B*15:02 prior to starting CBZ therapy.

Pharmacokinetic variability, efficacy and tolerability of eslicarbazepine acetate-A national approach to the evaluation of therapeutic drug monitoring data and clinical outcome

BACKGROUND

Eslicarbazepine acetate (ESL) is a new antiepileptic drug (AED), still insufficiently studied regarding pharmacokinetic variability, efficacy and tolerability. The purpose of this study was to evaluate therapeutic drug monitoring (TDM) data in Norway and relate pharmacokinetic variability to clinical efficacy and tolerability in a long-term clinical setting in patients with refractory epilepsy.

METHODS

This retrospective observational study included TDM-data from the main laboratories and population data from the Norwegian Prescription Database in Norway, in addition to clinical data from medical records of adult patients using ESL for up to three years, whenever possible.

RESULTS

TDM-data from 168 patients were utilized for assessment of pharmacokinetic variability, consisting of 71% of the total number of patients in Norway using ESL, 2011-14. Median daily dose of ESL was 800mg (range 400-1600mg), and median serum concentration of ESL was 53μmol/L (range 13-132μmol/L). Inter-patient variability of ESL was extensive, with 25-fold variability in concentration/dose ratios. Additional clinical data were available from 104 adult patients out of the 168, all with drug resistant focal epilepsy. After 1, 2 and 3 years follow-up, the retention rate of ESL was 83%, 72% and 64%, respectively. ESL was generally well tolerated as add-on treatment, but sedation, cognitive impairment and hyponatremia were reported. Hyponatremia (sodium <137mmol/L) was present in 36% of the patients, and lead to discontinuation in three.

CONCLUSION

Pharmacokinetic variability of ESL was extensive and the demonstration of usefulness of TDM requires further studies. In patients with drug resistant focal Epilepsy, the high retention rate indicated good efficacy and tolerability. Hyponatremia was observed in one third of the patients. The present results point to a need for individualization of treatment and TDM may be useful.