A systematic review of placebo-controlled trials of topiramate: How useful is a multiple-indications review for evaluating the adverse events of an antiepileptic drug?

Mechanisms of neurodevelopmental toxicity of topiramate

Prescriptions for antiseizure medications (ASMs) have been rapidly growing over the last several decades due, in part, to an expanding list of clinical indications for which they are now prescribed. This trend has raised concern for potential adverse neurodevelopmental outcomes in ASM-exposed pregnancies. Recent large scale population studies have suggested that the use of topiramate (TOPAMAX, Janssen-Cilag), when prescribed for seizure control, migraines, and/or weight management, is associated with an increased risk for autism spectrum disorder (ASD), intellectual disability, and attention-deficit/hyperactivity disorder (ADHD) in exposed offspring. Here, we critically review epidemiologic evidence demonstrating the neurobehavioral teratogenicity of topiramate and speculate on the neuromolecular mechanisms by which prenatal exposure may perturb neurocognitive development. Specifically, we explore the potential role of topiramate's pharmacological interactions with ligand- and voltage-gated ion channels, especially GABAergic signaling, its effects on DNA methylation and histone acetylation, whether topiramate induces oxidative stress, and its association with fetal growth restriction as possible mechanisms contributing to neurodevelopmental toxicity. Resolving this biology will be necessary to reduce the risk of adverse pregnancy outcomes caused by topiramate or other ASMs.

Protective effect of lacosamide and topiramate treatment against Pentylenetetrazole-induced kindling and associated cognitive dysfunction in rats

Cognitive impairment is considered the most common comorbidity in epilepsy. The aim of the present study was to explore the effects of long-term treatment with lacosamide and topiramate on epileptogenesis and related cognitive dysfunction in an experimental model of pentylenetetrazole (PTZ)-induced kindling. The latter was induced by the repeated administration of subconvulsive dose of PTZ (40 mg/kg, s.c.) on every alternate day for 8–9 weeks. Both drugs were applied daily in a dose of 10 mg/kg p.o. 30 min before PTZ injection. To assess behavioral comorbidities all rats underwent one active and one passive avoidance tests. The results show that lacosamide significantly suppressed the progression of kindling, while the effect of topiramate was not so pronounced on seizure development. Long-term treatment with both antiepileptic drugs managed to ameliorate the kindling-associated impairment of learning and memory. Lacosamide and topiramate improved active and passive learning abilities and facilitated the formation of short- and long-term memory traces. Both drugs failed to prevent the hyperactivity associated with epilepsy.

Psychobehavioural and Cognitive Adverse Events of Anti-Seizure Medications for the Treatment of Developmental and Epileptic Encephalopathies

The developmental and epileptic encephalopathies encompass a group of rare syndromes characterised by severe drug-resistant epilepsy with onset in childhood and significant neurodevelopmental comorbidities. The latter include intellectual disability, developmental delay, behavioural problems including attention-deficit hyperactivity disorder and autism spectrum disorder, psychiatric problems including anxiety and depression, speech impairment and sleep problems. Classical examples of developmental and epileptic encephalopathies include Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. The mainstay of treatment is with multiple anti-seizure medications (ASMs); however, the ASMs themselves can be associated with psychobehavioural adverse events, and effects (negative or positive) on cognition and sleep. We have performed a targeted literature review of ASMs commonly used in the treatment of developmental and epileptic encephalopathies to discuss the latest evidence on their effects on behaviour, mood, cognition, sedation and sleep. The ASMs include valproate (VPA), clobazam, topiramate (TPM), cannabidiol (CBD), fenfluramine (FFA), levetiracetam (LEV), brivaracetam (BRV), zonisamide (ZNS), perampanel (PER), ethosuximide, stiripentol, lamotrigine (LTG), rufinamide, vigabatrin, lacosamide (LCM) and everolimus. Bromide, felbamate and other sodium channel ASMs are discussed briefly. Overall, the current evidence suggest that LEV, PER and to a lesser extent BRV are associated with psychobehavioural adverse events including aggressiveness and irritability; TPM and to a lesser extent ZNS are associated with language impairment and cognitive dulling/memory problems. Patients with a history of behavioural and psychiatric comorbidities may be more at risk of developing psychobehavioural adverse events. Topiramate and ZNS may be associated with negative effects in some aspects of cognition; CBD, FFA, LEV, BRV and LTG may have some positive effects, while the remaining ASMs do not appear to have a detrimental effect. All the ASMs are associated with sedation to a certain extent, which is pronounced during uptitration. Cannabidiol, PER and pregabalin may be associated with improvements in sleep, LTG is associated with insomnia, while VPA, TPM, LEV, ZNS and LCM do not appear to have detrimental effects. There was variability in the extent of evidence for each ASM: for many first-generation and some second-generation ASMs, there is scant documented evidence; however, their extensive use suggests favourable tolerability and safety (e.g. VPA); second-generation and some third-generation ASMs tend to have the most robust evidence documented over several years of use (TPM, LEV, PER, ZNS, BRV), while evidence is still being generated for newer ASMs such as CBD and FFA. Finally, we discuss how a variety of factors can affect mood, behaviour and cognition, and untangling the associations between the effects of the underlying syndrome and those of the ASMs can be challenging. In particular, there is enormous heterogeneity in cognitive, behavioural and developmental impairments that is complex and can change naturally over time; there is a lack of standardised instruments for evaluating these outcomes in developmental and epileptic encephalopathies, with a reliance on subjective evaluations by proxy (caregivers); and treatment regimes are complex involving multiple ASMs as well as other drugs.

Drug Safety in Episodic Migraine Management in Adults. Part 2: Preventive Treatments

PURPOSE OF REVIEW

The aim of this review is to aid in decision-making when choosing safe and effective options for preventive migraine medications.

RECENT FINDINGS

In Part 2, we have compiled clinically relevant safety considerations for commonly used migraine prophylactic treatments. Preventive treatment of episodic migraine includes nonspecific and migraine-specific drugs. While medications from several pharmacological classes-such as anticonvulsants, beta-blockers, and antidepressants-have an established efficacy in migraine prevention, they are associated with a number of side effects. The safety of migraine-specific treatments such as anti-CGRP monoclonal antibodies and gepants are also discussed. This review highlights safety concerns of commonly used migraine prophylactic agents and offers suggestions on how to mitigate those risks.

Topiramate-related adverse events: Pattern and signals in the Korea Adverse Event Reporting System, 2010-2017

Despite safety concerns associated with topiramate use, the pattern of adverse events and signal analysis of antiepileptic drugs remain elusive.We aimed to determine patient demographics and characteristics of reported AEs of topiramate and to detect the associated signals by comparing those of other antiepileptics.We used the Korea Institute of Drug Safety & Risk Management-Korea Adverse Event Reporting System Database (KIDS-KD) from 2010 to 2017 to determine patient demographics and characteristics of reported AEs for topiramate and other antiepileptics. The proportional reporting ratio, reporting odds ratio, and information component were used in signal detection. Signals were compared against drug labels in Korea, the UK, the EU, and the US.A total of 1300 adverse events cases of topiramate were reported, and the number of topiramate-adverse event pairs was 1861. For topiramate, the proportion of women of childbearing age (20-39 years) with adverse events was more than double that for other antiepileptics. A majority of the 36 detected signals were of neuropsychiatric disorders such as cognitive disorders, concentration impaired, amnesia, hypoaesthesia. Patients with topiramate-induced adverse events were likely to be young and female. Also, adverse events related to carbonic anhydrase isoenzyme showed specifically great disproportionalities.Rigorous clinical management is needed to ensure proper and safe use of topiramate. Special precautions should be taken when prescribing in women of childbearing age.

Carbonation dysgeusia associated with topiramate

PURPOSE

A case of carbonation dysgeusia associated with the use of topiramate is reported in order to bring awareness to a lesser-known adverse effect of the medication so that providers may be able to more effectively counsel patients and provide potential solutions.

SUMMARY

A 39-year-old Caucasian woman with longstanding epilepsy was initiated on topiramate therapy after experiencing a generalized seizure (she reported not taking any antiepileptic medication for years). Topiramate was started at a dosage of 25 mg by mouth twice daily and after 3 weeks titrated to a dosage of 100 mg by mouth twice daily for maintenance therapy. After initiation of topiramate therapy, the patient began to experience an immediate change in her carbonation perception when drinking carbonated beverages; all carbonated beverages, including seltzer and beer, tasted "flat." The patient remained on topiramate for the subsequent 12 months without her carbonation perception returning to normal but noted that drinking carbonated beverages through straws slightly mitigated the adverse effect. Case assessment using the adverse drug reaction probability scale of Naranjo et al indicated that topiramate was the probable cause of the patient's carbonation taste perversion.

CONCLUSION

A 39-year-old Caucasian woman developed chronic carbonation dysgeusia after initiation of topiramate following a generalized seizure.

Revisiting the Efficacy and Tolerability of Topiramate for Tic Disorders: A Meta-Analysis

Background: Tic disorders (TDs) are chronic neuropsychiatric disorders that usually begin in childhood. Currently, antipsychotic drugs, such as aripiprazole and risperidone, are frequently used to treat TD. However, adverse reactions limit their further usage. The efficacy of topiramate has been reported in recent studies. This study aimed to investigate the efficacy and tolerability of topiramate in the treatment of children with TDs. Methods: In this study, we performed a meta-analysis to assess the efficacy and tolerability of topiramate for TDs and identified the randomized controlled trials to evaluate topiramate for children with TDs from PubMed, the China National Knowledge Infrastructure database, Web of Science, and relevant reference lists. Quality assessment followed the Cochrane Handbook for Systematic Reviews of Interventions. A modified Jadad scale was used to assess the quality of included studies. Risk ratio (RR) was calculated as the effect size of efficacy and tolerability of topiramate for TDs. Results: A total of 15 studies involving 1070 participants aged 2-17 were included in the present meta-analysis, and 693 (64.71%) participants were male cases, with 14 studies evaluating the efficacy of topiramate for the treatment of TD. The results suggested that topiramate was more effective than control drugs (RR: 1.13, 95% confidence interval: [1.06-1.20], I² = 36%, Q = 20.31, p = 0.09). For the adverse events, there were 15 trials included in the meta-analysis, and the results showed that topiramate had fewer adverse events than control drugs (RR: 0.54, 95% confidence interval: [0.46-0.65], I² = 45%, Q = 25.49, p = 0.03). Conclusion: Compared with haloperidol and tiapride, topiramate appears to be a promising medication with good efficacy and tolerability for children with TDs. In future studies, large-sample, double-blind, placebo-controlled trials are needed to confirm its efficacy and tolerability compared with atypical antipsychotic agents (such as risperidone or aripiprazole).

Current pharmacotherapy for tic disorders

Introduction: Though many unanswered questions about the pathophysiology of Tourette Syndrome remain, several pharmacotherapies for tics have been studied, with varying results in terms of efficacy and the strength of evidence.Areas covered: This literature review encompasses pharmacotherapies for tics. The pharmacotherapies discussed in this review include: alpha agonists, antipsychotics, topiramate, botulinum toxin, and dopamine depleters.Expert opinion: Once the presence of tics is confirmed and psychoeducation and support are provided to patients and caregivers, one must examine the degree of tic-related impairment and the presence of psychiatric comorbidities. These factors influence treatment decisions as the presence of comorbidity and related impairment may shift the treatment target. When selecting a medication for tics, the presence of ADHD (the most frequent comorbidity) strengthens the case for choosing an alpha agonist. The case for antipsychotic medications is strongest when tic-related impairment is severe and/or the tics are refractory to more conservative measures. All medications require drug safety monitoring procedures and reevaluation over time.

Topiramate reduces nocturnal eating in sleep-related eating disorder

Study Objectives

Sleep-related eating disorder (SRED) is a parasomnia characterized by partial arousals from sleep with compulsive consumption of food with impaired level of awareness and memory for the event. Small case series’ have demonstrated efficacy of topiramate in SRED. We conducted a placebo-controlled randomized clinical trial of topiramate to assess efficacy in SRED.

Methods

Thirty-four participants with an ICSD-2/ICSD-3 diagnosis of SRED with >6 months of symptoms and ≥3 sleep-related eating episodes per week were randomized to placebo or topiramate with flexible dosing to a maximum dosage of 300 mg for 13 weeks. Primary outcomes were percentage of nights with eating and Clinician Global Impression-Improvement (CGI-I). Intention-to-treat last observation carried forward (ITT LOCF) analysis was conducted.

Results

Mean age was 39.5 years, 74% were female, with mean duration of sleep-related eating of 13.7 years. SRED symptoms were significantly reduced with topiramate (74.7% to 33.2% nights/week; n = 15) compared to placebo (77.0% to 57.4%; n = 17) (p = 0.035). There were significantly more CGI-I responders on topiramate (71%) than placebo (27%) (p = 0.016). Level of wakefulness (r = −0.49) and memory for nighttime eating (r = −0.58) at baseline predicted topiramate response. The topiramate group lost significantly more weight than the placebo group (−8.5 lbs vs. +1.0 lbs, p = 0.001). The most common side effects were paresthesias and cognitive dysfunction.

Conclusions

This first randomized controlled trial demonstrating efficacy for treatment of SRED supports preliminary data on the use of topiramate for SRED. Side effects were prominent for topiramate. Limitations include a small sample size and a high drop-out rate in both study groups.

Clinical Trial Information

NCT00606411

Practice guideline recommendations summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders

OBJECTIVE

To make recommendations on the assessment and management of tics in people with Tourette syndrome and chronic tic disorders.

METHODS

A multidisciplinary panel consisting of 9 physicians, 2 psychologists, and 2 patient representatives developed practice recommendations, integrating findings from a systematic review and following an Institute of Medicine-compliant process to ensure transparency and patient engagement. Recommendations were supported by structured rationales, integrating evidence from the systematic review, related evidence, principles of care, and inferences from evidence.

RESULTS

Forty-six recommendations were made regarding the assessment and management of tics in individuals with Tourette syndrome and chronic tic disorders. These include counseling recommendations on the natural history of tic disorders, psychoeducation for teachers and peers, assessment for comorbid disorders, and periodic reassessment of the need for ongoing therapy. Treatment options should be individualized, and the choice should be the result of a collaborative decision among patient, caregiver, and clinician, during which the benefits and harms of individual treatments as well as the presence of comorbid disorders are considered. Treatment options include watchful waiting, the Comprehensive Behavioral Intervention for Tics, and medication; recommendations are provided on how to offer and monitor these therapies. Recommendations on the assessment for and use of deep brain stimulation in adults with severe, treatment-refractory tics are provided as well as suggestions for future research.

A New Kid on the Block? Carbonic Anhydrases as Possible New Targets in Alzheimer's Disease

The increase in the incidence of neurodegenerative diseases, in particular Alzheimer's Disease (AD), is a consequence of the world's population aging but unfortunately, existing treatments are only effective at delaying some of the symptoms and for a limited time. Despite huge efforts by both academic researchers and pharmaceutical companies, no disease-modifying drugs have been brought to the market in the last decades. Recently, several studies shed light on Carbonic Anhydrases (CAs, EC 4.2.1.1) as possible new targets for AD treatment. In the present review we summarized preclinical and clinical findings regarding the role of CAs and their inhibitors/activators on cognition, aging and neurodegeneration and we discuss future challenges and opportunities in the field.

Topiramate-Induced Chest Pain: A Case Report

Background:

Topiramate, an anticonvulsant used for prophylaxis of migraines and epilepsy, is commonly associated with adverse effects of cognitive dulling and fatigue. Chest pain is a potential adverse effect that to our knowledge has not been reported with the use of topiramate.

Case Presentation:

We present the case of a 38-year-old female with a seizure disorder who experienced chest pain after the first dose of topiramate. On day 1, she presented to the emergency department, was admitted, and over the course of 3 days had a chest X-ray, electrocardiogram (ECG), and echocardiogram, and her vitals, basic metabolic panel, complete blood counts, troponin, and d-dimer levels were monitored. The chest pain improved when the topiramate was held. No identifiable causes of chest pain were apparent, other than the topiramate.

Discussion:

The Naranjo probability scale was utilized to determine the causality of topiramate. The resulting score of 3 indicates that it is possible that the chest pain was due to the topiramate.

Conclusion:

This report demonstrates an example of a patient who experienced chest pain possibly caused by the initiation of topiramate. The objective of this case report is to increase the awareness of chest pain as an adverse effect of topiramate.

Real-world assessment of treatment with extended-release topiramate (Trokendi XR®) and comparison with previous immediate-release topiramate treatment

AIM

Examine clinical profile of extended-release topiramate (Trokendi XR^®) and compare treatment-emergent adverse events (TEAEs) associated with Trokendi XR versus previous immediate-release topiramate (TPM-IR) treatment.

PATIENTS & METHODS

Pilot retrospective study analyzing data extracted from medical charts of patients ≥6 years of age prescribed Trokendi XR.

RESULTS

Trokendi XR was the most commonly used to prevent migraine. The most common TEAEs recorded during topiramate treatment were cognitive symptoms (word-finding difficulty, attention/concentration difficulty, slowed thinking), paresthesia, gastrointestinal problems and decreased appetite/weight loss. TEAE incidence was significantly (p < 0.001) lower during Trokendi XR versus previous TPM-IR treatment.

CONCLUSION

Trokendi XR use and outcomes in clinical practice were consistent with established profile of topiramate. Results supported the potential for better tolerability of Trokendi XR versus TPM-IR.

Tourette syndrome and other chronic tic disorders: an update on clinical management

INTRODUCTION

The management of Tourette syndrome (TS) and other chronic tic disorders occurs in multiple stages and begins with comprehensive assessment and complex psychoeducation. Behavioral and pharmacological interventions (second stage) are needed when tics cause physical or psychosocial impairment. Deep brain stimulation surgery or experimental therapies represent the third stage. Areas covered: Discussed are recent advances in assessment and therapy of chronic tic disorders, encompassing the three stages of intervention, with the addition of experimental, non-invasive brain stimulation strategies. A PubMed search was performed using as keywords: 'tic disorders', 'Tourette syndrome', 'assessment', 'rating scales', 'behavioral treatment', 'pharmacological treatment', 'deep brain stimulation', 'transcranial magnetic (or current) stimulation', and 'transcranial current stimulation'. More than 300 peer-reviewed articles were evaluated. The studies discussed have been selected on the basis of novelty and impact. Expert commentary: Comprehensive assessment of tic disorders and psychoeducation are crucial to a correct active management approach. Behavioral treatments represent first line of active interventions, with increasing potential offered by telehealth. Antipsychotics and alpha agonists remain first line pharmacological interventions for tics, although VMAT-2 inhibitors appear promising. Deep brain stimulation is a potential option for medically refractory, severely disabled patients with tics, but age and target selection require further investigation.

Neurodevelopmental Effects of Antiepileptic Drugs

Increasing evidence suggests that exposure to certain antiepileptic drugs (AEDs) during critical periods of development may induce transient or long-lasting neurodevelopmental deficits across cognitive, motor and behavioral domains. The developing nervous system may endure prolonged chronic exposure to AEDs during pregnancy (in utero) or during childhood, which can lead to neurodevelopmental defects such as congenital neural tube defects, lower IQ, language deficits, autism and ADHD. To date, valproate is the most widely recognized AED to significantly negatively affect neurodevelopment, and demonstrates greater adverse effects than any other AEDs that have been assessed. Although some AEDs appear to have low risk (i.e., lamotrigine, levetiracetam), other AEDs have been implicated in a variety of studies detailed below, and many AEDs have not been adequately assessed. The purpose of this review article is to summarize our current understanding of the neurodevelopmental effects of AEDs.

Carbonic anhydrase activation enhances object recognition memory in mice through phosphorylation of the extracellular signal-regulated kinase in the cortex and the hippocampus

Rats injected with by d-phenylalanine, a carbonic anhydrase (CA) activator, enhanced spatial learning, whereas rats given acetazolamide, a CA inhibitor, exhibited impairments of fear memory consolidation. However, the related mechanisms are unclear. We investigated if CAs are involved in a non-spatial recognition memory task assessed using the object recognition test (ORT). Systemic administration of acetazolamide to male CD1 mice caused amnesia in the ORT and reduced CA activity in brain homogenates, while treatment with d-phenylalanine enhanced memory and increased CA activity. We provided also the first evidence that d-phenylalanine administration rapidly activated extracellular signal-regulated kinase (ERK) pathways, a critical step for memory formation, in the cortex and the hippocampus, two brain areas involved in memory processing. Effects elicited by d-phenylalanine were completely blunted by co-administration of acetazolamide, but not of 1-N-(4-sulfamoylphenyl-ethyl)-2,4,6-trimethylpyridinium perchlorate ^(C18), a CA inhibitor that, differently from acetazolamide, does not cross the blood brain barrier. Our results strongly suggest that brain but not peripheral CAs activation potentiates memory as a result of ERK pathway enhanced activation.

Antiepileptic drugs in migraine and epilepsy: Who is at increased risk of adverse events?

Background The impact of adverse events (AEs) of antiepileptic drugs (AEDs) have an impact on compliance and dropouts. We compared tolerability of AEs of AEDs among patients with migraine, epilepsy, or both. Methods Overall, 335 patients (epilepsy (n = 142), migraine (n = 131), and both (n = 62)), were evaluated with the Liverpool Adverse Events Profile (LAEP) to assess the magnitude, profile and occurrence rate of the AEs of valproate, topiramate, and lamotrigine. Results AEs were significantly more common with topiramate treatment (71.0%) and among migraineurs (69.5%), the latter being more prone to discontinue AEDs (46.6%). The profile of AEs with topiramate and valproate differed among groups. Moreover, treatment with both topiramate and valproate was associated, for all groups, with a worse tolerability profile compared to lamotrigine. Conclusion Our data suggest a specific drug and disease AE profile of AEDs. Specifically, migraineurs are the most affected by AEs, even though they receive very low dosages of AEDs. This finding might be considered a clinical implication of central sensitization mechanisms. Both the profile and tolerability of AEs, highly influencing quality of life, depended on the underlying conditions, and deeply impacted on treatment dropout. Therefore, before starting, switching or stopping AED treatment, all options need to be considered.