Erratum to “Safety of zonisamide therapy: Prospective follow-up survey”

Outcome measures in pediatric polypharmacy research: a scoping review

INTRODUCTION

Various methods have been used to interpret the reports of pediatric polypharmacy across the literature. This is the first scoping review that explores outcome measures in pediatric polypharmacy research.

OBJECTIVES

The aim of our study was to describe outcome measures assessed in pediatric polypharmacy research.

METHODS

A search of electronic databases was conducted in July 2017, including Ovid Medline, PubMed, Elsevier Embase, Wiley Cochrane Central Register of Controlled Trials (CENTRAL), EBSCO CINAHL, Ovid PsyclNFO, Web of Science Core Collection, ProQuest Dissertations and Thesis A&I. Data were extracted about study characteristics and outcome measures, and also synthesized by harms or benefits mentioned.

RESULTS

The search strategy initially identified 8169 titles and screened 4398 using the inclusion criteria after de-duplicating. After the primary screening, a total of 363 studies were extracted for the data analysis. Polypharmacy (prevalence) was identified as an outcome in 31.4% of the studies, prognosis-related outcomes in 25.6%, and adverse drug reactions in 16.5%. A total of 265 articles (73.0%) mentioned harms, including adverse drug reactions (26.4%), side effects (24.2%), and drug-drug interactions (20.9%). A total of 83 studies (22.9%) mentioned any benefit, 48.2% of which identified combination for efficacy, 24.1% combination for treatment of complex diseases, and 19.3% combination for treatment augmentation. Thirty-eight studies reported adverse drug reaction as an outcome, where polypharmacy was a predictor, with various designs.

CONCLUSIONS

Most studies of pediatric polypharmacy evaluate prevalence, prognosis, or adverse drug reaction-related out-comes, and underscore harms related to polypharmacy. Clinicians should carefully weigh benefits and harms when introducing medications to treatment regimens.

Zonisamide decreases current-source density of high Beta frequency of electroencephalogram

Background and Purpose:

The purpose of this study was to investigate changes in brain current-source density (CSD) of the high frequency band (22–30 Hz) induced by zonisamide (ZNS) in patients with newly diagnosed epilepsy and to correlate with the cognitive performances.

Methods:

We conducted a 24-week, open-labeled, prospective study in 19 patients. Eelectroencephalography (EEG) and neuropsychological tests (NPs) were conducted at baseline and 24 weeks after starting the medication. Six patients were excluded due to artifacts in EEG. One patient did not attend follow-up studies. Twelve patients who completed follow-up EEG and NPs were included. We used low-resolution brain electromagnetic tomography to determine CSD, and we obtained statistical nonparametric maps for the high beta frequency band (22–30 Hz) between pretreatment EEGs and post-treatment EEGs.

Results:

The CSD in the 22–30 Hz band decreased in the superior frontal, middle frontal, anterior cingulate, precentral, postcentral, and inferior parietal gyri of the left hemisphere, and the middle frontal, inferior frontal and anterior cingulate gyri of the right hemisphere. Among the NPs items, the performance of verbal fluency was significantly impaired after the 24-week ZNS trial.

Conclusions:

The CSD changes suggest ZNS may diminish the activity of cerebral networks related to verbal fluency.

Antiepileptic drug therapy: does mechanism of action matter?

This article represents a synthesis of presentations made by the authors during a scientific meeting held in London on 7 June 2010 and organized by GlaxoSmithKline. Each speaker produced a short précis of his lecture to answer a specific question, resulting in an overview of what we know about the relevance of the mechanisms of action of antiepileptic drugs in determining appropriate combination therapies for the treatment of drug-resistant epilepsy.

Pregnancy and epilepsy management and outcome: an update

Epilepsy affects one in 100 individuals. Although epilepsy is gender neutral, women face more challenges with regard to treatment than men. Treatment of women with epilepsy is a therapeutic challenge since they are unlikely to be medication free. An estimated 1 million women with epilepsy are of childbearing age. Each year, approximately 20,000 births occur in women with epilepsy. Despite these challenges, over 90% of women with epilepsy have normal healthy outcomes. Ensuring seizure control is of utmost importance to the health of the mother and fetus. Serum concentrations of antiepileptic drug (AED) decrease during pregnancy resulting in an increased risk of seizure activity, which may result in serious consequences such as maternal injury or fetal and/or maternal demise. Teratogenicity secondary to AED drug exposure has long been reported, especially with the older AEDs, and to some degree with newer agents. More recently, the discovery of long-term cognitive impairment has been reported in offspring exposed to valproate in utero. Choice of AED must balance seizure control with minimizing the risk of malformations and other health issues. Prenatal planning is warranted whenever possible in order to address these concerns. Supplementation with folic acid pregestationally may be helpful in preventing malformations such as spina bifida.

Teratogenicity of antiepileptic medications

Antiepileptic drugs (AEDs) are frequently used to treat several conditions that are common in women of childbearing age, including epilepsy, headaches, and mood disorders. Moreover, as in the case of epilepsy and severe psychiatric disease, clinicians frequently do not have the option of stopping these medications or switching to another class of drugs. Overall, AEDs have been associated with an increased risk of major congenital malformations, minor anomalies, specific congenital syndromes, and developmental disorders seen in childhood. However, the differential effects of individual AEDs remain uncertain. Data are accumulating which strongly suggest that these risks are highest in patients receiving polypharmacy and valproate. There is also modest evidence to suggest an increased risk for phenobarbital. While other older AEDs appear to carry some teratogenic risk, there is not adequate evidence to further stratify their risk. Clinical and basic science research regarding newer AEDs suggests equivalent, if not safer, profiles compared with older AEDs, but these data are inconclusive. Management of women with epilepsy should include a discussion of these risks, prophylactic treatment with folic acid, and the minimal use of polypharmacy and valproate needed to maintain optimum seizure control.

Zonisamide: review of pharmacology, clinical efficacy, tolerability, and safety

BACKGROUND

Zonisamide (ZNS), a sulphonamide derivative, is a new-generation anticonvulsant with multiple potential mechanisms that contribute to its antiepileptic efficacy and may also explain its as yet incompletely assessed utility for non-seizure disorders such as headaches, neuropathic pain, and weight loss.

OBJECTIVE

A review of the pharmacokinetics, pharmacodynamics, evidence for efficacy in different seizure types and non-seizure conditions, adverse effects, and tolerability of ZNS is presented.

METHODS

A review of all manuscripts published in the English literature on ZNS was performed in preparing this manuscript.

RESULTS/CONCLUSIONS

ZNS has a broad label for use in Japan, while the regulatory bodies in the USA and Europe have approved it for use only as an adjunctive therapy for partial seizures in adults. It has favorable pharmacokinetic characteristics, proven efficacy in seizure disorders, and is well tolerated in long-term use.

Long-term cognitive and mood effects of zonisamide monotherapy in epilepsy patients

This study was a prospective, randomized, open-label investigation of the long-term effects of zonisamide (ZNS) monotherapy on cognition and mood of patients with epilepsy. Forty-three patients with epilepsy received ZNS, with final dose groups of 100, 200, 300, and 400mg/day. Cognitive and mood tests were done twice, at baseline and 1 year after starting medication. Nine patients were withdrawn prior to their follow-up tests. Three patients (33%) dropped out during the titration period because of cognitive and mood problems. Thirty-four patients completed follow-up neuropsychological tests. After 1 year of treatment, 16 patients (47%) complained of cognitive deficits. Only 5 patients (15%) experienced mood changes. Although ZNS decreased seizure frequency and EEG abnormalities and did not elicit significant mood changes, it had negative effects on several cognitive tests. Worse performance on delayed word recall, Trail Making Test Part B, and verbal fluency was related to dose. In conclusion, ZNS has adverse effects on cognition even after 1 year of treatment.

Long-term efficacy and safety of zonisamide monotherapy in epilepsy patients

BACKGROUND AND PURPOSE

Zonisamide (ZNS) is a useful antiepileptic drug with a broad therapeutic spectrum. However, there is limited information on the long-term use of ZNS as a monotherapy. This study investigated the long-term effects of ZNS as a monotherapy for the treatment of epilepsy.

METHODS

We retrospectively analyzed the records of epilepsy patients treated with ZNS monotherapy at our clinic. We identified outcomes for patients treated with ZNS monotherapy for a minimum of 6 months. Efficacy was quantified as the percentage change in seizure frequency, and safety was assessed by the frequency and types of adverse events.

RESULTS

Sixty patients who received ZNS for a minimum of 6 months were included. The mean duration of treatment was 19.8 months (range, 6-37 months), and the mean ZNS dosage was 255 mg/day (range, 100-500 mg/day). Twenty-seven patients (45%) were seizure-free, and an additional 20 patients (33%) had above 50% seizure frequency reduction at the last follow-up visit. Partial seizures with or without secondary generalization and generalized seizures were well controlled by ZNS, whereas complex partial seizures were not. Forty-eight patients (80%) reported mild-to-moderate adverse events, including memory loss (35%), attention deficit (27%), and weight loss (20%).

CONCLUSIONS

Long-term ZNS monotherapy is effective at treating a broad spectrum of seizure disorders, except complex partial seizures. However, a specific adverse event, such as cognitive impairment, is common and long-lasting.

Antikonvulsive Komedikation von Topiramat und Zonisamid

We analysed patients with focal epilepsies treated with zonisamide (ZNS) as add-on treatment to topiramate (TPM) and other antiepileptic drugs (mean 2). Twenty-five patients were evaluated, and follow-up data were available in 19 (12 women, seven men, mean age 34 years). The mean time until first follow-up investigation was 17 weeks. At that point in time the mean ZNS dosage was 344 mg and mean TPM dosage was 398 mg. Eight patients (42%) achieved seizure frequency reduced by at least 50%. Six patients (31%) reported side effects, especially cognitive impairment and weight loss (>5 kg) in two patients. In the further course of treatment, ZNS was discontinued in two of three patients because of cognitive impairment. We conclude that add-on treatment including ZNS and TPM can not be recommended for chronic treatment of epilepsy.