Zonisamide-Induced Suicidal Ideation

The Use of Zonisamide for the Treatment of Psychiatric Disorders: A Systematic Review

OBJECTIVE

Traditional pharmacotherapy has undoubtedly improved the outcome of patients with psychiatric disorders, but partial efficacy or poor tolerability persists in a number of these subjects. Among different compounds, zonisamide has been used to address unmet needs of standard pharmacotherapy. The purpose of the present article is to provide a review about the use of zonisamide for the treatment of psychiatric conditions.

METHODS

A research in the main database sources has been conducted to obtain an overview of the use of zonisamide in psychiatric disorders or associated conditions (obesity and smoking cessation).

RESULTS

Most available data indicate the possible effectiveness of zonisamide for the treatment of acute phases of bipolar disorder, binge-eating disorder (BED), alcohol misuse, and obesity. A further assessment of the safety and tolerability of zonisamide is made necessary by the fact that, with the exception of BED, for all other disorders at least some data come from studies with combined pharmacological therapies.

CONCLUSIONS

Zonisamide may have some utility, especially as an adjunctive therapy, for the management of acute phases and weight gain in bipolar disorder and for prevention of alcohol misuse. Preliminary evidence indicates zonisamide as a candidate compound for the treatment of BED and obesity. However, open-label design and small sample sizes of most available studies prevent from drawing sound conclusions about the utility of this compound in psychiatry.

A randomized, controlled, double-blind, crossover trial of zonisamide in myoclonus-dystonia

OBJECTIVE

To evaluate the efficacy and safety of zonisamide in patients with myoclonus-dystonia.

METHODS

We conducted a randomized, double-blind, placebo-controlled crossover trial of zonisamide (300 mg/d) in 24 patients with myoclonus-dystonia. Each treatment period consisted of a 6-week titration phase followed by a 3-week fixed-dose phase. The periods were separated by a 5-week washout period. The co-primary outcomes were action myoclonus severity (section 4 of the Unified Myoclonus Rating Scale [UMRS 4]) and myoclonus-related functional disability (UMRS 5). Secondary outcomes included dystonia severity, assessed with the movement and disability subscales of the Burke-Fahn-Marsden-Dystonia Rating Scale (BFM), the Clinical Global Impression-Improvement scale (CGI), and safety measures. Wilcoxon signed-rank tests for paired data were used to analyze treatment effects.

RESULTS

Twenty-three patients (11 men, 12 women) were analyzed in the intention-to-treat analysis. Zonisamide significantly improved both action myoclonus (median improvement [95% confidence limits] -5 [-9.25 to -1.44], p = 0.003) and myoclonus-related functional disability (median improvement [95% confidence limits] -2 [-2.58 to -2.46], p = 0.007) compared to placebo. Zonisamide also significantly improved dystonia (BFM movement) compared to placebo (median improvement [95% confidence limits] -3 [-8.46 to 0.03], p = 0.009). No difference was found between zonisamide and placebo with respect to the CGI (median improvement [95% confidence limits] -1 [-1.31 to 0.09], p = 0.1). Zonisamide was well-tolerated.

CONCLUSIONS

Zonisamide is well-tolerated and effective on the motor symptoms of myoclonus-dystonia.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that zonisamide improves myoclonus and related disability in patients with myoclonus-dystonia.

Report of the WPA section of pharmacopsychiatry on the relationship of antiepileptic drugs with suicidality in epilepsy

INTRODUCTION

This report from the World Psychiatric Association Section on Pharmacopsychiatry examines the possible relationship of antiepileptic drugs with suicide-related clinical features and behaviors in patients with epilepsy.

MATERIALS AND METHODS

A systematic review of the MEDLINE search returned 1039 papers, of which only 8 were considered relevant. A critical analysis of the Food and Drug Administration (FDA) report on the increase risk for patients under antiepileptics to manifest suicidality is also included in this report.

RESULTS

The analysis of these studies revealed that the data are not supportive of the presence of a "class effect" on suicide-related behavior; on the contrary, there are some data suggesting such an effect concerning treatment with topiramate, lamotrigine, and levetiracetam for which further research is needed.

DISCUSSION

For the majority of people with epilepsy, anticonvulsant treatment is necessary and its failure for any reason is expected to have deleterious consequences. Therefore, clinicians should inform patients and their families of this increased risk of suicidal ideation and behavior, but should not overemphasize the issue. Specific subgroups of patients with epilepsy might be at a higher risk, and deserve closer monitoring and follow-up. Future research with antiepileptics should specifically focus on depression and suicidal thoughts.

Psychiatric adverse effects of zonisamide in patients with epilepsy and mental disorder comorbidities

Over the last few years, zonisamide has been proposed as a potentially useful medication for patients with focal seizures, with or without secondary generalization. Since psychiatric adverse effects, including mania, psychosis, and suicidal ideation, have been associated with its use, it was suggested that the presence of antecedent psychiatric disorders is an important factor associated with the discontinuation of zonisamide therapy in patients with epilepsy. We, therefore, set out to assess the tolerability profile of zonisamide in a retrospective chart review of 23 patients with epilepsy and comorbid mental disorders, recruited from two specialist pediatric (n=11) and adult (n=12) neuropsychiatry clinics. All patients had a clinical diagnosis of treatment-refractory epilepsy after extensive neurophysiological and neuroimaging investigations. The vast majority of patients (n=22/23, 95.7%) had tried previous antiepileptic medications, and most adult patients (n=9/11, 81.8%) were on concomitant medication for epilepsy. In the majority of cases, the psychiatric adverse effects of zonisamide were not severe. Four patients (17.4%) discontinued zonisamide because of lack of efficacy, whereas only one patient (4.3%) discontinued it because of the severity of psychiatric adverse effects (major depressive disorder). The low discontinuation rate of zonisamide in a selected population of patients with epilepsy and neuropsychiatric comorbidity suggests that this medication is safe and reasonably well-tolerated for use in patients with treatment-refractory epilepsy. Given the limitations of the present study, including the relatively small sample size, further research is warranted to confirm this finding.

Antiepileptic drugs and suicidality

The current study is a systematic review of the literature concerning the possible relationship of antiepileptics and suicide-related clinical features and behaviours. A MEDLINE search returned 863 papers but only five were chosen as relevant. A critical analysis of the Food and Drug Administration report is also included. Overall, the current review suggests there are no convincing data concerning a 'class effect' of antiepileptics in inducing any type of suicide-related behaviours. Further research is needed concerning topiramate, lamotrigine and maybe leviracetam. Clinicians are expected to inform patients and their families on the possible increased risk but it is important not to overemphasise the issue, since stopping or refusing to start antiepileptics may result in serious harm, including death of the patient. Future randomised controlled trials should specifically focus on issues concerning depression and suicidal thoughts in patients with epilepsy.

Zonisamide discontinuation due to psychiatric and cognitive adverse events: a case-control study

OBJECTIVES

Zonisamide (ZNS) is an antiepileptic drug (AED) that has been associated with psychiatric adverse events (PAE) and cognitive adverse events (CAE); controlled studies evaluating these adverse events are limited. Our objectives were to 1) determine the incidence of PAE and CAE leading to the discontinuation of ZNS and 2) identify risk factors for PAE and CAE associated with the discontinuation of ZNS.

METHODS

All patients exposed to ZNS at MINCEP Epilepsy Care between March 2000 and September 2008 were identified. Reasons for discontinuing ZNS were documented. Separate case-control studies were performed to identify risk factors associated with the discontinuation of ZNS due to PAE or CAE via multivariate binary logistic regression.

RESULTS

A total of 544 patients were exposed to ZNS during the study period. PAE and CAE were the most frequently identified reasons for terminating ZNS therapy. The incidence of PAE severe enough to be associated with the discontinuation of ZNS was 6.9%; the incidence of CAE was 5.8%. Factors associated with termination of ZNS therapy due to PAE were past psychiatric history (p = 0.005), symptomatic generalized epilepsy (p = 0.027), and lower maximum ZNS serum concentration (mean = 17.9 mg/L vs 34.7 mg/L, p < 0.001). Independent variables associated with discontinuing ZNS due to CAE were greater number of concomitant AEDs (p = 0.011) and lower maximum ZNS serum concentration (mean = 16.6 mg/L vs 30.6 mg/L, p = 0.002).

CONCLUSIONS

We have identified clinically relevant risk factors associated with the discontinuation of ZNS. Our findings support the concept that selected patients are relatively more vulnerable to CNS adverse events when exposed to ZNS.

Suicidality in people taking antiepileptic drugs: What is the evidence?

Suicide is an important cause of premature death. In the general population, most people who commit suicide have a psychiatric problem at the time. People with epilepsy are thought to be at increased risk from suicide and suicidality (suicidal ideation or behaviour). Standardized mortality ratios estimated for suicide in people with epilepsy are usually between 3 and 5. Risk factors for suicide in people with epilepsy have been suggested, including early age of onset of seizures, temporal lobe epilepsy, severe seizures and recent control of seizures. Psychiatric co-morbidity also seems to be an important factor in people with epilepsy who commit suicide. In recent years, suicidality has been recognized as a complication of several groups of drugs and, most recently, antiepileptic drugs (AEDs) have been implicated. The US FDA performed a meta-analysis of 199 placebo-controlled studies of 11 AEDs used for seizure control, psychiatric or 'other' indications. There were four completed suicides in those taking AEDs and none in those taking placebo. The odds ratio for suicidal behaviour or ideation was 1.8 (95% CI 1.24, 2.66), suggesting that people taking AEDs are more at risk than those taking placebo. The odds ratio was significantly raised for people taking AEDs for epilepsy, but not for the other indications. AEDs may affect mood by means of several mechanisms. In people with epilepsy, however, the concept of forced normalization (or alternative psychosis) may also play a part. In this situation, control of seizures (by AEDs or epilepsy surgery) may alternate with psychotic features or, less commonly, depression, although this is not fully understood. The risk of suicidal ideation and behaviour as adverse effects of AED treatment, although increased, seems low. As a result of the FDA's alert clinicians are supposed to inform patients and their families of this increased risk but it is important to place it in a proper perspective. Some people with epilepsy are more likely to develop psychiatric adverse effects with any AEDs, and these people should be followed closely whenever a new AED is introduced. Nonetheless, in people with epilepsy the risk of suicidality associated with AEDs needs to be balanced against the risk of not treating the seizures. In fact, the risk of stopping AEDs or refusing to start AEDs for the control of a seizure disorder may be significantly worse and may result in serious harm, including death of the patient.