Olanzapine-Induced Myoclonic Status

Generalised tonic–clonic seizures on the subtherapeutic dose of olanzapine

Olanzapine is a second-generation antipsychotic. Incidence of olanzapine-induced seizures (OIS) is low with monotherapy. Combination therapy with another antipsychotic, drug metabolism and old age are risk factors for OIS. Our patient was a 71-year-old man, admitted to the psychiatry unit. He was managed on the lines of bipolar affective disorder current episode depression and dementia. He was started on olanzapine 1.25 mg two times/day. The patient developed generalised tonic–clonic seizure that lasted for around two and a half minutes within 24 hours of olanzapine treatment. His electroencephalogram showed findings that were suggestive of mild slowing. Our case discusses the incidence of OIS on the subtherapeutic dose. This presentation involves multiple risk factors for OIS: a history of stroke, poststroke seizure, old age and cognitive impairment. Due to scarcity of evidence of OIS; mostly with recommended therapeutic dose range physicians may underestimate seizure risk at subtherapeutic doses.

De Novo Myoclonic Status Epilepticus After Benzodiazepine Withdrawal

Myoclonic status epilepticus (MSE) in patients without epilepsy, or de novo MSE, is a rare condition associated with several acute symptomatic etiologies, including drugs and toxins. We describe a 94-year-old woman with Alzheimer dementia and long use of mirtazapine 30 mg/d and alprazolam 1 mg/d who developed MSE approximately 24 hours after abrupt discontinuation of alprazolam. The patient was taking sulfamethoxazole/trimethoprim for urinary tract infection, diagnosed 2 weeks before admission. She had no history of seizures. Routine laboratory examinations were normal and head computed tomography showed no acute injuries. She received a loading dose of 1000 mg of intravenous valproate (VPA). Continuous electroencephalogram monitoring revealed very frequent generalized spikes and polyspikes in a markedly slowed background activity. Intravenous VPA 500 mg thrice a day and alprazolam 0.5 mg twice a day were prescribed, and antibiotic was switched to piperacillin/tazobactam. Myoclonic jerks ceased completely and electroencephalogram showed no epileptiform discharges 2 days after VPA treatment onset, with recovery of baseline neurological status. This is, to the best of our knowledge, the first report of de novo MSE related to abrupt discontinuation of benzodiazepines. Seizures and status epilepticus are potential adverse events after abrupt withdrawal of chronically used benzodiazepines, especially in conditions with intrinsic epileptogenic susceptibility, such as Alzheimer disease.

Prevalence and patterns of anti-epileptic medication prescribing in the treatment of epilepsy in older adults with intellectual disabilities

BACKGROUND

The prevalence of epilepsy is higher in people with intellectual disability (ID) and increases with the degree of ID. Although life expectancy for people with ID is increasing, people with ID coexisting with epilepsy have a higher mortality rate, particularly those who had recent seizures. There have been few observational studies of the prevalence and patterns of anti-epileptic prescribing among older people with ID and epilepsy. The aim of this study was to investigate prevalence and patterns of anti-epileptic prescribing in the treatment of epilepsy in a representative population of older people with ID and epilepsy.

METHODS

This was an observational cross-sectional study from wave 1 (2009/2010) of Intellectual Disability Supplement to the Irish Longitudinal Study on Aging, a nationally representative sample of 753 persons with ID aged between 41 and 90 years. Participants and/or proxies recorded medicines used on a regular basis and reported doctor's diagnosis of epilepsy; medication data were available for 736 (98%). Prescribing of anti-epileptic drugs (AEDs) for epilepsy in those with a doctor's diagnosis of epilepsy (N = 205) was the primary exposure of interest for this study. Participant exposure to these AEDs was then categorised into AED monotherapy and polytherapy. Participants/carers reported seizure frequency, when epilepsy was last reviewed and which practitioner reviewed epilepsy. In addition, medications that may lower the seizure threshold that were listed in the Maudsley prescribing guidelines in psychiatry were examined.

RESULTS

Of the 736 participants with reported medicines use, 38.9% (n = 287) were exposed to AEDs, and 30.6% (225) had a doctor's diagnosis of epilepsy. Of those with epilepsy (n = 225), 90.9% (n = 205) reported concurrent use of AEDs and epilepsy. Of these 205 participants, 50.3% (n = 103) were exposed to AED polytherapy, and 63 different polytherapy regimes were reported. The most frequently reported AEDs were valproic acid (n = 100, 48.7%), carbamazepine (n = 89, 46.3%) and lamotrigine (n = 57, 27.8%). In total, 13.7% had a concurrent psychotropic, which should be avoided in epilepsy, and 32.6% had a psychotropic where caution is required. Antipsychotics with potential epileptogenic potential accounted for 80% of these medications. Of those with AED polytherapy (n = 103), 29.5% (28) reported being seizure free for the previous 2 years.

CONCLUSIONS

Prevalence of epilepsy was high among older people with ID, and half were exposed to two or more AEDs. Despite the use of AED therapy, over half had seizures in the previous 2 years. As the primary goals of optimal AED treatment are to achieve seizure freedom without unacceptable adverse effects, this was not achievable for many older patients with ID and epilepsy. Our findings indicated that people with ID and epilepsy were often exposed to psychotropic medications that may lower the seizure threshold. Regular review of epilepsy and medicines (including medicines that may interact with AEDs or lower the seizure threshold) by multidisciplinary teams working to agreed standards may improve quality of prescribing. Improved exchange of information and coordination of care between specialists and primary care practitioners in line with expert consensus recommendations could bring substantial benefit.

Comparative analysis of the treatment of chronic antipsychotic drugs on epileptic susceptibility in genetically epilepsy-prone rats

Antipsychotic drugs (APs) are of great benefit in several psychiatric disorders, but they can be associated with various adverse effects, including seizures. To investigate the effects of chronic antipsychotic treatment on seizure susceptibility in genetically epilepsy-prone rats, some APs were administered for 7 weeks, and seizure susceptibility (audiogenic seizures) was evaluated once a week during treatment and for 5 weeks after drug withdrawal. Furthermore, acute and subchronic (5-day treatment) effects were also measured. Rats received haloperidol (0.2-1.0 mg/kg), clozapine (1-5 mg/kg), risperidone (0.03-0.50 mg/kg), quetiapine (2-10 mg/kg), aripriprazole (0.2-1.0 mg/kg), and olanzapine (0.13-0.66 mg/kg), and tested according to treatment duration. Acute administration of APs had no effect on seizures, whereas, after regular treatment, aripiprazole reduced seizure severity; haloperidol had no effects and all other APs increased seizure severity. In chronically treated rats, clozapine showed the most marked proconvulsant effects, followed by risperidone and olanzapine. Quetiapine and haloperidol had only modest effects, and aripiprazole was anticonvulsant. Finally, the proconvulsant effects lasted at least 2-3 weeks after treatment suspension; for aripiprazole, a proconvulsant rebound effect was observed. Taken together, these results indicate and confirm that APs might have the potential to increase the severity of audiogenic seizures but that aripiprazole may exert anticonvulsant effects. The use of APs in patients, particularly in patients with epilepsy, should be monitored for seizure occurrence, including during the time after cessation of therapy. Further studies will determine whether aripiprazole really has a potential as an anticonvulsant drug and might also be clinically relevant for epileptic patients with psychiatric comorbidities.

Dose-dependent olanzapine-induced myoclonus

Second-generation antipsychotics (SGA), mainly clozapine have been reported to induce myoclonus. Although olanzapine-induced myoclonus is reported, dose-dependent response has not been described. We report dose-related olanzapine-induced myoclonus in an early onset schizophrenia patient. We also suggest certain management strategies for such adverse side effects.

MELAS with recurrent complex partial seizures, nonconvulsive status epilepticus, psychosis, and behavioral disturbances: case analysis with literature review

Mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS) is a progressive neurodegenerative disorder associated with polygenetic, maternally inherited, mitochondrial DNA mutations. MELAS has multisystem presentation including neurological, muscular, endocrine, auditory, visual, cardiac, psychiatric, renal, gastrointestinal and dermatological symptoms. Clinical course and prognosis are variable, often leading to cognitive decline, disability, and premature death. Both convulsive status epilepticus (CSE) and nonconvulsive status epilepticus (NCSE) are reported with MELAS. This report illustrates a case of MELAS with recurrent complex partial seizures, NCSE, confusion, aggressive behaviors, hallucinations, and paranoid delusions. Rapid video/EEG confirmation of diagnosis and aggressive antiepileptic drug intervention are required. Further education of medical professionals regarding this disorder, its appropriate management, and the significance of NCSE is indicated to avoid delay of treatment.

Multifocal myoclonus induced by haloperidol

Haloperidol has long been used to manage agitation in dementia, but it is associated with increased side effects. We report the first case of a patient with severe Alzheimer's disease who presented with non-epileptic myoclonus just after haloperidol treatment was initiated.

Effects of olanzapine on ethanol withdrawal syndrome in rats

The present study was designed to investigate the effects of olanzapine, a serotonin-dopamine antagonistic atypical antipsychotic agent, on ethanol withdrawal syndrome in rats. Adult male Wistar rats were subjects. Ethanol (7.2%, v/v) was given to rats by a liquid diet for 21 days. Control rats were pair fed with an isocaloric liquid diet containing sucrose as a caloric substitute to ethanol. After 2nd, 4th and 6th h of ethanol withdrawal, rats were observed for 5 min, afterwards withdrawal signs that included locomotor hyperactivity, agitation, stereotyped behavior, tremor, wet dog shakes, abnormal posture and abnormal gait were recorded or rated. Olanzapine (0.5, 1 and 2 mg/kg) and saline were injected to the rats intraperitoneally 30 min before ethanol withdrawal assessment. A second series of injections was also given 30 min before the 6th-h-observation, and subjects were then tested for audiogenic seizures. Olanzapine (2 mg/kg) produced significant inhibitory effects on stereotyped behaviors and wet dog shakes at the 6th h of ethanol withdrawal. Contrary, the same dose caused some increases in the intensity of posture and gait impairments at the 2nd h of ethanol withdrawal. In addition, that dose was found to be ineffective on agitation, tremor, tail stiffness and audiogenic seizures. Our results suggest that acute olanzapine treatment has beneficial effects on stereotyped behavior and wet dog shakes, but it also has some adverse effects on posture and gait during ethanol withdrawal in rats. Overall, olanzapine does not seem to be an adequate and suitable drug in controlling of ethanol withdrawal syndrome.

Seizure incidence in psychopharmacological clinical trials: an analysis of Food and Drug Administration (FDA) summary basis of approval reports

BACKGROUND

Clinical trial data provide an approach to the investigation of the effects of psychopharmacological agents, and psychiatric disorders themselves, on seizure threshold.

METHODS

We accessed public domain data from Food and Drug Administration (FDA) Phase II and III clinical trials as Summary Basis of Approval (SBA) reports that noted seizure incidence in trials of psychotropic drugs approved in the United States between 1985 and 2004, involving a total of 75,873 patients. We compared seizure incidence among active drug and placebo groups in psychopharmacological clinical trials and the published rates of unprovoked seizures in the general population.

RESULTS

Increased seizure incidence was observed with antipsychotics that was accounted for by clozapine and olanzapine, and with drugs indicated for the treatment of OCD that was accounted for by clomipramine. Alprazolam, bupropion immediate release (IR) form, and quetiapine were also associated with higher seizure incidence. The incidence of seizures was significantly lower among patients assigned to antidepressants compared to placebo (standardized incidence ratio = .48; 95% CI, .36- .61). In patients assigned to placebo, seizure incidence was greater than the published incidence of unprovoked seizures in community nonpatient samples.

CONCLUSIONS

Proconvulsant effects are associated with a subgroup of psychotropic drugs. Second-generation antidepressants other than bupropion have an apparent anticonvulsant effect. Depression, psychotic disorders, and OCD are associated with reduced seizure threshold.

Drug-induced myoclonus: a French pharmacovigilance database study

Various drugs have been reported to induce myoclonus. However, this adverse event is not well known because of the difficult diagnosis and the lack of pharmaco-epidemiological or controlled studies. As far as we know, there are only case reports. In the literature, antiparkinsonian medications, antipsychotics, antidepressants, anesthetics, opiates and anti-infectious drugs have been reported in the occurrence of myoclonus. In a French pharmacovigilance database study, only 423 reports (0.2%) involved drug-induced myoclonus. The median age of patients was 55 years and 10% of these patients had a concomitant neurological disease. Only 16% of these reports had a strong imputability score (likely). The most frequently involved drugs were anti-infectious (15%), antidepressants (15%), anxiolytics (14%), and opiates agents (12%). Fifty-six percent of these reports were classified as serious adverse event. Concerning outcome, most patients (84%) recovered without sequels.