Status epilepticus after massive carbamazepine overdose

Management of acute carbamazepine poisoning: A narrative review

Standard management protocols are lacking and specific antidotes are unavailable for acute carbamazepine (CBZ) poisoning. The objective of this review is to provide currently available information on acute CBZ poisoning, including its management, by describing and summarizing various therapeutic methods for its treatment according to previously published studies. Several treatment methods for CBZ poisoning will be briefly introduced, their advantages and disadvantages will be analyzed and compared, and suggestions for the clinical treatment of CBZ poisoning will be provided. A literature search was performed in various English and Chinese databases. In addition, the reference lists of identified articles were screened for additional relevant studies, including non-indexed reports. Non-peer-reviewed sources were also included. In the present review, 154 articles met the inclusion criteria including case reports, case series, descriptive cohorts, pharmacokinetic studies, and in vitro studies. Data on 67 patients, including 4 fatalities, were reviewed. Based on the summary of cases reported in the included articles, the cure rate of CBZ poisoning after symptomatic treatment was 82% and the efficiency of hemoperfusion was 58.2%. Based on the literature review, CBZ is moderately dialyzable and the recommendation for CBZ poisoning is supportive management and gastric lavage. In severe cases, extracorporeal treatment is recommended, with hemodialysis as the first choice.

Pharmacological and Nonpharmacological Treatments for Painful Diabetic Peripheral Neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most prevalent chronic complications of diabetes. The lifetime prevalence of DPN is thought to be >50%, and 15%-25% of patients with diabetes experience neuropathic pain, referred to as "painful DPN." Appropriate treatment of painful DPN is important because this pain contributes to a poor quality of life by causing sleep disturbance, anxiety, and depression. The basic principle for the management of painful DPN is to control hyperglycemia and other modifiable risk factors, but these may be insufficient for preventing or improving DPN. Because there is no promising diseasemodifying medication for DPN, the pain itself needs to be managed when treating painful DPN. Drugs for neuropathic pain, such as gabapentinoids, serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, alpha-lipoic acid, sodium channel blockers, and topical capsaicin, are used for the management of painful DPN. The U.S. Food and Drug Administration (FDA) has approved pregabalin, duloxetine, tapentadol, and the 8% capsaicin patch as drugs for the treatment of painful DPN. Recently, spinal cord stimulation using electrical stimulation is approved by the FDA for the treatment for painful DPN. This review describes the currently available pharmacological and nonpharmacological treatments for painful DPN.

Anticonvulsant fatalities reported to the American Association of Poison Control Centers 2000 - 2019

BACKGROUND

Anticonvulsants are frequently prescribed, and exposures are commonly reported to American Association of Poison Control Centers sites. The purpose of this study was to describe the epidemiology of fatalities associated with oral anticonvulsant use, including patient demographics, specific medications, and the circumstances surrounding the deaths.

METHODS

This was a retrospective analysis of cases coded with oral anticonvulsants as a single substance and associated with a fatal outcome reported to the AAPCC National Poison Data System from 2000 to 2019. Polydrug ingestions and parenteral exposures were excluded. Patient characteristics, circumstances of the ingestion, specific medication, and chronicity of use were described.

RESULTS

We identified 126 cases that were classified as fatalities associated with single anticonvulsant use. The five most implicated anticonvulsants were carbamazepine, gabapentin, lamotrigine, phenytoin, and valproic acid. The majority (68.3%) of fatal cases were suicides. Phenytoin was implicated in eight (89%) adverse reactions and seven (70%) therapeutic errors. Valproic acid caused one (11.1%) adverse reaction and was associated with one (10%) therapeutic error. Three (75%) unintentional fatalities were caused by carbamazepine. The plurality (42.1%) of fatal ingestions occurred in acute-on-chronic use. An additional 40 (31.7%) were acute. Chronic use accounted for 15 (11.9%) of fatal exposures, including 5/10 of fatalities attributed to therapeutic error. The chronicity of medication use was unknown in 18 (14.3%) of fatal ingestions. Narrative summaries were available in 14 cases. Four of the patients presented to the emergency department with minimal symptoms. The other 10 had varying degrees of central nervous system (CNS) depression. Seizures were observed in six cases. Hyperammonemia was reported in seven of nine valproic acid ingestions.

CONCLUSIONS

Fatalities associated with isolated anticonvulsant use are uncommon and typically occur following intentional overdoses. Fatal adverse reactions and therapeutic errors are most associated with phenytoin use and disproportionately affect elderly patients.

Self-Injury with Carbamazepine Intoxication in an Elementary School-Aged Child

Carbamazepine is a common anticonvulsant medication used to treat seizure disorders and is generally considered a safe medication. We describe the case of a 9-year-old female who presented with acute altered mental status and respiratory failure requiring mechanical ventilation. She was found to be intoxicated with carbamazepine through a urine drug test which was confirmed by bloodwork. After her medical condition improved, the patient admitted to self-injury through ingestion to cope with the death of a family member. She received a complete psychiatric assessment and was eventually discharged without permanent neurologic sequelae. To our knowledge, this is the first case of intentional self-injury with carbamazepine intoxication in an elementary school-aged child. When intoxication is suspected in children presenting with altered mental status, all medications available at home should be investigated. Preadolescent children may engage in nonfatal self-injury behavior, and diagnosis requires a high index of suspicion.

An investigation on the effects of carbamazepine and sodium valproate on neuromuscular transmission

The aim of this study was to investigate the effects of sodium valproate (SV) and carbamazepine (CBZ) on neuromuscular transmission using single-fibre electromyography (SFEMG) in patients with epilepsy. We performed SFEMG during the voluntary contraction of extensor digitorum communis muscle. 30 epileptic patients taking SV, 25 epileptic patients taking CBZ, and 25 age-matched healthy volunteers were included in the study. Mean jitter values (MCD) of subjects taking SV and CBZ were compared with normal controls. MCD values of subjects taking SV and CBZ were statistically significantly higher than those of control group. Review of the correlation between disease duration and MCD values of patients showed that MCD values were increased with the prolonged use of drugs, and thus, indicated a positive relationship between these two parameters. These results suggest that both SV and CBZ reduce neuromuscular transmission in patients without a neuromuscular junction disease.

Thirteen years of oxcarbazepine exposures reported to US poison centers

Objectives:

Oxcarbazepine (OXC) is a 10-keto analogue of carbamazepine used in patients with partial and secondary generalized seizures. We evaluated ingestions of OXC reported to US poison centers for adverse effects from supratherapeutic doses and/or overdose.

Method:

Retrospective analysis of data reported to National Poison Data System from single-substance OXC ingestions between January 2000 and December 2012.

Results:

There were 18,867cases with a mean of 1451 exposures/year. The patients were predominantly adults with 5464 exposures in children <6 years (29%). The most commonly reported clinical effects were drowsiness ( n = 4703, 25%), vomiting ( n = 1559, 8%), tachycardia ( n = 590, 3%), agitated ( n = 342, 1.8%), hypotension ( n = 178, 0.9%), electrolyte disturbance ( n = 153, 0.8%), coma (n = 156, 0.8%), and seizures ( n = 121, 0.6%). There were 176 patients with a major effect of which 31 involved were children and 1728 (9%) patients with moderate effects of which 300 involved were children. Five deaths were reported in adults. Intentional exposure (e.g. suicide) was the reason for exposure in 68% of patients with major effects and in all fatalities. Fifty-three percent of adults and 38% of children were managed in a health-care facility (HCF). HCF utilization levels remained consistent.

Discussion:

Severe outcomes appear to be infrequent (<1%). Unlike other anticonvulsants OXC does not appear to be proconvulsant in overdose.

Conclusion:

Serious outcomes for OXC overdoses are unlikely in the pediatric patient. With only mild symptoms likely, observation at home may be appropriate for the majority of cases. In the adult population there appears to be few neurologic and cardiovascular complications even in the intentional exposure.

Hypoglycemia - a rare complication of carbamazepine overdose

Carbamazepine overdose usually presents with neurological manifestations such as ataxia, seizures and altered sensorium or cardiac manifestations that include tachycardia, hypotension and ventricular extra-systoles. We report a patient with carbamazepine overdose who manifested recurrent hypoglycemia on the third and fourth day following ingestion that resolved with supportive therapy.

Risk factors and the outcome of therapy in patients with seizure after Carbamazepine poisoning: A two-year cross-sectional study

Objective:

We aimed to investigate the frequency of seizure after acute carbamazepine poisoning and the important risk factors related to the outcomes of therapy.

Methods:

In this two-year cross-sectional study conducted in a University Hospital in Iran, 114 patients with acute carbamazepine poisoning were divided into two groups of with seizure (n = 8) and without seizure (n = 106) after intoxication. Demographic data, average amount of drug ingestion, time elapsed from ingestion to hospital admission, history of seizure before poisoning, mental status, visual disturbances and nystagmus, duration of hospitalization, the outcomes of therapy, arterial blood gas values and serum biochemical indices were compared between the two groups.

Findings:

Patients with seizure had an estimated (Mean ± SD) ingestion of 14,300 ± 570 mg carbamazepine, which was significantly higher (P < 0.0001) than the seizure-free group (4600 ± 420 mg). The estimated average time between drug ingestion and hospital admission in patients with seizure and the seizure-free group were 515 ± 275 and 370 ± 46 minutes, respectively (P < 0.0001). In this study, 104 out of the total number of patients had recovered without any complication. Need for respiratory support, including airway support or intubation were the most recorded complication. One patient died after status epilepticus and aspiration pneumonia.

Conclusion:

The ingested amount of carbamazepine and the time elapsed from the ingestion of drug to hospital admission may influence the occurrence of seizure after acute carbamazepine poisoning; however, the outcome of supportive care in these patients seems to be positive.

Plasma-exchange treatment for severe carbamazepine intoxication: a case study

Acute poisoning is an important cause of morbidity and mortality during childhood. This manuscript reports the positive outcome of a pediatric case with a history of accidental carbamazepine intake treated using plasma exchange. A 3-year-old male presented with severe carbamazepine intoxication. He was comatose and had generalized tonic clonic seizure, ventricular tachycardia, and hypotension. Although he did not respond to classical therapies, we performed two sessions of plasma exchange. The patient recovered rapidly and was discharged from the hospital six days from the time of carbamazepine ingestion with no complication or neurologic impairment. Plasma exchange can be performed safely in very small children, and it might be the first line treatment, particularly for intoxication with drugs that have high plasma-protein-binding properties.

Neurotoxic emergencies

This article is intended for clinicians treating neurotoxic emergencies. Presented are causative agents of neurotoxic emergencies, many of which are easily mistaken for acute psychiatric disorders. Understanding the wide variety of agents responsible for neurotoxic emergencies and the neurotransmitter interactions involved will help the psychiatrist identify and treat this challenging population.

Treatment of seizures in the neurologic intensive care unit

Seizures occur more often in the neurologic intensive care unit (NICU) than in general or other specialty ICUs, in part because of the patient population, but also due to the enhanced neurologic monitoring undertaken in such units. Especially important for the detection of seizures is the use of specialty trained personnel and the use of continuous electroencephalographic monitoring. The etiology of seizures often can be categorized either by primary brain pathology, at macro- or microscopic level, or by physiologic derangements of critical care illness, such as toxic or metabolic abnormalities. Particular etiologies at risk for seizures include hemorrhagic stroke and traumatic brain injury. The use of prophylactic antiepileptic drug administration remains controversial. If seizures occur, patients are typically treated with parenteral antiepileptic drugs. The duration of treatment is unclear in most situations, but data support limited treatment for early-onset ICU seizures that are easily controlled, with treatment not extending beyond a few weeks or a month. Late seizures, which occur more than 2 weeks after the insult, have a more ominous correlative risk for subsequent epilepsy and should be treated for extended periods of time or indefinitely. Electrolyte and glucose abnormalities, when corrected, usually lead to seizure control. This review concludes by examining the treatment algorithms for simple seizures and status epilepticus and the role newer antiepileptic use can play in the NICU.

Toxin-related seizures

Toxin-related seizures result from an imbalance in the brain's equilibrium of excitation-inhibition. Fortunately, most toxin-related seizures respond to standard therapy using benzodiazepines. However, a few alterations in the standard approach are recommended to ensure optimal care and expedient termination of seizure activity. If 2 doses of a benzodiazepine do not terminate the seizure activity, a therapeutic dose of pyridoxine (5 g intravenously in an adult and 70 mg/kg intravenously in a child) should be considered. Phenytoin should be avoided because it is ineffective for many toxin-induced seizures and is potentially harmful when used to treat seizures induced by theophylline or cyclic antidepressants.

Seizure aggravation by antiepileptic drugs

Seizure aggravation by antiepileptic drugs (AEDs) is an overestimated phenomenon. While it undoubtedly occurs, the quality of evidence in most published reports is poor. Although seizure aggravation can be examined in clinical trials in the same way as seizure improvement, this is rarely done. Before concluding that an increase in seizures after the introduction of a new drug represents pharmacodynamic aggravation, alternative explanations should be explored. These include spontaneous fluctuation of seizure frequency, the presence of known seizure aggravators (such as sleep deprivation, alcohol, and psychotropic medications), progression of epilepsy, the development of drug resistance, and replacement of a partially effective drug with a less effective drug. The risk of incorrectly blaming a drug for a deterioration in seizures can be minimized by establishing baseline seizure frequency over a period long enough to encompass the extremes of seizure fluctuation and by educating the patient that a temporal relationship may not be a causal relationship. When feasible, the patient should continue the drug long enough to establish if the deterioration is transient. If the drug is stopped, rechallenge should be considered. The risk of seizure aggravation can be minimized by accurate diagnosis of the epilepsy syndrome and appropriate choice of AED.

Management of a severe carbamazepine overdose with continuous venovenous hemodiafiltration

Carbamazepine (CBZ) is a commonly used antiepileptic agent. Common toxic effects include neurological abnormalities; ataxia, seizures, coma, cardiorespiratory problems; dysrhythmias; conduction disorders; respiratory depression; and eye abnormalities, such as nystagmus and ophthalmoplegia. Carbamazepine is highly protein bound. There is no antidote for the medication. Carbamazepine is not removed effectively through conventional hemodialysis. Supportive measures and charcoal hemoperfusion have been regarded as efficient treatment methods. We herein report a 17-year old girl to whom continuous venovenous hemodiafiltration lacking the albumin-enhance after suicidal overdose of CBZ was performed. We suggest continuous venovenous hemodiafiltration lacking the albumin-enhance as an alternative emergency treatment modality for cases who had ingested CBZ in toxic levels.

Detoxication treatment for carbamazepine and lithium overdose

This article reports detoxication treatments of a case of combined overdose of carbamazepine and lithium in a 38-year-old female with bipolar disorder. She was brought to the emergency unit after the family found her unresponsive and lying near empty packages for carbamazepine (corresponded to 7.7 g) and lithium carbonate (corresponded to 6.6 g) tablets. On admission, her blood pressure, heart rate and respiratory rate were 80/55 mmHg, 90 per minute and 13 per minute, respectively. Her GCS was 3 (E1, M1, V1). She received gastric lavage after intratracheal intubation, followed by administration of activated charcoal via gastric tube, and a large volume (800 ml/h) of lactate Ringer's solution by intravenous infusion. The serum levels of carbamazepine and lithium approximately 5 h after ingestion were 56.0 mug/ml and 3.56 mEq/l, respectively. The carbamazepine overdose was mainly treated by a 3 h charcoal hemoperfusion (CHP). The CHP treatment decreased serum carbamazepine levels by approximately 30-40% as compared with the levels simulated by Bayesian analysis using 1-point or 2-points serum level(s) (without detoxication treatment). For lithium overdose continuous infusion of Ringer's solution was effective, which increased serum sodium gradually and facilitated the elimination of lithium. In conclusion, the treatments with CHP and continuous infusion of Ringer's solution were considered to be effective for detoxification of carbamazepine and lithium overdose, respectively, when compared with those drug levels without detoxication treatment that simulated by Bayesian analysis method.

Management of Seizures in the Critically Ill

Seizures in a critically ill patient are not infrequent phenomena. Physicians are perplexed by the wide range of possible cranial or extracranial etiologies, alerted by the risk for further crucial organ compromise if seizures recur, and confused about the treatment options in an environment rich in complex drug interactions and multiple organ dysfunction. The advent of an armamentarium containing multiple new antiepileptic medications complicates the situation further, since several of them have less known mechanisms of action, side effects, or interactions with other intensive care unit (ICU) medications. This review contains useful information regarding the most common etiologies and treatment options for intensivists, consulting neurologists, neurosurgeons, or other specialized physicians treating ICU patients with seizures.

Chemically Induced Seizures

Drug- and toxin-associated seizures (DTS) may result from exposure to a wide variety of agents. Most DTS can be managed with supportive care. First-line anticonvulsant therapy should include benzodiazepines, unless agents require a specific antidote. Phenytoin is generally not expected to be useful for DTS and in some instances may be harmful. In this article the authors discuss the pathophysiology of DTS, the potential differential diagnosis, and the clinical presentation. They also review selected agents that cause DTS and provide an overview of how the clinician should approach the management of patients who have DTS.

Drug- and toxin-associated seizures

Drug- and toxin-associated seizures may result from exposure to a wide variety of agents. Obtaining a comprehensive history behind the exposure is generally more helpful than diagnostic testing. Most DTS may be managed with supportive care, including benzodiazepines, except in the case of agents that require a specific intervention or antidote.

Seizure Aggravation in Idiopathic Generalized Epilepsies

Seizures in the idiopathic generalized epilepsies (IGEs) usually remit completely with antiepileptic drugs (AEDs). Occasionally, however, they may be aggravated by AEDs. Before attributing exacerbation of seizures to an AED, alternative explanations need to be excluded. These include natural fluctuation of seizures, irregular compliance, maladjustment to the disease, comorbid illness, and development of tolerance. Aggravation may be due to a paradoxical reaction or drug-induced encephalopathy, sedative effects, or inappropriate use of a drug; and this need to be established, as it will guide management. An important caveat is that most data on aggravation of generalized seizures are based on anecdotal case reports or case series. Whether considering efficacy or aggravation, the interpretation of data from uncontrolled studies and case reports must be treated with caution. In practice, despite the fact that clear evidence is lacking, the possibility of seizure aggravation must be considered when treating people with IGEs. Predictive factors for seizure aggravation in a particular patient with a specific drug are yet to be fully defined. It is paramount to classify seizure type correctly in all patients. If this is not possible, a broad-spectrum AED should be used. Drugs that modulate Na+-channels and GABAergic drugs seem to be more prone to aggravating seizures, and therefore are best avoided in the initial management of IGE. Further studies are required to elucidate this phenomenon in full. It is interesting to speculate that paradoxical responses to AEDs may have pharmacogenetic value, serving as tools for a more precise and useful characterization of the epilepsies.

Mega-dose carbamazepine complicating third trimester of pregnancy

A case of coma due to carbamazepine ingestion with the intention of committing suicide at 33 weeks' gestation is presented. Management included activated charcoal administration and exchange plasmapheresis. A fetal non-stress test was non-reassuring but the Apgar score, cord blood gases and early neonatal outcome were normal. Differential diagnosis of coma in pregnancy should include investigation for drug intoxication.

Management of seizures in critically ill patients

For many neurologists, seizures in critically ill patients represent a difficult problem. Etiology can be elusive because of the complexity of the environment, and treatment decisions can be compromised by the paucity of evidence-based guidelines. Emerging data support a higher than previously thought incidence of nonconvulsive epileptic activity in this patient population, which is another important consideration. Although a seizure in the intensive care unit should be treated aggressively, prophylactic antiepileptic drug administration is dependent on the specific etiology, time of onset, and ensuing complications. After ischemic stroke, prophylactic treatment is not generally recommended, and after intracerebral hemorrhage treatment is recommended only after a few weeks. After subarachnoid hemorrhage, prophylactic treatment beyond discharge is also not recommended. Although there is no reason to believe that late seizures after severe head trauma cannot be prevented with prophylactic treatment, such an approach may be useful during the first week after the injury. Physicians, however, have to individualize the treatment to the critical patient after stroke or trauma based on the presence of additional factors that increase the risk for seizures, including structural cortical injuries and medications used in critical illness with epileptogenic potential. A general therapeutic scheme for seizures in the intensive care unit and the role newer antiepileptic drugs can play are also presented in this review.

Shared mechanisms of antidepressant and antiepileptic treatments: drugs and devices

Many treatments for the epilepsies and affective disorder share the properties of seizure suppression and mood stabilization. Moreover, affective disorders and the epilepsies appear to share partially similar pathogenic mechanisms. A component of the shared predisposition appears to arise from noradrenergic and serotonergic deficits. Increasing evidence supports the hypothesis that noradrenergic and/or serotonergic elevation is a mechanism of therapeutic benefit shared by most antidepressants and many antiepileptic medications. Medication induced alterations in GABAergic, glutamatergic, and CRH (corticotropin releasing hormone) containing neurons may also contribute to the shared therapeutic properties of antidepressant and antiepileptic medications.

Do not overlook acute isoniazid poisoning in children with status epilepticus

A previously healthy 2-year-old girl was admitted with generalized convulsive status epilepticus. She was in a stupor and could respond only to painful stimuli. She also had severe metabolic acidosis. Although initial liver function tests were normal, they were found to be moderately high on the fifth day of admission; however, they dropped to their normal ranges on the twelfth day of admission. Initially, the patient was diagnosed as having idiopathic status epilepticus, and classic anticonvulsant agents, including diazepam, phenytoin, and then phenobarbital, were given. However, her seizures did not subside, and diazepam infusion was initiated. After initiation of diazepam infusion, the seizures were completely controlled. On the fourth day of admission, her parents said that she had accidentally received 20 tablets (a total dose of 2000 mg) of isoniazid just before admission to our hospital. Later, we injected 200 mg of pyridoxine intravenously. During follow-up, her general condition improved, and anticonvulsant agents were discontinued because an electroencephalogram was found to be norma. She was discharged from the hospital on the twelfth day of admission. At the fourth month of follow-up, she was seizure free. Because of this case, we would like to re-emphasize that acute isoniazid poisoning should also be considered in a child with unexplained status epilepticus.