Massive overdose with controlled-release carbamazepine resulting in delayed peak serum concentrations and life-threatening toxicity

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.

Severe Carbamazepine Toxicity Treated with Continuous Venovenous Hemofiltration at Palestine Medical Complex: Two Case Reports

Carbamazepine intoxication is not uncommon and accounts for many cases of poisoning among anticonvulsive medications users. Since there is no specific antidote for carbamazepine overdose, management is limited to gastric decontamination and supportive therapy. With its high protein binding, the role of extracorporeal elimination in carbamazepine intoxication is still questionable. Here two cases of severe carbamazepine intoxication are presented; the cases were brought to the emergency department after the ingestion of 12,000 mg of controlled release carbamazepine for the first case, and unknown amounts of the same drug for the second case. Both cases were presented with altered mental status, convulsion, and high serum carbamazepine levels of more than 20 mcg/mL. They were intubated and treated with continuous venovenous hemofiltration, after which carbamazepine levels declined significantly along with subsequent clinical improvement and complete neurological recovery. Both cases were discharged home for further psychiatric care.

Combination Clearance Therapy and Barbiturate Coma for Severe Carbamazepine Overdose

A 15-year-old female subject presented comatose, in respiratory failure and shock, after the intentional ingestion of ∼280 extended-release 200-mg carbamazepine tablets with a peak serum concentration of 138 µg/mL (583.74 µmol/L). The patient developed clinical seizures and an EEG pattern of stimulus-induced rhythmic, periodic, or ictal discharges, suggestive of significant cortical dysfunction. Due to the extremely high drug serum concentration and clinical instability, a combination of therapies was used, including lipid emulsion therapy, plasmapheresis, hemodialysis, continuous venovenous hemodiafiltration, and endoscopic intestinal decontamination. The patient's elevated serum lactate level with a high mixed venous saturation suggested possible mitochondrial dysfunction, prompting treatment with barbiturate coma to reduce cerebral metabolic demand. The serum carbamazepine concentration declined steadily, with resolution of lactic acidosis, no long-term end-organ damage, and return to baseline neurologic function. The patient was eventually discharged in her usual state of health. In the laboratory, we demonstrated in vitro that the active metabolite of carbamazepine hyperpolarized the mitochondrial membrane potential, supporting the hypothesis that the drug caused mitochondrial dysfunction. We thus successfully treated a life-threatening carbamazepine overdose with a combination of modalities. Future studies are required to validate this aggressive approach. The occurrence of mitochondrial dysfunction must be confirmed in patients with carbamazepine toxicity and the need to treat it validated.

Adverse Drug Reactions in the Intensive Care Unit

Adverse drug reactions (ADRs) are undesirable effects of medications used in normal doses [1]. ADRs can occur during treatment in an intensive care unit (ICU) or result in ICU admissions. A meta-analysis of 4139 studies suggests the incidence of ADRs among hospitalized patients is 17% [2]. Because of underreporting and misdiagnosis, the incidence of ADRs may be much higher and has been reported to be as high as 36% [3]. Critically ill patients are at especially high risk because of medical complexity, numerous high-alert medications, complex and often challenging drug dosing and medication regimens, and opportunity for error related to the distractions of the ICU environment [4]. Table 1 summarizes the ADRs included in this chapter.

Severe Carbamazepine Intoxication in Children: Analysis of a 40-Case Series

BACKGROUND We compared the factors that might impact the severity and the prognosis of carbamazepine (CBZ) intoxication in children, as well as the efficacy levels of the treatment options. MATERIAL AND METHODS Demographic information and clinical and laboratory findings for 40 patients were evaluated retrospectively. Predictive parameters for the development of serious complications were studied. RESULTS Median age of patients was 14 years; 65% of the patients were female. The most common pathological clinical finding and laboratory abnormality were inability to awaken the patient and hyperglycemia (45% and 60%, respectively). The incidences of convulsion, coma, and respiratory failure were 14 (35%), 10 (25%), and 3 (7.5%), respectively. The Glasgow Coma Scale (GCS) scores and pH levels at emergency service admission were significantly lower in the severe intoxication group and the ICU admission group, and body temperature and serum glucose and lactate levels were significantly higher in these groups. A significantly negative correlation was found between the serum CBZ level and the GCS score, but the serum CBZ level was found to be significantly positively correlated with the lactate level. CONCLUSIONS According to our study, the GCS score at admission to hospital, the serum CBZ, glucose, pH, and lactate levels, and body temperature might be useful in predicting serious CBZ intoxication and prognosis in pediatric cases. We conclude that invasive treatment methods, such as hemodialysis or albumin-enhanced continuous venovenous hemodialysis, should be used in patients who do not respond to supportive treatment.

The Influence of Solid Microneedles on the Transdermal Delivery of Selected Antiepileptic Drugs

The aim of this project was to examine the effect of microneedle rollers on the percutaneous penetration of tiagabine hydrochloride and carbamazepine across porcine skin in vitro. Liquid chromatography-mass spectrometric analysis was carried out using an Agilent 1200 Series HPLC system coupled to an Agilent G1969A TOF-MS system. Transdermal flux values of the drugs were determined from the steady-state portion of the cumulative amount versus time curves. Following twelve hours of microneedle roller application, there was a 6.74-fold increase in the percutaneous penetration of tiagabine hydrochloride (86.42 ± 25.66 µg/cm²/h) compared to passive delivery (12.83 ± 6.30 µg/cm²/h). For carbamazepine in 20% ethanol, passive transdermal flux of 7.85 ± 0.60 µg/cm²/h was observed compared to 10.85 ± 0.11 µg/cm²/h after microneedle treatment. Carbamazepine reconstituted in 30% ethanol resulted in only a 1.19-fold increase in drug permeation across porcine skin (36.73 ± 1.83 µg/cm²/h versus 30.74 ± 1.32 µg/cm²/h). Differences in flux values of untreated and microneedle-treated porcine skin using solid microneedles for the transdermal delivery of tiagabine were statistically significant. Although there were 1.38- and 1.19-fold increases in transdermal flux values of carbamazepine when applied as 20% and 30% ethanol solutions across microneedle-treated porcine skin, respectively, the increases were not statistically significant.

Current Controversies in Gastrointestinal Decontamination

Most poisonings reported to American poison control centers occur in the home. The most common route of exposure is ingestion, which is responsible for most fatalities. The goal of gastrointestinal decontamination is to prevent absorption of the toxin. Trends in treating poisoned patients have changed over the past few decades in light of a move toward practicing evidence-based medicine. Efficacy and clinical outcome have come into question and have led to position papers published recently regarding syrup of ipecac, gastric lavage, activated charcoal, and whole-bowel irrigation. These different methods of decontamination and the scientific data supporting each one will be reviewed, and the current controversies surrounding each will be discussed.

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.

Overdose with antiepileptic drugs: the efficacy of extracorporeal removal techniques

Drug overdose is a growing problem among adolescents. Clinical severity depends on the drug and ingested amount, which in some cases may be life-threatening. We present a clinical case of a previously healthy teenage girl who ingested 16.4 g of carbamazepine and 14.5 g of valproic acid. She presented with profound disturbance of consciousness and toxic levels of both drugs, raised in the first hours after the ingestion. She was successfully treated with charcoal haemoperfusion followed by continuous venovenous hemodiafiltration. Overdose with the two drugs separately is common, but there are no reports of intoxication by simultaneous ingestion. High levels of carbamazepine and valproic acid can lead to severe systemic effects and management is made difficult by the absence of specific antidotes. Extracorporeal removal techniques are a good therapeutic option in these cases as they enhance the clearance by reducing the half-life of both drugs thereby preventing serious complications.

Extracorporeal treatment for carbamazepine poisoning: systematic review and recommendations from the EXTRIP workgroup

Context. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup was created to provide evidence and consensus-based recommendations on the use of extracorporeal treatments (ECTRs) in poisoning. Objectives. To perform a systematic review and provide clinical recommendations for ECTR in carbamazepine poisoning. Methods. After a systematic literature search, the subgroup extracted the data and summarized the findings following a pre-determined format. The entire workgroup voted via a two-round modified Delphi method to reach a consensus on voting statements, using a RAND/UCLA Appropriateness Method to quantify disagreement. Anonymous votes were compiled, returned, and discussed in person. A second vote determined the final recommendations. Results. Seventy-four articles met inclusion criteria. Articles included case reports, case series, descriptive cohorts, pharmacokinetic studies, and in-vitro studies; two poor-quality observational studies were identified, yielding a very low quality of evidence for all recommendations. Data on 173 patients, including 6 fatalities, were reviewed. The workgroup concluded that carbamazepine is moderately dialyzable and made the following recommendations: ECTR is suggested in severe carbamazepine poisoning (2D). ECTR is recommended if multiple seizures occur and are refractory to treatment (1D), or if life-threatening dysrhythmias occur (1D). ECTR is suggested if prolonged coma or respiratory depression requiring mechanical ventilation are present (2D) or if significant toxicity persists, particularly when carbamazepine concentrations rise or remain elevated, despite using multiple-dose activated charcoal (MDAC) and supportive measures (2D). ECTR should be continued until clinical improvement is apparent (1D) or the serum carbamazepine concentration is below 10 mg/L (42 the μ in μmol/L looks weird.) (2D). Intermittent hemodialysis is the preferred ECTR (1D), but both intermittent hemoperfusion (1D) or continuous renal replacement therapies (3D) are alternatives if hemodialysis is not available. MDAC therapy should be continued during ECTR (1D). Conclusion. Despite the low quality of the available clinical evidence and the high protein binding capacity of carbamazepine, the workgroup suggested extracorporeal removal in cases of severe carbamazepine poisoning.

Successful treatment of severe carbamazepine toxicity with 5% albumin-enhanced continuous venovenous hemodialysis

Carbamazepine overdose is a common, toxic ingestion, manifesting as central nervous system (CNS) and respiratory depression. Carbamazepine is highly protein bound with a large volume of distribution and, therefore, inefficiently removed by conventional hemodialysis. We describe the successful use of continuous venovenous hemodialysis (CVVHD) with 5% albumin enhanced dialysate in a 31-year-old female who developed CNS depression, hypotension and respiratory failure, requiring mechanical ventilation, after an intentional ingestion of approximately 10 g of extended release carbamazepine, Tegretol CR(®). The peak drug level was 26 mcg/ml, therapeutic range 8-12 mcg/ml, with toxicity often developing a level above 15 mcg/ml. Normal half-life of drug elimination is 35-60 h in carbamazepine naïve patients. In contrast, with albumin-enhanced dialysis, we observed a drug half-life of 18 h. She was extubated on day two and was transferred to inpatient psychiatry by day 3 without significant neurologic sequelae. In vitro studies have been done with bovine blood demonstrating significant carbamazepine removal using CVVHD with albumin-enhanced dialysate. There has been very limited experience using albumin-enhanced CVVHD in an adult patient with carbamazepine toxicity.

Severe carbamazepine intoxication unresponsive to albumin-enhanced continuous venovenous hemodiafiltration with low dialysate flow

Carbamazepine (CBZ) intoxication can be associated with severe toxicity, including neurological and cardio-respiratory abnormalities. Highly protein-bound, CBZ is not removed efficiently through conventional hemodialysis. Charcoal hemoperfusion is the most effective extracorporeal elimination therapy for CBZ intoxication. Recent reports have indicated that continuous venovenous hemodiafiltration (CVVHDF), albumin-enhanced continuous venovenous hemodialysis, high-flux hemodialysis and plasma exchange can be as effective as charcoal hemoperfusion. In contrast to recent reports, which demonstrated the effectiveness of CVVHDF with high dialysate flow in CBZ intoxication, we observed that serum CBZ level was decreased minimally by albumin-enhanced CVVHDF with low dialysate flow. Therefore, albumin-enhanced CVVHDF with high dialysate flow should be considered in severe CBZ intoxication, if hemoperfusion is unavailable because of the lack of facilities or if it cannot be performed.

Miscellaneous central nervous system intoxicants

The topic of central nervous system intoxicants encompasses a multitude of agents. This article focuses on three classes of therapeutic drugs, with specific examples in which overdoses require admission to the intensive care unit. Included are some of the newer antidepressants, the atypical neuroleptic agents, and selected anticonvulsant drugs. The importance of understanding pertinent physiology and applicable supportive care is emphasized.

Successful treatment of excessive dose of carbamazepine

Carbamazepine is used in the treatment of epilepsy; it is also prescribed for treatment of neuralgic pain syndromes and certain affective disorders. Carbamazepine intoxication with suicide attempt is a relatively common clinical problem that can result in coma, respiratory depression, arrhythmia, hemodynamic instability, and death. There is no specific antidote. Multiple-dose activated charcoal and hemodialysis are the main treatment for carbamazepine intoxication. In this paper, we report the case of a 19-year-old woman with excessive dose carbamazepin intoxication and our successful treatment with multiple-dose activated charcoal and hemodialysis.

Gastrointestinal decontamination in the acutely poisoned patient

Objective

To define the role of gastrointestinal (GI) decontamination of the poisoned patient.

Data Sources

A computer-based PubMed/MEDLINE search of the literature on GI decontamination in the poisoned patient with cross referencing of sources.

Study Selection and Data Extraction

Clinical, animal and in vitro studies were reviewed for clinical relevance to GI decontamination of the poisoned patient.

Data Synthesis

The literature suggests that previously, widely used, aggressive approaches including the use of ipecac syrup, gastric lavage, and cathartics are now rarely recommended. Whole bowel irrigation is still often recommended for slow-release drugs, metals, and patients who "pack" or "stuff" foreign bodies filled with drugs of abuse, but with little quality data to support it. Activated charcoal (AC), single or multiple doses, was also a previous mainstay of GI decontamination, but the utility of AC is now recognized to be limited and more time dependent than previously practiced. These recommendations have resulted in several treatment guidelines that are mostly based on retrospective analysis, animal studies or small case series, and rarely based on randomized clinical trials.

Conclusions

The current literature supports limited use of GI decontamination of the poisoned patient.

Carbamazepine and the active epoxide metabolite are effectively cleared by hemodialysis followed by continuous venovenous hemodialysis in an acute overdose

Hemodialysis (HD) and continuous venovenous hemodialysis (CVVHD) have an unproven role in the management of carbamazepine overdose. Albumin-enhanced CVVHD may accelerate carbamazepine (CBZ) clearance, but no pharmacokinetic data has been reported for traditional CVVHD without albumin enhancement. In addition, it is unclear whether the active CBZ-epoxide metabolite is removed with either mode of dialysis. We present a case of CBZ intoxication successfully managed with sequential HD and CVVHD. The CBZ half-life during CVVHD was 14.7 hours, compared with the patient's endogenous half-life of 30.8 hours. The CBZ-epoxide half-life was 3.2 hours during HD. We conclude that HD and CVVHD provide effective clearance of CBZ and the epoxide metabolite and should be considered in the management of an acute toxic ingestion.

Acute carbamazepine poisoning treated with resin hemoperfusion successfully

Carbamazepine (CBZ) poisoning has been occurring more frequently. We describe the use of synthesized resin-absorbed hemoperfusion in the therapy of a 48-year-old man who developed carotic, cardiovascular shock and multiorgan dysfunction due to a CBZ overdose (the highest concentration of drug >20 mg/L; therapeutic range, 8-12 mg/L). The treatment was very successful; and the patient eventually was discharged with a full recovery and no complications, although his diagnosis and treatment had been delayed for 56 hours. Hemoperfusion has a steady clearance of this drug without subsequent rebound or potential hazards. Resin hemoperfusion should be first considered for acute CBZ intoxication, especially when drug-induced gastrointestinal hypomotility prevents elimination via the gut and patient is under life-threatening condition.

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.

Limited efficacy of gastrointestinal decontamination in severe slow-release carbamazepine overdose

OBJECTIVE

To report the limited efficacy of both multiple doses of activated charcoal (MDAC) and whole bowel irrigation (WBI) in a patient with severe overdose of slow-release carbamazepine.

CASE SUMMARY

A 25-year-old man was admitted in a comatose state with seizures after a suicide attempt with slow-release carbamazepine. Serum carbamazepine concentration on admission (16 h postingestion) was 52.08 microg/mL. The patient was mechanically ventilated and treated with MDAC and a 4 hour charcoal hemoperfusion. Carbamazepine concentration at the end of hemoperfusion was 27.16 microg/mL. Despite continuous treatment with MDAC, a rebound in carbamazepine concentration to 36 microg/mL was observed 32 hours after hemoperfusion (58 h postingestion). WBI was performed over a 10 hour period. The carbamazepine concentration continued to increase to 38.55 microg/mL and seizures recurred. After WBI was performed, MDAC was reinstituted; 33 hours later (102 h postingestion), the carbamazepine concentration began to decline. The hospitalization course was complicated by pneumonia, which necessitated continuation of mechanical ventilation and administration of antibiotics. The patient recovered completely and was discharged without sequelae 15 days after admission.

DISCUSSION

Serum carbamazepine concentration and toxicity were effectively reduced by hemoperfusion. The role of MDAC coadministered during hemoperfusion cannot be ruled out. However, a rebound in carbamazepine concentration with recurrent seizures was observed despite MDAC and WBI. The most likely explanation for this rebound (65 h postingestion, 39 h posthemoperfusion) is prolonged absorption, possibly from a pharmacobezoar. Redistribution cannot be excluded, but this is not supported by the concentration-time course and previous reports.

CONCLUSIONS

Both MDAC and WBI may be ineffective in reducing absorption and enhancing elimination in overdose of slow-release carbamazepine. Repeated hemoperfusion or other elimination enhancement techniques should be considered when the clinical and toxicokinetic course suggests the presence of a refractory pharmacobezoar.

Carbamazepine poisoning managed with haemodialysis and haemoperfusion in three adolescents

Carbamazepine is a widely used antiepileptic agent. Accidental or suicidal overdose in children is not uncommon. Acute toxicity is associated with seizures, coma, arrhythmias and death in severe cases. Here we report three adolescents with carbamzepine overdose, two managed with standard low-flux haemodialysis and one with charcoal haemoperfusion. Our report emphasizes that haemodialysis might be a cheaper and easier alternative for carbamazepine overdose in milder cases, with fewer side-effects than haemoperfusion.

Toxicology case of the month: Carbamazepine overdose

A 29-year-old woman presents shortly after a massive overdose of carbamazepine controlled-release tablets. In anticipation of coma, she is electively intubated to safely enable gastrointestinal decontamination with nasogastric activated charcoal. She is admitted to the intensive care unit for ongoing supportive care, and further doses of activated charcoal are prescribed to enhance elimination of carbamazepine. Carbamazepine levels remain high and haemodialysis is carried out to further enhance elimination. Her coma resolves as levels fall, but clinical progress is complicated by anticholinergic delirium, ileus and bowel obstruction from charcoal concretions. She survives to medical discharge on day 12.

Continuous venovenous hemodiafiltration to treat controlled-release carbamazepine overdose in a pediatric patient

Carbamazepine (CBZ) intoxication is an important issue in acute poisoning practice. Highly protein-bound, CBZ is not removed efficiently through conventional hemodialysis. We describe the use of continuous venovenous hemodiafiltration (CVVHDF) in a 2-year-old boy who developed general tonic clonic seizure and respiratory depression due to controlled-release formula of CBZ overdose (peak drug level of > 20 microg.ml(-1), therapeutic range: 5-10 microg.ml(-1)). Serum CBZ concentrations fell to 0.25 microg.ml(-1) at the end of hemodiafiltration. The patient recovered rapidly and was discharged from hospital 4 days from the time of ingestion with no complications or neurologic impairment.

Influence of activated charcoal on the pharmacokinetics and the clinical features of carbamazepine poisoning

Carbamazepine (CBZ) poisoning has been associated with cases of severe toxicity and death. Multiple-dose activated charcoal was proposed to enhance the clearance of CBZ elimination, but there are no prospective controlled studies that demonstrated a change in clinical outcome after the use of multiple-dose activated charcoal. The aim of this study was to determine the CBZ elimination kinetics and the evolution of clinical features according to the dose of activated charcoal in acute poisoning patients. It is a prospective study for 6 months, from January to June 2004, including all pure acute CBZ-poisoned patients. Twelve patients were randomized to receive a multiple-dose activated charcoal (G1) or a simple dose of 1 g/kg (G2). Their mean age was 27.6+/-12.2 years; the Simplified Acute Physiology Score (SAPS II), 16.37+/-8.46; and the Acute Physiology and Chronic Health Evaluation (APACHE II), 8+/-3.96. They were 8 men and 4 women. The mean concentration of blood CBZ at hospital admission was of 29.42+/-6.68 mg/L. Each group includes 6 patients. The peak value of blood CBZ was comparable in the 2 groups: 33+/-3.46 mg/L (G1) vs 32.6+/-5.63 (G2) (P=.5); the requirement of mechanical ventilation was similar also (3 in each group). The duration of both coma and mechanical ventilation was significantly decreased in the first group compared with the second: 20.33+/-3.05 vs 29.33+/-4.11 hours for coma (P=.02) and 24.1+/-4.2 vs 36.4+/-3.6 hours for mechanical ventilation (P=.001). The length of stay was also significantly decreased in the first group: 30.3+/-3.4 vs 39.7+/-7.3 hours in the second group (P=.000006). Concurrently, we have noted a significant constant reduction of the half-life of CBZ from serum in the first group: 12.56+/-3.5 hours after multiple dose vs 27.88+/-7.36 hours after a simple dose (P=.0004). This decrease was correlated to the dose of charcoal. In summary, we can conclude that multiple-dose activated charcoal is more efficient than simple-dose; it permits a constant decrease of the half-life of blood CBZ without any rebound effect and could improve the prognosis by reducing the duration of coma and the length of stay.

Extracorporeal life support in a case of acute carbamazepine poisoning with life-threatening refractory myocardial failure

OBJECTIVE

To report the efficacy of extracorporeal life support (ECLS) in acute carbamazepine poisoning with sustained refractory myocardial failure and a high degree of conductance disturbances.

DESIGN AND SETTING

Case report from the toxicological and medical intensive care unit in a university hospital.

PATIENT

A 26-year-old man with severe myocardial failure unresponsive to 1.7 microg kg(-1) min(-1) epinephrine and 1.9 microg kg(-1) min(-1) norepinephrine (SvO2, 17.8% and cardiac index, 0.8 l min(-1) m(-2)) following a suicidal ingestion of 32 g slow-release carbamazepine.

INTERVENTIONS

ECLS (Jostra-Maquet centrifugal pump (Rotaflow) connected to a hollow-fiber membrane oxygenator).

MEASUREMENTS AND RESULTS

ECLS device allowed inotropic drug weaning while maintaining end-organ function and supported the patient until myocardial recovery. The plasma carbamazepine level was 224 micromol/l on admission and peaked at 338 micromol/l 101 h after admission with a prolonged gastrointestinal absorption phase despite multiple doses of activated charcoal. The patient survived and was successfully explanted on day 6. An extensive and regressive thrombosis of the inferior vena cava was noted. Cardiac function totally recovered and at 2-year follow-up. There were no significant sequelae.

CONCLUSIONS

We report a case of life-threatening myocardial failure with conductance disturbances secondary to an acute carbamazepine poisoning, demonstrating the efficacy of ECLS to assist recovery.