[Toxicological characteristic of neuroleptics--substituted benzamides]

At present in the medical practice the group of neuroleptics, substituted benzamides is widely used. According to literature data they cause acute intoxications under particular conditions. The group of substituted benzamides includes drugs such as amisulpride, tiapride, sulpiride and sultoprid. Substituted benzamides intake causes toxic actions: psychotropic and neurotoxic. The neuroleptic intoxication is an effect of overdosage, abuse and hypersensitization. Severe intoxications with drugs of this group may cause lethal outcome.

[Endogenous intoxication parameters in the assessment of a risk for pneumonias in acute azaleptin intoxications]

In cases of acute azaleptin poisoning (AAP), the parameters of endogenous intoxication (EI) were studied in patients both with complicated pneumonias and without them. The integral EI index endogenous intoxication coefficient (Cei) was developed, which simultaneously reflects the coupling capacity of albumin of hydrophilic toxins and lipid peroxidation products: Cei (MMWP x MDA/EAC) x 1000, where MMWP is medium molecular-weight peptides; MDA is malonic dialdehyde; EAC is the effective albumin concentration. The use of Cei significantly enhances the efficiency of diagnosis of early-stage EI and provides a more objective assessment of therapy in AAP patients. EI is more severe when poisoning is concurrent with complicated pneumonias. Cei is of informative value in the assessment of a risk for pneumonias in AAP, which may be used in various emergencies accompanied by EI.

Neonatal death following clozapine self-poisoning in late pregnancy: an unusual case report

The report presents a fatal poisoning of a neonate occurring in the final stage of gestational life and evoked by his mother, who, while 9 months pregnant, took a toxic dose of clozapine aiming at committing suicide. She was also severely poisoned, but ultimately was saved. The woman had been taking the medication due to schizophrenia and depression prior to conception, and the discontinuation of the drug in the course of pregnancy increased the risk of the woman attempting suicide. In the course of comprehensive toxicological analysis based on the developed analytical procedure with the use of LC-APCI-MS, clozapine and its two metabolites, norclozapine and clozapine-N-oxide, were determined in postmortem blood, liver and kidney in concentrations explaining the death of the neonate. The interpretation of the above-described case is complex and--apart from toxicological aspects--also involves issues associated with psychiatry, pharmacotherapy in pregnancy and medicolegal problems.

Zuclopenthixol-induced neuroleptic malignant syndrome in an adolescent girl

We present the case of a 14-year-old female who had many characteristics of neuroleptic malignant syndrome (NMS) without pyrexia following a single depot injection of 200 mg of zuclopenthixol. The patient presented with a change in mental status that had progressed over the preceding 48 hours. Subsequently, she became increasingly agitated and confused, and developed diffuse muscular rigidity, mutism, tremor, tachycardia, diaphoresis, sialorrhea, and incontinence. Results of laboratory tests showed elevated CPK levels, leukocytosis, and a low serum iron level. Bromocriptine and diazepam were used as initial treatment of a probable NMS and provided significant improvement. During the next seven days, she clinically improved but continued to exhibit emotional lability, logorrhea, elevated mood, and increased psychomotor activity. Therefore, bromocriptine and diazepam were discontinued and lorazepam and lithium were administered as treatment of a bipolar disorder. Four weeks later, she was discharged in stable condition. The presentation of this case report suggests that the primary psychiatric diagnosis is important in antipsychotic usage in the pediatric population, and that young patients receiving neuroleptic treatment should be monitored for the early signs of NMS. Using the diagnostic criteria of a neuroleptic toxicity spectrum may result in greater clinical awareness and earlier recognition of NMS.

Olanzapine overdose: a series of analytically confirmed cases

To describe the spectrum of clinical effects in olanzapine overdose and investigate the factors that predict severe outcomes. We analysed olanzapine-overdose events confirmed by drug analysis. Demographic, clinical and outcome data were recorded for each presentation. The relationship between dose and therapeutic olanzapine use, and outcomes (length of hospital stay, intensive care unit admission, mechanical ventilation, Glasgow coma score <9 and delirium) were investigated. Thirty-seven olanzapine overdose admissions were included. Median age was 30 years (interquartile range: 24-40 years), 24 women and 27 taking olanzapine therapeutically. Median ingested dose was 150 mg (range: 10-1600 mg). Olanzapine overdose was characterized by tachycardia (73%), central nervous system depression (43%), miosis (39%) and delirium (54%), which were either present on admission or developed within 6 h. There was no relationship between the dose and length of hospital stay, intensive care unit admission, Glasgow coma score <9 or delirium, but there was a trend towards more severe outcomes in patients not taking olanzapine therapeutically. Patients with delirium had an increased length of hospital stay and intensive care unit admission rate (50%) and 70% of them required physical or chemical restraint. Olanzapine overdose causes a high rate of delirium and central nervous system sedation that requires significant inpatient resources. Olanzapine overdoses should be initially observed for 6 h and patients not taking olanzapine regularly may have more severe effects.

Pharmacokinetics of Quetiapine in Overdose and the Effect of Activated Charcoal

The aim of the study was to investigate the pharmacokinetics of quetiapine overdose and the effect of charcoal. The data set included 204 concentration-time points from 54 quetiapine overdose events (median dose 2,700 mg (300-24,000 mg)). Charcoal was administered 0.5-6 h after 19 overdoses. A fully Bayesian methodology for population pharmacokinetic analysis was used and data were modelled using WinBUGS. Uncertainty in the dose history was considered in model building by estimating dose amount and dose time within a possible range. Inclusion of informative priors stabilized the model and population parameter values could be estimated well. A one-compartment model with first-order input and first-order elimination described the data. The final model included uncertainty in dose time. The median and interquartile range of the half-life for individual patients was 6.6 h (4.9-8.4 h). Charcoal was estimated to reduce fraction absorbed by 35%. Co-ingested CYP3A4 inhibitors appeared to decrease clearance and CYP3A4 inducers increase clearance. Charcoal administration may be beneficial after quetiapine overdose.

Serum Levels of Olanzapine in a Non-Fatal Overdose

Olanzapine is a widely used second generation antipsychotic drug. Case reports of intoxications have been published, but reports in the literature of non-fatal intoxications of olanzapine containing repeated measurements of serum levels are scarce. Therefore, this case of non-fatal olanzapine intoxication is presented, in which 19 blood samples were drawn during 2 weeks. The highest (initial) measured value was estimated at 800 pg/L. This patient ingested 550 mg of olanzapine resulting in clinical signs of intoxication, including seizures. Because the patient was found the day after the intoxication, the initial concentration had probably been higher. The pharmacokinetics of olanzapine has been described as linear and dose-proportional throughout the therapeutic dosing range. Large overdoses, however, have been described to show non-linear pharmacokinetics. In this study's series of serum concentrations, a two-phase elimination was seen, with an initial elimination half-life of about 24 h during the first 3 days, followed by a second phase with a half-life of about 2.5 days. The patient in this case recovered completely. Because the elimination time after intoxication can be considerably longer than expected, it is recommended that the patient's serum concentrations after intoxication be monitored.

A fatal case of amoxapine poisoning under the influence of chronic use of psychotropic drugs

A 43-year-old woman was found dead in a car in the supine position. She had been suffering from depression for 2 years and hesitation wounds on the left forearm and wrist were observed. On microscopic examination, pulmonary congestion and edema were observed with heart failure cells in many alveoli, thereby suggesting not only acute but also chronic heart failure. Drug screening in the blood by gas chromatography-mass spectrometry (GC-MS) revealed the presence of amoxapine and levomepromazine, and their concentrations in tissues were determined by GC-MS with three-step solvent extraction followed by acetylation. The concentration of amoxapine in the blood and liver was 0.86-1.77 and 18.76microg/ml, respectively; the levels were much higher than the therapeutic level but did not reach the lethal level. The concentrations of levomepromazine in tissues were within the therapeutic level. Based on the pathological and toxicological findings, the cause of death was determined to be amoxapine poisoning on the basis of chronic heart failure due to the chronic use of psychotropic drugs.

[Case of catecholamine-resistant shock caused by drug overdose]

A 27-year-old man with schizophrenia took an overdose of a psychotic agent. He became unconscious and had severe hypotension. Although he was diagnosed as having distributive shock caused by drug overdose and treated by hydration and catecholamine, the shock status was lasting. The use of vasopressin changed the situation dramatically. After the injection of vasopressin at maximum dose, 0.1 U/min, the dose of vasopressin could be tapered. He recovered from shock and was discharged on the third day without sequelae. There are an increasing number of reports that indicate that vasopressin is effective for distributive shock, especially catecholamine-resistant septic shock. It seems that the appropriate dose of vasopressin is under 0.04U/min considering the deterioration of cardiac function although the maximum dose of vasopressin was O.1U/min in this case. For that reason, monitoring by pulmonary artery catheter is recommended. The side effects of vasopressin should be discussed for appropriate use.

IMPACT OF LEGISLATIVE CHANGES ON PATTERNS OF ANTIPSYCHOTIC PRESCRIBING AND SELF-POISONING IN SCOTLAND: 2000-06

Recently, national guidelines have advocated greater use of atypical rather than typical antipsychotics in the treatment of schizophrenia. In addition, there have been safety concerns regarding the potential cardiotoxicity of certain antipsychotics taken in overdose. This has led regulatory authorities in the United Kingdom to restrict the use of thioridazine. The overall impact of these legislative changes on patterns of antipsychotic prescribing has received comparatively little attention. Therefore, we sought to examine the effects on community prescribing practices, and to determine whether this was accompanied by changes in patterns of antipsychotic poisoning. Between 2000-03, there was a rapid decline in the use of typical antipsychotics, whereas the use of atypical antipsychotics increased. The prevalence of atypical and typical antipsychotic prescribing has been approximately equal between 2003-06. During the same study period, hospital admissions due to typical antipsychotic poisoning also declined, however, the effects lagged behind changes in prescribing practice by 2-3 years. These data indicate that legislative changes that restrict the use of thioridazine and other typical antipsychotics are associated with a measurable reduction in the number of hospital admissions due to overdose with these agents.

[Pharmacokinetics of perospirone hydrochloride at an excessive dose and changes in the serum prolactin level]

A 36-year-old female, in whom 8 mg perospirone hydrochloride tablets had been prescribed, took 178 tablets (corresponding to 1,424 mg) as a single dose. After 4.5 hours, she was admitted under a diagnosis of acute drug intoxication. We investigated her clinical course and medical records including the laboratory data, and measured serial changes in the serum levels of perospirone hydrochloride and prolactin by HPLC and ELISA. Concerning the clinical course, the consciousness level on admission was JCS II-10, but normalized 18 hours after dosing. Thereafter, there were no intoxication symptoms or sequelae related to massive administration of this agent, and the patient was discharged 3 days after admission. There were no abnormalities in the laboratory data obtained on admission and 2 days after admission. The serum levels of perospirone hydrochloride were 695 ng/mL 4.5 hours after dosing and approximately 60 ng/mL 18 hours after dosing, when consciousness became clear. The t1/2 beta value was 8 hours, similar to that in healthy adults. Furthermore, the serum level of prolactin 4.5 hours after dosing was 49.5 ng/mL, but returned to the normal range 18 hours after dosing, when consciousness became clear.

Mental status change, myoclonus, electrocardiographic changes, and acute respiratory distress syndrome induced by quetiapine overdose

A 41-year-old man with bipolar disorder came to the emergency department with mental status changes, prolonged rate-corrected QT interval, and myoclonus after ingesting 4500 mg of quetiapine, an atypical antipsychotic drug. Within 24 hours, respiratory failure ensued, requiring intubation and mechanical ventilation. Chest radiograph demonstrated bilateral infiltrates consistent with acute respiratory distress syndrome (ARDS). To our knowledge, this is the first report of ARDS resulting from quetiapine overdose. Clinicians should be aware that in cases of large overdoses of quetiapine, patients should be closely monitored if mental status changes, electro-cardiographic changes, or hypoxia occur, preferably in an intensive care unit.

Aripiprazole exposures reported to Texas poison control centers during 2002-2004

Aripiprazole is an oral atypical antipsychotic drug used in the treatment of schizophrenia and potentially other behavior disorders. The purpose of this study was to describe the epidemiology of aripiprazole exposures reported to Texas poison control centers. Human aripiprazole exposures reported to six Texas poison control centers were identified and comparisons were made between isolated and nonisolated cases with respect to various demographic and clinical factors. Of 280 human exposures involving aripiprazole, 35% were isolated and 65% were nonisolated. The patients were female in 52% of isolated and 60% of nonisolated cases. Isolated cases were significantly more likely to involve children < 6 yr of age. Fifty-eight percent of isolated cases were unintentional while 68% of nonisolated cases were intentional. Nonisolated cases were much more likely to already be at or en route to a health care facility when the poison control center was contacted. Of those cases with a known medical outcome, no adverse clinical effect was reported in 52% of isolated cases and 35% of nonisolated cases. The adverse clinical effects associated with isolated aripiprazole exposures were mainly neurological, cardiovascular, and gastrointestinal, with the most frequently reported adverse clinical effect being drowsiness or lethargy. The most commonly reported treatments for isolated aripiprazole exposures were single dose of activated charcoal, cathartic, intravenous fluids, dilution, lavage, and antihistamines. In conclusion, isolated and nonisolated aripiprazole exposures varied with respect to patient age, exposure reason, management site, and clinical outcome.

Nonfatal Suicidal Olanzapine Overdose

There is an increase in the usage of olanzapine because of its relatively benign adverse effect profile. We report a case of suicidal overdose who survived after ingestion of 1600 mg of olanzapine requiring minimal intervention. Fluctuation in mental status suggestive of toxic delirium was noted during recovery from overdose. There was minimal alteration in the clinical and biochemical parameters. Olanzapine is safe in monointoxication as evident from this case study.

Amisulpride deliberate self-poisoning causing severe cardiac toxicity including QT prolongation and torsades de pointes

Although clinical trials of the antipsychotic amisulpride revealed no cardiac adverse effects, four patients with severe cardiac toxicity after overdose were reported to Australian poisons information centres in 2004-2005. All four had QT prolongation over 500 ms, two had rate-dependent bundle branch block, two developed torsades de pointes, and one died after cardiac arrest. Pending further studies, we recommend electrocardiogram assessment until at least 16 h after amisulpride overdose and, if QT interval is prolonged, cardiac monitoring until the patient is clinically well and conduction intervals are normal.

Tissue Distribution of Quetiapine in 20 Cases in Virginia

Quetiapine fumarate (Seroquel) is a dibenzothiazepine psychotropic agent that was introduced in 1997 for treating psychoses. Quetiapine is being found with increasing frequency in postmortem cases in Virginia. We report the postmortem results and histories of 20 quetiapine cases from the Office of the Chief Medical Examiner in Virginia covering the period 1999 through 2004. Quetiapine was extracted from blood using a basic drug solid-phase extraction (SPE) and identified by full scan electron impact gas chromatography-mass spectrometry (GC-MS). Quetiapine quantification was accomplished by forming the trimethylsilyl derivative with bis(trimethylsilyl)trifluoracetamide/trimethylchlorosilane and using selected ion monitoring GC-MS. The quetiapine trimethylsilyl derivative ions acquired were m/z 210, 239, and 322. Methapyrilene was the internal standard, and ions m/z 97 and 58 were monitored. The method was linear from 0.1 to 5.0 mg/L with a limit of quantitation of 0.1 mg/L. The quetiapine mean and range of concentrations found in each tissue are as follows: peripheral blood, 7.7 mg/L (0.14-37 mg/L, n = 17); heart blood, 23.63 mg/L (0.53-76 mg/L, n = 4); liver, 91 mg/Kg (1.1-510 mg/Kg, n = 19); bile, 44 mg/L (6.0-96 mg/L, n = 4); urine, 15 mg/L (1.9-37 mg/L, n = 8); gastric, 897 mg total (3.5-3960 mg, n = 7); and vitreous, 1.4 mg/L (0.2-3.2 mg/L, n = 5). The average of all blood concentrations in 18 cases in which quetiapine contributed to the cause of death was 7.95 mg/L (0.4-76 mg/L). The manner of death in 13 of those cases was suicide, two were undetermined, and three were accidents. In two cases in which quetiapine was an incidental finding, the blood concentrations were 0.14 and 1.0 mg/L. Quetiapine and other toxicological findings are presented with the cause and manner of death to assist in interpreting future quetiapine findings in postmortem samples.

Pontine haemorrhage mimicked by an olanzapine overdose

Olanzapine, an atypical antipsychotic of the thienobenzodiazepine class, has been on the market since 1996. Its popularity has increased over recent years because of excellent clinical results as well as a favourable side effect profile. Mirroring this increased olanzapine use has been a rise in the number of non-accidental overdoses. The clinical picture of olanzapine overdose can be surprisingly variable. In the case presented, the patient's low Glasgow Coma Score prevented an accurate history being taken. Examination revealed bilateral upgoing plantars, pinpoint pupils, increased tone, and brisk reflexes; however initial investigations, including an urgent CT head, were normal. The patient required 24 hours of intensive care before he regained consciousness and admitted to the overdose. Although there are several reports of olanzapine mimicking opiate intoxication in overdose, this is one of the first cases where overdose has mimicked an intracerebral event. The authors highlight some of the literature regarding clinical presentation and treatment options, and discuss the relation between olanzapine therapy and diabetes.

Quetiapine in Overdosage

Data on quetiapine overdosage are only sparsely available in the literature. This study provides additional data on the pharmacokinetics and clinical effects of intoxication with this atypical antipsychotic drug. The authors performed a retrospective analysis of all quetiapine intoxications reported to and screened by the toxicological laboratory of the Central Hospital Pharmacy The Hague between January 1999 and December 2003. Cases with known suggested amount of intake and medical outcome were included. From the patient's medical record and from the toxicological laboratory findings, patient demographic characteristics (gender, age), details of quetiapine intoxication (estimated time of ingestion, estimated amount of ingestion, and coingested drugs) and clinical parameters were obtained. Severity of intoxication was graded by the Poisoning Severity Score (PSS). Individual pharmacokinetic parameter values were calculated using a one-compartment open model and a Bayesian fitting procedure. Out of a total of 21 intoxications with quetiapine, 14 fulfilled the inclusion criteria. The ingested dose ranged from 1200 to 18,000 mg. The blood concentration ranged from 1.1 to 8.8 mg/L with a lag time of 1 to 26.2 hours between time of ingestion and blood sampling at the emergency ward. The most frequent findings were somnolence and tachycardia. The PSS was minor in 6 patients (43%), moderate in 5 patients (36%), and severe in 3 patients (21%). Severity of intoxication was not associated with a higher amount of quetiapine intake. The authors found no correlation between the serum concentration of quetiapine and the amount ingested. Elimination t(1/2) was not prolonged. It can be concluded that quetiapine intoxications appear to proceed mildly. Tachycardia and somnolence were the main clinical symptoms in our case series. No fatalities occurred. The severity of clinical symptoms was not associated with either a high serum concentration or the suggested amount ingested of quetiapine.

Antipsychotic poisoning in young children: a systematic review

The aim of this review was to determine the spectrum and severity of effects of unintentional antipsychotic poisoning in children. A computerised literature search of MEDLINE (1966 to February 2005) and EMBASE (1980 to February 2005) was undertaken. The Internet was searched using URL: www.google.com. The proceedings of the North American Congress of Clinical Toxicology (NACCT) and the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) were hand searched. All cases of unintentional antipsychotic (all classes) poisoning in children aged 0-6 years were included. The data extracted included the age, weight, antipsychotic, dose, clinical effects, treatment and outcomes. The toxic dose was estimated as the lowest dose causing objective adverse effects.Sixty-eight reports were identified. Few contained all of the required information. Most of the case series included multiple antipsychotics with limited information on individual drugs or all ages with limited paediatric information. For most antipsychotics the ingestion of one tablet caused symptoms that were sometimes severe and usually lasted from 1 to 3 days. Extrapyramidal symptoms (EPS) were often delayed for up to 12-24 hours. Chlorpromazine caused CNS depression, hypotension and miosis; EPS and cardiac effects were rare, and the toxic dose was estimated to be 15 mg/kg. Haloperidol caused drowsiness (rarely coma) and over one-half of patients had neuromuscular effects (mainly EPS), with a toxic dose estimated at 0.15 mg/kg. Thioridazine caused CNS depression and potentially cardiac effects, with a toxic dose of 1.4 mg/kg. Atypical antipsychotics caused significant CNS depression (except risperidone); EPS were less common. Toxic doses were clozapine 2.5 mg/kg, olanzapine 0.5 mg/kg and aripiprazole 3 mg/kg. EPS responded to anticholinergic drug treatment. In summary, unintentional antipsychotic ingestion in children can cause severe effects that last 1-3 days, often with one tablet. Children potentially ingesting a toxic dose or who are symptomatic should be considered for assessment in hospital. Most cases resolve with good supportive care. Toxic doses are only estimates that are based on limited data and should be used with caution until prospective studies are undertaken.