Antipsychotic poisoning in young children: a systematic review

Evaluation of various scoring systems as predictors of the need for intensive care unit admission and other adverse outcomes among patients with acute clozapine poisoning

Acute clozapine poisoning (ACP) is frequently reported worldwide. We evaluated the efficacy of the Poison Severity Score (PSS), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Rapid Emergency Medicine Score (REMS), and Modified Early Warning Score (MEWS) as predictors for intensive care unit (ICU) admission, mechanical ventilation (MV), mortality, and length of hospital stay in patients with ACP. A retrospective cohort study was conducted using records of patients diagnosed with ACP from January 2017 to June 2022 and admitted to an Egyptian poison control center. Analyzing 156 records showed that all assessed scores were significant predictors of the studied outcomes. The PSS and APACHE II score showed the highest area under the curve (AUC) as ICU admission predictors with insignificant variations. The APACHE II score showed the best discriminatory power in predicting MV and mortality. Nevertheless, MEWS exhibited the highest odds ratio (OR) as an ICU predictor (OR = 2.39, and 95% confidence interval = 1.86-3.27) and as a mortality predictor (OR = 1.98, and 95% confidence interval = 1.16-4.41). REMS and MEWS were better predictors of length of hospital stay compared with the APACHE II score. The simpler, lab-independent nature and the comparable discrimination but higher odds ratio of MEWS compared with APACHE II score justify MEWS' superior utility as an outcome predictor in ACP. We recommend using either the APACHE II score or MEWS, depending on the availability of laboratory investigations, resources, and the case's urgency. Otherwise, the MEWS is a substantially feasible, economical, and bedside alternative outcome predictor in ACP.

Abilifright: A Case Report of Massive Aripiprazole Overdose in a Toddler

Introduction

Aripiprazole is an atypical antipsychotic with unique receptor-binding properties that has a favorable safety profile in therapeutic doses compared to other antipsychotics. Massive aripiprazole overdose in children, however, presents with profound lethargy and may have neurologic, hemodynamic, and cardiac effects, often requiring admission to a high level of care.

Case Report

We describe a case of a 21-month-old male with a reported 52-milligram aripiprazole ingestion. Initial vital signs were remarkable for tachycardia and hypertension, which rapidly resolved. The patient did not develop hypotension throughout hospitalization. He experienced 60 hours of lethargy. Irritability associated with upper extremity spasms and tremors occurred from 36–72 hours post ingestion, which resolved without intervention. The initial electrocardiogram demonstrated ST-segment depressions in the anteroseptal leads; further cardiac workup was normal. Concurrent medical workup was unrevealing. Aripiprazole and dehydro-aripiprazole serum concentrations sent 46 hours after reported exposure were 266.5 nanograms per milliliter (ng/mL) and 138.6 ng/mL, respectively. He returned to neurologic baseline and was discharged 72 hours after ingestion.

Conclusion

Antipsychotics, including aripiprazole, should be considered as a potential toxicological cause of persistent central nervous system depression; ingestion of a single dose has the potential to cause significant toxicity.

Extent and Risks of Antipsychotic Off-Label Use in Children and Adolescents in Germany Between 2004 and 2011

OBJECTIVE

Only little is known about antipsychotic (AP) off-label use (OLU) in pediatric populations. It was the aim of this study to examine the frequency as well as the risks of off-label AP use in underaged patients.

METHODS

To calculate the frequency of off-label AP prescriptions for the years 2004-2011, we used claims data of more than two million minors aged 0-17 years. Off-label prescriptions were analyzed with regard to type of OLU, physician specialty, and underlying diagnoses. Incidence rates of selected adverse events were calculated for on-label as well as for OLU. The risk of poisoning associated with on- or OLU was assessed in a nested case-control study.

RESULTS

The annual share of pediatric AP users with off-label prescriptions varied between 52.3% and 71.1%. OLU by indication (42.8%-66.5%) was the most common type of OLU. Of the subjects with OLU by indication, 52.5% had a diagnosis of hyperkinetic disorder. Adverse events were scarce (incidence rates between 0.8 and 8.6 per 10,000 person-years), and no significant difference was observed between on- and OLU.

CONCLUSION

Because of their frequent use in hyperkinetic disorder patients, APs are commonly prescribed off-label for minors. Since OLU by contraindication was rare and the risk of the adverse events under study was similarly small for on- and OLU, this is not necessarily an indication for inappropriate treatment. It rather indicates that further randomized studies are needed to examine efficacy and safety of pediatric AP use in this indication.

Overdoses with Aripiprazole: Signs, Symptoms and Outcome in 239 Exposures Reported to the Danish Poison Information Centre

The aim of this study was to characterize the clinical signs and symptoms of exposures to aripiprazole overdoses. We retrospectively identified all aripiprazole exposures reported to the Danish Poison Information Centre (DPIC) from June 2007 to May 2015. Information concerning demographics, ingested dose and symptoms was extracted from the DPIC database and medical records. Information on death and admission to hospital was obtained from Danish national registers. We analysed 239 cases, 86 concerning single-drug exposures to aripiprazole, and 153 cases where aripiprazole had been taken with at least one other substance (mixed-drug). The median ingested aripiprazole dose was 105 mg (IQR: 50-1680 mg) in the single-drug exposure group and 120 mg (IQR: 60-225 mg) in the mixed-drug exposure group. The most commonly reported symptom was light sedation, reported in 63% of the single-drug group and 50% of the mixed-drug exposure group. There were no malignant arrhythmias or ECG abnormalities after single-drug exposures. No deaths were recorded in relation to the intake. We found a long-term mortality rate of 13 deaths per 1000 person-years (95% CI: 7; 23 per 1000 person-years), which is significantly higher than in an age- and gender-matched background population. In conclusion, we found that aripiprazole overdoses had few and mild symptoms predominantly related to the sedative properties. We detected a benign cardiovascular safety profile and no new safety concerns. Our findings may support an increased threshold of 300 mg for hospital admission after a single-drug exposure with aripiprazole and symptoms not worse than light sedation.

Toxicologic Emergencies in Patients with Mental Illness: When Medications Are No Longer Your Friends

Patients with psychiatric disorders are at risk for toxicologic emergencies. Psychotropic medications have numerous effects on the neurologic, cardiac, and other organ systems and interact with other medications, potentially leading to further side effects. It is important to become familiar with accepted psychiatric practice guidelines, common toxidromes, medical sequelae associated with prescribed medications, and the specific workup and treatment of overdoses of frequently prescribed psychotropics.

Comparison of pediatric atypical antipsychotic exposures reported to U.S. poison centers

CONTEXT

The rise in atypical antipsychotic prescribing increases the risk of pediatric exposures. Published studies in children are limited.

OBJECTIVE

The objectives are to evaluate national poison center data on atypical antipsychotic exposures in young children and compare toxicity amongst selected agents.

MATERIALS AND METHODS

A retrospective study of U.S. National Poison Data System single substance exposures, from 2005 to 2013, of five atypical antipsychotics in children <6 years old, followed to known outcome was performed. Data were evaluated for reason, clinical effects, management site and outcome.

RESULTS

There were 16,935 exposures included: 5018 aripiprazole, 1735 olanzapine, 3904 quetiapine, 4778 risperidone and 1500 ziprasidone. Median age was two years. Most common reason was unintentional-general (90.6%). Therapeutic error occurred more often with risperidone (19.9%). Clinical effects occurred in 59.4% of aripiprazole, 57.9% of olanzapine, 56.6% of ziprasidone, 40.1% of risperidone, and 29.3% of quetiapine. The most frequent were drowsiness/lethargy (35.6%), tachycardia (6.9%), agitation (4.0%), and ataxia (3.3%). Drowsiness/lethargy occurred most with aripiprazole (47.6%), ziprasidone (46.5%) and olanzapine (45.1%) and least with quetiapine (20.5%) and risperidone (28.6%). Tachycardia and agitation both occurred most often with olanzapine (11.4% and 12.7%, respectively). Management sites were non-health care facility (28.0%), treated/discharged from emergency department (48.9%), admitted - noncritical care (11.4%), critical care (9.5%), and other/unknown (2.2%). Admission was lowest for risperidone (13.9%) and quetiapine (11.9%) and highest for olanzapine (32.9%). Coded outcomes were no effect (53.3%), minor (33.7%), moderate (12.1%), major (0.9%) and no deaths. Moderate/major outcomes occurred most often with ziprasidone (20.5%) and olanzapine (19.0%) and least often with quetiapine (5.3%) and risperidone (10.9%).

DISCUSSION AND CONCLUSION

Overall outcomes were favorable, with major toxicity in <1% of exposures. Risperidone and quetiapine exposures resulted in less toxicity. This finding may be attributed to higher frequency of therapeutic errors for risperidone but the reason for less toxicity with quetiapine is unclear.

Atypical antipsychotic poisoning in young children: a multicentre analysis of poisons centres data

Although paediatric patients frequently suffer from intoxications with atypical antipsychotics, the number of studies in young children, which have assessed the effects of acute exposure to this class of drugs, is very limited. The aim of this study was to achieve a better characterization of the acute toxicity profile in young children of the atypical antipsychotics clozapine, olanzapine, quetiapine, and risperidone. We performed a multicentre retrospective analysis of cases with atypical antipsychotics intoxication in children younger than 6 years, reported by physicians to German, Austrian, and Swiss Poisons Centres for the 9-year period between January 1, 2001 and December 31, 2009. One hundred and six cases (31 clozapine, 29 olanzapine, 12 quetiapine, and 34 risperidone) were available for analysis. Forty-seven of the children showed minor, 28 moderate, and 2 severe symptoms. Twenty-nine cases were asymptomatic. No fatalities were recorded. Symptoms predominantly involved the central nervous and cardiovascular systems. Minor reduction in vigilance (Glasgow Coma Scale score >9) (62 %) was the most frequently reported symptom, followed by miosis (12 %) and mild tachycardia (10 %). Extrapyramidal motor symptoms were observed in one case (1 %) after ingestion of risperidone. In most cases, surveillance and supportive care were sufficient to achieve a good outcome, and all children made full recovery.

CONCLUSIONS

Paediatric antipsychotic exposure can result in significant poisoning; however, in most cases only minor or moderate symptoms occurred and were followed by complete recovery. Symptomatic patients should be monitored for central nervous system depression and an electrocardiogram should be obtained.

Effect of thioridazine on erythrocytes

BACKGROUND

Thioridazine, a neuroleptic phenothiazine with antimicrobial efficacy is known to trigger anemia. At least in theory, the anemia could result from stimulation of suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and by phospholipid scrambling of the cell membrane with phosphatidylserine exposure at the erythrocyte surface. Triggers of eryptosis include increase of cytosolic Ca²⁺-concentration ([Ca²⁺](i)) and activation of p38 kinase. The present study explored, whether thioridazine elicits eryptosis.

METHODS

[Ca²⁺](i) has been estimated from Fluo3-fluorescence, cell volume from forward scatter, phosphatidylserine exposure from annexin-V-binding, and hemolysis from hemoglobin release.

RESULTS

A 48 hours exposure to thioridazine was followed by a significant increase of [Ca²⁺](i) (30 µM), decrease of forward scatter (30 µM), and increase of annexin-V-binding (≥12 µM). Nominal absence of extracellular Ca²⁺ and p38 kinase inhibitor SB203580 (2 µM) significantly blunted but did not abolish annexin-V-binding following thioridazine exposure.

CONCLUSIONS

Thioridazine stimulates eryptosis, an effect in part due to entry of extracellular Ca²⁺ and activation of p38 kinase.

Overdose of atypical antipsychotics: clinical presentation, mechanisms of toxicity and management

Historically, treatment for schizophrenia focused on sedation. The advent of the typical antipsychotics resulted in treatment aimed specifically at the underlying disease, but these agents were associated with numerous adverse effects, and were not particularly effective at treatment of the negative symptoms of schizophrenia. As a result, numerous atypical agents have been developed over the past 2 decades, including several agents within the past 5 years. Overdose of antipsychotics remains quite common in Western society. In 2010, poison control centres in the US received nearly 43,000 calls related to atypical antipsychotics alone. Due to underreporting, the true incidence of overdose with atypical antipsychotics is likely much greater. Following overdose of an atypical antipsychotic, the clinical effects observed, such as CNS depression, tachycardia and orthostasis are largely predictable based on the unique receptor binding profile of the agent. This article, which focuses on the atypical antipsychotics commonly used in the treatment of schizophrenia, discusses the features commonly encountered in overdose. Specifically, agents that result in QT prolongation and the corresponding potential for torsades de pointes, as well as unique features encountered with the various medications are discussed. The diagnosis of this overdose is largely based on history. Routine use of drug screens is unlikely to be beneficial. The primary goal of management is aggressive supportive care. Patients with significant CNS depression with associated loss of airway reflexes and respiratory failure need advanced airway management. Hypotension should be treated first with intravenous fluids, with the use of direct acting vasopressors reserved for persistent hypotension. Benzodiazepines should be used for seizures, with barbiturates used for refractory seizures. Intravenous magnesium can be administered for patients with a corrected QT interval exceeding 500 milliseconds.

Pharmaceutical poisoning exposure and outcome analysis in children admitted to the pediatric emergency department

BACKGROUND

Pharmaceuticals involved in childhood poisoning vary, and treatment of poison exposure can be a challenge for primary physicians when children are unconscious or histories are lacking. Knowledge of the clinical manifestations and prognosis of poisoning will help primary physicians perform appropriate clinical assessments. In this study, we aim to report on patient characteristics, outcomes, and clinical features of pediatric poisoning in the emergency department.

METHODS

We retrospectively evaluated the medical records of 87 children younger than 18 years of age and presented to the emergency department with pharmaceutical poisoning (2001-2008). The detailed categories of pharmaceutical were reported, and their associations with patient outcomes were analyzed. Furthermore, children were divided into two groups, based on the reasons for poison exposure (accidental or intentional poisoning). Clinical features and outcomes between accidental or intentional poisoning were analyzed, and the cut-off age for high risk of intentional poisoning was also calculated.

RESULTS

Age groups of adolescents (48.3%) and preschool age (32.2%) children were the major representation. Neurologic system agents (48.3%) and analgesics (18.4%) were the most common causes of poisoning. Among the two major agents above, anxiolytic/hypnotic drugs (lorazepam) and acetaminophen were the most frequent causes. Of all children, 70.1% had duration of major symptoms for ≤1 day, and intentional poisoning caused significantly longer duration of hospital stay than accidental poisoning did (p=0.008). Moreover, female gender (p<0.001), older age (p<0.001), and analgesics (p=0.008) were more predominantly associated with intentional poisoning in children, and the cut-off age for high risk of intentional poisoning was over 10.5 years.

CONCLUSION

Neurologic system agents and analgesics were responsible for the majority of cases. Intentional poisoning caused longer hospital length of stay than accidental poisoning, and the factors associated with intentional poisoning were older age, female, and neurologic system agents.

Risperidone overdose causes extrapyramidal effects but not cardiac toxicity

OBJECTIVE

The aim of this study was to describe the clinical and electrocardiographic features of risperidone overdose, including the frequency of dystonic reactions.

METHODS

A consecutive series of admissions for risperidone overdose (>6 mg) were identified from a prospective database of poisoning admissions to a regional toxicology service. Data extracted included patient demographics, details of ingestion, clinical features including neurological findings and evidence of dystonias, electrocardiographic parameters (heart rate [HR], QRS, and QT intervals), complications, and medical outcomes including intensive care unit admission. In addition to descriptive statistics, visual inspection of plots of QT-HR pairs compared with the QT nomogram was performed.

RESULTS

There were 107 patients with 157 presentations, including 38 patients with 45 risperidone-alone overdoses. Of the 38 patients who ingested risperidone alone, the median age was 25 years (interquartile range [IQR],16-31 years), and 19 (50%) were female. The median dose ingested was 33 mg (IQR, 15-75 mg; range, 8-248 mg). Median length of stay was 16 hours (IQR, 8-18 hours), and none was ventilated or admitted to the intensive care unit. There were 5 cases (11%) with dystonic reactions, 26 (58%) with tachycardia (HR >or=100 beats/min), and no cases with hypotension (blood pressure <90 mm Hg). Only 1 patient (2%) recorded a decreased Glasgow Coma Scale score of 14, and there were no seizures or deaths. On review of electrocardiograms in 41 of the 45 cases where risperidone was ingested alone, there were no acute dysrhythmias. In 4 electrocardiograms (10%), there was an abnormal QT-HR pair, but all bar one were associated with an HR of greater than 110 beats/min. The median maximum QRS width was 80 milliseconds (IQR, 80-80 milliseconds; range, 40-120 milliseconds).

CONCLUSIONS

Risperidone taken alone in overdose causes minimal effects. Tachycardia and dystonic reactions were the main features of toxicity. Significant cardiac and other neurological features seem to be uncommon.

Respiratory failure following isolated ziprasidone ingestion in a toddler

Ziprasidone is an atypical antipsychotic approved for the treatment of schizophrenia and bipolar mania in adults and is used off label in children and adolescents. Despite increasing use of ziprasidone in both adult and pediatric populations, there remains a paucity of reports describing unintentional pediatric exposures. The following report describes a patient with isolated ziprasidone ingestion who required intubation secondary to respiratory failure. A 15-month-old previously healthy boy presented to the emergency department shortly after his father found him with approximately five partially dissolved 80-mg ziprasidone tablets in his mouth. The child was flaccid and lethargic with no eye opening, withdrawing from pain only. Two hours after arrival, he developed worsening CNS depression with inability to protect his airway and underwent endotracheal intubation. A serum ziprasidone level was 330 ng/mL by LC/MS. The patient was extubated approximately 14 h later and was discharged from the hospital shortly thereafter in good health without neurological sequelae. Isolated pediatric ingestion of ziprasidone resulting in the need for significant medical intervention has not been previously reported. We report a case of respiratory failure requiring intubation following accidental ziprasidone ingestion with confirmatory serum levels.

Pediatric ziprasidone overdose

We describe the first ziprasidone overdose with quantitative serum levels of a pediatric patient in coma and with pinpoint pupils. This case is an important contribution to the pediatric ziprasidone literature because it illustrates that ingestion of just 1 pill may result to profound mental status and respiratory depression in a child. H.C., a 30-month-old girl, presented to the emergency department approximately 30 minutes after an accidental ingestion of an adult family member's medication. The child was found on the floor surrounded by numerous pills and was witnessed to have ingested at least 1 tablet by a caregiver. After finding the child with the pills, the family observed the child for a brief period but transported her to the hospital after she became lethargic and unresponsive. The child received 2 doses of 0.4 mg of intravenous naloxone without change in her neurologic status. The child then underwent a rapid sequence intubation for airway protection and subsequently received gastrointestinal decontamination with 15 g of activated charcoal via the orogastric tube. Ziprasidone is an atypical antipsychotic drug that was approved by the Food and Drug Administration in February 2001 for the general treatment of schizophrenia in adults. Previously reported pediatric ziprasidone overdoses describe a syndrome of sedation, tachycardia, hypotonia, and coma consistent with that of the patient described in this paper. In pediatric ziprasidone overdose, QTc prolongation and hypotension have also been illustrated, but seizures have not been reported. An interesting aspect of this case is the development of pinpoint pupils unresponsive to naloxone. This phenomenon has been reported before with overdose of olanzapine, a similar atypical antipsychotic. The mechanism of miosis associated with overdose of atypical antipsychotics is unclear but is likely related to interference with central innervation of the pupil. Pupil size is maintained by a balance between sympathetic and parasympathetic neurohumeral tones. We propose that an overdose of an alpha-1 receptor blocking agent, such as ziprasidone, results in unopposed parasympathetic stimulation resulting in miosis.