Atypical antipsychotic medication poisoning: An evidence-based consensus guideline for out-of-hospital management

Brexpiprazole toxicity in a paediatric patient

Brexpiprazole is a relatively new drug that has no published research or applications within the paediatric population. Brexpiprazole targets multiple receptors and can manifest as multisystem symptoms when ingested in supratherapeutic quantities. In this report, we discuss the case of a child in early childhood who presented with delayed neurological and cardiac symptoms 24 hours after accidental ingestion of brexpiprazole. Due to delayed onset, this case highlights that a high index of suspicion and prolonged observation are necessary to appropriately manage brexpiprazole overdose or accidental ingestion.

Predictors for prolonged qt intervals in acute antipsychotic poisoned patients

Background

Acute antipsychotic poisoning is correlated to a high prevalence of qt interval prolongation.

Aim

This study aimed to evaluate early qt interval prolongation predictors in acute antipsychotic-poisoned patients.

Methodology

This prospective cohort study enrolled 70 symptomatic patients with acute antipsychotic poisoning. Sociodemographic data, toxicological, clinical, investigation, and outcomes were collected and analyzed. The estimation of the corrected qt interval (QTc) was performed using Bazett's method. Primary outcome was normal or abnormal length of QTc interval. Secondary outcomes included duration of hospital stay, complete recovery and mortality. The corrected qt interval was analyzed by univariate and multivariate logistic regression analysis.

Results

Patients were divided into groups A (normal QTc interval up to 440 msec; 58.6% of cases) and B (prolonged QTc interval ≥ 440 msec; 41.4% of cases). Patients in group B had significantly high incidences of quetiapine intake, bradycardia, hypotension, hypokalemia, and long duration of hospital stay. By multivariate analysis, quetiapine [Odd's ratio (OR): 39.674; Confidence Interval (C.I:3.426-459.476)], bradycardia [OR: 22.664; C.I (2.534-202.690)], and hypotension [OR: 16.263; (C.I: 2.168-122.009)] were significantly correlated with prolonged QTc interval.

Conclusion

In acute antipsychotic poisoning, quetiapine, bradycardia, and hypotension are early clinical predictors for prolonged QTc interval.

Toxicity and Adverse Effects in Clozapine-Related Presentations to a Medical Toxicology Service in Western Sydney

BACKGROUND

Clozapine is an anti-psychotic agent, reserved for treatment-resistant schizophrenia, with demonstrated efficacy in an otherwise therapeutically challenging patient population. We aimed to review the full spectrum casemix of clozapine presentations to our tertiary toxicology service.

METHODS

In this retrospective study, we reviewed consecutive clozapine related toxicity presentations to a tertiary medical toxicology inpatient and consultation service-including deliberate self-poisoning (DSP), adverse drug reaction (ADR), recreational use, and therapeutic misadventure over a 10-year period from 2011 to 2021. Data were extracted for demographics, ingested dose, exposure characteristics, and patient outcome.

RESULTS

We identified 83 patients with clozapine-related presentations over the 10-year period. Twenty-two patients were excluded. Of the remaining 61 patients, 28 patients presented with DSP, 20 patients with accidental overdose, and 13 patients with an ADR; no patients presented with recreational use. It was noted that ADRs were largely idiosyncratic reactions and not always related to dose adjustments. In the context of therapeutic misadventure and DSP, we noted that a lower mean dose achieved a higher poison severity score (PSS) in clozapine-naive patients when compared to those patients on regular clozapine.

CONCLUSIONS

The presentation of clozapine-related toxicity differs depending on the modality of ingestion, whether DSP, accidental, or as a result of ADR. Patients naive to clozapine therapy tend to experience higher PSS with lower doses ingested either in a deliberate self-poisoning or accidental ingestion context. This is likely due to tolerance to the sedative properties of clozapine. No patients manifested clinical toxicity greater than 8 hours after ingestion, with an observation period of 6 hours accurately identifying toxicity in most patients.

A Case of Antipsychiatry Polypill Overdose (200 Tablets) Successfully Treated With Hemodialysis: A Serious Encounter

Polypharmacy refers to using and consuming multiple drugs as part of the treatment for a disease or disorder. Polypharmacy can lead to an increase in the number of drug overdose emergencies. Age-related metabolic changes and reduced drug clearance in older adults can result in severe drug reactions and other clinical consequences, which can sometimes be fatal, raising concerns about the safety of polypharmacy. We discuss a case of a 50-year-old female who presented to us in a drowsy state after an antipsychiatry (antipsychotic and antidepressant) polypill overdose with 200 tablets and was successfully treated with hemodialysis. This case report highlights that prompt treatment initiation based on the patient's clinical status and drug serum levels is crucial to achieving the best outcomes.

Assessment of Risperidone Toxicity in Zebrafish (Danio rerio) Embryos

Risperidone is an antipsychotic medication used in the treatment of conditions like autism and schizophrenia. The goal of the current study was to examine the effects of risperidone in zebrafish embryos ( Danio rerio ) with regard to survival, development, and cardiac and neural systems. The results showed that concentrations above 100 μM were associated with deaths, teratogenic effects, and cardiotoxic and neurotoxic effects. The findings support the utility of zebrafish for toxicological screening studies.

Exhaustive in silico design and screening of novel antipsychotic compounds with improved pharmacodynamics and blood-brain barrier permeation properties

Antipsychotic drugs or neuroleptics are widely used in the treatment of psychosis as a manifestation of schizophrenia and bipolar disorder. However, their effectiveness largely depends on the blood-brain barrier (BBB) permeation (pharmacokinetics) and drug-receptor pharmacodynamics. Therefore, in this study, we developed and implemented the in silico pipeline to design novel compounds (n = 260) as leads using the standard drug scaffolds with improved PK/PD properties from the standard scaffolds. As a result, the best candidates (n = 3) were evaluated in molecular docking to interact with serotonin and dopamine receptors. Finally, haloperidol (HAL) derivative (1-(4-fluorophenyl)-4-(4-hydroxy-4-{4-[(2-phenyl-1,3-thiazol-4-yl)methyl]phenyl}piperidin-1-yl)butan-1-one) was identified as a "magic shotgun" lead compound with better affinity to the 5-HT2A, 5-HT1D, D2, D3, and 5-HT1B receptors than the control molecule. Additionally, this hit substance was predicted to possess similar BBB permeation properties and much lower toxicological profiles in comparison to HAL. Overall, the proposed rational drug design platform for novel antipsychotic drugs based on the BBB permeation and receptor binding might be an invaluable asset for a medicinal chemist or translational pharmacologist.Communicated by Ramaswamy H. Sarma.

A descriptive study of aripiprazole, brexpiprazole, and cariprazine exposures in children ages 0 to 5 years reported to United States poison centers

INTRODUCTION

Increased prescribing of antipsychotics and availability of new antipsychotics has resulted in increased exposures in children. Current data on aripiprazole, brexpiprazole, and cariprazine are limited.

METHODS

This was a retrospective database study utilizing the National Poison Data System from 2015 through 2021. We included cases of single substance exposures to aripiprazole, brexpiprazole, cariprazine, or lumateperone in children ages 0 to 5 years old with follow-up to a known outcome. Key outcomes were medical outcomes, clinical effects, and level of care if treated in a healthcare facility.

RESULTS

There were 3,573 aripiprazole, 137 brexpiprazole, 249 cariprazine, and one lumateperone exposure over the period. Primary outcomes were evaluated in 2,655 cases (2,390 aripiprazole, 96 brexpiprazole, and 169 cariprazine). Fifty-one percent were male and 77% were between 0 and 2 years old. Moderate effect was coded in 16.6% of aripiprazole, 23% of brexpiprazole, and 12% of cariprazine exposures. Major effect was coded in 0.6% of aripiprazole, 1% of brexpiprazole, and 2.4% of cariprazine exposures. Duration of symptoms was mostly between 8 and 24 h for 34.6% of aripiprazole, 30% of brexpiprazole, and 32% of cariprazine exposures. Over 60% of the children seen in a health care facility were discharged from the emergency department. The lowest doses resulting in at least a moderate effect and admission to a health care facility was 0.46 mg/kg for aripiprazole, 2.1 mg/kg for brexpiprazole, and 1.9 mg/kg for cariprazine. Important clinical effects included central nervous system depression, tremors, tachycardia, agitation, and vomiting.

CONCLUSION

Reported ingestions of aripiprazole, brexpiprazole, or cariprazine may result in neurologic symptoms like central nervous system depression or seizures in children. The prolonged duration of symptoms resulted in admission for at least a day for many cases. Further research should address optimal monitoring time and location for these exposures.

Assessment of Clinical Diagnostic Efficacy of Pulmonary Function Test Based on DBN-SVM of Pediatric Asthma and Cough Variant Asthma

The diagnosis of asthma depends on the unprejudiced proof of the varying airflow obstruction. The pulmonary function tests are carried out to evaluate the clinical value of different types of respiratory diseases in children or infants. This study is focused on the clinical evaluation of the pulmonary function tests in the diagnosis of pediatric asthma and cough variant asthma. A differential diagnosis method for chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap with complementary diagnostic value is proposed. For the pulmonary function tests, the COPD gene dataset was selected and feature selection was performed using the DBN-SVM scoring method. For analysis and comparison, the differential diagnosis models were built using ROC curves for the accuracy of the deep belief network model and the support vector machine model. The sensitive features associated with COPD and ACO classification using the deep belief network model were found to be in good agreement with known clinical diagnostic strategies. The clinical diagnosis tests for pulmonary pediatric asthma and cough variant asthma were conducted on two groups of children, with both groups containing a basis of comparison. 80 cases of pediatric asthma and cough variant asthma were admitted from 2013 to 2014 and 80 cases of children with a healthy physical examination. The results of the two groups were compared. The results showed that the levels of FEV1, PEF, and FVC were significantly lower (P < 0.05), in healthy children, and FEV1/FVC%, RV, and RV/TCL% were significantly higher (P < 0.05) in children with asthma and cough variant asthma during acute exacerbation and chronic persistence. There were no statistically significant differences in the duration of clinical remission (P > 0.05). Thus, the study suggests that confirmed cases of the diagnosis of pediatric asthma and cough variant asthma by pulmonary function tests were significantly higher than those of conventional tests (P < 0.05). From this study, we can conclude that pulmonary function tests can accurately diagnose pediatric asthma and cough variant asthma, and also accurately reflect the development of the child's disease, which is of high clinical value.

Toxicology of Psychoactive Substances

A trend in the increasing use of prescription psychoactive drugs (PADs), including antidepressants, antipsychotics, and mood stabilizers, has been reported in the United States and globally. In addition, there has been an increase in the production and usage of illicit PADs and emergence of new psychoactive substances (NPSs) all over the world. PADs pose unique challenges for critical care providers who may encounter toxicology issues due to drug interactions, side effects, or drug overdoses. This article provides a summary of the toxicologic features of commonly used and abused PADs: antidepressants, antipsychotics, mood stabilizers, hallucinogens, NPSs, caffeine, nicotine, and cannabis.

Successful Treatment of an Acute High-Dose Clozapine Poisoning without Detoxication

Patient: Male, 28-year-old

Final Diagnosis: Clozapine poisoning

Symptoms: Drowsiness • hyperventilation • impaired consciousness • respiratory insufficiency • tachycadia

Medication: —

Clinical Procedure: —

Specialty: Critical Care Medicine • Psychiatry

A Dilute and Shoot LC–MS/MS Method for Antipsychotics in Urine

Adherence to prescribed antipsychotics is an ongoing problem. Traditionally, estimates of adherence have been made from patient interviews, pill counting and blood testing. A number of methods for the analysis of antipsychotics in blood have been reported for both therapeutic drug monitoring and postmortem testing for toxicity. This report details a dilute and shoot method for the analysis of 19 different antipsychotics and metabolites. The method takes advantage of earlier reports demonstrating unique, prevalent urine metabolites for aripiprazole, brexpiprazole, haloperidol and lurasidone to enhance sensitivity for these analytes. With a fast analysis time and minimal sample preparation, this method can be used for quantitation of antipsychotics in urine. Finally, this method has been used to test samples for over a year with the results summarized in this report. While further improvements are certainly possible, this method is selective and sensitive for this group of important compounds.

Poison-related visits in a pediatric emergency department: A retrospective analysis of patients who bypass poison control centers

INTRODUCTION

Poison control centers (PCC) are an effective means to prevent unnecessary emergency department (ED) visits associated with poisoning exposures. However, not all patients with poison exposures utilize the PCC. The purpose of this study was to identify unintentional pediatric poisoning exposures presenting to a large US children's hospital that could have been managed onsite (i.e., at home) if consultation with a PCC had occurred prior to the ED visit.

METHODS

Using ED encounters from a tertiary children's hospital, unintentional pharmaceutical, chemical, or fume exposures occurring between October 1, 2014 and September 30, 2015 were identified from ICD-9-CM billing codes. Two specialists in poison information reviewed the medical records of the identified patients who had no contact with the PCC and determined whether these encounters were preventable through PCC triage. Descriptive statistics examined the differences between the encounters. Data were analyzed in R v3.2.4 (Vienna, Austria) and SAS v9.4 (SAS Institute, Cary, NC).

RESULTS

In the total study population (n = 231), 98 (42.4%) were PCC triaged and 133 (57.6%) were caregiver self-referred to the ED. For those who self-referred, 62 (46.6%) patients would have been recommended to be managed onsite instead of presenting at the ED for medical care. Analgesics and household cleaning products were the most common pharmaceutical and chemical exposures, respectively.

CONCLUSIONS

Nearly half of ED visits for pediatric patients with unintentional poisoning exposures could have been avoided by contacting a PCC. Educational and self-efficacy-based interventions are needed to expand the public's use of PCC services.

Drug Administration to the Wrong Nursing Home Residents Reported to the Québec Poison Center: A Retrospective Study

OBJECTIVE

This study examined the association between the administration of drugs to the wrong nursing home residents with a need for hospital treatment or as an indicator of mortality.

DESIGN

A retrospective observational study of medical records from February 1, 2016, to January 31, 2017.

SETTING

Calls made to the Quebec Poison Center.

PARTICIPANTS

Nursing home residents aged ≥65 years.

INTERVENTION(S)

Medication administered to the wrong resident.

MAIN OUTCOME MEASURE(S)

Death, hospital referral and treatment, number of drugs or type of drug classes.

RESULTS

Of the 6282 calls received by the Quebec Poison Center concerning medication errors, 494 cases were included in the retrospective study. Half of the patients (51%) received at least 5 different drugs that were not prescribed for them. Most patients (82%) were asymptomatic at the time of the call to the poison center; however, a third (34%) of the exposures were considered potentially toxic and were treated at the hospital. The most prominent drug classes involved include antihypertensives, antiarrhythmics, and antipsychotics. In particular, almost a quarter (23%) of cases of clozapine maladministration resulted in moderate or severe effects. No deaths were reported.

CONCLUSIONS/IMPLICATIONS

Medication errors in nursing homes are prevalent. The medical provider and probably the poison control center should be consulted as soon as possible when people are aware of administration of medication to the wrong patient, which is considered a medical emergency until proven otherwise. Public policies should seek for better surveillance and prompt intervention. Research should be undertaken to limit errors of drug administration to the wrong nursing home residents.

webPOISONCONTROL: can poison control be automated?

BACKGROUND

A free webPOISONCONTROL app allows the public to determine the appropriate triage of poison ingestions without calling poison control. If accepted and safe, this alternative expands access to reliable poison control services to those who prefer the Internet over the telephone. This study assesses feasibility, safety, and user-acceptance of automated online triage of asymptomatic, nonsuicidal poison ingestion cases.

METHODS

The user provides substance name, amount, age, and weight in an automated online tool or downloadable app, and is given a specific triage recommendation to stay home, go to the emergency department, or call poison control for further guidance. Safety was determined by assessing outcomes of consecutive home-triaged cases with follow-up and by confirming the correct application of algorithms. Case completion times and user perceptions of speed and ease of use were measures of user-acceptance.

RESULTS

Of 9256 cases, 73.3% were triaged to home, 2.1% to an emergency department, and 24.5% directed to call poison control. Children younger than 6 years were involved in 75.2% of cases. Automated follow-up was done in 31.2% of home-triaged cases; 82.3% of these had no effect. No major or fatal outcomes were reported. More than 91% of survey respondents found the tool quick and easy to use. Median case completion time was 4.1 minutes.

CONCLUSION

webPOISONCONTROL augments traditional poison control services by providing automated, accurate online access to case-specific triage and first aid guidance for poison ingestions. It is safe, quick, and easy to use.

A retrospective review of the prehospital use of activated charcoal

OBJECTIVE

We studied the complications and timing implications of prehospital activated charcoal (PAC). Appropriateness of PAC administration was also evaluated.

METHODS

We retrospectively reviewed prehospital records over 32 months for overdose cases, where PAC was administered. Cases were assessed for amount and type of ingestant, clinical findings, timing of PAC, timing of transport and arrival into the emergency department (ED), and complications. Encounter duration in cases of PAC was compared with that, for all cases during the study period, where an overdose patient who did not receive activated charcoal was transported.

RESULTS

Two thousand eight hundred forty-five total cases were identified. In 441 cases, PAC was given; and complications could be assessed. Two hundred eighty-one of these had complete information regarding timing of ingestion, activated charcoal administration, and transport. The average time between overdose and PAC was 49.8 minutes (range, 7-199 minutes; median, 41.0 minutes; SD, 30.4 minutes). Complications included emesis (7%), declining mental status (4%), declining blood pressure (0.4%), and declining oxygen saturation (0.4%). Four hundred seventeen cases of PAC had documentation of timing of emergency medical service (EMS) arrival on scene and arrival at the ED. Average EMS encounter time was 29 minutes (range, 10-53 minutes; median, 27.9 minutes). Two thousand forty-four poisoning patients were transported who did not receive PAC. The average EMS encounter time for this group was 28.1 minutes (range, 4-82 minutes; median, 27.3 minutes), not significantly different (P =.114).

CONCLUSIONS

Prehospital activated charcoal did not appear to markedly delay transport or arrival of overdose patients into the ED and was generally safe.

Current therapeutic options for Huntington's disease: good clinical practice versus evidence-based approaches?

Therapeutic decision-making in Huntington's disease (HD) is often guided by clinical experience, because of the limited empirical evidence available. The only medication for HD that has met the regulatory hurdle for approval is tetrabenazine, indicated for the treatment of chorea. However, its use has limitations, and in the setting of specific contraindications or comorbidities the treatment of choice for chorea is still the multipurpose antipsychotics. For the management of psychiatric disturbances, selective serotonin reuptake inhibitors (SSRIs) and mood stabilizers are often used, although empirical evidence is lacking. Finally, no known effective treatment is available for cognitive dysfunction in HD. We discuss the limited evidence available and current expert opinion on medical treatment of the dominant motor, psychiatric, and cognitive features of HD. This follows a brief introduction on the general principles of HD management and on evidence-based medicine in relation to clinical practice.

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.

Increased aripiprazole concentrations in an HIV-positive male concurrently taking duloxetine, darunavir, and ritonavir

OBJECTIVE

To report a case of increased aripiprazole concentrations during coadministration with darunavir, ritonavir, and duloxetine.

CASE SUMMARY

A 43-year-old HIV-positive Hispanic man received darunavir/ritonavir-based antiretroviral therapy (ART) in addition to aripiprazole and duloxetine for depression and anxiety. A month after the aripiprazole dosage was increased to 50 mg daily, the patient developed confusion and loss of coordination. Weeks later, he presented to the emergency department with fever, cough, headache, neck stiffness, back pain, and blurred vision and was admitted for possible meningitis. Because symptoms improved with pain control and intravenous fluids during hospitalization, he was discharged within a couple days after admission. One month later he was readmitted for worsening symptoms, and the resulting diagnostic workup showed unremarkable findings except for lymphadenopathy (LAD). This finding was attributed to discontinuing ARTs after his first admission. He was discharged on aripiprazole 50 mg daily, darunavir 800 mg daily, ritonavir 100 mg daily, and duloxetine 60 mg daily. A random steady-state concentration of aripiprazole was 1100 ng/mL (therapeutic concentration 100-200 ng/mL) obtained 49 days after discharge.

DISCUSSION

The Horn Drug Interaction Probability Scale demonstrated a possible relationship between the increased aripiprazole concentration and coadministration of darunavir/ritonavir and duloxetine, which inhibit CYP3A4 and 2D6. Potential confounders to the increased concentration include duloxetine inhibition of CYP2D6 polymorphism, possible 2D6 polymorphism, and exceeding aripiprazole's maximum dose. The initial presentation of confusion and loss of coordination may have been early signs of aripiprazole toxicity, which relapsed as shown by his symptoms prior to admission.

CONCLUSIONS

The interaction between aripiprazole and darunavir, ritonavir, and duloxetine may be significant. Clinicians should be cognizant of increased risk of aripiprazole toxicity in HIV-positive patients concurrently taking ritonavir-boosted ART and other cytochrome P450 inhibitors like duloxetine. Dose adjustments or monitoring parameters should be an area of research and discussion.

Compliance with atypical antipsychotic triage guidelines by Texas poison centers

Triage guidelines for poison center management of atypical antipsychotic ingestions were published in December 2007. This investigation determined whether Texas poison centers already complied with a simplified version of these guidelines. All acute aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone ingestions reported to Texas poison centers during 2000-2007 were identified. Exclusion criteria were the presence of coingestants, patient already at or en route to a health-care facility when the poison center was contacted, and chronic ingestion. Each case was evaluated whether it was managed in compliance with the simplified triage guidelines and the compliance rate calculated. For 2,611 total cases, the compliance rate was 64.1%. The rate was 71.7% for aripiprazole, 43.6% for clozapine, 71.6% for olanzapine, 60.8% for quetiapine, 65.5% for risperidone, and 59.0% for ziprasidone. The majority of acute atypical antipsychotic ingestions reported to Texas poison centers were managed according to a simplified version of recommended triage algorithm.

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.