Atypical antipsychotic overdose in the pediatric population

Association of Antipsychotic Treatment With Risk of Unexpected Death Among Children and Youths

IMPORTANCE

Children and youths who are prescribed antipsychotic medications have multiple, potentially fatal, dose-related cardiovascular, metabolic, and other adverse events, but whether or not these medications are associated with an increased risk of death is unknown.

OBJECTIVE

To compare the risk of unexpected death among children and youths who are beginning treatment with antipsychotic or control medications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted from 1999 through 2014 and included Medicaid enrollees aged 5 to 24 years in Tennessee who had no diagnosis of severe somatic illness, schizophrenia or related psychoses, or Tourette syndrome or chronic tic disorder. Data analysis was performed from January 1, 2017, to August 15, 2018.

EXPOSURES

Current, new antipsychotic medication use at doses higher than 50 mg (higher-dose group) or 50 mg or lower chlorpromazine equivalents (lower-dose group) as well as control medications (ie, attention-deficit/hyperactivity disorder medications, antidepressants, or mood stabilizers) (control group).

MAIN OUTCOMES AND MEASURES

Deaths during study follow-up while out of hospital or within 7 days after hospital admission, classified as either deaths due to injury or suicide or unexpected deaths. Secondary outcomes were unexpected deaths not due to overdose and death due to cardiovascular or metabolic causes.

RESULTS

This study included 189 361 children and youths in the control group (mean [SD] age, 12.0 [5.1] years; 43.4% female), 28 377 in the lower-dose group (mean [SD] age, 11.7 [4.4] years; 32.3% female), and 30 120 in the higher-dose group (mean [SD] age, 14.5 [4.8] years; 39.2% female). The unadjusted incidence of death in the higher-dose group was 146.2 per 100 000 person-years (40 deaths per 27 354 person-years), which was significantly greater than that in the control group (54.5 per 100 000 population; 67 deaths per 123 005 person-years) (P < .001). The difference was primarily attributable to the increased incidence of unexpected deaths in the higher-dose group (21 deaths; 76.8 per 100 000 population) compared with the control group (22 deaths; 17.9 per 100 000 population). The propensity score-adjusted hazard ratios were as follows: all deaths (1.80; 95% CI, 1.06-3.07), deaths due to unintentional injury or suicide (1.03; 95% CI, 0.53-2.01), and unexpected deaths (3.51; 95% CI, 1.54-7.96). The hazard ratio was 3.50 (95% CI, 1.35-9.11) for unexpected deaths not due to overdose and 4.29 (95% CI, 1.33-13.89) for deaths due to cardiovascular or metabolic causes. Neither the unadjusted nor adjusted incidence of death in the lower-dose group differed significantly from that in the control group.

CONCLUSIONS AND RELEVANCE

The findings suggest that antipsychotic use is associated with increased risk of unexpected death and appear to reinforce recommendations for careful prescribing and monitoring of antipsychotic treatment for children and youths and to underscore the need for larger antipsychotic treatment safety studies in this population.

Effect of lipid emulsion infusion on paliperidone pharmacokinetics in the acute overdose rat model: A potential emergency treatment for paliperidone intoxication

Paliperidone prolongs cardiac repolarization in a concentration-dependent manner. Meanwhile, continuous infusion of intravenous lipid emulsion (ILE) has been established as a detoxification therapy for lipophilic drugs. However, this change in pharmacokinetics of various drugs following ILE administration remains to be clarified. Our objective is to clarify the effect of continuous infusion of ILE on the pharmacokinetics of overdosed paliperidone in rats. Paliperidone (20mg/kg) was administered orally to free-moving male Wistar rats. Continuous infusion (initial loading dose: 4ml/kg for 10min, followed by 4ml/kg/h for 12h) of ILE or acetated Ringer's solution (AR) was initiated 30min after paliperidone administration. Plasma concentration profile of paliperidone was monitored for 12h after administration. The plasma concentration and tissue/plasma concentration ratios of paliperidone were compared between ILE and AR groups. The rat group infused with ILE showed a higher area under the concentration-time curve (mean [S.D.]: 6102 [900.9] vs. 3407 [992.1]nghml^-1, p=0.02) and longer elimination half-time (t_1/2) (4.1 [0.9] vs. 2.2 [0.4]h, p=0.02) compared with the AR group. Tissue/plasma concentration ratios of paliperidone were lower in ILE rats than in AR rats (1.98 [0.70] vs. 3.82 [1.47] in the heart, p=0.04; 0.28 [0.29] vs. 1.27 [0.58] in the brain, p<0.001). In conclusion, continuous infusion of ILE would reduce tissue distribution and prolonged the t_1/2 of paliperidone in rats. These results suggest that continuous infusion of ILE has potential as an emergency treatment for acute paliperidone intoxication.

Prolonged Antimuscarinic Delirium in a Child Due to Benztropine Exposure Treated With Multiple Doses of Physostigmine

An 11-year-old boy presented with an antimuscarinic toxidrome due to benztropine and risperidone ingestion. His delirium was prolonged and difficult to treat with benzodiazepines. Multiple doses of physostigmine successfully treated it. Benztropine is a potent antimuscarinic agent, whereas risperidone has not been reported to cause antimuscarinic toxicity. The use of physostigmine to treat benztropine intoxication in a pediatric patient has not previously been described. In this case, multiple doses were used and were well tolerated.

An unreported side effect of risperidone in children: sinus arrest with long pauses causing syncope

Risperidone has been reported as a well-tolerated antipsychotic in children. The most common side effects of risperidone are anxiety, headaches, insomnia, and agitation, which frequently appear with high doses. Although it is known that risperidone affects the cardiac conduction system, symptomatic bradycardia has not been reported previously in children. We report a child who developed syncope because of sinus arrest with long pauses (>3 seconds) with therapeutic doses of risperidone. This case suggests that close monitoring is mandatory even during therapeutic treatment with risperidone.

A systematic review of cardiovascular effects after atypical antipsychotic medication overdose

As the use of atypical antipsychotic medications (AAPMs) increases, the number of overdoses continues to grow. Cardiovascular toxicity was common with older psychiatric medications but seems uncommon with AAPM. We conducted a systematic literature review to describe the cardiovascular effects reported after overdose of 5 common AAPM: aripiprazole, olanzapine, quetiapine, risperidone, and ziprasidone. We included case reports and case series describing overdose of these 5 medications identified in a search of MEDLINE, EMBASE, and abstracts from major toxicology meetings. We found 13 pediatric cases (age, <7 years), 22 adolescent cases (age, 7-16 years), and 185 adult cases. No pediatric case described a ventricular dysrhythmia or a cardiovascular death. In the adolescent and adult cases, we found numerous reports of prolonged corrected QT interval and hypotension, but there were only 3 cases of ventricular dysrhythmia and 3 deaths that may have been due to direct cardiovascular toxicity. The results from case series reports were similar to the single case report data. Our review suggests that overdose of AAPM is unlikely to cause significant cardiovascular toxicity.

The QT interval and psychotropic medications in children: recommendations for clinicians

The use of psychotropic medications in children has increased significantly in the last few years. There have been several case reports of sudden death in children taking specific psychotropic medications. Fears that these deaths might have been caused by ventricular arrhythmias have been enhanced by reports of electrocardiographic abnormalities, including prolongation of the QTc interval, in patients taking these medications. Several factors including genetic susceptibility, pre-existing cardiac disease, abnormalities of drug clearance and concomitant use of other medications known to affect the QTc interval can increase the susceptibility of the heart to conduction abnormalities. This article discusses the potential of particular psychotropic drugs to prolong the QTc interval in children, and examines other factors that may contribute to conduction abnormalities. We aim to provide clear clinical recommendations for the prescription of these drugs and the monitoring of children taking them.

Olanzapine overdose in children and adolescents: two case reports and a review of the literature

Although the atypical antipsychotic olanzapine is increasingly being used in child and adolescent psychiatry, reports of olanzapine overdose in this young population are scarce. We report on two cases of adolescents who attempted suicide with an overdose of olanzapine: (1) A 14-year-old female ingested 275 mg olanzapine, which produced the highest reported nonlethal serum level (1503 ng/mL) and caused somnolence, agitation (acutely), and extrapyramidal symptoms (EPS; after 54 hours) but no major clinical complications. The serum olanzapine level dropped to 129 ng/mL within 48 hours; and (2) a 17-year-old male ingested 400 mg olanzapine, the highest reported nonlethal dose of olanzapine in adolescents, which produced respiratory suppression requiring intubation and mechanical ventilation; he recovered after 3 days. Based on clinical monitoring and postmortem data, the 2 patients survived the ingestion of high doses of olanzapine. We also provide a review of the literature, encompassing all reported cases of olanzapine overdose in children and adolescents and discuss symptoms, diagnosis, and treatment options, based on pharmacokinetic and pharmacodynamic considerations.

Overdoses and ingestions of second-generation antipsychotics in children and adolescents

OBJECTIVE

We reviewed the available published data on intentional or unintentional secondgeneration antipsychotic overdoses in children and adolescents. The prescribing of secondgeneration antipsychotics has continued to increase over the past decade for children, adolescents, and adults. The authors reviewed the existing literature to determine the circumstances, presenting problems, treatment, and outcomes of youths who were exposed to nontherapeutic doses of these medications.

METHODS

A systematic English-language Medline search of all reports (1989-2005) and a review of the bibliographies of all articles obtained was done to identify papers reporting an overdose or ingestion of a second-generation antipsychotic. Data were reviewed on clozapine, risperidone, olanzapine, ziprasidone, quetiapine, and aripiprazole. The annual reports of the American Association of Poison Control Centers National Data Collection System were reviewed from 1990 to 2003, the most recent report currently available. All fatalities in children and youths under 18 years of age were included.

RESULTS

The literature review identified 40 reports that included 63 patients, ranging in age from 1 day to 17 years of age. The clinical presentations included drowsiness, lethargy, agitation, irritability, combativeness, and tachycardia. There were 11 fatalities in the cases reviewed, 1 from clozapine overdose, 3 from risperidone overdose, 2 from olanzapine overdose, and 5 from quetiapine overdose. All other cases reported no significant sequelae and resolved without any reported clinical consequences. Duration of overdose symptoms ranged from 24 hours to 7 days. One case of clozapine intoxication showed resolution of symptoms in 6 hours and, in another case of olanzapine overdose, symptoms resolved in 13 days. The most frequently employed treatments included intubation, gastric lavage, activated charcoal, intravenous fluids, artificial respiration, and restraints or sedatives.

CONCLUSIONS

There is a need for future case reports to include serum medication level, weight of patient, coingestants, the health of the patient at baseline, relevant laboratory and toxicology studies and a standardized scale to rate the level of consciousness, such as the Glasgow Coma Scale. The existing pharmacovigilance data reports indicate these medications are relatively safe when taken in overdose, particularly when coingestants are not involved.

Toxicology and overdose of atypical antipsychotic medications in children: does newer necessarily mean safer?

PURPOSE OF REVIEW

Atypical antipsychotic medications (second-generation antipsychotics) have been increasingly used in the treatment of a number of psychotic disorders since their introduction in 1988, with the newest medication introduced in 2002. Justification for their use includes claims of equal or improved antipsychotic activity over first-generation antipsychotics, increased tolerability, and decreased side effects. However, there are still significant adverse effects and toxicities with this class of medications. Toxicologic exposures and fatalities associated with atypical antipsychotics continue to increase in the United States, with 32,422 exposures and 72 deaths in 2003. There have also been Food and Drug Administration warnings in the past year about how some atypical antipsychotics have been marketed to minimize the potentially fatal risks and claiming superior safety to other atypical antipsychotics without adequate substantiation, indicating the toxicologic potential of these agents may be underestimated.

RECENT FINDINGS

Continued research to evaluate adverse effects and tolerability of atypical antipsychotics compared with first-generation antipsychotics and each other is reviewed. This article also reviews the pharmacodynamics, pharmacokinetics, and drug interactions with these medications. New therapeutic monitoring recommendations for this class of medications have also been proposed. Finally, clinical toxicity in overdose and management are reviewed.

SUMMARY

While new atypical antipsychotic medications may have a safer therapeutic and overdose profile than first-generation antipsychotic medications, many adverse and toxic effects still need to be considered in therapeutic monitoring and overdose management.