Inadvertent administration of intravenous ziprasidone leading to bradycardia and QT interval prolongation

Antipsychotic Medications and Mortality in Children and Young Adults

Importance

Dose-related effects of antipsychotic medications may increase mortality in children and young adults.

Objective

To compare mortality for patients aged 5 to 24 years beginning treatment with antipsychotic vs control psychiatric medications.

Design, Setting, and Participants

This was a US national retrospective cohort study of Medicaid patients with no severe somatic illness or schizophrenia or related psychoses who initiated study medication treatment. Study data were analyzed from November 2022 to September 2023.

Exposures

Current use of second-generation antipsychotic agents in daily doses of less than or equal to 100-mg chlorpromazine equivalents or greater than 100-mg chlorpromazine equivalents vs that for control medications (α agonists, atomoxetine, antidepressants, and mood stabilizers).

Main Outcome and Measures

Total mortality, classified by underlying cause of death. Rate differences (RDs) and hazard ratios (HRs) adjusted for potential confounders with propensity score-based overlap weights.

Results

The 2 067 507 patients (mean [SD] age, 13.1 [5.3] years; 1 060 194 male [51.3%]) beginning study medication treatment filled 21 749 825 prescriptions during follow-up with 5 415 054 for antipsychotic doses of 100 mg or less, 2 813 796 for doses greater than 100 mg, and 13 520 975 for control medications. Mortality was not associated with antipsychotic doses of 100 mg or less (RD, 3.3; 95% CI, -5.1 to 11.7 per 100 000 person-years; HR, 1.08; 95% CI, 0.89-1.32) but was associated with doses greater than 100 mg (RD, 22.4; 95% CI, 6.6-38.2; HR, 1.37; 95% CI, 1.11-1.70). For higher doses, antipsychotic treatment was significantly associated with overdose deaths (RD, 8.3; 95% CI, 0-16.6; HR, 1.57; 95% CI, 1.02-2.42) and other unintentional injury deaths (RD, 12.3; 95% CI, 2.4-22.2; HR, 1.57; 95% CI, 1.12-2.22) but was not associated with nonoverdose suicide deaths or cardiovascular/metabolic deaths. Mortality for children aged 5 to 17 years was not significantly associated with either antipsychotic dose, whereas young adults aged 18 to 24 years had increased risk for doses greater than 100 mg (RD, 127.5; 95% CI, 44.8-210.2; HR, 1.68; 95% CI, 1.23-2.29).

Conclusions and Relevance

In this cohort study of more than 2 million children and young adults without severe somatic disease or diagnosed psychosis, antipsychotic treatment in doses of 100 mg or less of chlorpromazine equivalents or in children aged 5 to 17 years was not associated with increased risk of death. For doses greater than 100 mg, young adults aged 18 to 24 years had significantly increased risk of death, with 127.5 additional deaths per 100 000 person-years.

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.

QTc interval prolongation and torsade de pointes associated with second-generation antipsychotics and antidepressants: a comprehensive review

We comprehensively reviewed published literature to determine whether it supported the link between corrected QT (QTc) interval prolongation and torsade de pointes (TdP) for the 11 second-generation antipsychotics and seven second-generation antidepressants commonly implicated in these complications. Using PubMed and EMBASE, we identified four thorough QT studies (one each for iloperidone, ziprasidone, citalopram, and escitalopram), 40 studies specifically designed to assess QTc interval prolongation or TdP, 58 publications based on data from efficacy and safety trials, 18 toxicology studies, and 102 case reports. Thorough QT studies, QTc prolongation-specific studies, and studies based on efficacy and safety trials did not link drug-associated QTc interval prolongation with TdP. They only showed that the drugs reviewed caused varying degrees of QTc interval prolongation, and even that information was not clear and consistent enough to stratify individual drugs for this risk. The few toxicology studies provided valuable information but their findings are pertinent only to situations of drug overdose. Case reports were most informative about the drug-QTc interval prolongation-TdP link. At least one additional well established risk factor for QTc prolongation was present in 92.2 % of case reports. Of the 28 cases of TdP, six (21.4 %) experienced it with QTc interval <500 ms; 75 % of TdP cases occurred at therapeutic doses. There is little evidence that drug-associated QTc interval prolongation by itself is sufficient to predict TdP. Future research needs to improve its precision and broaden its scope to better understand the factors that facilitate or attenuate progression of drug-associated QTc interval prolongation to TdP.

Symptomatic bradycardia with oral aripiprazole and oral ziprasidone

OBJECTIVE

To describe the case of a patient who developed symptomatic bradycardia upon initiation of oral ziprasidone and later with oral aripiprazole, both of which resolved shortly after discontinuation of therapy.

CASE SUMMARY

An 18-year-old female with bipolar disorder was started on oral ziprasidone 80 mg at night and the dose was subsequently increased to 120 mg for management of acute mania and delusions. The patient developed symptomatic bradycardia (heart rate 31-35 beats/min), which resolved after ziprasidone was decreased to 80 mg. Three months later, the patient was readmitted for treatment of bipolar mania with psychotic features in the context of medication nonadherence. She was started on oral aripiprazole 15 mg daily (subsequently increased to 20 mg) in conjunction with 600 mg lithium carbonate twice daily. The patient again developed symptomatic bradycardia that resolved after discontinuation of aripiprazole.

DISCUSSION

This is the first case report of symptomatic bradycardia associated with the use of ziprasidone or aripiprazole. The Naranjo probability scale suggests that the likelihood of the atypical antipsychotic as the cause of bradycardia is probable for both ziprasidone and aripiprazole. Symptomatic bradycardia with the use of other atypical antipsychotics has been reported in the literature. Little is known about the mechanisms that contribute to the antipsychotic-associated bradycardic response.

CONCLUSIONS

Further studies are needed to better determine the relationship between antipsychotics and reflex bradycardia. Although bradycardia remains a relatively uncommon phenomenon seen with the use of these medications, the severity of this potential adverse effect warrants consideration when initiating antipsychotic therapy.