Aspiration Pneumonia: An Underappreciated Risk of Clozapine Treatment

Investigating in VigiBase over 6000 cases of pneumonia in clozapine-treated patients in the context of the literature: focus on high lethality and the association with aspiration pneumonia

BACKGROUND

The literature associates clozapine with pneumonia/aspiration pneumonia.

RESEARCH DESIGN AND METHODS

The international pharmacovigilance database (VigiBase™) uses the information component (IC) as statistical signal. VigiBase clozapine reports were analyzed for pneumonia/aspiration pneumonia from introduction to 10 May 2023.

RESULTS

There were 6392 cases of all types of pneumonia (5572 cases of pneumonia, 775 of aspiration pneumonia, and 45 combined). The IC was 3.52 for aspiration pneumonia, introduced as a VigiBase label in 2003, and 1.91 for pneumonia. Patients were reclassified as 3628 with no signs of aspiration and 1533 with signs. Signs of aspiration were strongly associated with some co-medications: olanzapine, odds ratio (OR) = 23.8, 95% confidence interval (CI), 14.9-38.0; risperidone OR = 18.6, CI, 11.4-30.4; valproic acid, OR = 5.5, CI, 4.5-6.6; and benzodiazepines OR = 5.5, CI, 4.5-6.6. In 2415 cases with completed data, fatal outcomes made up 45% (signs of aspiration made no difference), but there was wide variability from 0% (females <45 years of age; duration ≤30 days) to 76% (males >64 years of age; duration >1 year). During the first week, pneumonia was associated with 1) very high titration doses, 2) very small doses in Parkinson's disease, and 3) Japan vs other countries.

CONCLUSIONS

In clozapine-treated patients: 1) at least 30% of pneumonia cases may be aspiration pneumonia, 2) stopping some co-medications may decrease the risk of aspiration pneumonia, 3) average lethality in pneumonia was 45% but may be around 75% in geriatric patients with long-term treatment, and 4) safer titrations may sometimes require 5-mg tablets.

Respiratory aspiration during treatment with clozapine and other antipsychotics: a literature search and a pharmacovigilance study in VigiBase

INTRODUCTION

Antipsychotics (APs), during treatment or overdose, may be associated with respiratory aspiration.

AREAS COVERED

A PubMed search on September 30, 2022, provided 3 cases of respiratory aspiration during clozapine therapy and 1 case during an AP overdose. VigiBase records of respiratory aspiration associated with APs from inception until September 5, 2021, were reviewed. VigiBase, the World Health Organization's global pharmacovigilance database, uses a statistical signal for associations called the information component (IC).

EXPERT OPINION

The ICs (and IC₀₂₅) were 2.1 (and 2.0) for APs, 3.2 (and 3.0) for clozapine, 2.6 (and 2.4) for quetiapine, and 2.5 (and 2.2) for olanzapine. Cases of respiratory aspiration associated with APs included: 137 overdose/suicide cases (64 fatal) and 609 cases during treatment (385 fatal) including 333 taking clozapine (238 fatal). In logistic regression models of fatal outcomes, the odds ratios, OR, and (95% confidence intervals, CI) of significant independent variables were: a) 2.3 - 2.6 for clozapine in 3 samples of AP treatment of varying size, b) 1.9 (CI 1.0 to 3.5) for geriatric age in 284 patients on clozapine treatment, and c) 1.8 (CI 1.1 - 3.2) for antidepressant co-medication in 276 patients on non-clozapine APs. Multiple AP pharmacological mechanisms may explain respiratory aspiration.

Nursing research on a new silver-based antibacterial agent for pneumonia

As a highly contagious bacterium, pneumonia can cause a series of respiratory diseases, and its treatment has become a concern of people. This study mainly discusses the nursing research of a new silver-based antibacterial agent in the treatment of pneumonia. The following procedures were performed: (1) a sterilized expectoration suction device was inserted into the nasopharynx (7–8 cm), and the nasopharyngeal secretions were suck by controlling the pressure of the suction device; and (2) the catheter was washed with 2 mL of sterilized physiological saline, and the sample was immediately sent to the laboratory for bacterial culture of the lower airway and respiratory secretions to determine viral antigens. The drug resistance coefficient of the lysozyme, benzoate, and pneumonia bacteria is 4.5–26.8%. In addition, the fourth generation sefalos posephin and pneumonia bacteria presented drug sensitivity, and the drug resistance coefficient is 13.1–33.3%. The sensitivity to the new silver-based antimicrobial agent and lopenem is 100%. The sensitivity of other germs is between 2 and 5%. The results of the study indicate that the antibacterial properties of the new silver-based antibacterial agent increase with the degree of amino acid substitution of the same sample concentration. The new silver-based antibacterial agent has excellent antibacterial properties against Klebsiella pneumoniae.

Thrombocytopenia associated with clonidine in a case of clozapine-induced sialorrhea

Clozapine is approved by the US Food and Drug Administration for treatment-resistant schizophrenia and mitigation of suicidality in patients with schizophrenia or schizoaffective disorder. Clozapine requires monitoring of adverse events, such as hypotension, myocarditis, cardiomyopathy, seizures, severe neutropenia, and gastrointestinal hypomotility. Sialorrhea is another adverse event that can be bothersome for patients and result in nonadherence or the development of aspiration pneumonia. Clonidine, an α_2A adrenergic receptor agonist, is one medication option that can reduce or eliminate sialorrhea. Clonidine is generally well tolerated but can contribute to hypotension and sedation. One adverse event associated with clonidine not described in the literature is thrombocytopenia. Reported is a case of clonidine-associated thrombocytopenia when used for the treatment of clozapine-induced sialorrhea.

Potentially fatal outcomes associated with clozapine

Clozapine has been shown to be the most efficacious therapy for treatment resistant schizophrenia, estimated at one third of all schizophrenia cases. There is significant morbidity and mortality associated with clozapine including risk of agranulocytosis, aspiration pneumonia, bowel ischemia, myocarditis, seizures, and weight gain. Here we present a case of a 62-year-old man with chronic paranoid schizophrenia refractory to numerous antipsychotics who was started on clozapine therapy during an acute inpatient psychiatric admission. Within three weeks of starting clozapine, the patient developed flu-like symptoms, pleuritic chest pain, and was sent to a medical hospital for evaluation. After transfer, the patient had a rapidly deteriorating course with newly developed congestive heart failure, acute respiratory failure requiring intubation, and cardiovascular collapse requiring vasopressors. The patient expired within two days of transfer and four days after initial symptoms developed. The underlying etiology in this case is likely clozapine induced myocarditis leading to rapid cardiovascular collapse and death. Mortality with clozapine induced myocarditis has been estimated up to 24%. Given that 90% of clozapine cardiotoxic sequelae are seen in the first month post-initiation, more rigorous post-initiation surveillance is recommended for the first four weeks of clozapine with weekly cardiac enzymes (troponins, creatinine kinase-MB), EKG, and acute inflammatory markers (C-reactive protein, and erythrocyte sedimentation rate).

Risk of pleural empyema in patients with schizophrenia: a nationwide propensity-matched cohort study in Taiwan

OBJECTIVE

Thoracic infection and pneumonia are prevalent in patients with schizophrenia; however, it is unclear whether patients with schizophrenia are at an increased risk of developing pleural empyema.

DESIGN

A retrospective cohort study with propensity-matched cohorts with and without schizophrenia.

SETTING

Using the National Health Insurance Research Database of Taiwan.

PARTICIPANTS

We identified 55 888 patients with schizophrenia newly diagnosed in 2000-2011 and same number of individuals without schizophrenia as the comparison cohort, frequency matched by propensity scores estimated using age, sex, occupation, income, urbanisation, year of diagnosis and comorbidities.

PRIMARY OUTCOME MEASURES

We assessed incident pleural empyema by the end of 2011 and used the Cox proportional hazards model to calculate the schizophrenia cohort to comparison cohort HR of pleural empyema.

RESULTS

The overall incidence of pleural empyema was 2.44-fold greater in the schizophrenia cohort than in the comparison cohort (4.39vs1.80 per 10 000 person-years), with an adjusted HR of 2.87(95% CI 2.14 to 3.84). Stratified analyses by age, sex, occupation, income, urbanisation and comorbidity revealed significant hazards for pleural empyema associated with schizophrenia in all subgroups.

CONCLUSIONS

Patients with schizophrenia are at an increased risk of developing pleural empyema and require greater attention and appropriate support.

Sudden death in schizophrenia

PURPOSE OF REVIEW

To examine the recent literature regarding sudden death in patients with schizophrenia and synthesize salient conclusions based on this evidence.

RECENT FINDINGS

Sudden cardiac death (SCD) is the largest subset of sudden unexpected death (SUD), with up to 40% of SUD from cardiovascular causes. SCD has been associated with exposure to both first and second-generation antipsychotics. Clozapine [odds ratio (OR) 3.67, 95% confidence interval (CI) 1.94-6.94] confers the highest risk of SCD followed by risperidone (OR 3.04, 95% CI 2.39-3.86) then olanzapine (OR 2.04, 95% CI 1.52-2.74). SCD not associated with antipsychotic use has been correlated to several modifiable and nonmodifiable risk factors - obesity, smoking, dyslipidemia, diabetes, hypertension, age, sex, and history of cardiovascular disease. Other subsets of SUD include hematological and pulmonary causes, including agranulocytosis leading to sepsis, deep vein thrombosis leading to pulmonary embolisms, and aspiration pneumonia leading to sepsis.

SUMMARY

There is a huge paucity in genetic and pharmacogenetic data focused on SUD in schizophrenia. Future studies should emphasize the genetic aspects as well as clarify the underlying molecular mechanisms of these pathways. Additionally, early detection of those patients at high risk for SUD and discovery of preventive measures should also be emphasized.

Characterization of Admission Types in Medically Hospitalized Patients Prescribed Clozapine

BACKGROUND

Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia; however, rigorous monitoring is required to prevent or detect adverse drug events that contribute to morbidity and mortality. In addition to the Food and Drug Administration (FDA) boxed safety warnings specific to clozapine (agranulocytosis, hypotension, seizures, and cardiomyopathy/myocarditis), other adverse events such as pneumonia and gastrointestinal hypomotility have been reported in the literature to result in hospitalization.

OBJECTIVE

To explore the reasons for medical hospitalization in patients prescribed clozapine, a retrospective chart review was completed.

METHODS

Adults with schizophrenia or schizoaffective disorder prescribed clozapine were identified if they had a nonpsychiatric medical admission between 1/1/2003 and 8/1/2015. Demographics, admitting diagnosis, admitting service type, psychiatric consult information, clozapine dosing, and drug interactions were collected.

RESULTS

Overall, 104 patients, representing 248 hospitalizations, were admitted to a medical unit during the study period. The predominant admission types were for the management of either pulmonary (32.2%) or gastrointestinal (19.8%) illnesses. The most common pulmonary diagnosis was pneumonia, accounting for 58% of pulmonary admissions. Further, 61.2% of the gastrointestinal admissions were related to hypomotility, ranging from constipation to death. Clozapine was discontinued owing to neutropenia in 2 patients; however, in both cases concomitant chemotherapy had been given.

CONCLUSION

In patients prescribed clozapine admitted to nonpsychiatric medical settings, gastrointestinal and pulmonary illnesses were common, but not illnesses related to boxed warnings. Additional research is needed to better assess the causality and true incidence of gastrointestinal or pulmonary events associated with clozapine. Furthermore, clinicians must be prepared to prevent, detect, and manage potentially life-threatening events associated with clozapine.