Clozapine associated pericarditis and elevated troponin I

Clozapine-associated pericarditis and pancreatitis in children and adolescents: A systematic literature review and pharmacovigilance study using the VigiBase database

BACKGROUND

The literature has paid very little attention to pericarditis, pericardial effusion and pancreatitis during clozapine treatment in children and adolescents.

METHODS

Cases of clozapine-associated pericarditis and pancreatitis in children were studied using searches in: 1) PubMed (June 16, 2023), and 2) the World Health Organization's pharmacovigilance database (June 1, 2022), VigiBase. VigiBase uses a logarithmic measure of disproportionality called the information component (IC).

RESULTS

The PubMed search yielded 3 clozapine-associated pericarditis cases, 1 pancreatitis case and 1 with both. VigiBase provided a significant clozapine-associated pericarditis IC = 3.6 with an IC025 = 2.9 (only 3 cases were expected while 22 were observed). VigiBase provided a significant clozapine-associated pancreatitis IC = 2.2 with an IC025 = 1.4 (only 3 cases were expected while 16 were observed). In VigiBase clozapine-associated pericarditis and pericardial effusion in youth looked similar and on a continuum with myocarditis, as myocarditis, pericarditis and pancreatitis appeared to occur mainly during clozapine titration. Combining PubMed and VigiBase we identified: 1) 29 cases of at least possible clozapine-associated pericarditis/pericardial effusion (6 probable and 23 possible) including 7 cases with and 22 without myocarditis, and 2) 17 cases of clozapine-associated pancreatitis (1 definite and 16 possible). Two of the pancreatitis cases occurred during overdoses. No fatal outcomes were found in any clozapine-associated pericarditis and pancreatitis cases.

CONCLUSIONS

Despite the lack of attention in the literature to clozapine-associated pericarditis and pancreatitis, results demonstrate that they can happen in youth, particularly during titration. Pericarditis and pancreatitis appear to be forms of clozapine-associated inflammation during dose titration.

Clozapine-induced myocarditis in children and adolescents: a pharmacovigilance study using VigiBase and a systematic literature review

INTRODUCTION

Clozapine-induced myocarditis in children (age ≤18 yo) was studied from a PubMed search (18 July 2022) (9 cases) and from the World Health Organization's pharmacovigilance database, called Vigibase, of adverse drug reaction (ADR) reports (72 non-duplicated cases). VigiBase uses a logarithmic measure of disproportionality called the information component (IC). A logistic regression model of presence/absence (40/32) of seriousness in VigiBase was developed.

AREAS COVERED

VigiBase provided a significant myocarditis IC = 4.2 with an IC₀₂₅ = 3.8; only 4 clozapine-induced myocarditis cases were expected, while 72 were observed. The PubMed search identified 9 cases, while VigiBase identified 72 cases (of which 67 did not overlap with published cases). These 76 combined cases included 35 doubtful (most with missing information on the day of diagnosis), 19 possible and 22 probable, according to the ADR scale. After adjusting for confounders, quetiapine increased the risk of seriousness with an odds ratio (OR) of 17.6 (95% confidence interval CI, 1.56 to 198.6), while Australian origin decreased it with an OR = 0.13 (CI, 0.04 to 0.47).

EXPERT OPINION

These 41 cases of at least possible clozapine-induced myocarditis indicated that this ADR can definitively occur in children, particularly in the first 30 days of up-titration. Children's and adult cases appeared similar.

Successful clozapine rechallenge after myopericarditis: a case report

Clozapine-induced myocarditis and pericarditis are uncommon adverse effects of clozapine treatment. However, in most cases, they lead to clozapine discontinuation. Here, we describe a case of successful clozapine rechallenge after clozapine-induced myopericarditis. The patient, a 31-year-old male with treatment-resistant schizophrenia (TRS), developed dyspnea on exertion and chest pain on day 19 after the start of clozapine titration. An electrocardiogram (ECG) showed widespread, mild, convex ST interval elevation. While troponin levels were mildly elevated, the echocardiogram was unremarkable. A myopericarditis diagnosis was formulated, and clozapine was stopped, with a progressive resolution of clinical, laboratory and ECG abnormalities. After 6 months, a rechallenge with clozapine was attempted. A very slow titration scheme was adopted, along with close monitoring of clinical, laboratory and ECG parameters. Clozapine target dose was reached without the occurrence of any abnormality. Given the unique role of clozapine in the management of TRS, clozapine rechallenge may be considered after pericarditis, even with troponin levels elevation. Further studies are needed to update current clinical guidelines.

Implementation and Outcomes of a Clozapine-Associated Myocarditis Screening Program in a Region of South Australia-Lessons Learned

PURPOSE

Clozapine-associated myocarditis (CAM) is a serious complication, mostly occurring in the first month of treatment. Public mental health in South Australia introduced a screening protocol in 2011 using baseline and weekly C-reactive protein and troponin. The aim of this study was to assess protocol adherence and management of cases with positive screening results.

METHODS

We identified all patients commenced on clozapine in our area between 2012 and 2015. Those with abnormal C-reactive protein and/or troponin in the first 4 weeks of treatment were identified (potential cases). For those, we collected clinical characteristics and test results and reviewed their management.

FINDINGS

Protocol compliance increased to 80%. We identified 24 potential CAM cases, 8 at high risk based on established definition (7.6% of new commencements) and 9 formally diagnosed from 143 commenced on clozapine. Potential cases not meeting CAM definition were significantly more likely commenced on clozapine for the first time and have preexisting respiratory disease. Likely CAM cases were younger, and more often prescribed additional antipsychotics, specifically quetiapine. Seven (78%) of 9 patients diagnosed with CAM met published CAM definition. In 14 undiagnosed potential cases, 10 (71%) did not have timely testing to exclude CAM.

CONCLUSIONS

Maintaining a high index of suspicion, clinical monitoring and timely testing is important to supplement CAM screening protocols. More research is needed to identify those that can be safely rechallenged or even continue clozapine treatment with monitoring.

Clozapine-induced myocarditis, a widely overlooked adverse reaction

OBJECTIVE

We review the published cases of clozapine-induced myocarditis and describe reasons for the higher incidence in Australia (>1%) than elsewhere (<0.1%).

METHOD

Medline was searched to September 2014 using 'clozapine' as the sole term.

RESULTS

A total of around 250 cases of clozapine-induced myocarditis have been published. Fever among patients commencing clozapine has been reported internationally, and very few of these cases were investigated for myocarditis. The time to onset of fever is consistent with its being part of a prodrome of undiagnosed myocarditis, and the risk factors are similar to those for myocarditis. In more severe cases, clozapine is discontinued, avoiding fatalities which may occur with myocarditis. Furthermore, cases of sudden death and respiratory illness may well have been undiagnosed myocarditis. The diagnosis of myocarditis is confounded by the non-specific nature of the signs and symptoms, and it depends on appropriate investigations being conducted at the time of myocardial involvement or, for fatal cases, the affected area of the myocardium being sampled for histology.

CONCLUSION

It is likely that the incidence of myocarditis is around 3%. Implementation of monitoring procedures will increase case ascertainment and result in more patients benefiting from this valuable medication.

Antipsychotic Drug Treatment for Patients with Schizophrenia: Theoretical Background, Clinical Considerations and Patient Preferences

The cornerstone in treatment of psychosis is antipsychotic drugs. Treatment options have increased over the years; newer antipsychotic drugs with a proposed increased efficacy regarding negative and cognitive symptoms, but also a shift in side-effects from neurological side-effects to metabolic side-effects have arisen as the new challenge. The basis of successful pharmacological treatment is a fundamental understanding of the mechanisms of action, the desired effects and side-effects of antipsychotic drugs, a good relationship with the patient and a thorough monitoring of the patient before and during treatment. The clinically relevant aspects of antipsychotic drug treatment are reviewed; mechanism of antipsychotic drug action, clinical considerations in treatment, switching antipsychotic drugs, polypharmacy, safety and patient preference.

Acute myocarditis associated with clozapine

OBJECTIVE

A case of acute myocarditis associated with the commencement of clozapine is described, highlighting the onset, course and possible contributing factors. There is an urgent need to raise awareness about this potentially fatal complication of clozapine use.

RESULTS

A 20-year-old male with schizophrenia developed a sudden onset of myocarditis after commencement of clozapine. The patient recovered with intensive medical support. The symptoms occurred around 2 weeks after starting clozapine in an inpatient setting. Possible contributing factors may have been concomitant antidepressant use and unaccustomed physical activity.

CONCLUSIONS

Myocarditis is an increasingly recognized complication associated with the use of clozapine. It can be fatal if not recognized and treated early. Considering that clozapine remains the gold standard in treatment of resistant psychosis, there is an urgent need to raise awareness among medical and paramedical staff involved in the care of these patients. There are also implications for recommendations and regulations regarding the use of clozapine.

Myocarditis and cardiomyopathy linked with clozapine treatment

Clozapine is associated with a risk of myocarditis and cardiomyopathy. The exact mechanisms still remains unclear although there have been a range of proposals ranging from hypersensitivity reactions, toxic effects of the drug to vitamin deficiency. We present three cases where there were minor deviations of heart function or structure prior to the onset of clozapine treatment. One case developed a mild rise in troponin-1 levels within one month of clozapine treatment. We also review the current literature on the link between clozapine, myocarditis and cardiomyopathy and suggest clinical guidelines for monitoring patients for cardiac symptoms prior to commencing and while on clozapine treatment.

Myocarditis, pericarditis and cardiomyopathy in patients treated with clozapine

Clozapine is known to cause cardiac side-effects, including myocarditis, pericarditis and cardiomyopathy. Prompted by a case of clozapine-related pericarditis in our hospital we undertook a review of the literature for reports of myocarditis, pericarditis and cardiomyopathy occurring in patients treated with clozapine. This is the first comprehensive review of the literature on this topic.

Adverse cardiac effects associated with clozapine

OBJECTIVE

To review the published literature on serious adverse cardiac events associated with the atypical antipsychotic agent, clozapine, and to make recommendations for cardiac assessment of candidates for clozapine treatment and for monitoring of cardiac status after treatment is initiated.

DATA SOURCES

We searched the PubMed and MEDLINE databases for articles published from 1970 to 2004 that contain the keywords "clozapine and myocarditis," "clozapine and cardiomyopathy," "clozapine and cardiotoxicity," "clozapine and sudden death" or "clozapine and mortality." We also manually searched the bibliographies of these articles for related sources.

STUDY SELECTION

We reviewed the 30 case reports, case series, laboratory and clinical trials, data mining studies, and previous reviews identified by this search.

DATA SYNTHESIS

Recent evidence suggests that clozapine is associated with a low (0.015% to 0.188%) risk of potentially fatal myocarditis or cardiomyopathy. The drug is not known to be independently associated with pathologic prolongation of the QTc interval, but it may contribute to pathologic QTc prolongation in patients with other risk factors for this condition.

CONCLUSIONS

The low risk of a serious adverse cardiac event should be outweighed by a reduction in suicide risk for most patients taking clozapine. We provide recommendations for assessing and monitoring cardiac status in patients prior to and after initiation of treatment with clozapine.

Clozapine-related myocarditis and cardiomyopathy in an Australian metropolitan psychiatric service

OBJECTIVES

Myocarditis and cardiomyopathy are rarely reported complications of clozapine treatment. The incidence of clozapine-related myocarditis has been variably reported at between 0.03% and 0.19% of initiations and cardiomyopathy has been reported even less commonly. In our Brisbane-based service, nine of 94 patients initiated on clozapine over the previous 3 years appeared to have experienced myocarditis or cardiomyopathy. The unique co-location of our service with a major cardiothoracic hospital facilitated a review of identified cases to inform decisions regarding clozapine treatment and rechallenge in this service.

METHOD

Cases were identified by survey of psychiatric and cardiac medical staff at The Prince Charles Hospital and subjected to re-evaluation by a multidiscipline consensus panel. The panel compared cases to international reports and identified the clinical features that supported a diagnosis of clozapine-related myocarditis or cardiomyopathy.

RESULTS

This process resulted in the stratification of the nine cases into the following categories of diagnostic likelihood: three highly probable, three probable, and two possible cases of clozapine-related myocarditis, and one possible case of clozapine-related cardiomyopathy. Successful clozapine rechallenge/continuation was undertaken in two patients and the panel agreed that this was a viable future option for several other patients.

CONCLUSIONS

Findings of the panel review supported the initial clinical diagnoses. This confirmed that there was an apparent high incidence of clozapine-related myocarditis within this service, for which there was no clear reason. Mechanisms underlying clozapine-related myocarditis and cardiomyopathy, as well as successful clozapine continuation and rechallenge were considered, but definitive explanations remain unknown. This review highlighted the clinician's role in post-marketing drug surveillance to guide rational management of suspected adverse drug effects.

Pericarditis and polyserositis as a side effect of clozapine in an adolescent girl

A case report describes an adolescent girl with a treatment-resistant bipolar disorder, who developed pericarditis and polyserositis while being treated with clozapine. The sparse literature about this rare, severe side effect of clozapine is discussed. Clinical recommendations with regard to monitoring are given. If myocarditis/polyserositis occurs, clozapine has to be discontinued immediately.