Clozapine associated cardiomyopathy: a cluster of 3 cases

A Peculiar Case of Fentanyl-Induced Cardiomyopathy

An alarming rise in prescription and non-prescription misuse of opioids has been observed recently, leading to potentially devastating consequences. Opioid misuse contributes to cardiac risk burden and can cause diseases such as acute coronary syndrome, congestive heart failure, arrhythmias, QTc prolongation, and endocarditis. Here, we describe the case of a 35-year-old male with recreational fentanyl use who was found to have a cardiogenic shock on point-of-care ultrasound (POCUS), likely due to fentanyl-induced cardiomyopathy. Opioid-induced cardiomyopathy without any underlying cardiac disease in an adult appears to be a rare case. Our case highlights the importance of promptly recognizing fentanyl toxicity, screening for possible cardiomyopathy secondary to its use, and emergent resuscitation with the maintenance of ventilation, diuretics, and vasopressor support. The use of the reversal agent, naloxone, is a crucial part of management.

Safety of antipsychotics for the treatment of schizophrenia: a focus on the adverse effects of clozapine

Clozapine, a dibenzodiazepine developed in 1961, is a multireceptorial atypical antipsychotic approved for the treatment of resistant schizophrenia. Since its introduction, it has remained the drug of choice in treatment-resistant schizophrenia, despite a wide range of adverse effects, as it is a very effective drug in everyday clinical practice. However, clozapine is not considered as a top-of-the-line treatment because it may often be difficult for some patients to tolerate as some adverse effects can be particularly bothersome (i.e. sedation, weight gain, sialorrhea etc.) and it has some other potentially dangerous and life-threatening side effects (i.e. myocarditis, seizures, agranulocytosis or granulocytopenia, gastrointestinal hypomotility etc.). As poor treatment adherence in patients with resistant schizophrenia may increase the risk of a psychotic relapse, which may further lead to impaired social and cognitive functioning, psychiatric hospitalizations and increased treatment costs, clozapine adverse effects are a common reason for discontinuing this medication. Therefore, every effort should be made to monitor and minimize these adverse effects in order to improve their early detection and management. The aim of this paper is to briefly summarize and provide an update on major clozapine adverse effects, especially focusing on those that are severe and potentially life threatening, even if most of the latter are relatively uncommon.

Cardiovascular Disease in Clozapine-Treated Patients: Evidence, Mechanisms and Management

Myocarditis occurs in about 3% of those initiated on clozapine but monitoring reduces the risk of serious outcome. Cardiomyopathy may develop after myocarditis, or from prolonged tachycardia. Monitoring using echocardiography is not deemed cost effective. Tachycardia, orthostatic hypotension and reduced heart rate variability are a group of clozapine-related adverse effects associated with autonomic dysfunction and may have serious consequences in the long term. Elevated heart rate and poor heart rate variability can be treated with a β-blocker or a non-dihydropyridine calcium channel blocker, while orthostatic hypotension can be alleviated by increased fluid intake and abdominal binding, but may require pharmacological intervention. Adequate correction for heart rate may show that clozapine does not prolong the QT interval. Other cardiovascular effects, pulmonary embolism, metabolic syndrome, sudden cardiac death and particularly the excessive mortality from cardiovascular disease events may be more strongly associated with the combination of mental illness, lifestyle factors and poor treatment of cardiovascular disease and its risk factors than with clozapine treatment. In view of the efficacy of clozapine and the evidence of reduced mortality relative to other antipsychotics, clozapine should be prescribed when indicated and recipients should be enrolled in lifestyle programmes to increase exercise and improve diet, and referred for diagnosis and treatment of cardiovascular disease and its risk factors.

Systematic Review of Clozapine Cardiotoxicity

Clozapine is exceptionally effective in psychotic disorders and can reduce suicidal risk. Nevertheless, its use is limited due to potentially life-threatening adverse effects, including myocarditis and cardiomyopathy. Given their clinical importance, we systematically reviewed research on adverse cardiac effects of clozapine, aiming to improve estimates of their incidence, summarize features supporting their diagnosis, and evaluate proposed monitoring procedures. Incidence of early (≤2 months) myocarditis ranges from <0.1 to 1.0 % and later (3-12 months) cardiomyopathy about 10 times less. Diagnosis rests on relatively nonspecific symptoms, ECG changes, elevated indices of myocardial damage, cardiac MRI findings, and importantly, echocardiographic evidence of developing ventricular failure. Treatment involves stopping clozapine and empirical applications of steroids, diuretics, beta-blockers, and antiangiotensin agents. Mortality averages approximately 25 %. Safety of clozapine reuse remains uncertain. Systematic studies are needed to improve knowledge of the epidemiology, avoidance, early identification, and treatment of these adverse effects, with effective and practicable monitoring protocols.

Left Ventricular Thrombus as a Complication of Clozapine-Induced Cardiomyopathy: A Case Report and Brief Literature Review

A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient's workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV) thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

A systematic review of clozapine induced cardiomyopathy

BACKGROUND

Clozapine is a unique anti-psychotic medication that is most effective in the treatment of refractory schizophrenia and reducing suicidality. Cardiomyopathy is among the side effects of this medication that limits its use. There are a number of case reports, case series and expert opinion papers discussing clozapine induced cardiomyopathy, but there is no evidence-based review of the subject to guide clinicians.

METHODS

We undertook a systematic review of the literature on cardiomyopathy associated with clozapine. The primary systemic search was in MEDLINE but EMBASE, PsycINFO, and Cochrane were searched and manufacturers of clozapine were contacted for cases. Articles were then individually reviewed to find additional reports.

RESULTS

We identified 17 articles detailing 26 individual cases and 11 additional articles without individual case data. The mean age at time of diagnosis was 33.5 years. The mean dose of clozapine on presentation was 360 mg. Symptoms developed at an average of 14.4 months after initiating clozapine. The clinical presentation was generally consistent with heart failure: including shortness of breath (60%) and palpitations (36%). Echocardiography at presentation showed dilated cardiomyopathy in 39% of cases and was not specified in other cases.

CONCLUSION

There should be a low threshold in performing echocardiography in suspected cases of clozapine induced cardiomyopathy. Clozapine should be withheld in the setting of cardiomyopathy without other explanation. There is limited data on the safety of drug re-challenge in clozapine induced cardiomyopathy. Re-challenge may be considered in carefully selected cases but close monitoring and frequent echocardiography are required.