Clozapine-induced systemic lupus erythematosus

Unravelling cases of clozapine-related Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in patients reported otherwise: A systematic review

BACKGROUND

The drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a drug-induced hypersensitivity reaction.

AIMS

Aim was to review reports of clozapine-related reactions fulfilling the registry of severe cutaneous adverse reaction (RegiSCAR) criteria for DRESS syndrome reported as such or otherwise, to provide a descriptive overview of demographic patterns, clinical manifestations, and DRESS course and investigate associations between demographic, DRESS parameters, and clinical outcomes.

METHODS

This review was conducted following preferred reporting items for systematic reviews and meta-analyses guidelines and registered with PROSPERO (registration number CRD42020156385). We searched PubMed/Embase/PsychInfo/Cochrane for reports of clozapine-related reactions meeting RegiSCAR criteria. Associations between RegiSCAR scores and time-to-recovery with demographic/clinical variables were assessed. Demographic/clinical characteristics of patients with versus without reported DRESS were compared using non-parametrical tests.

RESULTS

We identified 26 reports of 27 patients meeting RegiSCAR criteria. Males (n = 19, 70.4%) and patients with schizophrenia (n = 18, 66.7%) were mainly affected. Twelve patients (44.4%) received clozapine-monotherapy. DRESS symptoms manifested within a month after clozapine initiation (n = 24, 88.9%). Lungs and liver were the most common organs involved (n = 12, 44.4%; n = 11, 40.7%), with a mean time to recovery of 33.75 days. Clozapine rechallenge led to DRESS recurrence in four patients. Death rate was 7.4%. No associations were detected between RegiSCAR criteria or days to recovery with any demographic/clinical variables. No differences between patients with versus without reported DRESS were detected.

CONCLUSIONS

Clozapine-related DRESS may be rare, but also underreported. Clinicians need to be aware of it even in patients under clozapine-monotherapy or without skin rash.

Machine Learning for Predicting Risk of Drug-Induced Autoimmune Diseases by Structural Alerts and Daily Dose

An effective approach for assessing a drug’s potential to induce autoimmune diseases (ADs) is needed in drug development. Here, we aim to develop a workflow to examine the association between structural alerts and drugs-induced ADs to improve toxicological prescreening tools. Considering reactive metabolite (RM) formation as a well-documented mechanism for drug-induced ADs, we investigated whether the presence of certain RM-related structural alerts was predictive for the risk of drug-induced AD. We constructed a database containing 171 RM-related structural alerts, generated a dataset of 407 AD- and non-AD-associated drugs, and performed statistical analysis. The nitrogen-containing benzene substituent alerts were found to be significantly associated with the risk of drug-induced ADs (odds ratio = 2.95, p = 0.0036). Furthermore, we developed a machine-learning-based predictive model by using daily dose and nitrogen-containing benzene substituent alerts as the top inputs and achieved the predictive performance of area under curve (AUC) of 70%. Additionally, we confirmed the reactivity of the nitrogen-containing benzene substituent aniline and related metabolites using quantum chemistry analysis and explored the underlying mechanisms. These identified structural alerts could be helpful in identifying drug candidates that carry a potential risk of drug-induced ADs to improve their safety profiles.

Clinical determinants of fever in clozapine users and implications for treatment management: A narrative review

OBJECTIVES

To identify the clinical determinants of fever in clozapine users and their impact on management of clozapine treatment.

METHODS

Articles published in English or French identified with a MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search, from inception through February 2019, using the term "clozapine" in combination with "fever" OR "hyperthermia" OR "body temperature" OR "pyrexia" OR "febrile" OR "heat" OR "thermoregulation". Information extracted for each medical condition were frequency, time to onset after initiation of clozapine treatment, characteristics of fever, associated symptoms, laboratory tests used for diagnosis, course, lethality, discontinuation of clozapine. Data were synthesized narratively.

RESULTS

Our search yielded 394 unique hits published from 1993 to 2018. We included 73 articles in the review: two meta-analyses, 14 reviews, six epidemiological studies, 11 clinical studies and 40 case reports. During clozapine initiation, fever is most frequently benign and transient but should be closely monitored as it may be the first stage of potentially life-threatening adverse drug reactions (ADR) (agranulocytosis, neuroleptic malignant syndrome myocarditis, hepatitis, pancreatitis, nephritis, colitis, etc.). Other ADR associated with fever are independent of duration of exposure to clozapine (heat stroke, pneumonia, pulmonary embolism, necrotizing colitis). If fever is due to intercurrent infection, therapeutic drug monitoring is recommended to adjust clozapine daily dosage.

CONCLUSION

Benign causes of fever are much more frequent than life-threatening ADR during clozapine treatment. Discontinuation should not be considered as automatic in the event of fever, especially during the early phase of clozapine initiation.

Successful clozapine rechallenge in a patient with suspected drug induced lupus

Clozapine is the most effective treatment for patients with refractory schizophrenia. Clozapine is also associated with serious and potentially lethal side effects including drug induced lupus (DIL). There have been four previous published case reports describing clozapine inducing a lupus-like syndrome including one previous case where a clozapine rechallenge was attempted without success. This case report describes a successful clozapine rechallenge in a patient with suspected DIL.

Clozapine Rechallenge After Major Adverse Effects: Clinical Guidelines Based on 259 Cases

BACKGROUND

Clozapine is widely prescribed for treatment-refractory schizophrenia, but its use is limited by many potentially life-threatening adverse effects. The risk of rechallenge after these complications has never been comprehensively assessed in controlled studies. Thus, clinical guidelines must rely on the published case reports. The number of such reports is likely to increase over time, and updated analyses of larger samples are needed, as they may lead to changes in clinical guidelines.

STUDY QUESTIONS

How safe is the clozapine rechallenge after life-threatening adverse effects?

STUDY DESIGN

The published case reports of clozapine rechallenge were identified in a MEDLINE search. We added 121 cases reported from 2012 through 2017 to the 138 cases reported from 1972 through 2011 analyzed by us in a previous publication. The 95% confidence intervals (CIs) of the successful rechallenge rate were calculated for each adverse effect with at least 5 published case reports. The rechallenge was considered a valid clinical option when the lower end of the CI range was at least 50%.

RESULTS

A successful outcome was documented in 128/203 patients rechallenged after neutropenia (63.0%, CI, 56.0%-69.6%), 3/17 after agranulocytosis (17.7%, CI, 4.7%-44.2%), 11/17 after myocarditis (64.7%, CI, 38.6%-84.7%), and 7/7 after neuroleptic malignant syndrome (100%, CI, 56.1%-100%). Among the 15 patients with other clozapine-induced adverse effects, the rechallenge was successful in those with eosinophilia, cardiac complications other than myocarditis (QTc prolongation, pericarditis, cardiomyopathy, and atrial flutter), and gastrointestinal hypomotility. The rechallenge failed in patients who had developed pancreatitis or renal insufficiency.

CONCLUSION

Clozapine rechallenge is a reasonable clinical option after return to baseline for patients who had developed neutropenia and neuroleptic malignant syndrome, but not after agranulocytosis or myocarditis. Data are insufficient to formulate rechallenge guidelines for any other clozapine-related adverse effects.

Medical Complications of Psychiatric Treatment: An Update

Psychiatric medications are used commonly in hospitalized patients and are particularly indicated in patients who are critically ill to manage many conditions. Due to their many indications in the intensive care unit (ICU), psychiatric medications should be closely monitored in these medically compromised patients for adverse reactions and medical complications because they may affect essentially all organ systems. These range from life-threatening reactions to other less significant effects, such as sedation, to other detrimental complications, such as pancreatitis. Knowledge of psychopharmacology as well as the diagnosis and treatment of these complications is imperative in treating patients in the ICU.

When can patients with potentially life-threatening adverse effects be rechallenged with clozapine? A systematic review of the published literature

BACKGROUND

Clozapine is widely prescribed for treatment refractory patients with schizophrenia, but its use is limited by potentially life threatening adverse effects. Rechallenge after these complications has been occasionally attempted in patients with severe psychotic symptoms.

OBJECTIVE

To review the outcome of clozapine rechallenge after potentially life threatening adverse effects.

METHODS

Electronic, all-language, literature search (1972-2011) followed by demographic and clinical data extraction. The outcome of rechallenge was considered favorable when the lower bound of the 95% confidence interval (CI) of the proportion of patients who could continue clozapine was >50%.

RESULTS

Altogether, 138 patients (mean age: 36.3years, 65.7% male, 57.6% Caucasian, virtually all with schizophrenia spectrum diagnosis) underwent clozapine rechallenge after developing neutropenia (n=112), agranulocytosis (n=15), neuroleptic malignant syndrome (NMS) (n=5), myocarditis (n=4), pericarditis (n=1) and lupus erythematosus (n=1). Rechallenge strategies were heterogeneous and not systematically evaluated. Clozapine rechallenge was successful in 78/112 patients (69.6%, CI: 60.6-77.4) after neutropenia, 3/15 (20%, CI: 7.1-45.2) after agranulocytosis, 5/5 (100%, CI: 56-100) after NMS, 3/4 (75%, CI: 30-95) after myocarditis, 1/1 after pericarditis, and 0/1 after clozapine-induced lupus. Successfully rechallenged patients were followed for 16-96weeks. None of the rechallenged patients died.

CONCLUSIONS

Although controlled studies are clearly needed, using a priori, confidence interval-based criteria, case reports/series suggest that in refractory patients who benefited from clozapine, careful rechallenge can be considered after neutropenia and NMS, but not after agranulocytosis and myocarditis.