Clozapine-associated neuroleptic malignant syndrome: two new cases and a review of the literature

Reintroduction of Clozapine following Neuroleptic Malignant Syndrome in a Young Patient with Resistant Schizophrenia

The incidence of neuroleptic malignant syndrome justifies the immediate discontinuation of the drug in question and the reinstitution of therapy with another drug. In the case of resistant schizophrenia treated with clozapine, there are insufficient therapeutic options. We report the case of a young patient followed up for resistant schizophrenia who developed neuroleptic malignant syndrome after 5 years of therapy with clozapine. Clozapine therapy was successfully reinitiated, and the dosage was increased to 300 mg/day over 62 days. In light of this clinical case and a review of the literature, we report the possibility of reintroducing clozapine following an incidence of malignant syndrome in patients with resistant schizophrenia with respect to certain rules; in particular, a slow increase in dose after a reasonable period of time and close monitoring.

Clozapine Withdrawal Catatonia: A Case Report

Catatonia, which is associated with gamma-aminobutyric acid (GABA) hypoactivity, often responds robustly to benzodiazepines. It has been reported to be a consequence of abrupt discontinuation of clozapine, an antipsychotic used for treatment-resistant schizophrenia. Clozapine discontinuation, sometimes necessitated by medical concerns, can carry the risk of adverse outcomes, including catatonia. We present the case of a 66-year-old African-American male with schizoaffective disorder (depressive subtype) and a complex medical history. He discontinued clozapine abruptly due to medication unavailability, and, seven days later, presented with catatonic symptoms, initially unrecognized by emergency room clinicians. His symptoms included self-neglect, auditory hallucinations, isolation, psychomotor retardation, fixed gaze, and thought blocking. An attempt to reinstate clozapine led to orthostatic hypotension, prompting admission to an inpatient psychiatry unit. Attempt to initiate risperidone for psychosis worsened the catatonia, which then responded rapidly to intravenous lorazepam challenge. This facilitated the re-introduction of clozapine with slow re-titration.

Clozapine as a treatment for catatonia: A systematic review

Catatonia is a neuropsychiatric disorder characterised by altered movement, speech, and behaviour. Clozapine is an established therapy for treatment-resistant schizophrenia, but its role in catatonia has not been systematically examined. In this systematic review, we aimed to assess the evidence for clozapine as a treatment for catatonia. Full text original research articles in English where at least one patient with catatonia was treated with clozapine were included, provided catatonia did not occur solely in the context of neuroleptic malignant syndrome. Results were tabulated with calculations of summary statistics presented. Risk of bias was assessed with the Tool for Evaluating the Methodological Quality of Case Reports and Case Series. 182 patients were included, 81 from cohort studies and 101 from case reports or case series. 119/182 patients (65 %) had a specified underlying diagnosis of schizophrenia. Over 80 % of reported patients with catatonia had at least partial remission following treatment with clozapine across both cohort studies and case reports and case series. Among the case reports and series, 24/101 patients (23.8 %) followed clozapine withdrawal. Overall, 25 studies were of low quality, 60 of moderate quality and 8 of high quality. Our findings should be interpreted with caution, as the reliance on case reports, case series and small cohort studies is susceptible to reporting biases, regression to the mean and confounding by other treatments. Future research could use large healthcare databases to ascertain outcomes in those on clozapine with a history of catatonia given the difficulty and expense of conducting randomised controlled trials.

Toxicity and Adverse Effects in Clozapine-Related Presentations to a Medical Toxicology Service in Western Sydney

BACKGROUND

Clozapine is an anti-psychotic agent, reserved for treatment-resistant schizophrenia, with demonstrated efficacy in an otherwise therapeutically challenging patient population. We aimed to review the full spectrum casemix of clozapine presentations to our tertiary toxicology service.

METHODS

In this retrospective study, we reviewed consecutive clozapine related toxicity presentations to a tertiary medical toxicology inpatient and consultation service-including deliberate self-poisoning (DSP), adverse drug reaction (ADR), recreational use, and therapeutic misadventure over a 10-year period from 2011 to 2021. Data were extracted for demographics, ingested dose, exposure characteristics, and patient outcome.

RESULTS

We identified 83 patients with clozapine-related presentations over the 10-year period. Twenty-two patients were excluded. Of the remaining 61 patients, 28 patients presented with DSP, 20 patients with accidental overdose, and 13 patients with an ADR; no patients presented with recreational use. It was noted that ADRs were largely idiosyncratic reactions and not always related to dose adjustments. In the context of therapeutic misadventure and DSP, we noted that a lower mean dose achieved a higher poison severity score (PSS) in clozapine-naive patients when compared to those patients on regular clozapine.

CONCLUSIONS

The presentation of clozapine-related toxicity differs depending on the modality of ingestion, whether DSP, accidental, or as a result of ADR. Patients naive to clozapine therapy tend to experience higher PSS with lower doses ingested either in a deliberate self-poisoning or accidental ingestion context. This is likely due to tolerance to the sedative properties of clozapine. No patients manifested clinical toxicity greater than 8 hours after ingestion, with an observation period of 6 hours accurately identifying toxicity in most patients.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

A qualitative analysis of literature reporting and linking psychosis to COVID-19 infection. Findings from a postgraduate journal club

Acute exacerbations of psychosis have been reported with COVID-19 infection and medications used for its treatment. Terms "psychosis", "psychotic", "COVID-19″ and "coronavirus" were searched on "PubMed" and "GOOGLE SCHOLAR", yielding 84 articles. 14 case reports were selected based on pre-defined criteria and analyzed. Among selected articles,10 attributed psychosis to COVID-19 infection. In 3 articles, psychosis was diagnosed despite concurrent delirium. In 8 and 3 articles respectively, a clear temporal demarcation of psychosis and COVID-19 infection and steroid use was not described. Psychosis can occur secondary to GMC, or exposure to medication. Due process should be followed to ascertain the same.

INTRODUCTION

Neurotropic coronavirus infection is associated with numerous neurological and neuropsychiatric manifestations. Such presentations before, during and after the infection have been reported. Among these presentations, acute exacerbations of psychosis have been reportedly linked with COVID-19 infection and medications used for its treatment.

METHODOLOGY

Search engines "PubMed" AND "GOOGLE SCHOLAR" were searched using specific search terms during June 2021. Out of 84 articles that came up, we selected 14 articles based on pre-determined inclusion and exclusion criteria. Selected articles were analysed and discussed in the departmental journal club.

RESULTS

In 10 articles, diagnosis of psychosis was attributed to COVID-19 infection. In 3 of those articles, despite reporting concurrent delirium like presentation, diagnosis was still reported as psychosis. In 8 articles, the temporal correlation between onset of psychosis, onset of COVID-19 was not clearly demarcated. In 3 articles, clear demarcation between psychosis associated with steroid use and with a general medical condition (COVID-19) was not clearly presented. Only 2 articles did mention using a structured diagnostic system. In patients (3/17) with prior history of psychiatric illness, diagnosis was reported as relapse of psychosis (2/17), without specifying the criteria used for diagnosing a relapse.

CONCLUSION

Acute exacerbation of psychosis can occur secondary to a general medical condition (GMC), or after exposure to a medication. However, due process should be followed to ascertain that the psychosis is indeed secondary to a GMC, or a medication, and not a de-novo presentation, or delirium.

Recognition and management of clozapine adverse effects: A systematic review and qualitative synthesis

OBJECTIVE

Clozapine is substantially underutilized in most countries and clinician factors including lack of knowledge and concerns about adverse drug effects (ADEs) contribute strongly to treatment reluctance. The aim of this systematic review was to provide clinicians with a comprehensive information source regarding clozapine ADEs.

METHODS

PubMed and Embase databases were searched for English language reviews concerned with clozapine ADEs; publications identified by the automated search were manually searched for additional relevant citations. Following exclusion of redundant and irrelevant reports, pertinent information was summarized in evidence tables corresponding to each of six major ADE domains; two authors reviewed all citations for each ADE domain and summarized their content by consensus in the corresponding evidence table. This study was conducted in accordance with PRISMA principles.

RESULTS

Primary and secondary searches identified a total of 305 unique reports, of which 152 were included in the qualitative synthesis. Most clozapine ADEs emerge within 3 months, and almost all appear within 6 months, after initiation. Notable exceptions are weight gain, diabetic ketoacidosis (DKA), severe clozapine-induced gastrointestinal hypomotility (CIGH), clozapine-induced cardiomyopathy (CICM), seizures, and clozapine-induced neutropenia (CIN). Most clozapine ADEs subside gradually or respond to dose reduction; those that prompt discontinuation generally do not preclude rechallenge. Rechallenge is generally inadvisable for clozapine-induced myocarditis (CIM), CICM, and clozapine-induced agranulocytosis (CIA). Clozapine plasma levels >600-1000 μg/L appear more likely to cause certain ADEs (e.g., seizures) and, although there is no clear toxicity threshold, risk/benefit ratios are generally unfavorable above 1000 μg/L.

CONCLUSION

Clozapine ADEs rarely require discontinuation.

Drug information update. Atypical antipsychotics and neuroleptic malignant syndrome: nuances and pragmatics of the association

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal adverse event associated with the use of antipsychotics. Although atypical antipsychotics were initially considered to carry no risk of NMS, reports have accumulated over time implicating them in NMS causation. Almost all atypical antipsychotics have been reported to be associated with NMS. The clinical profile of NMS caused by certain atypical antipsychotics such as clozapine has been reported to be considerably different from the NMS produced by typical antipsychotics, with diaphoresis encountered more commonly, and rigidity and tremor encountered less frequently. This article briefly discusses the evidence relating to the occurrence, presentation and management of NMS induced by atypical antipsychotics.

Atypical Neuroleptic Malignant Syndrome Associated with Use of Clozapine

The Neuroleptic Malignant Syndrome (NMS) is a medical emergency of infrequent presentation in the emergency department, which is associated with the use of psychiatric drugs, such as typical and atypical antipsychotics. Our case addresses a 55-year-old patient diagnosed with undifferentiated schizophrenia for 10 years, who had been receiving clozapine and clonazepam as part of their treatment. This patient presents the symptoms of Neuroleptic Malignant Syndrome without fever, which improves with treatment especially with the withdrawal of clozapine. In the absence of fever and clinical improvement, the patient is considered to have an atypical presentation of this disease.

Characterization and Clinical Management of Clozapine-Induced Fever

Objective:

To characterize clozapine-induced fever and suggest clinically relevant management recommendations.

Data Sources:

Literature was accessed through MEDLINE (1966–June 2007) using the terms clozapine, fever, and adverse effects. In addition, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

All English-language articles about human studies ot fever associated with the use of clozapine were evaluated.

Data Synthesis:

Mild to high-grade fever frequently accompanies clozapine therapy. Fever usually occurs within 10–15 days after treatment initiation and has been reported to last between 2 and 4 days. The mechanism and clinical implications of clozapine-induced fever are unclear. The primary concern for clinicians, with regard to these fevers, is the possibility of 2 serious conditions: agranulocytosis with infection or neuroleptic malignant syndrome (NMS). However, the presence of fever during clozapine therapy does not appear to predict agranulocytosis, NMS, or an increased rate of drug discontinuation at 1 year.

Conclusions:

Available data suggest that clozapine-induced fevers are benign: once infectious and other medical causes for fever are ruled out, clozapine therapy can be continued.

Therapeutic Options in the Treatment of Clozapine-Induced Adverse Effects

Objective:

To review the therapeutic options in the management of clozapine-induced adverse effects.

Data Sources:

A MEDLINE search (from 1966 to present) was conducted, and English-language studies and review articles were retrieved to review the adverse effects of clozapine and their management.

Study Selection and Data Extraction:

All studies evaluating clozapine's adverse effects, such as agranulocytosis, seizures, neuroleptic malignant syndrome, hypersalivation, weight gain, sedation, fatigue, orthostatic hypotension, eosinophilia, delirium, new-onset diabetes, constipation, nausea, tachycardia, myocarditis, and pancreatitis, and their management were included.

Data Synthesis:

Clozapine, an atypical antipsychotic that has been proven effective and comparable, as well as superior, to conventional antipsychotics in treatment-resistant schizophrenia, is also being used in the treatment of a wide variety of other psychiatric conditions, including suicidal ideation, tardive dyskinesia, and affective disorders such as depression, bipolar disorders, and schizoaffective disorder. Although clozapine exhibits a markedly low incidence of extrapyramidal symptoms compared with similar medications, it has other adverse effects, some of which are potentially life threatening, requiring careful monitoring. The adverse effects of clozapine range from benign drooling, weight gain, nausea, and constipation, to life-threatening agranulocytosis, seizures, and neuroleptic malignant syndrome (NMS). Mandatory periodic white blood cell monitoring has resulted in dramatic reduction in mortality due to clozapine-induced agranulocytosis, promoting high adherence by patients. Prompt diagnosis and treatment of adverse effects of clozapine has also been effective in reducing complications, including mortality due to other serious adverse effects such as NMS and seizure. Other adverse effects are comparatively benign and can be managed effectively.

Conclusions:

Clozapine has a wide variety of adverse effects, some of which are potentially life threatening. Clinicians should be aware of possible severe complications and emergency management. Differentiating between minor and major adverse effects and initiating appropriate intervention is essential for a positive therapeutic outcome when prescribing clozapine.

Neuroleptic Malignant Syndrome: No Longer Exclusively a “Neuroleptic” Phenomenon

Objective:

To review the literature concerning the incidence of neuroleptic malignant syndrome (NMS) associated with the use of atypical antipsychotics.

Data Sources:

Cases were identified through a search of MEDLINE (1986–March 2004) using the terms neuroleptic malignant syndrome, antipsychotic, clozapine, risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole.

Study Selection and Data Extraction:

Case reports of possible NMS secondary to second-generation antipsychotics were selected for review. Reports meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for NMS were considered. Case reports in which 1 of the 2 major diagnostic criteria was met were also included in the analysis. Furthermore, at least one minor criterion was met. Case reports in which patients received traditional antipsychotics were excluded.

Data Synthesis:

NMS is a rare and sometimes fatal disease. Several theories exist as to how NMS develops, and an equally large amount of diagnostic criteria are available. However, the majority of available data are based on the first-generation neuroleptics and very few exist with regard to the second-generation antipsychotics.

Conclusions:

Although there are numerous case reports of NMS occurring secondary to the use of second-generation antipsychotics, the incidence has never been fully elucidated. While the reasons for this remain uncertain, not all cases of second-generation–induced NMS fulfill the diagnostic criteria established for traditional neuroleptics and therefore may not be reported as such.

Risks and Benefits of Rapid Clozapine Titration

Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS) during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

Bioenergetic disruption of human micro-vascular endothelial cells by antipsychotics

Antipsychotics (APs) are widely used medications, however these are not without side effects such as disruption of blood brain barrier function (BBB). To investigate this further we have studied the chronic effects of the typical APs, chlorpromazine (CPZ) and haloperidol (HAL) and the atypical APs, risperidone (RIS) and clozapine (CLZ), on the bioenergetics of human micro-vascular endothelial cells (HBVECs) of the BBB. Alamar blue (AB) and ATP assays showed that these APs impair bioenergenesis in HBVECs in a concentration and time dependent manner. However since these effects were incomplete they suggest a population of cell bioenergetically heterogeneous, an idea supported by the bistable nature by which APs affected the mitochondrial transmembrane potential. CPZ, HAL and CLZ inhibited the activity of mitochondrial complexes I and III. Our data demonstrates that at therapeutic concentrations, APs can impair the bioenergetic status of HBVECs, an action that help explains the adverse side effects of these drugs when used clinically.

Second-generation antipsychotics and neuroleptic malignant syndrome: systematic review and case report analysis

BACKGROUND

Neuroleptic malignant syndrome (NMS) is a rare, severe, idiosyncratic adverse reaction to antipsychotics. Second-generation antipsychotics (SGAs) were originally assumed to be free from the risk of causing NMS, however several cases of NMS induced by SGAs (SGA-NMS) have been reported.

OBJECTIVES

The aim of this study was to systematically review available studies and case reports on SGA-NMS and compare the presentation of NMS induced by different SGAs.

DATA SOURCES

Citations were retrieved from PubMed up to November 2013, and from reference lists of relevant citations.

STUDY ELIGIBILITY CRITERIA

Eligibility criteria included (a) primary studies reporting data on NMS, with at least 50 % of the sample receiving SGAs; or (b) case reports and case reviews reporting on NMS induced by SGA monotherapy, excluding those due to antipsychotic withdrawal.

STUDY APPRAISAL AND SYNTHESIS METHODS

A standardized method for data extraction and coding was developed for the analysis of eligible case reports.

RESULTS

Six primary studies and 186 individual cases of NMS induced by SGAs were included. Primary studies suggest that SGA-NMS is characterized by lower incidence, lower clinical severity, and less frequent lethal outcome than NMS induced by first-generation antipsychotics. Systematic analysis of case reports suggests that even the most recently marketed antipsychotics are not free from the risk of inducing NMS. Furthermore, clozapine-, aripiprazole- and amisulpride-induced NMS can present with atypical features more frequently than other SGA-NMS, i.e. displaying less intense extrapyramidal symptoms or high fever.

LIMITATIONS

Case reports report non-systematic data, therefore analyses may be subject to bias.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Clinicians should be aware that NMS is virtually associated with all antipsychotics, including those most recently marketed. Although apparently less severe than NMS induced by older antipsychotics, SGA-NMS still represent a relevant clinical issue.

Fever development in neuroleptic malignant syndrome during treatment with olanzapine and clozapine

Neuroleptic malignant syndrome (NMS) is the most dangerous life-threatening complication of antipsychotic medication. It's development is connected with the blockade of dopaminergic transmission (D2 receptors) in the nigrostriatal system of the brain. Fever is one of the main symptoms of this syndrome and it's elevation is due to the activation of the immune system. Numerous studies report that treatment with clozapine (doses 37.5-600 mg) or olanzapine (doses 10-25 mg) or the use of these drugs in polytherapy cause pyrexia between 37.8-40.6 °C. Additionally, levels of proinflammatory interleukins such as IL-6, IL-1,TNF-α were increased. The aim of this article is to describe how olanzapine and clozapine influence fever development in NMS, in relation to the dose of the drug taken by schizophrenic patients including changes in immunological system.

Case reports of neuroleptic malignant syndrome in context of quetiapine use

A retrospective analysis was followed on 20 case reports covering the possible correlation between the atypical antipsychotic, quetiapine, and neuroleptic malignant syndrome (NMS), determined by the study of 7 different NMS criteria guidelines. A great majority (19) of the case studies did not meet the requirements of all 7 guidelines, frequently due to unreported information. Nor was quetiapine proven to be the sole cause of the possible NMS in the two age groups investigated. Only one case was found to have no other medication or medical conditions confounding the relationship of quetiapine and NMS symptoms, and that case was in the context of a significant quetiapine overdose. The other 19 cases demonstrated the difficulty of identifying the cause of NMS when polypharmacy and other medical conditions are involved. The authors note the need for caution in deciding both the presence of NMS and the causal factors of the symptoms.

Extensive Deep Venous Thrombosis in a Patient with Neurolept Malignant Syndrome despite Being on Prophylaxis

The risk of venous thromboembolism (VTE) in patients with Neuroleptic malignant syndrome (NMS) and those on antipsychotic medications is well established. We present here a case whereby the patient had NMS and developed extensive deep venous thrombosis (DVT) despite being on standard DVT Prophylaxis. Our case illustrates that empiric intravenous heparin for the initial few days after the onset of NMS may be considered in those with high risk of VTE, as in such patients standard DVT prophylaxis may not be sufficient. To standardize as to which patients with NMS would be at the highest risk of VTE while on standard DVT prophylaxis, the role of a standardized scoring system and a double-blind randomized trial in the future would probably be beneficial.

Resolution of symptoms in neuroleptic malignant syndrome

Although neuroleptic malignant syndrome (NMS) manifests consistently with hyperthermia, muscle rigidity, altered mental state, and autonomic instability, heterogeneity exists in the onset, initial manifestations, course, laboratory findings, response to treatment, and pattern of resolution. Comorbid physical conditions tend to confuse the picture. We report a case of NMS with such a presentation.

A case report of neuroleptic malignant syndrome

A 32-year-old male patient with a history of treatment resistant paranoid schizophrenia developed neuroleptic malignant syndrome (NMS) during changeover of his antipsychotic medication from zuclopenthixol depot to clozapine. This case highlights the difficulties of cross-tapering two antipsychotics-that is, converting from a typical depot medication to an oral atypical antipsychotic.

Neuroleptic Malignant Syndrome Secondary to Quetiapine

Objective:

To report a case of neuroleptic malignant syndrome (NMS) secondary to quetiapine in which the patient developed extrapyramidal symptoms (EPS).

Case Summary:

A 34-year-old male with a history of severe brain damage, mental retardation, and seizures was admitted to the hospital with changes in mental status, development of tremors, and a temperature of 39.9 °C. Initial differentia) diagnoses included seizure, aspiration, stroke, and infection. Once these were excluded, NMS was considered. The patient exhibited other characteristics of NMS during hospitalization, including lead pipe rigidity, tachycardia, and high creatine kinase level (up to 12,654 IU/L). Drug therapy on presentation included quetiapine 200 mg 3 times per day, guanfacine 2 mg/day. carbamazepine 400 mg every 12 hours, valproic acid 500 mg twice daily, and lorazepam 2 mg (unknown schedule). He reportedly had received these medications for at least a month before admission. On hospital day 2, quetiapine was discontinued. The patient received traditional treatment (or NMS, which included bromocriptine, dantrolene, intravenous fluids, and supportive care. The NMS resolved in 7 days.

Discussion:

In cases of NMS, clinicians previously believed that the risk for developing severe adverse effects such as EPS was lower with atypical versus typical antipsychotics. We identified 13 cases of NMS secondary to quetiapine in the literature via a search of MEDLINE/PubMed (1950–2008), and Iowa Drug Information Service (1966–2008). Seventy-five percent of previous reports of NMS secondary to quetiapine had reactions that included EPS, Common patient characteristics in our report and others included male sex, history of mental retardation, and treatment modalities used in NMS. Unique characteristics in this case included length of therapy without dosage change or titration and no known history of drug-related EPS. The Naranjo probability scale indicated a probable relationship between the development of NMS and quetiapine.

Conclusions:

NMS with associated EPS has been previously associated with quetiapine. Clinicians should be aware that NMS with EPS can occur with quetiapine at steady state doses without recent dosage adjustments or titration.

Increases in C-Reactive Protein May Predict Recurrence of Clozapine-Induced Fever

OBJECTIVE

To report a case of recurrent clozapine-induced fever that was associated with a rise in C-reactive protein (CRP).

CASE SUMMARY

A 73-year-old man with Lewy Body dementia was admitted for psychosis. He was treated with clozapine (initial dose 12.5 mg/day, titrated to 75 mg/day over 15 days). On day 15 of clozapine therapy, he developed a benign fever (maximum 38.4 °C) that was associated with a rise in the CRP level (3.96 mg/dL). The level normalized when clozapine was discontinued. However, when the patient was rechallenged with clozapine, the CRP level became elevated (4.36 mg/dL) after 3 days of therapy, with a subsequent recurrence of fever (38.7 °C).

DISCUSSION

We postulate that the elevation in CRP levels and the subsequent fever were caused by the effects of clozapine on the cytokine system via interleukin-6 and tumor necrosis factor-α, resulting in an inflammatory response with an acute phase reaction. This case is unique, as it is the first reported in the literature associating a recurrence of clozapine-induced fever with the known immunomodulatory effects of clozapine on cytokines and CRP level. According to the Naranjo probability scale, this adverse effect is probably associated with clozapine.

CONCLUSIONS

Clozapine-related fever is generally benign but difficult to assess and manage, as it can be confused with much more serious conditions. Further research is needed to study whether CRP is a useful tool in predicting and managing clozapine fever.

Clozapine-associated myocarditis: a review of 116 cases of suspected myocarditis associated with the use of clozapine in Australia during 1993-2003

BACKGROUND

Clozapine is an antipsychotic medication associated with a lower suicide rate compared with other antipsychotic agents. Clozapine is used specifically in patients for whom previous therapy was inadequate or not tolerated, and is the only antipsychotic agent associated with the development of myocarditis.

OBJECTIVE

To retrospectively review all adverse drug reaction reports voluntarily submitted to the Australian Adverse Drug Reactions Unit mentioning suspected myocarditis in clozapine-treated patients.

PATIENTS AND METHODS

We accessed all electronic database entries and case reports citing suspected myocarditis associated with clozapine therapy from January 1993 through to December 2003, inclusive.

RESULTS

116 case reports of suspected myocarditis amongst clozapine-treated patients were identified during the specified time frame (incidence between 0.7% and 1.2% of treated patients). Median patient age for these cases was 30 years (SD 11.1 years) compared with 37 years from the Clopine registry. The condition developed within a median 16 days (mean 19.8 days; SD 17.3 days) of commencing clozapine for the bulk of patients developing myocarditis within 6 months (n=93, 80.2%). For all cases with known treatment commencement and cessation dates (n=106), the condition developed within a median 17 days (mean 171.7 days, SD 530.9 days). Over nine-tenths of cases were prescribed clozapine within the dose range of 100 mg/day to 450 mg/day. Sixty patients (51.8%) recovered from their episode when reported or during follow-up reports, whereas 17 patients (14.7%) had not yet recovered: 27 patients (23.3%) had unknown outcome when reported and the remaining 12 patients (10.3%) died.

CONCLUSION

Clozapine is uncommonly but importantly related to myocarditis, often fatal or near fatal and sometimes in relatively young patients with early onset after treatment initiation. The most striking feature about this condition is the wide diversity of nonspecific symptoms that occur in afflicted patients. Additional pharmacovigilance, improved reporting systems and further investigation of mechanisms of drug-induced myocarditis and related cardiovascular conditions (such as heart failure) are clearly warranted. A case-control study would be suitable for investigation of baseline predictors.

Olanzapine-Associated Neuroleptic Malignant Syndrome

Neuroleptic malignant syndrome (NMS) is a rare but potentially serious complication of neuroleptic drugs. It may vary in both presenting characteristics and severity. Several different criteria for diagnosis exist, and each differs from the others slightly. We describe a 66-year-old woman with chronic paranoid schizophrenia who was prescribed olanzapine along with several other psychiatric drugs and an antihypertensive drug. The patient displayed several characteristics of NMS during therapy with olanzapine, including fever, elevated creatine kinase level, leukocytosis, and mild muscle rigidity. When olanzapine was held, the signs and symptoms improved and then returned with rechallenge of olanzapine. For this reason, olanzapine was considered strongly associated with this patient's apparent NMS episode. The patient's beta-blocker therapy may have masked additional signs of NMS. In addition, the patient tolerated other neuroleptics that were started in the hospital after the suspected NMS episode. The variation among different diagnostic criteria makes this syndrome a challenging diagnosis at times, in particular when atypical antipsychotics are suspected as the causative agent.

Fatal neuroleptic malignant syndrome in a previously long-term user of clozapine following its reintroduction in combination with paroxetine

A 77-year-old patient with initial behavioral and psychological symptoms of dementia was treated with clozapine (50 mg/daily). Since no clinical benefit was apparent, clozapine was discontinued after six weeks and the patient started on paroxetine (20 mg/daily). After three weeks on paroxetine, he was given another trial of clozapine at a starting dosage of 25 mg/daily. While clozapine had previously been well tolerated, this time he rapidly developed fever, mental confusion, lethargy, muscle spasms and rigidity. The diagnosis of neuroleptic malignant syndrome was delayed, because there was no leukocytosis and serum creatine phosphokinase was initially not elevated. Subcutaneous apomorphine was then given but, after an initial improvement, the patient developed a multiple organ failure syndrome and died.

Modern antipsychotic drugs: a critical overview

Conventional antipsychotic drugs, used for a half century to treat a range of major psychiatric disorders, are being replaced in clinical practice by modern "atypical" antipsychotics, including aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone among others. As a class, the newer drugs have been promoted as being broadly clinically superior, but the evidence for this is problematic. In this brief critical overview, we consider the pharmacology, therapeutic effectiveness, tolerability, adverse effects and costs of individual modern agents versus older antipsychotic drugs. Because of typically minor differences between agents in clinical effectiveness and tolerability, and because of growing concerns about potential adverse long-term health consequences of some modern agents, it is reasonable to consider both older and newer drugs for clinical use, and it is important to inform patients of relative benefits, risks and costs of specific choices.

Neuroleptic malignant syndrome due to three atypical antipsychotics in a child

Neuroleptic Malignant Syndrome (NMS) is a rare, potentially fatal and idiosyncratic drug reaction. It is characterized by a sudden loss of body temperature control, renal and respiratory failure, muscle rigidity, loss of consciousness and impairment of autonomic nervous system. Although NMS was previously associated with the use of classical high-potency neuroleptics, cases have started to emerge with atypical neuroleptics. This article discusses the first case of NMS in a child, induced by the use of risperidone, olanzapine and quetiapine.

Drug-induced movement disorders in children and adolescents

The use of psychotropic medication among children and adolescents is increasing with a concomitant increase in the incidence of drug-related movement disorders. This class of adverse reactions to medications can be divided into those that are acute in onset, others that are continuous as long as the offending drug is administered, and a final category consisting of symptoms that are persistent, even after the causative agent has been discontinued. Within these three categories, this review discusses the epidemiology, risk factors, clinical features and treatment of acute dystonic reactions, drug-induced parkinsonism, neuroleptic malignant syndrome, serotonin syndrome, acute akathisia, and the tardive syndromes. In addition, drugs that commonly cause tremor, chorea, or myoclonus are included.

Neuroleptic malignant syndrome in an adolescent after brief exposure to olanzapine

A 17-year-old African-American male developed neuroleptic malignant syndrome (NMS) with hyperthermia, autonomic instability, increased muscle tone, rhabdomyolysis, and obtundation after a maximum of 2 days of treatment with olanzapine and 1 day of treatment with divalproex sodium. Intensive care unit (ICU)-level care was required. Paranoid psychosis with catatonia was present after recovery from the NMS. Because of his continued psychotic symptoms following resolution of the NMS, the alternate atypical antipsychotic, clozapine, was started under close observation. Reports of NMS resulting from atypical antipsychotic agents are generally uncommon, and much more so in the child and adolescent population. However, these agents are frequently prescribed in this population and require due caution.

Movement disorder emergencies

Movement disorders may present acutely, and failure to recognize and exclude important differential diagnoses can result in significant morbidity or mortality. Unfortunately, much of the literature pertaining to this topic is scattered and not easily accessible. This review aims to address this deficit. Movement disorder emergencies are discussed according to their most likely mode of presentation. Diagnostic considerations and early management principles are reviewed, along with appropriate pathophysiology where relevant.

The evaluation and management of patients with neuroleptic malignant syndrome

NMS is a rare but fatal syndrome that needs to be considered in the perioperative period. Although many aspects remain unexplored and controversial, with greater awareness of the condition, new concepts are coming into light. Definitive treatment guidelines remain an important issue to be addressed. Efforts have been initiated in that direction and all cases can be reported on a toll-free hotline ( 1-888-667-8367) or online (www.nmsis.org).

Olanzapine-associated neuroleptic malignant syndrome: Is there an overlap with the serotonin syndrome?

Background

The neuroleptic malignant syndrome is a rare but serious condition mainly associated with antipsychotic medication. There are controversies as to whether "classical" forms of neuroleptic malignant syndrome can occur in patients given atypical antipsychotics. The serotonin syndrome is caused by drug-induced excess of intrasynaptic 5-hydroxytryptamine. The possible relationship between neuroleptic malignant syndrome and serotonin syndrome is at present in the focus of scientific interest.

Methods

This retrospective phenomenological study aims to examine the seventeen reported olanzapine – induced neuroleptic malignant syndrome cases under the light of possible overlap between neuroleptic malignant syndrome and serotonin syndrome clinical features.

Results

The serotonin syndrome clinical features most often reported in cases initially diagnosed as neuroleptic malignant syndrome are: fever (82%), mental status changes (82%) and diaphoresis (47%). Three out of the ten classical serotonin syndrome clinical features were concurrently observed in eleven (65%) patients and four clinical features were observed in seven (41%) patients.

Conclusion

The results of this study show that the clinical symptoms of olanzapine-induced neuroleptic malignant syndrome and serotonin syndrome are overlapping suggesting similarities in underlying pathophysiological mechanisms.

Olanzapine induced neuroleptic malignant syndrome--a case review

Neuroleptic malignant syndrome is the rarest and the most serious of the neuroleptic induced movement disorders. Although potent neuroleptics are more frequently associated with NMS, atypical antipsychotic drugs may also be a cause of NMS. Three databases were searched using the terms 'olanzapine' and 'neuroleptic' 'malignant syndrome'. Case reports were selected and reviewed from among all articles that fulfilled the search criteria. Twenty six cases were reviewed. Twenty cases fulfilled the criteria published by Sachdev et al. Olanzapine was the most probable cause of NMS in 16 cases. The absence of rigidity was described in only two of 16 highly probable olanzapine induced NMS cases, which is not as often as it is reported in clozapine associated NMS (36%). It was found that prior NMS is an important risk factor in NMS.

The use of atypical antipsychotics in traumatic brain injury

The use of antipsychotic medication in treating individuals with traumatic brain injury (TBI) has been controversial. Much of the caution derives from animal studies (and limited human data) with regard to typical antipsychotics. Of note, however, is that similar assumptions have been made about the newer generation of atypical antipsychotics as well. Because these agents have different mechanisms of action as well as different neurotransmitter targets, this may very well be unwarranted. In this article, mechanisms of action of typical and atypical antipsychotics are discussed, with particular attention paid to their use in TBI. Indications and contraindications are presented, and recommendations are made for the responsible prescribing of antipsychotic medications after TBI.

Neuroleptic malignant syndrome induced by atypical antipsychotics

A review of the English literature confirms that neuroleptic malignant syndrome (NMS) occurs with both traditional and atypical antipsychotic medications. Published reports of NMS induced by the traditional antipsychotics have given the practitioner valuable information on the prevention and treatment of this adverse effect. Case reports have also been published concerning NMS and clozapine, risperidone, olanzapine and quetiapine. By evaluating the case reports of atypical antipsychotic-induced NMS, valuable information may be obtained concerning similarities or differences from that induced by the traditional antipsychotics. The case reports of NMS with atypical antipsychotics were evaluated for diagnosis, age/sex of patient, risk factors, antipsychotic doses and duration of use, symptoms of NMS, and clinical course.

Switching treatment-resistant patients with schizophrenia or schizoaffective disorder to olanzapine: a one-year open-label study with five-year follow-up

OBJECTIVE

To determine whether patients with treatment-resistant schizophrenia or schizoaffective disorder would respond when switched to olanzapine and whether they could maintain their response on this atypical antipsychotic.

RESEARCH DESIGN AND METHODS

In this single-center, observational, 1-year open-label study, a cohort of patients was switched to olanzapine due to failure on previous treatment. The patients were followed up (retrospectively) for an additional 5 years. Patients had schizophrenia or schizoaffective disorder and all but one were treatment-resistant. The starting dose was 10 mg/day, with dosage adjustments based on physician judgment.

MAIN OUTCOME MEASURES

The CGI-S and CGI-I scales were the primary outcome measures. During the observation period, positive and negative symptoms, hospital readmission rates and duration of hospitalization were measured, and treatment-emergent adverse events recorded.

RESULTS

Mean age of patients (n = 25) was 39.7 years; 19 were male, and all were Caucasian. The mean number of antipsychotics used prior to olanzapine was 4.6 with risperidone (76%) being the most common. The mean duration of olanzapine therapy was 8.6 months. The average number of hospital admissions per patient dropped from 1.32 during the year prior to olanzapine therapy to 0.39 after starting olanzapine. Total number of hospital days was 1042 the year before and 258 the year after olanzapine treatment. The mean CGI-S score improved from markedly ill at baseline to borderline/mildly ill at study end. The mean CGI-I score was rated much improved at study end. Few adverse events occurred during the study. Twelve patients remained on olanzapine monotherapy after 5 years of treatment (mean duration of 62 months).

CONCLUSIONS

Olanzapine may be a treatment option for patients who fail to respond to treatment with other antipsychotics. Importantly, this is one of the first reports showing that patients with schizophrenia can be maintained on atypical antipsychotic monotherapy for at least 5 years.

Olanzapine-associated neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is an uncommon but serious idiosyncratic reaction associated with antipsychotic medication. The purpose of this study was to reveal and analyze the clinical characteristics of the reported cases of NMS in patients given the novel antipsychotic olanzapine. A MEDLINE search related to olanzapine-induced NMS cases reported in the international literature was conducted. All cases were critically reviewed and examined against three different sets of NMS diagnostic criteria (DSM-IV, Addonizio, Levenson). The authors identified 17 cases of possible NMS associated with olanzapine. Ten of the reported NMS cases were definitely NMS meeting all three sets of criteria and three cases were probable NMS meeting two sets of criteria. Most of the patients exhibited a full-blown NMS. There were four definite NMS cases associated with olanzapine monotherapy. Three of them had concurrent serious physical illnesses and one had a previous NMS episode. Olanzapine can cause NMS, mainly in susceptible or predisposed patients.

Atypical neuroleptic malignant syndrome associated with olanzapine

Neuroleptic malignant syndrome (NMS) is a potentially life-threatening adverse effect of antipsychotic agents. It generally is characterized by fever, altered mental status, rigidity, and autonomic dysfunction. A 53-year-old man developed NMS without rigidity while taking olanzapine. Such atypical cases may support either a spectrum concept of NMS or the theory that NMS secondary to atypical antipsychotics differs from that caused by conventional neuroleptics. More flexible diagnostic criteria than currently mandated by the the Diagnostic and Statistical Manual of Mental Disorders, Fourth Revision, may be warranted.