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

Optimizing antidepressant and clozapine co-prescription in clinical practice: A systematic review and expert recommendations

OBJECTIVES

To synthesize the information relevant for clinical practice on clozapine-antidepressant co-prescription concerning pharmacokinetic drug-drug interactions (DDI), adverse drug reactions (ADRs) associated with the co-prescription, antidepressant add-on for clozapine-resistant symptoms and antidepressant add-on for clozapine-induced ADRs.

METHODS

Articles were identified with MEDLINE, Web of Sciences and PsycINFO search from inception through April 2023. Data were synthesized narratively.

RESULTS

ADRs are most often induced by the co-prescription of antidepressants that inhibit CYP enzymes (fluvoxamine, fluoxetine, paroxetine). Fluvoxamine add-on is hazardous because of its potent inhibition of clozapine metabolism and has few indications (lowering daily number of clozapine tablets, reducing norclozapine-induced metabolic disturbances and other dose-dependent clozapine-induced ADRs). ADR frequency may be reduced by therapeutic drug monitoring and knowledge of other factors impacting clozapine metabolism (pneumonia, inflammation, smoking, etc.). Improvement of negative symptoms is the most documented beneficial effect of antidepressant add-on for clozapine-resistant psychotic symptoms. The add-on antidepressant should be chosen according to its safety profile regarding DDI with clozapine: antidepressants inhibiting clozapine metabolism or increasing the anticholinergic load should be avoided. Other indications of antidepressant add-on (affective or obsessive compulsive symptoms, sialorrhea, and enuresis) are poorly documented.

CONCLUSION

Antidepressant add-on to clozapine is associated with potential benefits in clozapine users as this strategy may contribute to reduce the burden of clozapine-resistant symptoms or of clozapine-induced ADRs. Further studies are needed to determine whether antidepressant add-on can reduce the risk of clozapine discontinuation.

New tricks for an old dog: A repurposing approach of apomorphine

Apomorphine is a 150-year old nonspecific dopaminergic agonist, currently indicated for treating motor fluctuations in Parkinson's disease. At the era of drug repurposing, its pleiotropic biological functions suggest other possible uses. To further explore new therapeutic and diagnostic applications, the available literature up to July 2018 was reviewed using the PubMed and Google Scholar databases. As many of the retrieved articles consisted of case reports and preclinical studies, we adopted a descriptive approach, tackling each area of research in turn, to give a broad overview of the potential of apomorphine. Apomorphine may play a role in neurological diseases like restless legs syndrome, Huntington's chorea, amyotrophic lateral sclerosis, Alzheimer's disease and disorders of consciousness, but also in sexual disorders, neuroleptic malignant(-like) syndrome and cancer. Further work is needed in both basic and clinical research; current developments in novel delivery strategies and apomorphine derivatives are expected to open the way.

Neuroleptic malignant syndrome and subsequent clozapine-withdrawal effects in a patient with refractory schizophrenia

Here, we report a female patient developing neuroleptic malignant syndrome following the use of a combination of clozapine and haloperidol. Subsequently, the patient presented withdrawal effects after an abrupt discontinuation of clozapine. Psychiatrists not aware of possible clozapine-withdrawal effects may misdiagnose as a part of the primary mental illness or as the initial symptoms worsening, if unrecognized.

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.

Neuroleptic Malignant Syndrome: A Review from a Clinically Oriented Perspective

Neuroleptic malignant syndrome (NMS) is a rare but potentially life-threatening side-effect that can occur in response to treatment with antipsychotic drugs. Symptoms commonly include hyperpyrexia, muscle rigidity, autonomic dysfunction and altered mental status. In the current review we provide an overview on past and current developments in understanding the causes and treatment of NMS. Studies on the epidemiological incidence of NMS are evaluated, and we provide new data from the Canada Vigilance Adverse Reaction Online database to elaborate on drug-specific and antipsychotic drug polypharmacy instances of NMS reported between 1965 and 2012. Established risk factors are summarized with an emphasis on pharmacological and environmental causes. Leading theories about the etiopathology of NMS are discussed, including the potential contribution of the impact of dopamine receptor blockade and musculoskeletal fiber toxicity. A clinical perspective is provided whereby the clinical presentation and phenomenology of NMS is detailed, while the diagnosis of NMS and its differential is expounded. Current therapeutic strategies are outlined and the role for both pharmacological and non-pharmacological treatment strategies in alleviating the symptoms of NMS are discussed.

Possible contribution of XYY syndrome to neuroleptic malignant syndrome in a child receiving quetiapine

PURPOSE

A case of early neuroleptic malignant syndrome (NMS) in a child with XYY syndrome after three weeks of quetiapine therapy is reported.

SUMMARY

A four-year-old, 23-kg boy with a history of oppositional defiant disorder, mood disorder, and XYY syndrome was brought to the emergency care center (ECC) for evaluation secondary to somnolence, gait disturbances, and altered mental status. Three weeks prior, he was started on a daily oral dose of quetiapine 25 mg; this was adjusted upward to 400 mg daily. He had been experiencing episodes of severe confusion, somnolence, and extreme agitation. He was also ataxic and unbalanced on his feet. Upon evaluation at the ECC, he was found to have an elevated creatine kinase (CK) concentration, as well as elevated CK-MB and CK-MM levels, both of which were indicative of skeletal muscle damage. He was slightly diaphoretic and displayed mild rigidity accompanied by varying degrees of agitation and confusion. The diagnosis of NMS secondary to quetiapine therapy was made. Quetiapine was discontinued, and the patient was admitted for observation. His symptoms steadily resolved over the course of his hospital stay, and his total CK levels, as well as CK isoenzyme levels, fell over the course of observation. Quetiapine was not restarted at discharge, and no new medications were prescribed.

CONCLUSION

A four-year-old boy with XYY syndrome developed signs and symptoms consistent with early NMS after three weeks of quetiapine therapy. High-dose quetiapine, along with possible baseline liver dysfunction secondary to XYY syndrome, may have contributed to the development of NMS in this patient, which resolved after the discontinuation of quetiapine.

Neuroleptic malignant syndrome associated with atypical antipsychotic drugs

Neuroleptic malignant syndrome (NMS) is a rare but potentially severe idiosyncratic adverse reaction usually seen in the context of treatment with antipsychotic drugs. Although NMS is historically associated with the classic or 'typical' antipsychotic drugs, it is also a potential adverse effect of atypical antipsychotic drugs. The widespread use of atypical antipsychotic drugs highlights the need to examine the data relating to the symptomatology, diagnosis, classification and management of NMS with these newer agents. We used MEDLINE and EMBASE to identify NMS case reports and systematic reviews published to June 2008 related to the atypical antipsychotic drugs clozapine, olanzapine, risperidone, paliperidone, aripiprazole, ziprasidone, amisulpride and quetiapine. Case reports and reviews were systematically examined. Our review suggests that, in general, NMS associated with atypical antipsychotic drugs manifests in a typical manner. One notable exception is clozapine-induced NMS, which appears less likely to manifest with extrapyramidal features, including rigidity and tremor. The available literature highlights the divergence of opinion relating to the core diagnostic features of NMS and its conceptualization as a categorical versus dimensional disorder. Both these issues have relevance for the identification of atypical or milder forms of NMS, which are sometimes seen with atypical antipsychotic drugs.

Association Between Selective Serotonin-Reuptake Inhibitors, Second-Generation Antipsychotics, and Neuroleptic Malignant Syndrome

Objective

To review the published reports of neuroleptic malignant syndrome (NMS) associated with the use of selective serotonin-reuptake inhibitors (SSRIs) and second-generation antipsychotics.

Data Source:

Information was selected from a MEDLINE search of English-language literature (1950–May 2008). Manual search of all published cases indexed in MEDLINE (English language only) of NMS associated with second-generation antipsychotics was also performed.

Study Selection And Data Extraction:

Pertinent information from all reports obtained was included, with specific emphasis on patient age, sex, second-generation antipsychotic involved, SSRI or other antidepressant involved, time of onset of NMS symptoms in relation to medication changes, treatment administered, and outcome of the reaction.

Data Synthesis:

NMS has been reported with every second-generation antipsychotic agent. It is unclear whether concomitant therapy with other agents may increase the risk of NMS development via pharmacodynamic or pharmacokinetic mechanisms or both, The suggested pharmacodynamic mechanism for increased risk of NMS with concomitant use of SSRIs is the effect of serotonin on dopamine release. Serotonin further inhibits dopamine release and thereby may worsen a hypodopaminergic state induced by antipsychotics. Pharmacokinetic factors may also play a role in some NMS cases involving an SSRI by increasing antipsychotic concentrations. An examination of case reports seems to indícale that at least in some casos, a temporal relationship exists with the addition of an SSRI to existing antipsychotic therapy.

Conclusions:

The use of SSRIs may be associated with an increased risk of NMS development in (hose receiving second-generation antipsychotics. Clinicians should closely monitor patients for the potential development of NMS.