Clozapine, elevated heart rate and QTc prolongation

Evaluating Monitoring Guidelines of Clozapine-Induced Adverse Effects: a Systematic Review

BACKGROUND AND OBJECTIVES

Despite the evidence that no other antipsychotic is effective as clozapine for the treatment of resistant schizophrenia, it is associated with various metabolic, neuroendocrine, cardiovascular, and gastrointestinal adverse effects. Guidelines aiming to address the monitoring of clozapine's (serious) adverse effects can be helpful to prevent and treat these effects. However, many of these guidelines seem to lack one or more important monitoring recommendations. We aimed to systematically review the content and quality of existing monitoring guidelines/recommendations for clozapine-induced adverse effects.

METHODS

A comprehensive and systematic literature search, using the MEDLINE, Embase, Web of Science, and Cochrane databases, was conducted for guidelines/recommendations on the monitoring of clozapine-induced adverse events, published between January 2004 and April 2023 (last search 16 April 2023). Only peer-reviewed published guidelines reporting on the comprehensive monitoring of all major clozapine-induced adverse effects and including evidence-based recommendations, developed after the year 2004, were included. Studies reporting on the monitoring of adverse effects of clozapine without being a formal guideline, guidelines reporting on the monitoring of one or a limited number of adverse effects of clozapine, guidelines that were not peer reviewed or published, expert opinion papers without formal consensus guideline development, or guidelines developed before the year 2004, were excluded. The Appraisal of Guidelines for Research and Evaluation II (AGREE-II) tool was used to evaluate the guidelines/recommendations' quality.

RESULTS

Only one guideline met the inclusion criteria. This consensus statement made recommendations for hematological monitoring, and the monitoring of metabolic, cardiac, and three other adverse effects. Highest scores for the qualitative assessment were found for the domains "scope and purpose" (66.7%), "clarity of presentation" (44.4%), and "editorial independence" (66.7%). Lowest scores were found for "rigor of development" (14.6%) and "applicability" (0%).

CONCLUSIONS

Future guidelines should develop more comprehensive recommendations about specific clozapine-induced adverse effects, including constipation, myocarditis, tachycardia, and seizures, as well as include a rechallenge policy. There is an urgent need for well-developed, methodologically stringent, guidelines.

REGISTRATION

PROSPERO registration number, CRD42023402480.

Evaluation and Comparison of the Effectiveness of Atropine Eye Drops, Ipratropium Bromide Nasal Spray, and Amitriptyline Tablet in the Management of Clozapine-Associated Sialorrhea in Patients With Refractory Schizophrenia: A Randomized Clinical Trial

PURPOSE

Clozapine, a second-generation antipsychotic medication, is mainly indicated for managing treatment-resistant schizophrenia. Among all the nonthreatening adverse effects of clozapine, sialorrhea is a stigmatizing complication occurring in approximately 31.0% to 97.4% of patients. In this study, 2 topical agents (atropine eye drop and ipratropium nasal spray) and a systemic medication (amitriptyline) were compared simultaneously for the management of clozapine-associated sialorrhea.

METHODS

We conducted a randomized, single-blinded, non-placebo-controlled clinical trial from June 2022 to January 2023. Eligible patients were randomly allocated into 3 mentioned groups. Patients were monitored for sialorrhea weekly based on scales, including the Toronto Nocturnal Hypersalivation Scale, Clinical Global Impression-Improvement, and Clinical Global Impression-Severity for 1 month. Possible adverse drug reactions and adherence were also recorded.

RESULTS

Twenty-four patients, including 6, 10, and 8 individuals in ipratropium bromide nasal spray, atropine eye drop, and amitriptyline groups, completed the study, respectively. The cohort's demographic, baseline clinical, and sociocultural characteristics were comparable among the 3 groups. Within-group comparisons, between times baseline and week 4, demonstrated that significant differences were in groups atropine and amitriptyline based on Toronto Nocturnal Hypersalivation Scale, in 3 groups based on Clinical Global Impression-Improvement, and also in only-atropine group based on Clinical Global Impression-Severity. Likewise, between-group comparisons showed that atropine was significantly more effective in clozapine-associated sialorrhea management than amitriptyline and ipratropium, in the first 2 weeks and second 2 weeks of study, respectively. Regarding safety, the interventions were tolerated relatively well.

CONCLUSIONS

Conclusively, atropine is more efficacious than amitriptyline, within the first 2 weeks of study and also relative to ipratropium, overall. As time effect was significant between atropine and amitriptyline, according to analysis of covariance test, further investigation with longer follow-up duration would be prudent. In addition, expanding patient population with larger sample size should be conducted for more precision.

The impact of adjunctive aripiprazole on QT interval: A 12-week open label study in patients on olanzapine, clozapine or risperidone

OBJECTIVE

To evaluate the effect of adjunct aripiprazole on QT of patients clinically stabilized on atypical antipsychotics.

METHODS

The dataset was from an open-label 12-week prospective trial that evaluated adjunctive use of 5 mg/day of aripiprazole on metabolic profile in patients with schizophrenia, or schizoaffective disorder stabilized on olanzapine, clozapine, or risperidone. Bazett-corrected QT (QTc) was manually calculated from ECGs measured at baseline (before aripiprazole) and week 12, by two doctors blind to the diagnosis and atypical antipsychotic. The change in QTc (∆QTc: baseline QTc-week 12 QTc) and the number of participants in normal, borderline, prolonged, and pathological groups after 12 weeks were analyzed.

RESULTS

Fifty-five participants, mean age of 39.3 (SD 8.2) years, were analyzed. The ∆QTc after 12 weeks was 5.9 ms (p = 0.143) for the whole sample; 16.4 ms (p = 0.762), 3.7 ms (p = 0.480) and 0.5 ms (p = 0.449), for the clozapine, risperidone and olanzapine group, respectively. There was no significant statistical difference comparing the change in QTc overall, and between atypical antipsychotic groups, when evaluating from baseline to endpoint. However, stratifying the sample based on sex-dependent QTc cut-offs showed a 45% decrease in abnormal QTc readings (p = 0.049) after aripiprazole initiation; 20 subjects had abnormal QTc at baseline, while only 11 subjects had abnormal QTc at 12 weeks. 25.5% of participants showed a reduction in at least one QTc severity group, while 65.5% had no change and 9.0% worsened in QTc group, after 12 weeks of adjunct aripiprazole.

CONCLUSION

Low-dose adjunctive aripiprazole did not prolong QTc in patients stabilized on either olanzapine, risperidone, or clozapine. More controlled studies evaluating the QTc effect of adjunctive aripiprazole should be done to confirm and support these findings.

Homocysteine Levels and Clinical Outcomes in Schizophrenia—A Pilot Randomized Controlled Trial

Background:

There is an increasing need for proactive and individualized responses to various diseases in today’s progressive health-care fraternity. Accordingly, the approach to schizophrenia patients encompasses novel developments in the area of personalized medicine. Antipsychotic drugs in clinical practice necessitate biomarkers for the prediction of treatment outcomes and monitoring to ensure an appropriate choice of duration of chronic therapies. Hence, we studied the relation between homocysteine levels in peripheral blood and the effectiveness as well as the safety of haloperidol and olanzapine in schizophrenia treatment.

Materials and Methods:

A prospective randomized parallel-group open-label interventional clinical trial was conducted on 40 mild to moderate schizophrenia patients. To compare the efficacy of olanzapine and haloperidol Brief Psychiatric Rating Scale (BPRS) score was used. Homocysteine levels of peripheral blood and Abnormal Involuntary Movement Scale scores were evaluated.

Results:

BPRS score improved in both groups on day 14 and day 28. But significantly more with olanzapine ( P value =.001). The olanzapine group showed a higher reduction (13.91±0.47 to 9.74±0.5) in homocysteine levels than the haloperidol group. Also, the BPRS scores negatively correlated ( r = –0.66) to homocysteine levels.

Conclusion:

Therefore, our study shows that peripheral blood homocysteine levels can be used to predict and assess the treatment outcome in schizophrenia patients. Biomarker driven approach in schizophrenia will allow the patients to be treated promptly with the right drug. In this light, personalized treatment holds great potential in the future.

Efficacy of long-acting injectable versus oral antipsychotic drugs in early psychosis: A systematic review and meta-analysis

AIM

Long-acting injectable antipsychotic drugs (LAIs) are often used as an alternative to oral antipsychotics (OAPs) in individuals with psychosis who demonstrate poor medication adherence. Previous meta-analyses have found mixed results on the efficacy of LAIs, compared to OAPs, in patients with psychotic disorders. The objective of this meta-analysis was to compare the effectiveness of using LAIs versus OAPs in the early stages of psychosis.

METHODS

Major electronic databases were used to search for any studies examining the comparative effectiveness (i.e., relapse, adherence, hospitalization, and all-cause discontinuation) of any LAIs versus OAPs in early stages of psychosis. Studies published up to 6 June, 2019 were included and no language restriction was applied. Inclusion criteria were a diagnosis of schizophrenia or related disorder, where patients were in their first episode or had a duration of illness ≤5 years. Data were analysed using a random-effects model.

RESULTS

Fifteen studies (n = 10 584) were included, of which were 7 RCTs, 7 observational studies, and 1 post-hoc analysis. We found that LAIs provided advantages over OAPs in terms of relapse rates. No significant differences were found between LAI and OAP groups in terms of all-cause discontinuation, hospitalization, and adherence rates. However, considering only RCTs revealed advantages of LAIs over OAPs in terms of hospitalization rates.

CONCLUSIONS

LAIs may provide benefits over OAPs with respect to reducing relapse and hospitalization rates in early psychosis patients. There is a need for larger and better-designed studies comparing OAPs and LAIs specifically in early psychosis patients.

Antipsychotic Drug-Induced Increases in Peripheral Catecholamines are Associated With Glucose Intolerance

The second-generation antipsychotic drugs are widely used in the field of psychiatry, for an expanding number of different conditions. While their clinical efficacy remains indispensable, many of the drugs can cause severe metabolic side-effects, resulting in an increased risk of developing cardiometabolic disorders. The physiological basis of these side-effects remains an ongoing area of investigation. In the present study, we examined the potential role of peripheral catecholamines in antipsychotic-induced glucose intolerance. Adult female rats were acutely treated with either the first-generation antipsychotic drug haloperidol (0.1, 0.5 or 1 mg/kg) or the second-generation drugs risperidone (0.25, 1.0 or 2.5 mg/kg), olanzapine (1.5, 7.5 or 15 mg/kg) or clozapine (2, 10 or 20 mg/kg) or vehicle. Fasting glucose levels were measured and then animals were subjected to the intraperitoneal glucose tolerance test. Levels of peripheral norepinephrine, epinephrine and dopamine were concurrently measured in the same animals 75, 105 and 135 min after drug treatment. All antipsychotics caused glucose intolerance, with strongest effects by clozapine > olanzapine > risperidone > haloperidol. Plasma catecholamines were also increased by drug treatment, with greatest effects for norepinephrine and epinephrine caused by clozapine > risperidone > olanzapine > haloperidol. Importantly, there were strong and statistically significant associations between norepinephrine/epinephrine levels and glucose intolerance for all drugs. These findings confirm that increases in peripheral catecholamines co-occur in animals that exhibit antipsychotic-induced glucose intolerance, and these effects are strongly associated with each other, providing further evidence for elevated catecholamines as a substrate for antipsychotic metabolic side-effects.

Estimation of cardiac QTc intervals in people prescribed antipsychotics: a comparison of correction factors

BACKGROUND

A prolonged electrocardiogram (ECG) QT interval is associated with cardiac events and increased mortality. Antipsychotics can prolong the QT interval. The QT interval requires correction (QTc) for heart rate using a formula or QT-nomogram. The QT and QTc can be calculated automatically by the ECG machine or manually; however, machine-measured QT(c) intervals may be inaccurate.

OBJECTIVE

We aimed to investigate the mean QTc and proportion of prolonged QTc intervals in people taking antipsychotic medicines.

METHODS

We conducted an observational retrospective chart review and data analysis of all consecutive patients taking antipsychotics, with an ECG record, admitted to the psychiatric unit of a large tertiary hospital in Brisbane, Australia, between 1 January 2017 and 30 January 2019. We investigated the mean QTc of people taking antipsychotics to determine differences using (a) machine versus manual QT interval measurement and (b) QTc correction formulae (Bazett, Fridericia, Framingham, Hodges and Rautaharju) and the QT-nomogram. We also determined the number of people with a prolonged QTc using different methods and compared rates of prolonged QTc with antipsychotic monotherapy and polypharmacy.

RESULTS

Of 920 included people, the mean (±SD) machine-measured, Bazett-corrected QT interval (recorded from the ECG) was 435 ms (±27), significantly longer (p < 0.001) than the mean manually measured corrected QT intervals with Fridericia 394 ms (±24), Framingham 395 ms (±22), Hodges 398 ms (±22) and Rautaharju 400 ms (±24) formulae. There were significantly more people with a prolonged QTc using machine-measured QT and the Bazett formula (12.0%, 110/920) when compared with manually measured QT and the Fridericia formula (2.2%, 20/920) or QT-nomogram (0.7%, 6/920). Rates of QTc prolongation did not differ between people taking antipsychotic polypharmacy compared with monotherapy.

CONCLUSION

Machine-measured QTc using the Bazett formula overestimates the QTc interval length and number of people with a prolonged QTc, compared with other formulae and the QT-nomogram. We recommend manually measuring the QT and correcting with the Fridericia formula or QT-nomogram prior to modifying antipsychotic therapies.

Relationship between clozapine dose and severity of obsessive-compulsive symptoms

Evidence supports the fact that clozapine can induce stressful obsessive-compulsive symptoms (OCS). Although clozapine's robust inhibition of serotonergic neurotransmission is believed to be a key mechanism underlying clozapine-induced OCS, the exact mechanism(s) are not fully understood. Intuitively, it is reasonable to believe that the dose of clozapine is likely related to emergent OCS severity. However, there is conflicting evidence where both positive and inverse relationships have been demonstrated between clozapine dose and emergent OCS severity. Upon examination of clozapine's receptor profile, in particular its affinity for 5-HT_2A and D₂ receptors, we hypothesize that there is a biphasic relationship between clozapine dose and emergent OCS severity. We present here a preliminary analysis of published cases in the literature to support our hypothesis.

QTc Interval Prolongation with Therapies Used to Treat Patients with Parkinson's Disease Psychosis: A Narrative Review

In addition to the classic motor symptoms of Parkinson's disease (PD), people with PD frequently experience nonmotor symptoms that can include autonomic dysfunction and neuropsychiatric symptoms such as PD psychosis (PDP). Common patient characteristics, including older age, use of multiple medications, and arrhythmias, are associated with increased risk of corrected QT interval (QTc) prolongation, and treatments for PDP (antipsychotics, dementia medications) may further increase this risk. This review evaluates how medications used to treat PDP affect QTc interval from literature indexed in the PubMed and Embase databases. Although not indicated for the treatment of psychosis, dementia therapies such as donepezil, rivastigmine, memantine, and galantamine are often used with or without antipsychotics and have minimal effects on QTc interval. Among the antipsychotics, data suggesting clinically meaningful QTc interval prolongation are limited. However, many antipsychotics have other safety concerns. Aripiprazole, olanzapine, and risperidone negatively affect motor function and are not recommended for PDP. Quetiapine is often sedating, can exacerbate underlying neurogenic orthostatic hypotension, and may prolong the QTc interval. Pimavanserin was approved by the US Food and Drug Administration (FDA) in 2016 and remains the only FDA-approved medication available to treat hallucinations and delusions associated with PDP. However, pimavanserin can increase QTc interval by approximately 5-8 ms. The potential for QTc prolongation should be considered in patients with symptomatic cardiac arrhythmias and those receiving QT-prolonging medications. In choosing a medication to treat PDP, expected efficacy must be balanced with potential safety concerns for individual patients.

A Focused Review of the Metabolic Side-Effects of Clozapine

The second generation antipsychotic drug clozapine represents the most effective pharmacotherapy for treatment-resistant psychosis. It is also associated with low rates of extrapyramidal symptoms and hyperprolactinemia compared to other antipsychotic drugs. However, clozapine tends to be underutilized in clinical practice due to a number of disabling and serious side-effects. These are characterized by a constellation of metabolic side-effects which include dysregulation of glucose, insulin, plasma lipids and body fat. Many patients treated with clozapine go on to develop metabolic syndrome at a higher rate than the general population, which predisposes them for Type 2 diabetes mellitus and cardiovascular disease. Treatments for the metabolic side-effects of clozapine vary in their efficacy. There is also a lack of knowledge about the underlying physiology of how clozapine exerts its metabolic effects in humans. In the current review, we focus on key studies which describe how clozapine affects each of the main symptoms of the metabolic syndrome, and cover some of the treatment options. The clinical data are then discussed in the context of preclinical studies that have been conducted to identify the key biological substrates involved, in order to provide a better integrated overview. Suggestions are provided about key areas for future research to better understand how clozapine causes metabolic dysregulation.

Antipsychotic prescribing patterns on admission to and at discharge from a tertiary care program for treatment-resistant psychosis

Retrospective data were collected from 330 individuals who were treated at a tertiary care program for treatment-resistant psychosis between 1994 and 2010. The main objectives were to compare the use of antipsychotic monotherapy to polypharmacy and to characterize within-individual changes in treatment and symptomatology between admission and discharge. At admission, individuals who were prescribed only one antipsychotic were comparable to those who were prescribed at least two antipsychotics with regard to demographics and symptom severity. The use of psychotropic medications other than antipsychotics was also similar between the two groups. However, the magnitude of antipsychotic utilization was greater in individuals who were receiving antipsychotic polypharmacy. In addition, a greater proportion received excessive doses at admission. Similar findings were observed when the two antipsychotic prescribing practices were compared at discharge. Three important patterns were identified when investigating within-individual changes. First, fewer individuals were prescribed more than one antipsychotic at discharge. This was accompanied by a general decrease in the magnitude of antipsychotic utilization. Second, the number of individuals who were prescribed clozapine had increased by discharge. Most who were already prescribed clozapine at admission had their doses increased. Third, improvements in symptomatology were observed across all of the subscales included in the Positive and Negative Symptom Scale (PANSS); 57.9% of individuals experienced a relative reduction in total PANSS scores exceeding 20%. Based on these findings, it is possible to alleviate symptom severity while reducing antipsychotic utilization when patients are treated at a tertiary care program for treatment-resistant psychosis.

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.