Anticholinergic differences among patients receiving standard clinical doses of olanzapine or clozapine

A quality improvement program for managing clozapine-induced constipation in a long-term structured residential setting for persons with serious mental illness

OBJECTIVES

The goal of this quality improvement project (QIP) was to increase awareness of the serious medical consequences of clozapine-associated constipation to front line nursing staff and patients with schizophrenia.

METHODS

The QIP was developed iteratively by psychiatric nurses, psychiatrists and pharmacists with input from patients. The processes involved a literature review, development of educational materials for staff and patients, and the creation of a daily bowel movements log (BML). Implementation involved review of the BML at treatment team meetings, and deployment of pharmacological and non-pharmacological interventions to resolve constipation and increase awareness and knowledge of this clinical concern.

OUTCOMES

The initial pilot screened for symptoms of constipation in patients receiving clozapine and non-clozapine antipsychotic agents and intervening as necessary during multidisciplinary team meetings. Patients benefited from relief of constipation and improved bowel habits. Staff benefited from improved knowledge and making requisite changes in workflow and practice. Feedback allowed refinements to be made to the educational materials for patients and staff. Since full implementation, bowel habits are routinely monitored, and interventions are reviewed for effectiveness. Staff satisfaction with this QIP is reflected in answers to a structured questionnaire and in patient reports (n = 50).

CONCLUSIONS

Clozapine, the only approved and efficacious medication for treatment-resistant schizophrenia is significantly underutilized. Medically consequential constipation can be a serious barrier to retention of patients benefiting from clozapine. Increased awareness and use of educational materials for patients and staff, routine monitoring of bowel habits combined with pharmacological and non-pharmacological interventions can successfully address this clinical problem.

Management of Cholinergic Rebound After Abrupt Withdrawal of Clozapine: A Case Report and Systematic Literature Review

BACKGROUND

Cholinergic discontinuation symptoms, also known as "cholinergic rebound," from abrupt clozapine discontinuation are characterized by a range of somatic and psychiatric symptoms.

OBJECTIVE

The objective of this study was to describe the clinical features and management options for clozapine withdrawal-associated cholinergic rebound syndrome (henceforth referred to as CWCRS) and present an illustrative case report.

METHODS

Based on a literature search of the databases PubMed, OVID Medline, and Embase as well as reviewing reference lists of relevant past reviews, we carried out a systematic review of case reports on the management of CWCRS from 1946 to 2023.

RESULTS

We identified 10 previously published articles on the clinical management of CWCRS, with a total of 18 patients (6 female, 12 male) with an average age of 43 years (standard deviation 14). Half of the patients had a history of tardive dyskinesia. The mean dose of clozapine before discontinuation was 351 mg/day, with duration of clozapine treatment ranging from 3 weeks to 9 years. Clozapine was the most effective treatment, followed by benztropine.

CONCLUSIONS

Given the small number of cases and the nonexperimental nature of the available studies, this review could not provide reliable data to guide management of CWCRS. The findings, however, suggest that clozapine may be more effective than other commonly used treatment options. With the high rates of discontinuation among patients on clozapine, there is a pressing need for further research into the epidemiology, natural history, and management of clozapine withdrawal syndromes.

Pharmacological interventions for antipsychotic-related sialorrhea: a systematic review and network meta-analysis of randomized trials

Antipsychotic-induced sialorrhea carries a significant burden, but evidence-based treatment guidance is incomplete, warranting network meta-analysis (NMA) of pharmacological interventions for antipsychotic-related sialorrhea. PubMed Central/PsycInfo/Cochrane Central database/Clinicaltrials.gov/WHO-ICTRP and the Chinese Electronic Journal Database (Qikan.cqvip.com) were searched for published/unpublished RCTs of antipsychotic-induced sialorrhea (any definition) in adults, up to 06/12/2023. We assessed global/local inconsistencies, publication bias, risk of bias (RoB2), and confidence in the evidence, conducting subgroup/sensitivity analyses. Co-primary efficacy outcomes were changes in saliva production (standardized mean difference/SMD) and study-defined response (risk ratios/RRs). The acceptability outcome was all-cause discontinuation (RR). Primary nodes were molecules; the mechanism of action (MoA) was secondary. Thirty-four RCTs entered a systematic review, 33 NMA (n = 1958). All interventions were for clozapine-induced sialorrhea in subjects with mental disorders. Regarding individual agents and response, metoclopramide (RR = 3.11, 95% C.I. = 1.39-6.98), cyproheptadine, (RR = 2.76, 95% C.I. = 2.00-3.82), sulpiride (RR = 2.49, 95% C.I. = 1.65-3.77), propantheline (RR = 2.39, 95% C.I. = 1.97-2.90), diphenhydramine (RR = 2.32, 95% C.I. = 1.88-2.86), benzhexol (RR = 2.32, 95% C.I. = 1.59-3.38), doxepin (RR = 2.30, 95% C.I. = 1.85-2.88), amisulpride (RR = 2.23, 95% C.I. = 1.30-3.81), chlorpheniramine (RR = 2.20, 95% C.I. = 1.67-2.89), amitriptyline (RR = 2.09, 95% C.I. = 1.34-3.26), atropine, (RR = 2.03, 95% C.I. = 1.22-3.38), and astemizole, (RR = 1.70, 95% C.I. = 1.28-2.26) outperformed placebo, but not glycopyrrolate or ipratropium. Across secondary nodes (k = 28, n = 1821), antimuscarinics (RR = 2.26, 95% C.I. = 1.91-2.68), benzamides (RR = 2.23, 95% C.I. = 1.75-3.10), TCAs (RR = 2.23, 95% C.I. = 1.83-2.72), and antihistamines (RR = 2.18, 95% C.I. = 1.83-2.59) outperformed placebo. In head-to-head comparisons, astemizole and ipratropium were outperformed by several interventions. All secondary nodes, except benzamides, outperformed the placebo on the continuous efficacy outcome. For nocturnal sialorrhea, neither benzamides nor atropine outperformed the placebo. Active interventions did not differ significantly from placebo regarding constipation or sleepiness/drowsiness. Low-confidence findings prompt caution in the interpretation of the results. Considering primary nodes' co-primary efficacy outcomes and head-to-head comparisons, efficacy for sialorrhea is most consistent for the following agents, decreasing from metoclopramide through cyproheptadine, sulpiride, propantheline, diphenhydramine, benzhexol, doxepin, amisulpride, chlorpheniramine, to amitriptyline, and atropine (the latter not for nocturnal sialorrhea). Shared decision-making with the patient should guide treatment decisions regarding clozapine-related sialorrhea.

Cholinergic Functioning, Cognition, and Anticholinergic Medication Burden in Schizophrenia

Acetylcholine (ACh) signaling is critical for central nervous function and is known to be abnormal in schizophrenia (SZ), a chronic neuropsychiatric disorder in which cognitive deficits persist, despite treatment. This review provides a summary of the clinical evidence linking ACh abnormalities to SZ-associated cognitive deficits, an overview of ACh-based pro-cognitive strategies attempted in SZ, and a survey of recent studies that describe the impact of anticholinergic medication burden on cognitive outcomes in SZ. Methodological challenges that currently limit more substantial investigation of ACh in SZ patients and future directions are also discussed.

Hemodynamic and white blood cells parameters in patients with first-episode psychosis: a pilot longitudinal study

OBJECTIVE

Patients with schizophrenia are at higher risk of cardiovascular (CVS) related mortality. Close attention is being paid to the clinical utility of readily available CVS markers.

METHODS

A pilot one-year longitudinal study in inpatients with first-episode psychosis (FEP) was carried out to determine markers of inflammation and endothelial dysfunction (monocyte- and neutrophil-to-lymphocyte ratios) and basal blood pressure, pulse, and derived hemodynamic parameters (PP: pulse pressure; RPP: rate pressure product; and MAP: mean arterial pressure).

RESULTS

After one year, PP and RPP increased, as did systolic blood pressure and heart rate. Systolic blood pressure, PP, total white blood cells, and neutrophils correlated with weight gain. After one year, correlations between monocyte-to-lymphocyte ratio and RPP and MAP were observed.

CONCLUSION

Our study indicates worsening CVS health over the first year of treatment and emphasises the importance of early monitoring of CVS status using easily accessible parameters to prevent CVS-related mortality.Key pointsPatients with schizophrenia are at higher risk of cardiovascular mortality.The CVS risk could be evaluated using affordable, routinely available CVS markers such as monocyte- and neutrophil-to-lymphocyte ratios, blood pressure, and pulse together with the derived parameters.Our pilot study in first-episode psychosis patients indicates worsening of CVS health based on these parameters during the first year of treatment, the early monitoring of CVS status is highly relevant in clinical practice.

Clozapine and Constipation: A Review of Clinical Considerations and Treatment Options

Psychosis, a break in reality which is manifested as hallucinations, delusions or the disruption in thought process, is the hallmark of schizophrenia. Despite novel pharmacotherapy advancements of antipsychotic medications that have resulted in some patients having the ability to return to social settings and thereby decreasing psychotic symptoms and reducing hospital admissions, there is still a sub-population of patients who remain symptomatic. Treatment-resistant schizophrenia is defined as failure of treatment with at least two different antipsychotics with the proper length of treatment and titration. Clozapine has been heralded as a drug to resolve the puzzle of treatment-resistant schizophrenia. Clozapine has one side effect that is well known, being the development of agranulocytosis. However, there is another side effect that can limit clozapine’s use and can also be life-threatening. Recently, at the end of January 2020, the FDA issued a communications statement which “[strengthened] an existing warning that constipation caused by the schizophrenia medicine clozapine can, uncommonly, progress to serious bowel complications.” After identifying ten cases of constipation from between 2006 to 2016 that progressed to hospitalization, surgery, and even death, the FDA focused their attention on this often overlooked, common side effect, especially when considering the strong anticholinergic effects of clozapine. Although patients are screened by their physicians for agranulocytosis by weekly lab monitoring, constipation is also a complication that needs to be identified and treated. Much like opioid-induced constipation, constipation can also be reduced with the use of laxatives and reduction in the co-prescribing of anticholinergic therapies with clozapine.

Clozapine: why wait to start a laxative?

Clozapine, the antipsychotic of choice for treatment-resistant schizophrenia, has a number of side-effects, some of which are potentially life-threatening. Historically viewed as a relatively minor side-effect, there is increasing awareness of the potentially severe sequalae of constipation secondary to clozapine-induced gastrointestinal hypomotility (CIGH). These include ileus, intestinal obstruction, bowel ischaemia, gastrointestinal necrosis, toxic megacolon and death. CIGH is significantly more common than clozapine-induced blood dyscrasias and has a higher mortality rate. Although strict criteria must be followed to assertively monitor, detect and treat blood dyscrasias in patients taking clozapine, no such framework exists for CIGH. We recommend that prescribing guidelines, regulatory agencies and information from manufacturers should more clearly highlight the risks identified in the literature. Furthermore, we recommend that, in people taking clozapine, constipation should be prevented by prophylactic treatment with laxatives rather than treated only when clinically identified.

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Prevalence and Factors Associated With Clozapine-Related Constipation: An Observational Study

BACKGROUND

Despite being a very effective treatment for resistant schizophrenia and bipolar disorder, use of clozapine is limited by adverse effects. Constipation is a common but potentially life-threatening adverse effect of clozapine that is understudied. The objective was to study the prevalence and factors associated with constipation in those receiving clozapine compared with control subjects.

METHODS

Fifty patients in age group of 18 to 55 years receiving clozapine were compared with 50 patients in the same age group receiving medications other than clozapine. Presence of constipation was ascertained using the World Gastroenterology Organization Practice Guidelines definition. The severity of constipation was assessed using Constipation Assessment Scale and Bristol Stool Form Scale, and anticholinergic burden was assessed using Anticholinergic Burden Scale.

RESULTS

Among clozapine-treated patients, 28 (56%) had constipation as compared with 11 (22%) in the control subjects (P < 0.001); the odds of developing constipation was 4.5 (95% confidence interval, 1.9-10.8). Kaplan-Meier survival analysis showed median time to onset of constipation in clozapine-treated patients was 60 days (SE, 13.1 days; 95% confidence interval, 34.3-85.7 days) and median dose of clozapine was 300 mg/d (interquartile range, 312 mg/d). Clozapine group had high Constipation Assessment Scale scores (P = 0.005, Cohen d = 1.17) and higher prevalence of types 1 and 2 Bristol stool types (Fisher exact P = 0.005, Cramer V = 0.59).

CONCLUSIONS

Constipation was prevalent in more than half of patients receiving clozapine, which was severe and took longer time for recovery. Limitations include using a hospital-based sample and that dietary habits and lifestyle factors were not studied.

Tachycardia in patients treated with clozapine versus antipsychotic long-acting injections

Tachycardia is a known adverse effect during clozapine treatment. However, prevalence reported differs widely between studies and hitherto there are no studies comparing clozapine-treated patients with a similar control group. The present study was carried out to assess the prevalence of tachycardia in patients treated with clozapine and antipsychotic long-acting injections (LAI). Data on heart rate (HR), concomitant medication, and relevant anthropometric and laboratory measurements were collected for all clozapine-treated patients (n=174) in a defined catchment area and compared with data on patients treated with LAI (n=87). In total, 33% of patients on long-term clozapine treatment had tachycardia (HR>100) compared with 16% in the LAI group (P<0.001). The mean HR was 91 in the clozapine group and 82 in the LAI group (P<0.001). Clozapine dose correlated with HR. The majority of patients with HR more than 100 received no specific treatment for tachycardia. In conclusion, the prevalence of tachycardia was twice as high in patients treated with clozapine as in a similar patient group with severe schizophrenia spectrum disorder. The tachycardia was in many cases clinically unnoticed. Tachycardia during antipsychotic treatment is a common phenomenon that must be monitored for actively and, when noticed, further investigated and treated.

Clozapine induced gastrointestinal hypomotility: A potentially life threatening adverse event. A review of the literature

OBJECTIVE

The haematological and cardiac complications of clozapine have been well documented. Recent evidence from pharmacovigilance databases suggests that gastrointestinal (GI) complications are the leading cause of clozapine related deaths. This review aims to describe clinical features along with preventative and treatment options.

METHOD

A review of MEDLINE via PubMed searching for all articles published up to February of 2016. Inclusion criteria were articles that provided clinical or epidemiological information relating to the diagnosis, outcome, management or pathophysiology of clozapine related gastrointestinal disorders in humans.

RESULTS

Three large case series were identified with 104 cases, 20 of these reported clinical details. A further 52 cases reports were included. Median age was 40, with 79% being male, mean daily clozapine dose was 453 mg. Mortality was 38% with survivors being younger (39 vs. 42), on lower daily doses (400 mg vs. 532 mg), more likely to be female (32% vs. 6%). Four patients were re-challenged with clozapine following CIGH, two suffered a recurrence.

CONCLUSION

Risk factors for CIGH appear to be older age, male gender, patients in the first four months of treatment, co-prescription of constipating agents, higher daily dose of clozapine, and previous CIGH. Risk factors for death were older age and male gender. Patients receiving clozapine should be counselled about the dangers of constipation and to report new GI symptoms. Once severe CIGH has occurred clozapine should be halted and reviewed with bowel symptoms managed promptly. Re-challenging with clozapine may present substantial risks due to the severity of CIGH and a paucity of evidence. From the available evidence a treatment strategy has been proposed. Further prospective data regarding CIGH are needed to allow a better assessment of the scale of the problem with the development and testing of treatment strategies.

Prevalence and Predictors of Clozapine-Associated Constipation: A Systematic Review and Meta-Analysis

Constipation is a frequently overlooked side effect of clozapine treatment that can prove fatal. We conducted a systematic review and meta-analysis to estimate the prevalence and risk factors for clozapine-associated constipation. Two authors performed a systematic search of major electronic databases from January 1990 to March 2016 for articles reporting the prevalence of constipation in adults treated with clozapine. A random effects meta-analysis was conducted. A total of 32 studies were meta-analyzed, establishing a pooled prevalence of clozapine-associated constipation of 31.2% (95% CI: 25.6-37.4) (n = 2013). People taking clozapine were significantly more likely to be constipated versus other antipsychotics (OR 3.02 (CI: 1.91-4.77), p < 0.001, n = 11 studies). Meta-regression identified two significant study-level factors associated with constipation prevalence: significantly higher (p = 0.02) rates of constipation were observed for those treated in inpatient versus outpatient or mixed settings and for those studies in which constipation was a primary or secondary outcome measure (36.9%) compared to studies in which constipation was not a specified outcome measure (24.8%, p = 0.048). Clozapine-associated constipation is common and approximately three times more likely than with other antipsychotics. Screening and preventative strategies should be established and appropriate symptomatic treatment applied when required.

Influence of Antipsychotic and Anticholinergic Loads on Cognitive Functions in Patients with Schizophrenia

Many patients with schizophrenia show cognitive impairment. There is evidence that, beyond a certain dose of antipsychotic medication, the antipsychotic daily dose (ADD) may impair cognitive performance. Parallel to their D2 receptor antagonism, many antipsychotics show a significant binding affinity to cholinergic muscarinic receptors. Pharmacological treatment with a high anticholinergic daily dose (CDD) significantly impairs attention and memory performance. To examine the relationships between individual cognitive performance and ADD and/or CDD, we conducted a retrospective record-based analysis of a sample of n = 104 in patients with a diagnosis of schizophrenia, all of whom had completed a comprehensive neuropsychological test battery. To calculate the individual ADD and CDD, the medication at the time of testing was converted according to equivalence models. After extracting five principal cognitive components, we examined the impact of ADD and CDD on cognitive performance in the medicated sample and subgroups using multiple regression analysis. Finally, locally weighted scatterplot smoothing (Loess) was applied to further explore the course of cognitive performance under increasing dosage. Results showed significant negative effects of ADD on performance in tests of information processing speed and verbal memory. No effects were found for CDD. The potential neuropsychopharmacological and clinical implications are discussed.

Olanzapine-induced ischemic colitis

Ischemic colitis (IC) is an uncommon adverse event associated with antipsychotic agents, more commonly found with phenothiazine drugs and atypical neuroleptics such as clozapine. The risk of developing ischemic colitis increases when anticholinergic drugs are associated. We report the case of a 38-year-old woman with a history of schizoaffective disorder who had been on chronic quetiapine for 3 years, and presented to the ER because of diarrhea for 5 days. Four months previously, olanzapine had been added to her psychiatric drug regimen. Physical examination revealed abdominal distension with abdominal tympanic sounds and tenderness. Emergency laboratory tests were notable for increased acute phase reagents. Tomography revealed a concentric thickening of the colonic wall in the transverse, descending and sigmoid segments, with no signs of intestinal perforation. Colonoscopy demonstrated severe mucosal involvement from the sigmoid to the hepatic flexure, with ulcerations and fibrinoid exudate. Biopsies confirmed the diagnosis of ischemic colitis. The only relevant finding in her history was the newly added drug to her baseline regimen. An adverse effect was suspected because of its anticholinergic action at the intestinal level, and the drug was withdrawn. After 6 months of follow-up clinical, laboratory and endoscopic recovery was achieved. Therefore, antipsychotic medication should be considered as a potential cause of ischemic colitis, particularly atypical antipsychotics such as clozapine and olanzapine; despite being uncommon, this adverse event may result in high morbidity and mortality.

Saliva secretion disorder in a schizophrenic patient - a problem in dental and psychiatric treatment: a case report

OBJECTIVE

Saliva secretion disorder may appear in patients at any age and represents a serious problem in interdisciplinary treatment. It is manifested by hyposecretion or hypersecretion of saliva. One of the major groups of patients who have been diagnosed with saliva secretion disorder includes those treated with neuroleptics. Among patients taking neuroleptics, schizophrenic patients represent the least cooperative group in terms of doctor-patient relationship. Schizophrenia is a mental disorder exacerbated by uncontrolled neuroleptic dose reduction or regardless of applied pharmacotherapy.

METHOD

This paper presents a clinical case of a 30-year-old schizophrenic patient with saliva secretion problems.

RESULTS

In schizophrenia, thought disorders (TD) and social functioning impairment have a negative impact on patients' somatic health care. Saliva hyposecretion and its health consequences, such as parodontitis and caries, are the reasons why the patients decide to have a dental appointment.

CONCLUSION

This paper contains important information for dentists, psychiatrists, and psychologists, as it raises an issue of a proper interdisciplinary care approach provided to schizophrenic patients. It emphasises the importance of psychoeducation and draws attention to social functioning of mentally ill patients.

Clozapine-associated pneumonia and respiratory arrest secondary to severe constipation

Clozapine is often the drug of choice within patients suffering from treatment-resistant paranoid schizophrenia. It has a complex side effects profile which includes potentially fatal agranulocytosis. Clozapine has also become increasingly associated with a range of other side effects including constipation and pneumonia. We report on a case of clozapine-induced severe constipation leading to a silent presentation of pneumonia with a subsequent respiratory arrest. To our knowledge, this is the first case report of pneumonia secondary to severe constipation occurring in the absence of respiratory aspiration of feculent vomitus. We suggest a new pathological mechanism by way of severe constipation leading to diaphragmatic dysfunction and subsequent clozapine-induced pneumonia. In addition, implications for clinical practice are outlined.

Olanzapine and benztropine as a cause of ischemic colitis in a 27-year-old man

Ischemic colitis is a rare adverse effect of antipsychotic medications and is most commonly associated with the phenothiazine class of antipsychotics and atypical antipsychotics such as clozapine and olanzapine. The risk is further increased when antipsychotics are taken in conjunction with anticholinergics. A 27-year-old man with a history of bipolar disorder and depression presented to the emergency department with 6 days of constipation, abdominal pain, nausea, and nonbloody vomiting. He later developed multiple episodes of hematochezia and fever. Within the preceding 2 weeks, his medication regimen of divalproex sodium, aripiprazole, and trihexyphenidyl, had been changed to olanzapine, benztropine, and bupropion. The patient's physical examination showed diffuse abdominal tenderness, guarding, and distension and laboratory tests revealed a leukocytosis. A computed tomographic scan of the abdomen/pelvis showed colitis extending from the splenic flexure to the sigmoid colon, without evidence of perforation. A colonoscopy revealed severe ischemic colitis involving the descending and sigmoid colon, which was confirmed on biopsy. Given the temporal association between the new medications and onset of symptoms, the patient's ischemic colitis was likely caused by olanzapine or the combination of olanzapine and benztropine, likely secondary to their anticholinergic properties. Thus, providers should take a thorough history and counsel patients regarding the risks of constipation when starting antipsychotic medications, particularly those with anticholinergic activity. Despite the fact that ischemic colitis is such a rare adverse effect of antipsychotic medications, it is important to consider because of its potentially fatal outcomes.

Risk factors for ileus in patients with schizophrenia

Constipation is a known side effect of psychotropics that possess high affinity for muscarinic cholinergic receptors. In severe cases, constipation progresses to ileus and bowel ischemia, with multiple fatalities related to sepsis and perforation described in the literature, primarily among patients with schizophrenia. A historical prospective database study was performed using registry data from psychiatric and somatic hospitals, combined with the prescription database to examine associations between medications and ileus. Only cases with an ICD-10 diagnosis of schizophrenia (F20) and a concurrent diagnosis of ileus in the years 1996-2007 were included in the study. A total of 26,720 patients with schizophrenia were identified with 123 cases of ileus noted in the study period. Increasing age (OR: 1.03 CI: 1.01-1.04) and female sex (OR: 1.60 CI: 1.10-2.31) were associated with an increased risk of ileus. Treatment with clozapine (OR: 1.99 CI: 1.21-3.29), high-potency first-generation antipsychotics (OR: 1.81 CI: 1.01-3.23), tricyclic antidepressants (OR: 2.29 CI: 1.29-4.09), anticholinergics (OR: 1.48 CI: 1.00-2.19), and opioids (OR: 2.14 CI: 1.36-3.36) were associated with an increased risk of ileus. The onset of ileus occurred on average more than 3 years after the first prescription of the offending drug. Aripiprazole and amisulpride were not associated with ileus. Nine of the ileus cases (7.3%) had a fatal course. Treatment with clozapine (OR: 6.73 CI: 1.55-29.17) or anticholinergics (OR: 5.88 CI: 1.47-23.58) were associated with increased risk of fatal ileus. Patients receiving psychotropics associated with significant anticholinergic properties should undergo proper monitoring and interventions in order to minimize the burden of constipation and the risk of ileus.

Augmenting clozapine with sertindole: a double-blind, randomized, placebo-controlled study

Clozapine augmentation with antipsychotic drugs is widely used despite sparse evidence supporting this strategy. Sertindole is a nonsedating atypical antipsychotic drug with low affinity for cholinergic receptors, which makes it potentially suitable for augmentation of clozapine. The study design was a 12-week, double-blind, randomized, placebo-controlled study including patients with International Statistical Classification of Diseases, 10th Revision schizophrenia (F20.0-F20.3) and treated with clozapine for at least 6 months who had not achieved sufficient response. Patients were randomized 1:1 to either sertindole 16 mg or placebo, and assessment was done at baseline and after 6 and 12 weeks. Assessment included the Positive and Negative Syndrome Scale, Clinical Global Impression, Udvalg for Kliniske Undersøgelser, World Health Organization Quality of Life Brief, Drug Attitude Inventory, fasting glucose, lipids, and electrocardiogram. Clozapine augmentation with sertindole was not superior to placebo regarding total score or subscale score of the Positive and Negative Syndrome Scale, Clinical Global Impression, World Health Organization Quality of Life Brief, or Drug Attitude Inventory. No increased adverse effects compared with placebo were found. Four patients randomized to sertindole experienced a significant worsening of psychosis, and 2 of them required psychiatric admission. Metabolic parameters were unchanged during the study, but augmentation of clozapine with sertindole was associated with a 12-millisecond (SD, 20-millisecond) QTc prolongation compared with 0 millisecond (SD, 20 milliseconds) in the placebo group (P < 0.03). Augmentation with sertindole showed no benefits compared with placebo. Psychiatrists should be aware that augmentation might not add any benefits for the patients and in some cases worsen psychosis.

Pharmacotherapy for treatment-resistant schizophrenia

Schizophrenia is a disabling mental illness with a lifetime prevalence of 0.7% worldwide and significant, often devastating, consequences on social and occupational functioning. A range of antipsychotic medications are available; however, suboptimal therapeutic response in terms of psychotic symptoms is common and affects up to one-third of people with schizophrenia. Negative symptoms are generally less amenable to treatment. Because of the consequences of inadequate symptom control, effective treatment strategies are required for people with treatment-resistant schizophrenia. Clozapine has been shown to be more effective than other antipsychotics in treatment-resistant populations in several studies; however, the occurrence of adverse effects, some of which are potentially life-threatening, are important limitations. In addition to those who are intolerant to clozapine, only 30% to 50% experience clinically significant symptom improvement. This review describes the recent evidence for treatment strategies for people not responding to nonclozapine antipsychotic agents and people not responding or only partially responding to clozapine.

Gastrointestinal hypomotility: an under-recognised life-threatening adverse effect of clozapine

AIM

To highlight some problems that may occur when investigating clozapine-associated deaths including (i) that death may be related to gastrointestinal hypomotility and (ii) that post-mortem blood clozapine and norclozapine concentrations may not reflect ante-mortem concentrations.

CASE REPORTS

A 41-year-old male died 40 min after admission to hospital as a result of aspiration complicating severe, clozapine-induced constipation. At post-mortem the small bowel was dilated and contained bloodstained mucus, particularly within the jejunum. The large bowel was considerably dilated and contained large quantities of foul-smelling, bloodstained fluid and a small amount of stool. Its lining was focally congested, but there was no other obvious abnormality. Analysis of serum obtained on admission revealed clozapine and norclozapine concentrations of 0.56 and 0.43 mg/L, respectively, whereas post-mortem femoral whole blood obtained <34 h after death showed clozapine and norclozapine concentrations of 3.73 and 1.75 mg/L, respectively. In 6 out of a further 12 clozapine-associated deaths investigated 2002-9 there were reports of gastrointestinal tract problems of varying severity.

CONCLUSIONS

Severe constipation or paralytic ileus in clozapine-treated patients may lead to intestinal necrosis and/or perforation, or pulmonary aspiration. In some such cases the immediate cause of death may be obvious, but in others only careful assessment of the clinical course of the terminal illness may reveal gastrointestinal hypomotility as a likely underlying cause of death.

Management of schizophrenia with medical disorders: cardiovascular, pulmonary, and gastrointestinal

Medical illnesses are particularly common in patients who have schizophrenia and one of the major tasks for consultation-liaison psychiatrists, and others, is to determine which medications are safest in which co-morbid condition. The authors review the relative risks for various antipsychotics, especially focusing on cardiovascular, pulmonary, and gastrointestinal co-morbid illnesses. The authors further review the atypical antipsychotics' cardiovascular risks, especially for prolonging QT intervals, in trying to avoid the risk for torsades de pointes. The relative risk for anticholinergic actions for these medicines is also reviewed, as this is especially important in the medically ill or elderly. The authors also review the relative safety of antipsychotics in patients who have liver disease and pulmonary disease. Finally, the authors review specific drug interactions that may be problematic when treating the medically ill with atypical antipsychotics.

Altered Mental Status from Olanzapine Overdose Treated with Physostigmine

BACKGROUND

Olanzapine is commonly prescribed to patients with schizophrenia. One retrospective study demonstrates the efficacy of physostigmine in reversing mental status changes induced by olanzapine. We report two patients with delirium due to confirmed olanzapine overdose treated with physostigmine. One patient's mental status transiently returned to normal. The other patient completely recovered. CASE 1: A 25-year-old man ingested 300 mg of olanzapine. On presentation, he was agitated, delirious, tachycardic, had dry skin and mucous membranes, and dilated pupils (6 mm) minimally reactive to light. Physostigmine, 0.5 mg, was given intravenously (IV) without effect. Additional physostigmine doses of 1.5 mg IV administered 5 minutes later and then 1 mg IV resulted in the patient having a clear sensorium and normal mentation. The patient's mental status continued to remain normal for the duration of his hospital stay. Olanzapine was identified in the urine by high performance liquid chromatography. CASE 2: A 20-year-old female ingested 600 mg of olanzapine. On presentation, she was tachycardic, obtunded, and minimally responsive to painful stimuli, with decreased bowel sounds, dry skin and dry mucous membranes. Physostigmine, 2 mg, was given IV. Shortly thereafter she regained full consciousness and began speaking coherently. She remained in this condition for approximately 30 minutes, and then became obtunded. Her serum olanzapine concentration was 1230 ng/mL. No further doses of physostigmine were administered. On day 3 of admission her mental status returned to normal.

CONCLUSION

We report two cases of olanzapine-induced mental status changes treated with physostigmine. The utility of physostigmine as a safe or necessary antidote in the setting of olanzapine overdose remains to be determined.

Atypical antipsychotics, neurocognitive deficits, and aggression in schizophrenic patients

The purpose of this study was to compare the effects of olanzapine, clozapine, and haloperidol on neurocognitive function in schizophrenic patients who present with documented episodes of physical aggression and to determine whether change in cognitive function is related to aggression. One hundred physically aggressive schizophrenic inpatients were assigned to a randomized, double-blind, parallel-group, 12-week treatment, and received cognitive evaluations at baseline. There were 33, 34, and 33 subjects in the clozapine, olanzapine, and haloperidol groups, respectively. They were administered a battery of tests assessing psychomotor function, general executive function, visual and verbal memory, and visuospatial ability. A general cognitive index was derived from the above battery. The overall score on the Modified Overt Aggression Scale was used to measure the number and severity of the aggressive events. Psychiatric symptoms and side effects were also assessed. The improvement in the general cognitive index differed significantly among the 3 treatment groups, with olanzapine being superior to both haloperidol and clozapine. Further analyses revealed significantly greater improvement with olanzapine in several cognitive domains. Furthermore, improvement in the general cognitive index was significantly associated with a decrease in aggression in the olanzapine group but not in the other 2 medication groups. In violent schizophrenic patients, olanzapine treatment is associated with better cognitive functioning relative to haloperidol and clozapine. This improvement in neurocognitive function is associated with a decrease in aggressive behavior. As clozapine markedly reduced aggression, there may be different pathways for the antiaggressive effect of olanzapine and that of clozapine.

Adverse effects of atypical antipsychotics : differential risk and clinical implications

Antipsychotic drugs can be of great benefit in a range of psychiatric disorders, including schizophrenia and bipolar disorder, but all are associated with a wide range of potential adverse effects. These can impair quality of life, cause stigma, lead to poor adherence with medication, cause physical morbidity and, in extreme cases, be fatal. A comprehensive overview of tolerability requires a review of all available data, including randomised controlled trials (RCTs), observational studies and postmarketing surveillance studies. Assessing the relative tolerability of atypical antipsychotics is hampered by the paucity of RCTs that compare these drugs head-to-head, and limited and inconsistent reporting of adverse effect data that makes cross-study comparisons difficult. Despite methodological problems in assessment and interpretation of tolerability data, important differences exist between the atypical antipsychotics in the relative risk of acute extrapyramidal symptoms (highest risk: higher doses of risperidone), hyperglycaemia and dyslipidaemia (highest risk: clozapine and olanzapine), hyperprolactinaemia (highest risk: amisulpride and risperidone), prolongation of heart rate-corrected QT interval (QTc) [highest risk: ziprasidone and sertindole] and weight gain (highest risk: clozapine and olanzapine). Sedation, antimuscarinic symptoms, postural hypotension, agranulocytosis and seizures are more common with clozapine than with other atypical antipsychotics. The variation in their tolerability suggests that it is misleading to regard the atypical antipsychotics as a uniform drug class, and also means that the term 'atypical antipsychotic' has only limited usefulness. Differences between the atypical agents in terms of efficacy and pharmacodynamic profiles also support this view. As tolerability differs between specific conventional and atypical drugs, we conclude that broad statements comparing the relative risk of specific adverse effects between 'atypical' and 'conventional' antipsychotics are largely meaningless; rather, comparisons should be made between specific atypical and specific conventional drugs. Adverse effects are usually dose dependent and can be influenced by patient characteristics, including age and gender. These confounding factors should be considered in clinical practice and in the interpretation of research data. Selection of an antipsychotic should be on an individual patient basis. Patients should be involved in prescribing decisions and this should involve discussion about adverse effects.

Dose-dependent constipation with higher doses of quetiapine: a case series

Quetiapine is a dopamine D2 and serotonin 5-HT2 antagonist with antipsychotic and mood-stabilizing properties. Recent studies suggest that higher doses of quetiapine combine superior therapeutic efficacy with good tolerability. We present five patients, in whom treatment with higher doses of quetiapine was associated with constipation. Our observations raise the question of dose-dependent constipation under treatment with quetiapine.

A model of anticholinergic activity of atypical antipsychotic medications

BACKGROUND

Atypical antipsychotics clozapine, olanzapine, and quetiapine have significant affinity for the muscarinic receptors in vitro, while aripiprazole, risperidone, and ziprasidone do not. Dissimilarity in binding profiles may contribute to the reported differences in the anticholinergic effects of these antipsychotics. However, it is difficult with the available data to predict the likelihood of anticholinergic effects occurring with various doses of an atypical antipsychotic.

METHODS

We developed a model to assess the potential anticholinergic activity (AA) of atypical antipsychotics at therapeutic doses. A radioreceptor assay was used to measure in vitro AA at 6 clinically relevant concentrations of aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone. Using published pharmacokinetic data, in combination with the measured in vitro AA, dose-AA curves were generated.

RESULTS

Clozapine, and to a lesser extent olanzapine and quetiapine showed dose-dependent increases in AA. At therapeutic doses, the AA (in pmol/mL of atropine equivalents) was estimated to range from 27-250, 1-15, and 0-5.4 pmol/mL for clozapine, olanzapine, and quetiapine, respectively. Aripiprazole, risperidone, and ziprasidone did not demonstrate AA at any of the concentrations studied.

CONCLUSIONS

Therapeutic doses of clozapine, olanzapine, and, to a lesser extent, quetiapine are associated with clinically relevant AA.

Hypersalivation induced by olanzapine with fluvoxamine

Hypersalivation has been reported as a side effect of atypical antipsychotics such as clozapine and olanzapine. As it is very common for antipsychotics to cause dry mouth due to anticholinergic effects, hypersalivation seems to be paradoxical. We present the case of a 34-year-old Japanese man with delusional disorder, somatic type (DSM-IV). He had chronic neck pain as well as somatic hallucination with hypochondriacal delusion for 4 years. Since combination therapy with atypical antipsychotics and selective serotonin reuptake inhibitors (SSRIs) has been introduced in the treatment of refractory psychiatric disorders such as schizophrenia, olanzapine (10 mg/day) was added to fluvoxamine treatment (200 mg/day) in this case. Subsequently, hypersalivation was induced without any extrapyramidal symptoms. It is suggested that hypersalivation was an adverse effect of olanzapine. Possible interaction olanzapine with fluvoxamine might increase the risk of the adverse effect. When combination therapy of atypical antipsychotics and SSRI is introduced, it should be used cautiously with careful observation. Underlying pharmacological and clinical problems will be discussed.

Severe tachycardia following low-dose clozapine treatment

OBJECTIVE

To report a case of severe and sustained tachycardia that developed asymptomatically on a low dose of clozapine (150 mg daily).

METHOD

Case report.

RESULTS

Serially monitored 24 h heart rate after the introduction of clozapine showed an increase in the 24 h mean from 87 to 126 bpm, a reduction of pulse variability and anomalies in sleep-wake regulation. Cessation of clozapine was followed by a rapid return to preclozapine activity. Application of the Naranjo Adverse Drug Reaction Probability Scale indicated a probable relationship between clozapine and the sustained tachycardia.

CONCLUSIONS

Severe and sustained tachycardia can develop asymptomatically with a relatively low dose of clozapine and a slow titration rate. The severity of the tachycardia may not be revealed in isolated pulse measurements and may escape clinical detection without closer monitoring of heart rate.

Heart rate variability during sleep in patients with schizophrenia treated with olanzapine

Cardiac adverse events in patients treated with atypical antipsychotics have gained increasing interest in recent years. In the present study, heart rate variability (HRV), which is a sensitive parameter reflecting central autonomic cardiac control, was investigated during treatment with olanzapine. Ten physically healthy male patients with schizophrenia, who displayed predominantly negative symptoms, were studied in the sleep laboratory under drug-free baseline conditions and after 4 weeks of olanzapine medication. HRV was assessed during different sleep stages both in the time and frequency domains. Only slight changes in HRV were shown during treatment, and appeared to be independent of sleep stages. Spectral analysis indicated a slight shift of the sympathovagal balance in favour of the sympathetic tone, which was consistent with an elevation of heart rate in the time domain; total HRV was not altered. These changes are in accordance with olanzapine's receptor profile exerting anticholinergic and anti-adrenergic properties. In conclusion, taken together with findings from previous studies demonstrating that olanzapine does not cause clinically significant changes of the QTc interval, the present results are consistent with the known cardiac safety profile of olanzapine.

Muscarinic mechanisms of antipsychotic atypicality

The interactions of the atypical antipsychotic drugs (APD) clozapine, olanzapine, risperidone, quetiapine and ziprasidone with muscarinic receptors were reviewed. Only clozapine and olanzapine have marked affinity for muscarinic receptors in radioligand binding studies; however, the affinity of these compounds is considerably lower than classical muscarinic antagonists. Although functional assays in cell lines transfected with muscarinic receptors suggest that olanzapine and clozapine have weak partial agonist activity at muscarinic receptors, particularly M4 receptors, studies in vitro and in vivo indicate that the compounds function as antagonists. In animal studies and in humans, clozapine has pronounced antimuscarinic effects whereas olanzapine has weak antimuscarinic effects. However, olanzapine significantly occupies central muscarinic receptors in humans. Overall, the role of muscarinic receptors in the antipsychotic effects of clozapine and olanzapine is controversial and complex.

Serum antimuscarinic activity during clozapine treatment

This study attempts: (1) to verify that serum antimuscarinic activity is related to clozapine dose, and more importantly to clozapine plasma concentrations; (2) to explore whether norclozapine has serum antimuscarinic activity; (3) to explore whether antimuscarinic activity is related to clozapine side effects; and (4) to compare the serum antimuscarinic activities of clozapine with those of antiparkinsonian drugs and other antipsychotics. In 39 patients participating in a double-blind clozapine study, the [3H]QNB assay was used to measure serum antimuscarinic activity: (1) on baseline medications; (2) after a 4-week haloperidol trial; (3) after a 16-week clozapine trial of either 100, 300, or 600 mg/d; and (4) after 1 or 2 consecutive 16-week clozapine trials with remaining doses in nonresponders. Clozapine levels predicted serum antimuscarinic activity better than clozapine dose. At the end of the 1st clozapine trial, the correlation with the levels explained 69% of the variance of serum antimuscarinic activity (r = 0.83, P < 0.001, N = 34). Clozapine levels were good predictors of serum antimuscarinic activity only in patients taking 300 or 600 mg/d. After correcting for clozapine levels, the within-subject correlation between norclozapine levels and serum antimuscarinic activity was relatively high and significant (r = 0.54, F = 26.7, df = 1.65, P < 0.001). Constipation was significantly associated with higher serum antimuscarinic activity during the 1st clozapine trial. Clozapine was associated with clearly higher antimuscarinic activity than other antipsychotics or low doses of antiparkinsonians. In vitro studies and new clinical studies are needed to verify whether norclozapine may significantly contribute to antimuscarinic activity during clozapine treatment.

Effects of olanzapine and clozapine upon pulse rate variability

Based upon their in vitro receptor binding profiles, the atypical antipsychotics clozapine and olanzapine exhibit cholinergic receptor binding of similar potency. Data comparing the in vivo anticholinergic effects, however, of these neuroleptics upon neurocardiac control are sparse. The goal of this study was to compare the in vivo effects of clozapine and olanzapine upon neurocardiac control by assessment of the pulse rate variability (PRV) in schizophrenic patients and healthy controls. Twenty patients with schizophrenia (according to DSM-III-R criteria) treated with either clozapine (100-600 mg/day) or olanzapine (10-20 mg/day), and ten healthy controls, were recruited into the study. PRV was assessed by continuously recording the skin blood volume in the fingertip of the second digit under resting conditions and PRV parameters were calculated. When significant differences in PRV parameters between the patients and controls were detected by Kruskal-Wallis tests, Mann-Whitney tests were used to test for group differences between the olanzapine- and clozapine-treated patients. In comparison to the healthy controls, the PRV parameters of the clozapine- and olanzapine-treated schizophrenic patients were significantly reduced. Indeed the reduction of PRV was significantly greater in the clozapine-treated group compared to the olanzapine-treated group (P<0.05). Compared to the controls, only the clozapine-treated patients showed a significantly diminished low-frequency (LF)/high frequency (HF)-ratio, a PRV parameter reflecting sympatho-vagal balance. The significantly greater reductions in PRV parameters of the clozapine-treated compared to olanzapine-treated patients may be caused by clozapine's higher affinity for alpha(1)-adrenergic receptors in vivo compared with olanzapine. The similar LF/HF ratios of the healthy controls and olanzapine-treated patients suggests that the sympathetic-parasympathetic modulation of PRV remains relatively unchanged even during olanzapine treatment.

The use of concomitant medications in psychiatric inpatients treated with either olanzapine or other antipsychotic agents: a naturalistic study at a state psychiatric hospital

Concomitant medications are frequently used in the treatment of resistant psychiatric conditions to augment the primary psychotropic agent or to ameliorate side effects. The present study evaluated the prescription of concomitant psychiatric medications for psychiatric inpatients that were prescribed either olanzapine at its first commercial availability or another first-line antipsychotic agent. Sixty-nine newly admitted patients (mainly with schizophrenia) who were prescribed either olanzapine (n = 35) or another first-line antipsychotic agent (n = 34) were assessed (for the prescription of other concomitant psychotropic drugs) before (2-4 weeks prior to study) and following 8 weeks of treatment (unless discharged sooner). The results indicate that significantly fewer olanzapine-treated subjects were prescribed anticholinergic agents as compared to those prescribed other first-line antipsychotic agents, and a similar trend was noted in the prescription of mood stabilizers as well. Olanzapine-treated subjects used less as needed (PRN) antipsychotic medication compared to pre-olanzapine treatment period. Olanzapine-treated subjects used more anxiolytic agents compared to the control group in the early stages of treatment, probably due to the greater baseline severity of illness. These data suggest that olanzapine use is associated with less use of anticholinergic and mood-stabilizing agents as compared to older antipsychotic agents. These results also suggest that there is less need for PRN antipsychotic medication following olanzapine treatment. More severely ill subjects may require more anxiolytics during olanzapine initiation. The need for less anticholinergic and mood-stabilizing agent use with olanzapine could lead to greater adherence to long-term treatment and perhaps decreased cost (i.e. use of blood and organ system monitoring with mood stabilizers). At the end of treatment, olanzapine-treated subjects had statistically significantly lesser concomitant medicine usage compared to control subjects.

A current review of olanzapine's safety in the geriatric patient: from pre-clinical pharmacology to clinical data

OBJECTIVE

Olanzapine (OLZ) is unique among currently available antipsychotic medications in its antagonism of a range of receptor systems including dopamine, norepinephrine, serotonin, acetylcholine, and histamine. Olanzapine's mechanistic complexity provides a broad efficacy profile in patients with schizophrenia and acute, pure or mixed mania. Patients experience symptomatic relief of mania, anxiety, hallucinations, delusions, and agitation/aggression and reduced depressive, negative, and some cognitive symptoms. This paper will review the safety profile of OLZ, focusing on the elderly, where data are available.

METHOD

Preclinical and clinical studies of OLZ are reviewed, with emphasis on its possible effects on the cholinergic system and the histamine H(1) receptor. Weight change and related metabolic considerations, cardiac and cardiovascular safety, and motor function during treatment with OLZ are also reviewed.

RESULTS AND CONCLUSION

In vitro receptor characterization methods, when done using physiologically relevant conditions allow accurate prediction of the relatively low rate of anticholinergic-like adverse events, extrapyramidal symptoms, and cardiovascular adverse events during treatment with OLZ. Currently available clinical data suggest olanzapine is predictably safe in treating adult patients of any age with schizophrenia and acute bipolar mania, as well as in treatment of patients with some types of neurodegenerative disorders.

The central cholinergic system profile of olanzapine compared with placebo in Alzheimer's disease

OBJECTIVE

The objective of this analysis was to compare the treatment-emergent central anticholinergic-like adverse events experienced during treatment with olanzapine versus placebo in patients with psychosis and/or agitation due to Alzheimer's disease (AD). In addition, changes in cognition were assessed in a subgroup of patients with mild to moderate cognitive impairment.

METHODS

Double-blind data were compared for placebo and three fixed olanzapine dosages (5 mg/day, 10 mg/day, and 15 mg/day) in 206 nursing home-residing patients with AD for five a priori selected central nervous system anticholinergic-like adverse events: confusion, delirium, delusions, hallucinations, abnormal thinking. Mean change from baseline to endpoint on the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) was measured for a subgroup of 43 patients who had mild to moderate cognitive impairment at baseline.

RESULTS

There were no significant differences in central anticholinergic-like adverse events at any olanzapine dose compared to placebo. Additionally, in the 43-patient subgroup, there were no significant differences in mean change in ADAS-Cog scores between placebo and the three olanzapine dose subgroups.

CONCLUSION

Olanzapine did not differ significantly from placebo for any of the five central nervous system anticholinergic events nor on the ADAS-Cog. Olanzapine's initially reported potent in vitro muscarinic receptor affinity is not consistent with this clinical study of central nervous system anticholinergic-like adverse events in patients with AD.

A Perspective on the Primary Care of Patients With Behavior, Mood, and Thought Disturbances: Clinical Applications of Olanzapine

Primary care practitioners are in an ideal position to initiate treatment for patients with behavior, mood, and thought disturbances. It is believed that early identification and treatment of these symptomatic features of primary or secondary central nervous system disorders may significantly reduce morbidity and benefit the patient, his/her family, and involved caregivers, including the primary care physician. A broad list of central nervous system-active medications are utilized by family physicians to treat patients who exhibit symptoms of agitation, altered mood, and disordered thought. Some medications have demonstrated superiority over placebo or active medicines in reported clinical trials. This article is a brief overview of the safety and efficacy from reported studies of the use of medications frequently used to treat symptoms related to behavior, mood, and thought disturbances, with a specific focus on the clinical applicability of olanzapine.