Death from clozapine-induced constipation: case report and literature review

Rhabdomyolysis during adjunctive treatment with cariprazine in a clozapine-resistant schizophrenia patient

We report the case of a 49-year-old male treatment-resistant schizophrenia patient, whose treatment with clozapine and sertraline was supplemented with cariprazine 1.5 mg/day while regularly presenting for electroconvulsive therapy. After 3 weeks of adjunctive treatment with cariprazine, blood tests revealed pronounced signs of rhabdomyolysis, including a creatine kinase serum level of 20 386 U/L and an AST serum level of 696 U/L. Clinically, the patient did not report somatic symptoms other than mild back pain. After discontinuation of cariprazine and normal saline infusion, the above-mentioned findings resolved rapidly. Although very rare, rhabdomyolysis can be a potentially dangerous side effect of cariprazine and clinicians should be aware of its possible occurrence.

Drug-induced bowel complications and toxicities: imaging findings and pearls

The use of diverse types of drugs can result in a variety of acute and chronic complications that affect almost any organ. The bowel is one of the organs impacted by the side effects of medications. Imaging frequently plays a crucial role in the detection and characterization of complications occurring in the bowel. They include pseudomembranous colitis or antibiotic-associated colitis; angioedema induced by angiotensin-converting enzyme inhibitors; nonsteroidal anti-inflammatory drug-induced enteropathy; cocaine toxicity; clozapine-induced hypomobility; and bowel toxicity induced by chemotherapeutic agents. It is imperative that radiologists are fully aware of these complications and toxicities as well as the relevant findings. In this way, proper treatment can be implemented immediately. The treatment will involve discontinuation of a drug or a change in regimen.

Clozapine-Induced Constipation: A Case Report and Review of Current Management Guidelines

Clozapine is a second-generation antipsychotic recommended after the failure of two or more antipsychotics for treatment-resistant schizophrenia. Clozapine proved to also decrease recurrent suicidal behaviors in schizophrenia spectrum disorders. Yet, physicians often use clozapine as a last resort despite its proven efficacy due to its side effect profile. A noted side effect of clozapine is agranulocytosis, which requires a weekly complete blood count with differentials. Clozapine's anticholinergic activity causes colonic hypomotility, leading to constipation, and only a few studies examined clozapine-induced constipation (CIC). Few of the reported complications of CIC include bowel obstruction or bowel perforation due to fecal impaction. Herein we document a case report of CIC and also conducted a review of published case reports examining the complexity and management of CIC. CIC is a critical condition if unresolved as it can lead to mortality. Future directions and guidelines should be developed for early diagnosis and treatment for CIC, which will provide reassurance and directions for both the physicians and patients.

Prevalence and predictors of laxatives use in clozapine-related constipation: an observational study

Clozapine-induced constipation is a frequently overlooked side effect that can prove fatal. This study aimed to investigate the prevalence of constipation and the breakdown of laxatives, and to identify whether use of laxative may be predicted by demographics or baseline metabolic markers in 53 Japanese treatment-resistant schizophrenia inpatients switched to clozapine. Differences of present age, onset age and duration of illness, previous antipsychotic dose using the chlorpromazine equivalent, and 10-items of metabolic markers, including fasting plasma glucose and ratio of triglyceride to high-density lipoprotein cholesterol levels were compared between the laxative and nonlaxative user groups. Sequential changes of defecation scores using Bristol stool form scale, and clozapine dosage at 1, 2 and 3 months were evaluated within each group. Multiple linear stepwise regression analysis was performed to assess the predicting use of laxatives. Half of subjects required treatment with laxative, were significantly older and had longer durations of illness than nonlaxative users. Magnesium oxide and lubiprostone were mainly used singly or in combination. Longer disease duration, and lower levels of fasting blood glucose and insulin resistance were predicting the use of laxatives. Screening and preventive strategies for minimizing clozapine-related constipation should be established in future study.

Second-generation antipsychotics and constipation: A review of the literature

Antipsychotics are the cornerstone in the management of psychotic disorders and schizophrenia. They are effective agents but also have a wide range of side effects. In the recent literature constipation as possible side effect has received little attention. A review of the literature concerning constipation associated with antipsychotics was performed. Overall constipation is a rarely studied or reported side effect of antipsychotic medication. Nevertheless constipation is a common side effect. Antipsychotic agents differ in their liability to induce constipation. Constipation can be severe and can lead to serious consequences such as paralytic ileus, bowel occlusion and death. Active screening, monitoring and treatment are recommended. Further research on incidence, prevalence, underlying mechanisms and preventive measures is required.

Focussing on the fundaments - assessing and treating Clozapine Induced Gastrointestinal Hypomotility

Background: Clozapine is a second-generation antipsychotic used in treatment-resistant Schizophrenia (TRS). Clozapine Induced Gastrointestinal Hypomotility (CIGH) is the commonest cause of clozapine related death, yet remains under-recognised and under-monitored.Aims and hypothesis: To review the pharmacological management of CIGH. We hypothesised that pharmacological interventions would reduce the incidence of adverse outcomes associated with CIGH.Methods: We retrospectively reviewed consecutive patients treated on clozapine over a one year period on a male acute psychiatric ward. Information on patient demographics, CIGH symptomatology, treatment and outcome were extracted.Results: In total, 14 male patients with a mean age of 43 years (standard deviation 10 years) were included. Of these, 9 patients experienced CIGH during admission, in all cases presenting as constipation. Among patients experiencing CIGH, 8 of 9 (89%) patients received one or more interventions. This was most commonly a stimulant, or osmotic laxative. By discharge, the 8 patients treated were in full remission of CIGH symptoms.Conclusions: A high proportion of patients treated with clozapine experience CIGH, presenting most commonly as constipation. Whilst potentially life-threatening, CIGH can be successfully treated in an acute inpatient setting. Active monitoring of CIGH symptoms in patients initiated, or reinitiated on clozapine is recommended.Key pointsA high proportion of patients treated with Clozapine experience constipation, the cardinal feature of Clozapine Induced Gastrointestinal Hypomotility.Whilst potentially life-threatening, CIGH can be successfully treated in an acute inpatient setting with simple interventions.Active monitoring of CIGH symptoms in patients initiated, or reinitiated on clozapine is recommended.Future research on the potential benefit of prophylactic intervention would be beneficial.

Clozapine-induced stercoral colitis: a surgical perspective

We describe a case of a 46-year-old man with schizophrenia treated with clozapine who presented as an emergency with abdominal pain on the background of a 1 month history of constipation. The initial presenting symptoms were vague and a diagnosis was difficult to establish. Initial CT of the abdomen and pelvis demonstrated only minor abnormalities. He continued to deteriorate until a further CT scan revealed worsening stercoral colitis. He subsequently underwent an emergency total colectomy and ileostomy formation and had a complicated prolonged postoperative recovery. This case highlights the risks that clozapine can have on slowing bowel transit and the dangerous consequences that can occur if not identified early.

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.

LEARNING OBJECTIVES:

After reading this article you will be able to: •

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.

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.

Effects of antipsychotics on intestinal motility in zebrafish larvae

BACKGROUND

Antipsychotics are essential for the treatment of schizophrenia. However, due to side effects, both continuity of treatment and patients' general health can be jeopardized. Some of these drugs, especially clozapine, have a class of side effects attributed to their antimuscarinic properties, such as dysmotility, a condition in which muscles of the digestive system become impaired. Dysmotility may also alter the speed, strength or coordination of the digestive organs, causing distention, disturbing gastrointestinal transit, leading to symptoms such as bloating, nausea, vomiting, and even malnutrition. In this study, our aim was to develop an in vivo assay capable of identifying and studying the antimuscarinic effects of antipsychotics in a zebrafish model.

METHODS

We performed video recordings of in vivo 5-day postfertilization (dpf) zebrafish larvae gastrointestinal tracts and analyzed the frequency of spontaneous and regular cycles of contractions of the gut.

KEY RESULTS

The assay was first validated with treatment with atropine. We showed that this antimuscarinic drug reduces peristaltic cycles. Subsequently, the larvae were treated with the antipsychotics haloperidol, risperidone, and clozapine. Neither haloperidol nor risperidone reduced gut motility, but clozapine significantly reduced the frequency of cycles of contractions (P<.0001), which confirms the existing clinical data.

CONCLUSIONS & INFERENCES

We conclude that this zebrafish assay efficiently identifies anticholinergic side effects of antipsychotics, and can thus be a quick and useful way to screen for this property in new drugs.

Characterization of Admission Types in Medically Hospitalized Patients Prescribed Clozapine

BACKGROUND

Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia; however, rigorous monitoring is required to prevent or detect adverse drug events that contribute to morbidity and mortality. In addition to the Food and Drug Administration (FDA) boxed safety warnings specific to clozapine (agranulocytosis, hypotension, seizures, and cardiomyopathy/myocarditis), other adverse events such as pneumonia and gastrointestinal hypomotility have been reported in the literature to result in hospitalization.

OBJECTIVE

To explore the reasons for medical hospitalization in patients prescribed clozapine, a retrospective chart review was completed.

METHODS

Adults with schizophrenia or schizoaffective disorder prescribed clozapine were identified if they had a nonpsychiatric medical admission between 1/1/2003 and 8/1/2015. Demographics, admitting diagnosis, admitting service type, psychiatric consult information, clozapine dosing, and drug interactions were collected.

RESULTS

Overall, 104 patients, representing 248 hospitalizations, were admitted to a medical unit during the study period. The predominant admission types were for the management of either pulmonary (32.2%) or gastrointestinal (19.8%) illnesses. The most common pulmonary diagnosis was pneumonia, accounting for 58% of pulmonary admissions. Further, 61.2% of the gastrointestinal admissions were related to hypomotility, ranging from constipation to death. Clozapine was discontinued owing to neutropenia in 2 patients; however, in both cases concomitant chemotherapy had been given.

CONCLUSION

In patients prescribed clozapine admitted to nonpsychiatric medical settings, gastrointestinal and pulmonary illnesses were common, but not illnesses related to boxed warnings. Additional research is needed to better assess the causality and true incidence of gastrointestinal or pulmonary events associated with clozapine. Furthermore, clinicians must be prepared to prevent, detect, and manage potentially life-threatening events associated with clozapine.

A Guide to the Management of Clozapine-Related Tolerability and Safety Concerns

Clozapine is a highly effective antipsychotic medication, which provides a range of significant benefits for patients with schizophrenia, and is the standard of care for treatment-resistant schizophrenia as well as for reducing the risk of suicidal behaviors in schizophrenia and schizoaffective disorder. However, clozapine is widely underutilized, largely because prescribing clinicians lack experience in prescribing it and managing its adverse events (AEs). Clozapine is associated with 3 uncommon but immediately dangerous AEs, agranulocytosis, myocarditis/cardiomyopathy, and seizures, as well as AEs that may become dangerous if neglected, including weight gain, metabolic syndrome and constipation, and others that are annoying or distressing such as sedation, nighttime enuresis and hypersalivation. Because of the risk of agranulocytosis, clozapine formulations are available only through restricted distribution via a patient registry, with mandatory, systematized monitoring for absolute neutrophil count using a specific algorithm. We identified articles on managing clozapine-associated AEs by searching PubMed using appropriate keywords and search techniques for each topic. A review of the prevalence and clinical characteristics of clozapine-associated AEs shows that these risks can be managed efficiently and effectively. The absolute risks for both agranulocytosis and myocarditis/cardiomyopathy are low, diminish after the first 6 months, and are further reduced with appropriate monitoring. Weight gain/metabolic disorders and constipation, which develop more gradually, can be mitigated with regular monitoring and timely interventions. Sedation, hypersalivation, and enuresis are common but manageable with ameliorative measures and/or medications.

Unrecognized clozapine-related constipation leading to fatal intra-abdominal sepsis - a case report

Clozapine is the preferred antipsychotic used for the treatment of resistant schizophrenia with suicidal ideation. The drug is started at a low dose and gradually increased to a target dose of 300–450 mg/day. It is well known to cause agranulocytosis and neutropenia. Several cases of fatal sepsis have been reported in neutropenic patients and emphasis is placed on monitoring for agranulocytosis; however, clozapine also causes intestinal hypomotility and constipation, which if unrecognized can lead to intestinal obstruction, bowel necrosis, and intra-abdominal sepsis. Reduced behavioral pain reactivity in schizophrenics may alter the ability to express pain, potentially leading to a delay in the presentation for medical attention. We report a case of fatal intra-abdominal sepsis secondary to an unrecognized case of clozapine-related constipation.

Medical management of patients on clozapine: A guide for internists

Clozapine was approved by the US Food and Drug Administration in 1989 for the management of treatment-resistant schizophrenia, and has since proven to reduce symptom burden and suicide risk, increase quality of life, and reduce substance use in individuals with psychotic disorders. Nevertheless, clozapine's psychiatric benefits have been matched by its adverse effect profile. Because they are likely to encounter medical complications of clozapine during admissions or consultations for other services, hospitalists are compelled to maintain an appreciation for these iatrogenic conditions. The authors outline common (eg, constipation, sialorrhea, weight gain) and serious (eg, agranulocytosis, seizures, myocarditis) medical complications of clozapine treatment, with internist-targeted recommendations for management, including indications for clozapine discontinuation.

Rare and very rare adverse effects of clozapine

Clozapine (CLZ) is the drug of choice for the treatment of resistant schizophrenia; however, its suitable use is limited by the complex adverse effects' profile. The best-described adverse effects in the literature are represented by agranulocytosis, myocarditis, sedation, weight gain, hypotension, and drooling; nevertheless, there are other known adverse effects that psychiatrists should readily recognize and manage. This review covers the "rare" and "very rare" known adverse effects of CLZ, which have been accurately described in literature. An extensive search on the basis of predefined criteria was made using CLZ and its combination with adverse effects as keywords in electronic databases. Data show the association between the use of CLZ and uncommon adverse effects, including ischemic colitis, paralytic ileus, hematemesis, gastroesophageal reflux disease, priapism, urinary incontinence, pityriasis rosea, intertriginous erythema, pulmonary thromboembolism, pseudo-pheochromocytoma, periorbital edema, and parotitis, which are influenced by other variables including age, early diagnosis, and previous/current pharmacological therapies. Some of these adverse effects, although unpredictable, are often manageable if promptly recognized and treated. Others are serious and potentially life-threatening. However, an adequate knowledge of the drug, clinical vigilance, and rapid intervention can drastically reduce the morbidity and mortality related to CLZ treatment.

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.

Infection and inflammation leading to clozapine toxicity and intensive care: a case series

OBJECTIVE

To describe 3 cases of clozapine toxicity associated with infectious and/or inflammatory processes.

CASE SUMMARIES

Three patients stable on clozapine therapy prior to a medical hospital admission developed clozapine toxicity. It was suspected that an acute infectious and/or inflammatory process in each patient was related to abrupt mental status changes, onset of sialorrhea, myoclonus, and/or need for ventilatory support. Investigations of altered mental status did not reveal alternative causes and presentations were not consistent with neuroleptic malignant syndrome, other acute neurologic complications, or psychiatric decompensation. All patients improved after clozapine dose reductions allowing for transfer from intensive care units. Using the Naranjo ADR Probability Scale for each case, a probable relation between clozapine toxicity and the infectious and/or inflammatory process was determined.

DISCUSSION

Clozapine toxicity may manifest with multiple symptoms, including sedation, sialorrhea, and hypotension. In addition to overdose and drug interactions; infection and/or inflammation may precipitate clozapine toxicity. This may be related to cytokine-mediated inhibition of cytochrome P450 1A2. The likelihood of toxicity via this mechanism has not been well characterized, thus careful monitoring is required for medically ill patients receiving clozapine. Clozapine is extensively bound to the acute phase reactant, α-1 acid glycoprotein, which may unpredictably protect against clinical toxicity. C-reactive protein has also been investigated to relate clozapine toxicity to infection and/or inflammation.

CONCLUSION

Clozapine toxicity developed in 3 patients admitted to a medical setting suspected to be related to infection and/or inflammation. Clinicians should be aware of this potential adverse drug event with clozapine.

Rapid development of fatal bowel infarction within 1 week after clozapine treatment: a case report

Although there have been reported fatalities associated with clozapine-induced bowel infarction, in all of these cases, the patients had taken clozapine for months to years. We present here the case of a 47-year-old single man who died suddenly due to bowel infarction and sepsis 1 week after taking clozapine.

Life-threatening haematemesis associated with clozapine: a case report and literature review

Clozapine is regarded as a second-line and in some cases last-line antipsychotic known for its common life-threatening side effects, such as agranulocytosis, constipation and cardiomyopathies, but rarely haematemesis. We report a case of severe haemetemesis in a chronic schizophrenic patient managed with clozapine. The patient was a 46-year-old male being managed for chronic schizophrenia with treatment resistance who developed sudden severe haematemesis following commencement of clozapine for 6 weeks. The patient had 1.1 l of blood transfusion. The relevant literature is reviewed. Clozapine can be associated with a life-threatening haematemesis. Psychiatrists and other medical specialists need to be alert to the fatality of clozapine-induced haematemesis in the treatment of psychiatric disorders.

Reintroduction of Clozapine After Perforation of the Large Intestine—A Case Report and Review of the Literature

OBJECTIVE

To report on a patient who was successfully rechallenged with clozapine after perforation of the large intestine and pulmonary embolism postoperatively, and provide a literature review on clozapine rechallenge.

CASE SUMMARY

A 46-year-old Japanese man with treatment-resistant schizophrenia developed constipation and slight abdominal discomfort while taking clozapine 275 mg/day. He developed appendicitis, leading to perforation of the large intestine. During the postsurgery period, a partial embolism of the pulmonary artery was revealed. The patient's constipation was relieved when clozapine was discontinued, but other antipsychotics failed to control his delusions well. After thorough discussion, it was decided to rechallenge with clozapine. The low dose of clozapine 200 mg/day was tolerable for his delusion, and his constipation was managed with laxatives and exercises until 8 months after the accident.

DISCUSSION

Clozapine is a gold standard medication in treatment-resistant schizophrenia but is associated with various adverse effects, some of which are life-threatening. Reintroduction of clozapine after severe adverse drug effects when other medications are not effective almost always poses a clinical dilemma for mental health professionals. A PubMed search (to January 25, 2013) using the key words clozapine and rechallenge found 50 articles. There were only sporadic positive case reports regarding the rechallenge after clozapine-related serious gastrointestinal problems.

CONCLUSIONS

From the currently available evidence, most psychiatrists appear to avoid reintroduction of clozapine. However, the evidence is too weak to draw a definitive conclusion about reintroduction of this drug. Reintroduction of clozapine after initial adverse effects in patients with treatment-resistant schizophrenia may warrant case-by-case judgment, but needs to be further investigated.

Clozapine for the treatment of schizophrenia

INTRODUCTION

Despite considerable progress in the pharmacological treatment of schizophrenia, about 30% of patients are minimally responsive to antipsychotics and there is still an excessively high rate of mortality in schizophrenia patients. Clozapine , a D(2)-5HT(2) antagonist, was the first antipsychotic to demonstrate efficacy in treatment-resistant patients, and to be associated with the lowest risk of death.

AREAS COVERED

The pharmacodynamics, pharmacokinetics, clinical efficacy, safety and cost-effectiveness of clozapine are covered in this article, based on a literature review (PubMed) from 1975 to 2012. Pivotal, as well as supporting, randomized controlled trials are reviewed, along with observational and/or naturalistic safety studies. This review of clozapine will allow the reader to determine the place for clozapine in the schizophrenia treatment landscape.

EXPERT OPINION

Studies conducted so far suggest that clozapine is the treatment of choice for schizophrenic patients who are refractory to treatment, display violent behaviors, or who are at high risk of suicide. However, it is also the antipsychotic with the worst side effect profile, the highest risk of complications, and the most difficult to prescribe. Experience with clozapine should therefore be included in the education of future physicians.

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.

Prevalence and severity of antipsychotic related constipation in patients with schizophrenia: a retrospective descriptive study

Background

Antipsychotic are the cornerstone in the treatment of schizophrenia. They also have a number of side-effects. Constipation is thought to be common, and a potential serious side-effect, which has received little attention in recent literature.

Method

We performed a retrospective study in consecutively admitted patients, between 2007 and 2009 and treated with antipsychotic medication, linking different electronic patient data to evaluate the prevalence and severity of constipation in patients with schizophrenia under routine treatment conditions.

Results

Over a period of 22 months 36.3% of patients (99) received at least once a pharmacological treatment for constipation. On average medication for constipation was prescribed for 273 days. Severe cases (N = 50), non-responsive to initial treatment, got a plain x-ray of the abdomen. In 68.4% fecal impaction was found.

Conclusion

A high prevalence of constipation, often severe and needing medical interventions, was confirmed during the study period. Early detection, monitoring over treatment and early intervention of constipation could prevent serious consequences such as ileus.

Plasma clozapine, norclozapine, and the clozapine:norclozapine ratio in relation to prescribed dose and other factors: data from a therapeutic drug monitoring service, 1993-2007

Therapeutic drug monitoring of plasma clozapine and of its principal plasma metabolite N-desmethylclozapine (norclozapine) (predose or "trough" sample) can help in monitoring adherence, in dose adjustment, and in minimizing the risk of toxicity. To obtain data to assist in the interpretation of analytical results, the results from a clozapine therapeutic drug monitoring service, 1993-2007, have been audited. There were 104,127 samples from 26,796 patients [18,750 (70%) men aged at time of first sample (median, range) 34 (10-89) years, and 7763 (30%) female aged 38 (12-90) years]. Clozapine was not detected (plasma concentration <0.01 mg/L) in 1.5% of samples (prescribed clozapine dose up to 900 mg/d). Plasma clozapine was either below 0.35 mg/L or greater than 0.60 mg/L in 42.5% and 28.4% of samples, respectively; in 0.4% samples plasma clozapine was 2.0 mg/L or more. Although plasma clozapine was broadly related to prescribed dose, there was much variation: 1.2% of samples had plasma clozapine >1.0 mg/L at prescribed clozapine doses up to 150 mg/d (76.2% < 0.35 mg/L), whereas 23.3% of samples had plasma clozapine < 0.35 mg/L at doses of 850 mg/d and over (18.0% > 1.0 mg/L). The highest plasma clozapine and norclozapine concentrations encountered were 4.95 and 2.45 mg/L, respectively. Although the median plasma clozapine:norclozapine ratio was 1.25 at plasma clozapine concentrations < 0.35 mg/L, the median ratio was 2.08 at plasma clozapine concentrations > 1.0 mg/L. Data (median, 10th-90th percentile) for both clozapine and norclozapine by prescribed clozapine dose band are useful in assessing partial adherence. Analysis of the plasma clozapine:norclozapine ratio by clozapine concentration provides clear evidence that clozapine N-demethylation becomes saturated at higher plasma clozapine concentrations and adds urgency to the requirement for dose adjustment should smoking habit change. A clozapine:norclozapine ratio greater then 2 suggests either a nontrough sample, or that clozapine N-demethylation has become saturated.

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.

Successful Clozapine Rechallenge Following Surgical Repair of a Bowel Obstruction

As a consequence of its significant anticholinergic properties, constipation is a commonly reported adverse event in patients treated with clozapine. This side effect is often self-limiting and can be managed with high-fiber diets, adequate hydration, and standard over-the-counter and prescription preparations. However, severe cases of constipation can become more serious and may lead to intestinal obstruction, intestinal perforation, fecal impaction, or paralytic ileus. In this particular case, we report on a 44-year-old woman who presented with a suspected clozapine-induced bowel obstruction. Following total abdominal colectomy with ileosigmoid anastomosis, the patient was rechallenged with clozapine and tolerated the titration to a therapeutic dose and maintenance therapy without further incident.

Life-threatening constipation associated with clozapine

OBJECTIVE

The aim of this paper was to describe the association of clozapine with life-threatening constipation.

METHOD

Case report.

RESULTS

A 53-year-old man presented to the emergency department with severe abdominal pain and bilious vomiting after being on clozapine for over a year for schizoaffective disorder. Surgery revealed severe faecal impaction in the large and small bowel. Clozapine was ceased. There were significant difficulties in the subsequent psychiatric management. Clozapine was gradually reintroduced with concurrent laxative administration, which resulted in another episode of severe constipation with faecal impaction.

CONCLUSIONS

Clozapine can be associated with potentially life-threatening constipation. Psychiatrists, especially consultation liaison psychiatrists, physicians, surgeons and radiologists, should be aware of the seriousness of clozapine-induced constipation and its potentially fatal complications.

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.

Paralytic ileus associated with combined atypical antipsychotic therapy

First- and second-generation antipsychotics commonly cause mild and sometimes severe gastrointestinal motility depression. We discuss a case of a patient who developed paralytic ileus during his treatment with a combination of second-generation antipsychotics. The patient did not receive other medication that could cause depression of intestinal motility than the above-mentioned combination of antipsychotics and no other etiology could be found for the ileus. Furthermore we discuss the theoretical background of antipsychotics induced gastrointestinal motility depression and we provide the literature review of case reports of this topic.

Case report: rapidly fatal bowel ischaemia on clozapine treatment

BACKGROUND

There have been previous reported deaths due to clozapine-induced constipation. In all these cases patients have experienced prior abdominal symptoms over a period of weeks or months.

CASE PRESENTATION

We report the sudden death due to constipation of a healthy young male patient on clozapine without any known history of prior abdominal symptoms.

CONCLUSION

Psychiatrists need to be alert to the medical emergencies which can occur in the context of clozapine treatment and also need to make other clinicians who may have contact with their patients aware of these.

Modern antipsychotic drugs: a critical overview

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

Complete rectal prolapse in young patients: psychiatric disease a risk factor of poor outcome

OBJECTIVE

Complete rectal prolapse is rare before the age of 50. The aim of our study was to identify the risk factors of total rectal prolapse before this age and to determine the surgical outcome in this specific group of patients.

PATIENTS AND METHODS

The charts of all patients, younger than 50 years old, treated for total rectal prolapse between June 1995 and December 2001 were reviewed. Associated conditions were noted and pre and postoperative functions were compared in regards of constipation and evacuations problems, anal continence (Wexner score), recurrent prolapse and overall satisfaction. All patients underwent an abdominal rectopexy according to the Orr-Loygue procedure.

RESULTS

During the study period, 28 patients (21 females) with a mean age of 34 +/- 9 years were treated for a total rectal prolapse in our institution. Five patient (17.8%) had minor complications. After a mean follow up of 25 months, the global continence improved significantly (Wexner score: 4.9 vs 2; P = 0.014): 8 patients suffering from liquid stools incontinence before surgery were continent after rectopexy, while 2 continent patients became incontinent to liquid stools after surgery. Fourteen patients had chronic psychiatric disease requiring permanent treatment. These patients suffered more frequently from constipation (12/14 vs 5/14; P =0.006) and required more often a digital evacuation before surgery (6/14 vs 1/14; P = 0.07) than non psychiatric patients. They also suffered from more severe constipation and required more enemas after surgery (1/14 vs 6/12; P = 0.03) compared to patients without psychiatric disease. The only two patients, who had recurrence also had psychiatric disease.

CONCLUSION

Chronic psychiatric disease requiring long-term medication is observed in 50% of patients with total rectal prolapse under the age of 50 years. Moreover, the medically induced constipation in these patients could represent a cause of poorer functional outcome. Therefore, we recommend the identification of this preoperative risk factor to assess the results of total rectal prolapse treatment in patients younger than 50 years of age.

Fatalities associated with therapeutic use and overdose of atypical antipsychotics

Since 1989, several novel antipsychotic drugs have become available for use including clozapine, risperidone, olanzapine, quetiapine and ziprasidone. These agents represent a substantial improvement in the treatment of schizophrenia and related disorders and are considered to have a favourable adverse effect profile relative to traditional antipsychotics. Nonetheless, in rare cases, people have died as a result of taking atypical antipsychotic drugs at therapeutic and supratherapeutic doses. Toxic doses of atypical antipsychotics are highly variable: some patients have died while taking therapeutic doses and others have survived massive overdoses. Toxicity may be increased by coingestion of other agents, particularly drugs with similar metabolic pathways. Atypical antipsychotics are metabolised predominantly by cytochrome p450 (CYP) isoenzymes, particularly CYP1A2 (clozapine and olanzapine), CYP3A4 (clozapine, quetiapine and ziprasidone) and CYP2D6 (olanzapine and risperidone). Concurrent prescription of other drugs that inhibit these isoenzymes may increase the probability of adverse events in patients taking atypical antipsychotics. Deaths due to atypical antipsychotic toxicity are often related to cardiovascular complications, but pulmonary, neurological, endocrine and gastrointestinal complications have also caused fatalities. Prevention and management of atypical antipsychotic overdose are of increased clinical relevance as prescription of these drugs increases.