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

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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Risk of gastrointestinal Hypomotility in schizophrenia and schizoaffective disorder treated with antipsychotics: A retrospective cohort study

OBJECTIVE

The risk of gastrointestinal hypomotility (GIHM) with the use of antipsychotic medications in patients with schizophrenia remains inadequately recognized. The aim of this study was to explore the incidence of GIHM and its risks in patients with schizophrenia treated with antipsychotics.

METHODS

We conducted a retrospective cohort study using the National Health Insurance Research Database. We identified adult (≥ 20years of age) patients with a first-time diagnosis of schizophrenia or schizoaffective disorder in the Registry for Catastrophic Illness Patients during the period from 2001 to 2011. Each subject in the cohort was followed until their corresponding diagnosis of GIHM was made, until the time of death, or to December 31, 2012. The incidence rates of each outcome were calculated. Cox proportional hazards regression with time-dependent covariates for antipsychotics use was employed to evaluate the associations between different types of antipsychotics and the risk of GIHM.

RESULTS

Our study found that the incidence densities of constipation, ileus, and ischemic bowel disease were 42.5, 4.4, and 0.1 per 1000 person-years. In terms of the risk of hypomotility with the use of antipsychotics, clozapine and quetiapine were significant in developing constipation, with a hazard ratio of 2.15 and 1.34, respectively. High-potency first-generation antipsychotics and clozapine were also significant in the occurrence of ileus, with a hazard ratio of 1.30 and 1.95, respectively. Similar associations were found in an anticholinergic agent subgroup analysis.

CONCLUSION

Patients receiving antipsychotics such as high-potency first-generation antipsychotics, clozapine, or quetiapine should undergo proper evaluation and intervention to minimize the disease burden and life-threatening outcomes of treatment.

Clozapine-induced acute gastrointestinal necrosis: a case report

Background

Clozapine is known to cause fecal impaction and ileus with resultant colonic necrosis due to compression of colonic mucosa. There are rare reports of clozapine causing necrosis of other portions of the gastrointestinal tract unrelated to constipation. We describe a case of acute necrosis of the upper gastrointestinal tract and small bowel to due to clozapine and quetiapine.

Case presentation

A 66-year-old white man with a past medical history of schizophrenia, maintained on clozapine and quetiapine, presented with hypoxic respiratory failure caused by aspiration of feculent emesis due to impacted stool throughout his colon. His constipation resolved with discontinuation of clozapine and quetiapine, and his clinical condition improved. These medicines were restarted after 2 weeks, resulting in acute gastrointestinal necrosis from the mid esophagus through his entire small bowel. He died due to septic shock with Gram-negative rod bacteremia.

Conclusions

Clozapine may cause acute gastrointestinal necrosis.

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.