Clozapine-induced intestinal obstruction

Clozapine-Related Functional Bowel Obstruction: A Rare Adverse Effect Unmasking Quetiapine and Benztropine Interaction Raising Need for Bowel Surveillance

Randomized controlled trials demonstrate a significant decline in hospital admissions and length of stay following the initiation of clozapine in individuals with bipolar disorder and schizophrenia, along with an increase in quality-adjusted life years. The morbidity and mortality associated with clozapine-induced gastrointestinal hypomotility (CIGH) is greater than agranulocytosis. Despite this, we only have clozapine risk evaluation and mitigation strategies by the US Food and Drug Administration for white cell count monitoring, but none exists for CIGH. Our case highlights CIGH due to multiple factors and recommendations to prevent it and enhance clozapine compliance by conducting a thorough literature review.

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.

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.

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.