Necrotising colitis related to clozapine? A rare but life threatening side effect

Electric Shock Sensation and Recurrent Falls as a Side Effect of Clozapine Therapy: A Case Report

Clozapine is an atypical antipsychotic that acts by blocking mainly dopamine 4 receptors. It is usually prescribed for treatment-resistant schizophrenia as well as treatment-resistant bipolar disorder. Clozapine has a wide profile of side effects that result from blocking different receptors all over the body. A 42-year-old Middle Eastern female is known to have suffered from schizoaffective disorder for many years and had frequent relapses despite compliance with treatment. She was commenced on Clozapine; the patient started complaining of an electric shock sensation throughout her body that resulted in recurrent falls with bilateral leg fractures. She was started on sodium valproate to exclude the possibility of seizure activity but the electric shock sensation did not subside. The decision was made to switch her to aripiprazole and gradually taper down and stop Clozapine which improved her symptoms. Careful monitoring of patients who receive Clozapine is recommended especially during the tapering phase due to the risky adverse events it can bring about. It is essential to understand the side effects in order to tackle them as soon as they arise.

Clozapine-Related Diarrhea and Colitis: Report of 4 Cases

BACKGROUND

During clozapine treatment, diarrhea is a rare but clinically relevant adverse effect. Cases of microscopic colitis and eosinophilic colitis have been previously reported.

PROCEDURES

We present 4 patients who developed severe diarrhea in early weeks of clozapine therapy.

FINDINGS

Two patients had significant peripheral eosinophilia 1 week after diarrhea symptoms. One of these patients also had Charcot-Leyden crystals in stool afterward, confirming the presence of eosinophils in the gut lumen. One of our patients had a confirmed microscopic colitis and later also neutropenia, which required treatment.

CONCLUSIONS

Charcot-Leyden crystals in stool may be associated with concurrent diarrhea and eosinophilia during clozapine treatment, which is a previously unreported finding. Occurrence of blood dyscrasias with diarrhea symptoms during clozapine treatment needs further investigation to understand the possible shared mechanisms.

Clinical determinants of fever in clozapine users and implications for treatment management: A narrative review

OBJECTIVES

To identify the clinical determinants of fever in clozapine users and their impact on management of clozapine treatment.

METHODS

Articles published in English or French identified with a MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search, from inception through February 2019, using the term "clozapine" in combination with "fever" OR "hyperthermia" OR "body temperature" OR "pyrexia" OR "febrile" OR "heat" OR "thermoregulation". Information extracted for each medical condition were frequency, time to onset after initiation of clozapine treatment, characteristics of fever, associated symptoms, laboratory tests used for diagnosis, course, lethality, discontinuation of clozapine. Data were synthesized narratively.

RESULTS

Our search yielded 394 unique hits published from 1993 to 2018. We included 73 articles in the review: two meta-analyses, 14 reviews, six epidemiological studies, 11 clinical studies and 40 case reports. During clozapine initiation, fever is most frequently benign and transient but should be closely monitored as it may be the first stage of potentially life-threatening adverse drug reactions (ADR) (agranulocytosis, neuroleptic malignant syndrome myocarditis, hepatitis, pancreatitis, nephritis, colitis, etc.). Other ADR associated with fever are independent of duration of exposure to clozapine (heat stroke, pneumonia, pulmonary embolism, necrotizing colitis). If fever is due to intercurrent infection, therapeutic drug monitoring is recommended to adjust clozapine daily dosage.

CONCLUSION

Benign causes of fever are much more frequent than life-threatening ADR during clozapine treatment. Discontinuation should not be considered as automatic in the event of fever, especially during the early phase of clozapine initiation.

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:

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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.

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.