Page 2: Health Product InfoWatch – June 2017

New health product safety information

The following topics have been selected to raise awareness and, in some cases, to stimulate reporting of similar adverse reactions.

Review article

Clozapine and life-threatening gastrointestinal hypomotility – Update

Key points

  • Healthcare professionals are reminded that clozapine may be associated with life-threatening gastrointestinal hypomotility.
  • Additional deaths involving intestinal obstruction in patients taking clozapine have been reported since the last Health Canada communication.
  • Health Canada will continue to monitor this safety issue.

Clozapine is an atypical antipsychotic agent indicated in the management of treatment-resistant schizophrenia.Footnote 1 Clozapine use is limited to patients who have not responded to, or are intolerant of, conventional antipsychotic medications.

The anticholinergic activity of clozapine is associated with varying degrees of impairment of intestinal peristalsis, ranging from constipation to intestinal obstruction, fecal impaction and paralytic ileus.Footnote 1 On rare occasions, these cases have been fatal. Health Canada previously communicated to healthcare professionals in January 2011 on the risk of life-threatening gastrointestinal hypomotility with clozapine.Footnote 2 Since this communication, additional deaths related to intestinal obstruction with the use of clozapine have been reported to Health Canada.

Healthcare professionals are reminded of the potential for life-threatening gastrointestinal hypomotility suspected of being associated with the use of clozapine. Particular care is necessary in patients who are receiving concomitant medications known to cause constipation (especially those with anticholinergic properties such as some antipsychotics, antidepressants and antiparkinsonian treatments), have a history of colonic disease or a history of lower abdominal surgery as these may exacerbate the situation.Footnote 1 It is vital that constipation is recognized and actively treated.Footnote 1 Health Canada will continue to monitor this safety issue.


Footnote 1

Clozaril (clozapine) [product monograph]. Etobicoke (ON): HLS Therapeutics Inc.; 2016.

Return to footnote 1 referrer

Footnote 2

Smith E, Brûlé-Brown D. Clozapine and life-threatening gastrointestinal hypomotility. Can Advers Reaction Newsl 2011;21(1):1.

Return to footnote 2 referrer

Article citation: Health Canada. Clozapine and life-threatening gastrointestinal hypomotility – Update. Health Product InfoWatch June 2017.

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