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Published on: March 22, 2024
Extended-release nifedipine and the risk of intestinal obstruction: a population-based study
David N Juurlink1, Chelsea Hellings2, Tara Gomes3
1The Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada Sunnybrook Research Institute, Toronto, Ontario, Canada Department of Medicine, University of Toronto, Toronto, Ontario, Canada Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
Objectives:
To examine the risk of bowel obstruction in older adults during treatment with extended-release nifedipine compared with patients treated with amlodipine.
Design:
Retrospective cohort study using multiple linked healthcare databases.
Setting:
Ontario, Canada from 1 April 1997 to 31 December 2010.
Participants:
We identified patients aged 66 years and older who started treatment with Adalat XL, an extended-release nifedipine product employing a tablet delivery system associated with mechanical bowel obstruction. For comparison, we studied patients receiving amlodipine, a long-acting calcium channel blocker that does not utilise the same delivery system and has not been implicated as a cause of bowel obstruction. Propensity score matching was used to ensure similarity of patients receiving the two drugs.
Primary Outcome Measure:
HR for the association between extended-release nifedipine relative to amlodipine and hospitalisation for bowel obstruction during therapy.
Results:
Over the 13-year study period, we identified 103 657 patients treated with extended-release nifedipine and 204 733 patients treated with amlodipine. In these two groups, 591 (0.6%) and 1185 (0.6%) of patients were hospitalised for bowel obstruction, respectively. We found no difference in the risk of bowel obstruction among patients treated with extended-release nifedipine compared with amlodipine (HR 1.09, 95% CI 0.96 to 1.24).
Conclusions:
Bowel obstruction during treatment with extended-release nidefipine is rare, and the risk is not appreciably greater than that during treatment with amlodipine.
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