Traditional laxatives in preventing opioid-induced constipation in adult patients with cancer: a systematic review and meta-analysis protocol

Abstract

Introduction: Opioid-induced constipation (OIC) affects up to 90% of patients with cancer receiving long-term opioid-related analgesic therapy, resulting in various potential complications, compromised pain management and decreased quality of life. Laxatives stimulate or facilitate bowel evacuation. Traditional laxatives, such as polyethylene glycol and lactulose, are widely used because of their low cost, easy accessibility and tolerability. OIC prophylaxis with laxatives is recommended for patients receiving opioid therapy. However, systematic reviews that support this practice are lacking. They have primarily focused on patients with existing constipation and the effectiveness of other pharmacological therapies. Thus, we are conducting a systematic review to evaluate the efficacy and safety of traditional laxatives in preventing OIC in adult patients with cancer.

Methods and analysis: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols 2015 statement was used to guide the reporting of this protocol. Database searches will be performed in PubMed, Embase, Web of Science, Cochrane Library and EBSCO from inception to a date within 6 months of the submission of the full systematic review (estimated 31 December 2024). Reference lists will also be accessed for additional studies, including Google Scholar, for the inclusion of grey literature. A combination of Medical Subject Headings/Emtree and free-text terms will be used when searching the core concepts of 'OIC', 'laxative' and 'cancer.' The eligibility criteria will be defined by the type of population (patients with cancer receiving opioid therapy), type of intervention (traditional laxatives) and type of study (randomised controlled trials and quasi-experimental trials). Two reviewers will independently select eligible studies, extract data and assess the methodological risk of bias. A third reviewer will be invited to reach a consensus if necessary. Subgroup and sensitivity analyses will be conducted to explore sources of heterogeneity.

Ethics and dissemination: Ethical approval is not required, as patients will not be included in systematic reviews and meta-analyses. We will publish this study in a peer-reviewed journal and communicate the results at open conferences.PROSPERO registration numberCRD42024507127.

Keywords: Cancer pain; Gastroenterology; Nursing Care; Patient-Centred Care; Systematic Review.