Laxatives for the management of constipation in palliative care patients

Background Constipation is a common problem for palliative care patients which can generate considerable suffering for patients due to both the unpleasant physical symptoms and psychological preoccupations that can arise. There is uncertainty about the 'best' management of constipation in palliative care patients and variation in practice between palliative care settings. Objectives To determine the effectiveness of laxative administration for the management of constipation in palliative care patients, and the differential efficacy of the laxatives used to manage constipation. Search strategy We searched The Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue four, 2005), MEDLINE (1966 to January 2005), EMBASE (1980 to January 2005), CANCERLIT, PUBMED, Science Citation Index, CINAHL, The Cochrane Library, SIGLE, NTIS, DHSS-DATA, Dissertation Abstracts, Index to Scientific and Technical Proceedings and NHS-NRR and reference lists of articles. Selection criteria Randomised controlled trials (RCTs) comparing laxatives for constipation in palliative care patients. Data collection and analysis Two review authors independently assessed trial quality and extracted patient-reported data measuring changes in stool frequency and ease of passing stools, using objective and validated scales. Tolerance or adverse effects of laxatives used were also sought. The appropriateness of synthesizing data from the controlled trials depended upon the clinical and statistical homogeneity of studies identified. If the controlled trials were homogeneous, a meta-analysis would be attempted. Main results Four trials involving 280 people were included. Between these trials, the laxatives lactulose; senna; danthron combined with poloxamer (Co-danthramer); Misrakasneham; magnesium hydroxide combined with liquid paraffin (Milpar) were evaluated. All four trials included number and frequency of bowel movements and relative ease of defecation as part of the assessment of laxative efficacy. All of the laxatives demonstrated a limited level of efficacy, although a significant number of participants required rescue laxatives in each of the studies. The only significantly different treatments were in the trial where lactulose plus senna were more effective than danthron combined with poloxamer. Patient preference did not favour either treatment option. Other related systematic reviews have similarly identified that there is a lack of evidence to support the use of one laxative, or combination of laxatives, over another. Authors' conclusions The treatment of constipation in palliative care is based on inadequate experimental evidence, such that there are insufficient RCT data. Recommendations for laxative use can be related to costs as much as to efficacy. There have been few comparative studies, equally there have been few direct comparisons between different classes of laxative and between different combinations of laxatives. There persists an uncertainty about the 'best' management of constipation in this group of patients.