A clinical comparison of laxatives in a hospice

Abstract

Codanthramer standard strength was compared by means of a randomized crossover clinical trial with a mixture of equal proportions of lactulose and senna. Subjects were hospice inpatients who had cancer but had had no bowel diversion or evidence of intestinal obstruction. Lactulose/senna produced a significantly greater stool frequency than codanthramer in patients receiving strong opioid analgesia and reduced the usage of rectal measures. Patients' subjective assessment of bowel function indicated that lactulose/senna was more likely than codanthramer to relieve constipation or to restore normality. The incidence of diarrhoea was greater with lactulose/senna, but not significantly so when measured by patients' perceptions. Despite the difference in efficacy, patient preference was evenly divided between the agents, although there was some criticism of codanthramer's taste. It is concluded that standard strength codanthramer is less effective than the same volume of lactulose and senna in equal proportions and is more expensive. Strong codanthramer may redress the cost imbalance, but this remains to be tested. It is also suggested that a laxative dose protocol related to dose of opioid analgesia may improve the effectiveness of oral laxative therapy.