Sodium docusate: the Emperor’s new laxative?
Constipation is a common problem in hospitalised people and, like many common conditions, its treatment is not supported by a strong evidence base. A range of different therapeutic options are available and some of these predate the modern requirement for systematic testing prior to widespread use. One such option is sodium docusate.
Sodium docusate (also called dioctyl sodium sulfosuccinate and can be as a calcium salt but this is not currently available in the UK) is classified as a stool softener. It is variously described as a surfactant, surface-wetting agent, emulsifier or detergent, which suggests that it reduces surface tension to promote greater interaction between water and solid stool. This implies that the cause of constipation is an inability of water within the bowel to enter the dry stool. However, it is more likely that constipated people have too little water in their bowel overall rather than it being present but unable to integrate with other bowel contents. Water does not usually have difficulty entering faeces and it is their main component, even in constipated people.
On the plus side, sodium docusate is generally well tolerated, is easy to take and has few side effects. It is often given with a stimulant laxative such as senna and this practice may be justified by the belief that it is kinder to soften the stools to make them easier to pass. Unfortunately numerous recent review articles have suggested that the evidence that it is effective is, at best, weak.1-8 Yet it continues to be used commonly and is infrequently deprescribed.9,10 Could it be that its actions are so subtle that only the wisest and most competent patients and physicians can detect its effects? Could it be the Emperor’s new laxative?
So, what evidence is there that it does work? A literature search identified ten studies that compared the use of docusate (sodium or calcium salt) to another treatment or a placebo. They have been performed in heterogeneous populations and with varying methodological quality and outcomes, which makes meta-analysis difficult. Studies that suggested a beneficial effect of docusate are older (1956 to 1968) and had major weaknesses such as allowing additional laxatives only in the docusate arm,11 inadequate placebo group for comparison,12 or excluding people from analysis who responded to placebo therapy.13 The majority of studies suggest that docusate is not better than placebo. It appears that both fibre (psyllium) and sennosides are more effective than docusate and that the addition of docusate does not improve the efficacy or tolerability of sennosides.
So is it important if we prescribe a drug that doesn’t do much but has few side effects? Well not only are we adding to polypharmacy with all its associated burden to the patient, the pharmacy, nursing staff and health service finances, but also we are potentially delaying the commencement of an effective treatment while we wait to see if it works. This may have profound implications in terms of morbidity and prolonged hospital stays that are hard to quantify. Why don’t we all just stop prescribing it before someone points out that we’re actually achieving nothing?
Author of Essential Geriatrics
- Bosshard W, Dreher R, Schnegg J, et al. The treatment of chronic constipation in elderly people: an update. Drugs Aging 2004; 21 (14): 911-930
- Ramkumar D, Rao SSC. Efficacy and safety of traditional medical therapies for chronic constipation: systematic review. Am J Gastroenterol 2005;100:936-71.
- Gallagher PF, O’Mahony D, Quigley EMM. Management of chronic constipation in the elderly. Drugs and Aging 2008; 25(10): 807-21.
- Fleming V, Wade WE. A review of laxative therapies for treatment of chronic constipation in older adults. Am J Geriatr Pharmacother 2010;8:514–550.
- Gallegos-Orozco JF, Foxx-Orenstein AE, Sterler SM, et al. Chronic constipation in the elderly. Am J Gastroenterol 2012; 107:18–25.
- Gandell D, Straus SE, Bundookwala M, et al. Treatment of constipation in older people. CMAJ 2013; 185(8): 663-70.
- Schuster BG, Kosar L, Kamrul R. Constipation in older adults: stepwise approach to keep things moving. Canadian Fam Phys 2015; 61: 152-8.
- Vazquez Roque M, Bouras EP. Epidemiology and management of chronic constipation in elderly patients. Clin Intervent Aging 2015; 10: 919-30.
- Sera L, McPherson ML. Management of opioid-induced constipation in hospice patients. Am J Hospice & Pall Med 2017; DOI: 10.1177/1049909117705379
- MacMillan TE, Kamali R, Cavalcanti RB. Missed opportunity to deprescribe: docusate for constipation in medical inpatients. Am J Med 2016; 129: 1001.e1-1001.e7.
- Cass LJ, Willem SF. Doxinate in the treatment of constipation. Am J Gastrenterol 1956; 26: 691-8.
- Harris R. Constipation in geriatrics: management with dioctyl sodium sulfosuccinate. Am J Dig Dis 1957; 2: 487-92.
- Hyland CM, Foran JD. Dioctyl sodium sulphosuccinate as a laxative in the elderly. Practitioner 1968; 200: 698-9.
- Goodman J, Pang J, Bessman AN. Dioctyl sodium sulfosuccinated: an ineffective prophylactic laxative. J Chronic Dis 1976; 29: 59-63.
- Fain AM, Susat R, Herring M, et al. Treatment of constipation in geriatric and chronically ill patients: a comparison. Southern Med J, 1978; 71: 677-80.
- Chapman RW, Sillery J, Fontana DD, et al. Effect of oral dioctyl sodium sulfosuccinate on intake-output studies of human small and large intestine. Gastroenterology 1985; 89: 489-93.
- Castle SC, Cantrell M, Israel DS, et al. Constipation prevention: empiric use of stool softeners questioned. Geriatrics 1991; 46: 84-6.
- McRorie JW, Daggy BP, Morel JG, et al. Psyllium is superior to docusate sodium for treatment of chronic constipation. Aliment Pharmacol Ther 1998; 12: 491-7.
- Hawley PH, Byeon JJ. A comparison of sennosides-based bowel protocols with and without docusate in hospitalized patients with cancer. J Palliative Med 2008; 11: 575-81.
- Tarumi Y, Wilson MP, Szafran O, et al. Randomized, double-blind, placebo-controlled trial of oral docusate in the management of constipation in hospice patients. J Pain Symptom Manage 2013; 45: 2-13.