BNF for Children 2011-2012

BNFC 2011–2012 1.6 Laxatives 571.6 Laxatives1.6.1 Bulk-forming laxatives1.6.2 Stimulant laxatives1.6.3 Faecal softeners1.6.4 Osmotic laxatives1.6.5 Bowel cleansing preparations1.6.6 Peripheral opioid-receptorantagonistsBefore prescribing laxatives it is important to be surethat the child is constipated and that the constipation isnot secondary to an underlying undiagnosed complaint.Laxatives should be prescribed by a healthcare professionalexperienced in the management of constipationin children. Delays of greater than 3 days between stoolsmay increase the likelihood of pain on passing hardstools leading to anal fissure, anal spasm and eventuallyto a learned response to avoid defaecation.In infants, increased intake of fluids, particularly fruitjuice containing sorbitol (e.g. prune, pear, or apple), maybe sufficient to soften the stool. In infants under 1 yearof age with mild constipation, lactulose (section 1.6.4)can be used to soften the stool; either an oral preparationcontaining macrogols or, rarely, glycerol suppositoriescan be used to clear faecal impaction. The infantshould be referred to a hospital paediatric specialist ifthese measures fail.The diet of children over 1 year of age should bereviewed to ensure that it includes an adequate intakeof fibre and fluid. An osmotic laxative containingmacrogols (section 1.6.4) can also be used, particularlyin children with chronic constipation; lactulose is analternative in children who cannot tolerate a macrogol.If there is an inadequate response to the osmotic laxative,a stimulant laxative (section 1.6.2) can be added.Treatment of faecal impaction may initially increasesymptoms of soiling and abdominal pain. In childrenover 1 year of age with faecal impaction, an oral preparationcontaining macrogols (section 1.6.4) is used toclear faecal mass and to establish and maintain softwell-formed stools. If disimpaction does not occur after2 weeks, a stimulant laxative (section 1.6.2) can beadded. If the impacted mass is not expelled followingtreatment with macrogols and a stimulant laxative, asodium citrate enema can be administered. Althoughrectal administration of laxatives may be effective, thisroute is frequently distressing for the child and may leadto persistence of withholding. A phosphate enema maybe administered under specialist supervision if disimpactiondoes not occur after a sodium citrate enema; abowel cleansing preparation (section 1.6.5) is an alternative.Manual evacuation under anaesthetic may benecessary if disimpaction does not occur after oral andrectal treatment, or if the child is afraid.Long-term regular use of laxatives is essential to maintainwell-formed stools and prevent recurrence in childrenwith chronic constipation or a history of faecalimpaction; intermittent use may provoke relapses. Inchildren with chronic constipation, laxatives should becontinued for several weeks after a regular pattern ofbowel movements or toilet training is established. Thedose of laxatives should then be tapered gradually, overa period of months, according to response. Some childrenmay require laxative therapy for several years.For children with chronic constipation, it may benecessary to exceed the licensed doses of somelaxatives. Parents and carers of children should beadvised to adjust the dose of laxative in order toestablish a regular pattern of bowel movements inwhich stools are soft, well-formed, and passed withoutdiscomfort.Laxatives should be administered at a time thatproduces an effect that is likely to fit in with thechild’s toilet routine.For the role of laxatives in the treatment of irritablebowel syndrome, see p. 49. For the prevention of opioidinducedconstipation in palliative care, see p. 18.Pregnancy If dietary and lifestyle changes fail tocontrol constipation in pregnancy, moderate doses ofpoorly absorbed laxatives may be used. A bulk-forminglaxative should be tried first. An osmotic laxative, suchas lactulose, can also be used. Bisacodyl or senna maybe suitable, if a stimulant effect is necessary.Laxatives are also of value in drug-induced constipation(see Prescribing in Palliative Care, p. 18), in distal intestinalobstruction syndrome in children with cystic fibrosis,for the expulsion of parasites after anthelmintictreatment, and to clear the alimentary tract beforesurgery and radiological procedures (section 1.6.5).The laxatives that follow have been divided into 5main groups (sections 1.6.1–1.6.5). This simple classificationdisguises the fact that some laxatives havea complex action.1.6.1 Bulk-forming laxativesBulk-forming laxatives are of value if the diet is deficientin fibre. They relieve constipation by increasing faecalmass which stimulates peristalsis; children and theircarers should be advised that the full effect may takesome days to develop.During treatment with bulk-forming laxatives, adequatefluid intake must be maintained to avoid intestinalobstruction. Proprietary preparations containing a bulkingagent such as ispaghula husk are often difficult toadminister to children.Bulk-forming laxatives may be used in the managementof children with haemorrhoids, anal fissure, and irritablebowel syndrome.ISPAGHULA HUSKCautions adequate fluid intake should be maintainedto avoid intestinal obstructionContra-indications difficulty in swallowing, intestinalobstruction, colonic atony, faecal impactionSide-effects flatulence and abdominal distension(especially during the first few days of treatment),gastro-intestinal obstruction or impaction; hypersensitivityreportedLicensed use Isogel c licensed for use in children(age range not specified by manufacturer)1 Gastro-intestinal system