258 - Management of suspected acute CIGH

Management of suspected acute CIGH

264 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 1 Prevention and simple management of CIGH A slow clozapine titration may reduce the risk of developing constipation, with dose increments not exceeding 25mg/day or 100mg/week.21 Increasing dietary fibre intake to at least 20–25g/day can increase stool weight but can decrease gut transit time20,22 (fibre decreases or increases transit time depending on the initial transit time).23 If fibre intake is increased it is important that adequate fluid intake (1.5–2L/day) is also maintained to avoid intestinal obstruction.8,20,24 Daily food and fluid charts would be ideal to monitor fibre and fluid intake, especially during the titration phase of clozapine. Regular exercise (150 minutes/week)25 in addition to a high-fibre diet and increased fluid intake also assists in the prevention of CIGH.26,27 Active monitoring of patients, including direct questioning, is essential. Patients often do not self-­report even life-­threatening constipation.8 Use of stool charts daily for the first 4 weeks and weekly or monthly thereafter is recommended. If there is a change from usual baseline bowel habit or fewer than three bowel movements a week,11 an abdominal examination is indicated.8 Where this excludes intestinal obstruction, both a stimulant and stool-­softening laxative should be started, as suggested by the Porirua protocol28 (for example senna 15mg at night and docusate 100mg three times daily).8,28,29 Bulk-­forming laxatives are not usually effective in slow-­transit constipation2,30 and therefore should be avoided. There is some evidence that lactulose and polyethylene glycol (for example Movicol®) are effective2,31 and could be considered in addition to the stimulant and softener combination.28 Most people with CIGH will need a stimulant laxative such as senna or bisacodyl, or both. These should not be withheld on the basis that long-­term use of stimulants is usually proscribed. In addition to laxative treatment, a review of the anticholinergic burden of other prescribed medicines should be undertaken. Consideration may be made of reducing the clozapine dose, but this step alone cannot be considered treatment of CIGH – use of laxatives is still essential. Choice of laxative should also be guided by the patient’s previous response to certain agents in association with consideration of the required speed of action. Lactulose takes up to 72 hours of regular use to work,32 so is of no use for urgent treatment. Stimulant laxatives are usually the fastest acting (6–10 hours). Laxative doses should be increased every 24 hours until resolution of symptoms (usual maximum daily dose of senna is 30mg, bisacodyl 20mg and docusate 500mg). Glycerin or bisacodyl suppositories can be used and are usually effective within 30 minutes but there are no data on their use in CIGH. In fact, published data supporting laxative choice for antipsychotic-­related constipation are sparse and of poor quality.12 Management of suspected acute CIGH Up to 30% of patients on long-­term clozapine will suffer severe GI hypomotility unless preventative steps are taken.33 Signs and symptoms that warrant immediate medical attention are abdominal pain, distension, vomiting, overflow diarrhoea, absent bowel sounds, acute abdomen, feculent vomitus and symptoms of sepsis.7,8,21,34–38 There have been case reports of fatalities occurring only hours after first symptoms present,39 and this emphasises the urgency for prompt assessment and management (including cessation of clozapine). There should therefore be a low threshold for referral to emergency medical services when conservative management fails or constipation is severe and acute.8,40