Zaponex Fact Sheet Constipation

Transcription

1 Important Information The information provided in this fact sheet is intended for healthcare professionals and should not be used as a patient information leaflet. The information in this document is not intended as a definitive treatment strategy, but as a suggested approach for clinicians. It is based on information from scientific literature and previous successful experience. Each case should, of course, be considered individually. Background SmPC statement The Summary of Product Characteristics for Zaponex (clozapine) states that constipation is a very common (>1/10) side effect of Zaponex. 1 Probably on account of its anticholinergic properties, clozapine has been associated with varying degrees of impairment of intestinal peristalsis, ranging from constipation to intestinal obstruction, faecal impaction and paralytic ileus (see section 4.8). On rare occasions these cases have been fatal. Particular care is necessary in patients who are receiving concomitant medications known to cause constipation (especially those with anticholinergic properties such as some antipsychotics, antidepressants and antiparkinsonian treatments), have a history of colonic disease or a history of lower abdominal surgery as these may exacerbate the situation. It is vital that constipation is recognised and actively treated. 1 Paralytic ileus is a contraindication for clozapine use. 1 The World Gastroenterology Organisation global guideline on constipation uses the Rome Criteria III to define constipation. 2 is identified when 2 or more of the following criteria are present: straining lumpy or hard stools Feeling of incomplete evacuation sensation of anorectal blockage or obstruction manual or digital manoeuvres applied to facilitate defecation fewer than 3 defecations per week Clozapine-induced constipation is a recognised side effect of clozapine; the reported incidence varies from 14 to 60%. 3 5 Clozapine dose and plasma levels are correlated to the risk of constipation. 6 Factors such as caffeine intake, fever or certain co-medication 7 can potentially lead to increased plasma levels and therefore, could also increase the risk of developing constipation. 8 Another important risk factor for the development of constipation is co-medication of drugs that can also induce constipation (Table 1). In particular, drugs that also have anticholinergic propensities, such as certain drugs to combat hypersalivation, should be avoided in clozapine-treated patients. Additional risk factors for constipation include a history of bowel surgery, constipation or gastrointestinal pathology, 1,8 but also hypothyroidism, diabetes, Parkinson s disease and multiple sclerosis are known to predispose for constipation. December 2013 M. Jollie-Helthuis, MD Page 1 of 9

2 Although constipation is a common side effect of clozapine use, clinicians are often not aware that their patients are suffering from constipation. One reason for this could be that HCPs may often not systematically assess gastrointestinal problems. In addition, patients may be reluctant to talk about their bowel habits or they may not be aware of these problems themselves, as they could exhibit reduced pain sensitivity. 9,10 It is, however, very important to take constipation seriously, as the frequency is high and neglected constipation can have detrimental consequences. Table 1. Medication associated with constipation. 2 Group Examples Analgesics Non-steroidal anti-inflammatory agents, opiates, tramadol Anticholinergics Atropine, antidepressants (e.g SSRIs), antipsychotics, antiparkinsonian drugs Anticonvulsants Phenytion Antihistamines Antihypertensives Calcium channel antagonists, clonidine, hydralazine, MAO inhibitors, methyldopa Bisphosphonates Pamidronate, risedronate Chemotherapeutic agents Vinca derivatives Diuretics Furosemide, hydrochlorothiazide Metal ions Aluminium (antacids, sucralfate), barium sulphate, bismuth, calcium, iron, heavy metals (arsenic, lead, mercury) Resins Cholestyramine, polystyrene Serious motility impairment of the gastrointestinal system If neglected, clozapine-induced constipation can lead to serious motility impairment of the gastrointestinal system, such as intestinal (pseudo-) obstruction, faecal impaction and paralytic ileus. Warning signs for these serious consequences of constipation include abdominal pain, abdominal dilation and vomiting. 8 Palmer et al. 8 reviewed 102 cases of clozapine-induced gastrointestinal hypomotility; 50% of cases appear during the first year of treatment and the period with the greatest risk is during the first 4 months (30% of cases). The pre-onset treatment duration ranged from 3 days to 15 years. 8 Of the 102 cases, 28 patients died and among these patients, clozapine doses were higher. Although this high death rate is probably a reporting artefact, it is clear that gastrointestinal hypomotility forms a highly serious health threat. The SmPC lists intestinal obstruction/paralytic ileus/faecal impaction as very rare (1 per 10,000) side effects of clozapine therapy. Palmer et al. however, conclude that in their study, the prevalence is around 3 cases per 1000 patients exposed to clozapine. 8 Warning signs: Abdominal pain Abdominal dilation Vomiting December 2013 M. Jollie-Helthuis, MD Page 2 of 9

3 Mechanism is thought to be primarily mediated through the anticholinergic activity of clozapine, although antiserotonergic effects also seem to be involved. 8 Indeed, the antipsychotics with the highest affinity for muscarinic receptors (clozapine, olanzapine, quetiapine) have been associated more frequently with constipation. 10 Anticholinergic activity disrupts the normal functioning of the intestines, ranging from diminished duodenal motility, contractions, colon transit, gastrocolic reflex and postprandial increase of the colon activity. 10 In addition to the anticholinergic effects, the use of clozapine may contribute to the increased risk of constipation through its propensity to induce sedation, which may lead to lower physical activity and a more sedentary lifestyle. A diet low in fibre and limited fluid intake, which may be more frequent in patients suffering from mental illnesses, may also add to developing constipation. 10,11 Management Prevention A gastrointestinal history and/or abdominal examination is recommended in all patients prior to starting clozapine. 12 If there is pre-existing constipation, it should be adequately treated before clozapine initiation. 8 It is important that patients, as well as carers, clinical and nursing staff, are aware of the gastrointestinal side effects of antipsychotic treatment. It is recommended to discuss the risk of constipation before starting clozapine treatment and to provide the patient with appropriate lifestyle advice as a preventive measure. Such advice may include: Dietary advice (up to 25 g fibre/day) and fluid intake (up to 1.5 to 2 litres/day) 2,8,12 14 Regular exercise and mobility 12,13 Privacy of toileting Do not ignore the urge to defecate Any concomitant medication that can also cause constipation, such as opiates and anticholinergics, should be stopped if feasible (Table 1). If this is not possible, the patient should be monitored with increased intensity and/or prophylactic laxatives may be considered. Also for patients with a history of constipation, or predisposition due to comorbid disorders such as hypothyroidism, diabetes, Parkinson s disease and multiple sclerosis, increased monitoring and/or prophylactic laxatives may be considered. Monitoring bowel habits Since neglected constipation can lead to severe complications, it is vital that the symptoms are recognised and the condition is actively treated in an early stage. As mentioned before, patients may not always be aware of constipation or are less likely to report abdominal complaints. Therefore, clinicians should actively and systematically screen and monitor for symptoms and complications of constipation. 10 This monitoring may vary from questioning the patient for bowel movements to abdominal and rectal examination, depending on the patients medical history and mental status. Weekly screening is especially advised during the first 4 months of treatment as this seems to be a higher-risk period. 8 December 2013 M. Jollie-Helthuis, MD Page 3 of 9

4 For additional support, it may be considered to supply patients with a stool diary, which allows patients and HCPs to follow changes in defecation in time. An example for such an evaluation diary, based on the Bristol Stool Form Scale, 15 is given in Image 1. It is advised to start the use of such a diary before commencing clozapine treatment in order to obtain a baseline reference. Image 1. Example of a stool diary Date/week Frequency type 1 type 2 type 3 type 4 type 5 type 6 type 7 Monday Tuesday Wednesday Thursday Friday Saturday Sunday Treatment of constipation When a clozapine-treated patient develops constipation, it is important to make a full assessment of the patient s condition and to determine the contribution that Zaponex is making to the constipation. In this assessment, it is also important to exclude causes of constipation other than clozapine. 2 For instance, colorectal cancer should be excluded in all patients older than 50 years who report a change in bowel habit. 2 After exclusion of other causes than clozapine, 2 history and examination may guide initial management, which should be directed at the suspected cause. The World Gastroenterology Organisation global guideline on constipation provides a management scheme for approach of constipation at different stages of functional constipation. An overview of this 3-step management scheme for functional constipation, including treatment options respective for each step, is given in table 2. Table 2. Treatment options for functional constipation{lindberg 2011 #2045 Step 1 Recommend changes in lifestyle, diet, and fluid intake Administer fibre supplementation or other bulk-forming agents. Stop or reduce medications (other than clozapine) that cause constipation Step 2 Add osmotic laxatives, such as milk of magnesia, polyethylene glycol (PEG) (macrogol) or lactulose. Step 3 Use stimulant laxatives, enemas, and prokinetic drugs. Bisacodyl/sodium picosulfate is the first choice stimulant laxative for temporary use. Oral or rectal stimulant laxatives should be used short term Prokinetic drugs are designed to be taken daily. Bulking agents - Psyllium - Calcium polycarbophil - Bran - Methylcellulose Osmotic laxatives - Polyethylene glycol (PEG) (macrogol) - Lactulose - Milk of magnesia Stimulant laxatives: - Bisacodyl/sodium picosulfate - Senna Prokinetic drugs: - Prucalopride - Lubiprostone December 2013 M. Jollie-Helthuis, MD Page 4 of 9

5 Treatment of clozapine-induced constipation Every patient presenting with clozapine-induced constipation should again be given advice on diet, fluid intake and physical activity and sufficient fibre intake should be ensured (step 1 in table 2). 14 However, this is not thought to be sufficient to treat constipation and additional pharmacological intervention is recommended. 8,12 To our knowledge, there are no comparative clinical studies published on the effectiveness of different treatment regimens for clozapine-induced constipation. De Hert et al. retrospectively reviewed the treatment strategies to resolve constipation induced by antipsychotics in 273 patients during 22 months. 36.3% of patients had at least one new pharmacological intervention for constipation. The most frequently used drugs were polyethylene glycols (PEG) macrogol 4000 (30.6%) and 3350 (22.5%) followed by the stimulant laxative sodium picosulphate (25.4%). These 3 constituted 75% of all drugs used to combat constipation. 16 The effectiveness however, was not addressed in this study. The Maudsley Prescribing guidelines advises to use bulk-forming laxatives and stimulants in combination in case of any signs of constipation induced by clozapine. 14 The World Federation of Societies of Biological Psychiatry guidelines advice to use lactulose, macrogol or sodium picosulphate in case of constipation induced by antipsychotics. 12 Bulkforming agents (fibre) alone are not thought to be effective in resolving established constipation, and should be used in combination with step 2 or 3 agents. 8 A reduction in clozapine dose, if possible, may also be helpful. 17,18 In the treatment of long term clozapine-induced constipation, maintenance laxatives may be required, but continuous use of stimulant laxatives is best avoided. 13 In patients with obstructive symptoms or colonic dilatation, bulk laxatives and fibre supplementation should be avoided. 2,8 In summary, World Gastroenterology Organisation global guideline on constipation step 1 measures (table 2) should be taken in each patient who commences clozapine treatment. If a patient presents with signs of constipation, a combination of step 2 and/or step 3 measures should be added. Patients who have acute onset of symptoms, have severe symptoms, or who are not responding to treatment may need referring to a specialist for further investigation. Treatment of constipation in the elderly The elderly are generally more prone to get constipated 2 and they are more susceptible to clozapineinduced constipation than younger patients. 1 Importantly, the World Gastroenterology Organisation global guideline on constipation 2 indicates that the treatment of functional constipation in the elderly requires a more sturdy approach. In line with this, clozapine-induced constipation may be more difficult to treat in the elderly and extra caution is advised. 1 Serious motility impairment of the gastrointestinal system Severe constipation needs to be managed but does not generally warrant clozapine discontinuation. 19 However, in case of serious motility impairment of the gastrointestinal system, such as intestinal obstruction, faecal impaction and paralytic ileus, clozapine use should be stopped immediately 19 and the condition needs to be treated instantly by a specialist consultant. In almost all literature reports on severe gastrointestinal hypomotility clozapine indeed was stopped, 20 but in two publications 17,18 the problem resolved after clozapine dose reductions and treatment of the condition. December 2013 M. Jollie-Helthuis, MD Page 5 of 9

6 Rechallenges after gastrointestinal hypomotility Clozapine is among the drugs for which constipation is very common side effect. If it is possible to treat the patient with antipsychotics which have less potential to cause such effects, such as risperidone, ziprasidone and aripiprazole, 10 this would be advisable. However, some patients, who are otherwise resistant to treatment, need to recontinue clozapine treatment. A review by Nielsen et al. states that clozapine discontinuation with potential rechallenge (provided there is appropriate surveillance and management or prophylactic therapy) is possible for ileus or subileus. 19 It is important to note though, that a patient who has suffered from these conditions needs to have recovered completely first before restarting clozapine treatment. Existing paralytic ileus is a contraindication for clozapine use. 1 There are several case reports addressing re-initiation of clozapine treatment following severe clozapine-associated gastrointestinal hypomotility. Table 3 gives an overview of these publications, including the preventive measures that were taken to prevent a recurrence of gastrointestinal hypomotility. In summary of this information, it is advisable to follow preventive procedures such as described previously in this document. In addition, intensified monitoring, the use of prophylactic (osmotic) laxatives or dose reductions may be considered. If the patient is known to be unable to report symptoms of constipation, periodical abdominal physical examination and abdominal X-rays may be considered. Table 3. Rechallenges after gastrointestinal hypomotility Publication Diagnosis Rechallenge successful Poetter et al. 21 Ikai et al. 20 Partial small bowel obstruction Paralytic obstruction and colon perforation Yes, at second try with bethanechol Yes Preventive measures Conventional laxatives supplemented with muscarinic stimulant bethanechol Gradual clozapine titration in the presence of laxatives and breath control exercises. Dose reduction. Weekly abdominal physical examination and monthly abdominal X-rays for the first 4 months Monitoring of the patient s bowel movement, instructing patient on the use of milk of magnesia Notifying treatment team of potential dangers, severe dose reduction Dahmen et al. 22 Bowel obstruction Yes McKinnon et Chronic Yes al. 23 constipation and bowel infarction Rege et al. 24 Severe faecal No Concurrent use of laxatives, dose reduction impaction and sepsis Leong et al. 25 Necrotising colitis Yes Not mentioned Seller et al. 11 Faecal impaction Yes Slow increase in dosage and attention was paid to proper diet and stool patterns. December 2013 M. Jollie-Helthuis, MD Page 6 of 9

7 Advice for daily practice: Patients who take concomitant medication known to cause constipation are at increased risk Be aware of warning signs indicative for serious constipation: - Abdominal pain - Abdominal dilation - Vomiting Discuss the risk of constipation before starting clozapine treatment and provide the patient with appropriate lifestyle advice on diet, fluid intake and exercise Actively and systematically screen and monitor for symptoms and complications of constipation Use bulk-forming or osmotic laxatives in combination with stimulants in case of any signs of constipation In case of serious motility impairment of the gastrointestinal system, clozapine use should be stopped immediately and the patient needs to be referred to a specialist If other antipsychotics are not an option a patient can be restarted on clozapine, but preventive measures should be taken December 2013 M. Jollie-Helthuis, MD Page 7 of 9

8 References 1. Leyden Delta BV. Zaponex Summary of Product Characteristics (2012) Lindberg, G. et al. World Gastroenterology Organisation global guideline: --a global perspective. J Clin Gastroenterol 45, (2011). 3. Safferman, A., Lieberman, J. A., Kane, J. M., Szymanski, S. & Kinon, B. Update on the clinical efficacy and side effects of clozapine. Schizophr Bull 17, (1991). 4. Lieberman, J. A. et al. Clinical effects of clozapine in chronic schizophrenia: response to treatment and predictors of outcome. Am J Psychiatry 151, (1994). 5. Hayes, G. & Gibler, B. Clozapine-induced constipation. Am J Psychiatry 152, 298 (1995). 6. Leon, J. de, Odom-White, A., Josiassen, R. C., Diaz, F. J., Cooper, T. B. & Simpson, G. M. Serum antimuscarinic activity during clozapine treatment. J Clin Psychopharmacol 23, (2003). 7. Zaponex Medical Information Clozapine dosing and metabolism. Fact sheet ( 8. Palmer, S. E., McLean, R. M., Ellis, P. M. & Harrison-Woolrych, M. Life-threatening clozapineinduced gastrointestinal hypomotility: an analysis of 102 cases. J Clin Psychiatry 69, (2008). 9. Dworkin, R. H. Pain insensitivity in schizophrenia: a neglected phenomenon and some implications. Schizophr Bull 20, (1994). 10. Hert, M. de et al. Second-generation antipsychotics and constipation: a review of the literature. Eur. Psychiatry 26, (2011). 11. Seller, Koen & Niehaus. Clozapine-induced intestinal obstruction- a critical examination of four cases. South African Journal of Psychiatry 1 (2006). 12. Hasan, A. et al. World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, part 2: update 2012 on the long-term treatment of schizophrenia and management of antipsychotic-induced side effects. World J. Biol. Psychiatry 14, 2 44 (2013). 13. Young, C. R., Bowers, M. B. & Mazure, C. M. Management of the adverse effects of clozapine. Schizophr Bull 24, (1998). 14. Taylor, D., Paton, C. & Kapur, S. The Maudsley Prescribing Guidelines in Psychiatry. 11th Edition (Informa Healthcare, 2012). 15. Lewis, S. J. & Heaton, K. W. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol 32, (1997). 16. Hert, M. de et al. Prevalence and severity of antipsychotic related constipation in patients with schizophrenia: a retrospective descriptive study. BMC Gastroenterol 11, 17 (2011). 17. Rondla, S. & Crane, S. A case of clozapine-induced paralytic ileus. Emerg Med J 24, e12 (2007). 18. Pelizza, L., Luca, P. de, La Pesa, M. & Borella, D. Clozapine-induced intestinal occlusion: a serious side effect. Acta Biomed 78, (2007). 19. Nielsen, J., Correll, C. U., Manu, P. & Kane, J. M. Termination of clozapine treatment due to medical reasons: when is it warranted and how can it be avoided? J Clin Psychiatry 74, (2013). 20. Ikai, S., Suzuki, T., Uchida, H., Mimura, M. & Fujii, Y. Reintroduction of Clozapine After Perforation of the Large Intestine--A Case Report and Review of the Literature. Annals of Pharmacotherapy 47, e31 (2013). 21. Poetter, C. E. & Stewart, J. T. Treatment of Clozapine-Induced With Bethanechol. Journal of Clinical Psychopharmacology 33, (2013). 22. Dahmen, M. M., Stoner, S. C. & Khan, R. Successful Clozapine Rechallenge Following Surgical Repair of a Bowel Obstruction. Journal of Pharmacy Practice 22, (2009). December 2013 M. Jollie-Helthuis, MD Page 8 of 9

9 23. McKinnon, N. D., Azad, A., Waters, B. M. & Joshi, K. G. Clozapine-induced bowel infarction: a case report. Psychiatry (Edgmont) 6, (2009). 24. Rege, S. & Lafferty, T. Life-threatening constipation associated with clozapine. Australas Psychiatry 16, (2008). 25. Leong, Q. M., Wong, K. S. & Koh, D. C. Necrotising colitis related to clozapine? A rare but life threatening side effect. World J Emerg Surg 2, 21 (2007). December 2013 M. Jollie-Helthuis, MD Page 9 of 9