Skip to main content
          Skip to FDA Search
          Skip to in this section menu
          Skip to footer links


U.S. flagAn official website of the United States government

					Here’s how you know
          			Dot gov**The .gov means it’s official.**Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.
							      SSL**The site is secure.** The **https://** ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely. 
			U.S. Food and Drug Administration
				
        Search
            Menu
							
						Search FDA
									
									Submit search 
		Featured
							Contact FDA
	                FDA Guidance Documents
	                Recalls, Market Withdrawals and Safety Alerts
	                Press Announcements
	                Warning Letters
	                Advisory Committees
	                En Español

					Products
            Food
							Drugs
							Medical Devices
							Radiation-Emitting Products
							Vaccines, Blood, and Biologics
							Animal and Veterinary
							Cosmetics
							Tobacco ProductsTopics
            About FDA
							Combination Products
							Regulatory Information
							Safety
							Emergency Preparedness
							International Programs
							News and Events
							Training and Continuing Education
							Inspections and Compliance
							Science and ResearchInformation For
            Consumers
	            Patients
	            Industry
	            Health Professionals
	            Federal, State and Local Officials 
 In this section:

                FDA Drug Safety Podcasts

FDA Drug Safety Podcasts Home
          Drugs
          Drug Safety and Availability
          FDA Drug Safety Podcasts
          FDA strengthens warning that untreated constipation caused by schizophrenia medicine clozapine (Clozaril) can lead to serious bowel problemsFDA Drug Safety Podcasts FDA strengthens warning that untreated constipation caused by schizophrenia medicine clozapine (Clozaril) can lead to serious bowel problems
  
  					FDA Drug Safety Podcast
	
    Share
    Post
    Linkedin

    Email
    PrintListen

Welcome to the FDA Drug Safety Podcast for health care professionals from the Division of Drug Information. This is Lesley Navin, Advanced Practice Nurse.

On January 28, 2020, FDA strengthened an existing warning that constipation caused by the schizophrenia medicine clozapine (brand names Clozaril, Fazaclo ODT, and Versacloz) can progress to serious bowel complications. This can lead to hospitalization or even death if constipation is not diagnosed and treated quickly. Constipation is a frequent and known side effect of clozapine, but serious and fatal events continue to be reported.

Clozapine affects bowel function in a majority of patients producing effects ranging from constipation, a common occurrence, to serious but uncommon bowel problems, including complete blockage of the bowel. We found that because of the way clozapine works this risk is greater with clozapine than with the other schizophrenia medicines in its drug class. The risk is further increased at higher doses of clozapine and when co-prescribed with anticholinergics and other medicines that cause constipation, including opioids.

We are requiring a new warning and updates about this risk be added to the prescribing information of all clozapine products. Clozapine is used to treat schizophrenia in patients whose symptoms are not controlled with standard treatment. It is effective in reducing the risk of suicidal thinking and self-harm in patients with schizophrenia or schizoaffective disorder.

Health care professionals should evaluate bowel function before starting patients on clozapine and avoid co-prescribing clozapine with anticholinergics. Advise patients of the significant risk of constipation and life-threatening bowel issues and the need to stay hydrated to prevent constipation.

Advise patients to contact a health care professional right away if they have difficulty passing stool, do not have a bowel movement at least three times a week or less than their normal frequency, or are unable to pass gas. Consider prophylactic laxative treatment when starting clozapine in high-risk patients.

We reviewed the period from 2006 to 2016 and identified 10 cases describing constipation that progressed to serious bowel problems resulting in hospitalization, surgery, or death. This number includes only cases submitted to FDA or found in the medical literature, so there may be additional cases about which we are unaware.

Side effects involving clozapine should be reported to FDA’s MedWatch program at www.fda.gov/medwatch.

A link to the full communication detailing specific information for health care professionals and the complete Data Summary can be found at www.fda.gov/DrugSafetyCommunications. If you have drug questions, you can reach us at druginfo@fda.hhs.gov.

And follow us on Twitter @FDA_Drug_Info. Thanks for listening.

Related Information

FDA Drug Safety Communication: FDA strengthens warning that untreated constipation caused by schizophrenia medicine clozapine (Clozaril) can lead to serious bowel problems
	FDA Drug Safety Podcast: FDA strengthens warning that untreated constipation caused by schizophrenia medicine clozapine (Clozaril) can lead to serious bowel problems

                                                                                  Content current as of:
      01/14/2022
              
              
Regulated Product(s)
		 DrugsFDA Drug Safety Podcasts
 
 Footer Links
    FDA Archive
          About FDA
          Accessibility
      Visitor Information
          Website Policies / Privacy
          No FEAR Act
          Vulnerability Disclosure Policy
      FOIA
          HHS.gov
          USA.gov
    Contact FDA
      Follow FDA on Facebook
      Follow FDA on X
      Follow FDA on Instagram
      Follow FDA on LinkedIn
      View FDA videos on YouTube
      Subscribe to FDA RSS feeds
    FDA Homepage
    Contact Number
      1-888-INFO-FDA (1-888-463-6332) Back toTop