How to use CANASA®

Follow your doctor's instructions about how often and how long to use CANASA. Follow these steps to use CANASA:

  1. Have a bowel movement just before using CANASA at bedtime
  2. Detach 1 CANASA suppository from the strip of suppositories
  3. Hold the suppository upright and carefully peel open the plastic at the precut line to remove the suppository
  4. Using gentle pressure, insert the pointed end of the suppository completely into your rectum
  5. Keep (retain) the suppository in your rectum for 1 to 3 hours or longer, if possible

Do not handle the suppository too much because it may begin to melt from the heat of your hands and body. CANASA can cause staining of clothing, other fabrics, and other surfaces.

If you miss a dose of CANASA, use it as soon as possible, unless it is almost time for the next dose. Do not use 2 CANASA suppositories at the same time to make up for a missed dose.

Please see Patient Information within the full Prescribing Information for detailed instructions.


Do not use CANASA if you are:

  • allergic to medicines that contain salicylates, including aspirin.
  • allergic to mesalamine or any of the ingredients in CANASA. See Patient Information in the full Prescribing Information for a complete list of ingredients in CANASA.
Ask your doctor if you are not sure if your medicine is listed.

Before using CANASA, tell your doctor if you:

  • have a history of allergic reaction to the medicine sulfasalazine (Azulfidine).
  • have kidney problems.
  • have ever had inflammation of the sac around your heart (pericarditis).
  • have liver problems.
  • have any other medical conditions.
  • are pregnant or plan to become pregnant. It is not known if CANASA can harm your unborn baby.
  • are breastfeeding or plan to breastfeed. CANASA can pass into your breast milk. Talk to your doctor about the best way to feed your baby if you use CANASA.
Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking CANASA with nonsteroidal anti-inflammatory drugs (NSAIDs) may cause kidney problems. Taking CANASA with azathioprine or 6-mercaptopurine may cause blood problems. Your doctor may do certain tests during treatment with CANASA.

What are the possible side effects of CANASA?

CANASA may cause serious side effects, including:

  • Kidney Problems. Your doctor will do certain tests before you start using CANASA and during your treatment.
  • Acute Intolerance Syndrome or Other Allergic Reactions. When this happens, it is usually in people who have had an allergic reaction to sulfasalazine. Stop using CANASA and tell your doctor right away if you get any of these symptoms: cramps, stomach (abdominal) pain, bloody diarrhea, chest pain, decrease in the amount of urine, fever, headache, rash, shortness of breath, or fatigue.
  • Liver Problems. This can happen in people who have a history of liver problems and have taken other medicines that contain mesalamine. Tell your doctor right away if you get any of these symptoms while using CANASA: yellowing of your eyes, itchy skin, feeling very tired, flu-like symptoms, nausea or vomiting.
The most common side effects of CANASA include: dizziness, acne, inflammation of the large intestine (colitis), rectal pain, fever, and rash.

Tell your doctor if you have any side effect that bothers you or does not go away. These are not all of the possible side effects of CANASA.

What is CANASA?

CANASA (mesalamine) 1000 mg rectal suppository is a prescription medicine used to treat adults with active ulcerative proctitis (ulcerative rectal colitis). It is not known if CANASA is safe and effective in children.

Please also see the Patient Information within the full Prescribing Information.

Allergan® and its design are trademarks of Allergan, Inc.

CANASA® is a registered trademark of Aptalis Pharma Canada ULC, an Allergan affiliate.

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The health information described in this site is provided for educational purposes only and is not intended to substitute for discussions with a healthcare provider.