Canasa (Mesalamine)

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Canasa Brand

We don't sell this brand-version medication.

Mesalamine (Generic alternate to Canasa) Generic

We don't sell this generic-version medication.

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Table of contents:

Canasa is a prescription medication used to treat active ulcerative proctitis (ulcerative rectal colitis) in adults. It contains mesalamine and is administered in the form of a rectal suppository. Mesalamine is a type of anti-inflammatory agent that works by decreasing inflammation in the colon. Mesalamine belongs to a class of drugs called 5-aminosalicylic acid. It works by reducing inflammation in the epithelial cells that line the colon.

Mesalamine does not cure ulcerative proctitis, but it may decrease the number of stools, the amount of mucus/blood in the stools, and the rectal bleeding caused by irritation/swelling of the colon/rectum. Its anti-inflammatory action may result from its ability to block the enzyme cyclooxygenase (COX) and inhibit prostaglandin production in the colon. COX and prostaglandins (a group of lipids) are both involved in generating an inflammatory response.

Uses and Dosage

Canasa is administered rectally as a suppository. The specific dosage and frequency of use will depend on the strength of your prescription and your medical condition. Be sure to follow your doctor's instructions carefully.

To use Canasa rectal suppository:

  1. Wash your hands thoroughly before and after use.
  2. Remove the suppository from its foil wrapper.
  3. Lie on your left side with your left leg extended and your right knee bent.
  4. Gently insert the suppository, pointed end first, into the rectum.
  5. Push the suppository in as far as it can go with your finger.
  6. Stay lying down for at least 30 minutes to allow the medication to work.
  7. Wash your hands again after use.

If your prescription is of 1000-milligram strength, insert it once a day at bedtime. If you are using a lower strength, then your doctor may direct you to use it 1 to 3 times a day. You should follow your doctor's instructions carefully. The dosage will depend on your medical condition, response to therapy, and the strength of your prescription. During your treatment with this medication, be sure to drink plenty of fluids, unless directed otherwise by your doctor, as it will help prevent kidney stones.

Side effect

Common Side Effects of Canasa (Mesalamine):

  • Dizziness
  • Tiredness
  • Headache
  • Rectal pain
  • Fever
  • Rash
  • Vomiting
  • Gas

Serious Side Effects of Canasa (Mesalamine):

  • Cramping
  • Pain in the stomach
  • Bloody stool/diarrhea
  • Chest pain
  • Urine retention
  • Shortness of breath
  • Yellowing of the skin or eyes
  • Severe headache

Form and Strength

Canasa (Mesalamine) is available in the following forms and strength:

Canasa: Rectal Suppository

  • 500 mg
  • 1000 mg


  • Canasa should be used with caution in patients with known allergies to salicylates, sulfasalazine, or any component of Canasa.
  • Canasa should also be used with caution in patients with impaired kidney function, as it can cause kidney problems.
  • Patients taking Canasa should be closely monitored for worsening of symptoms, development of new symptoms, or signs of hypersensitivity reactions.
  • Canasa may interact with certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Patients with a history of liver disease, blood disorders, or other medical conditions should discuss the risks and benefits of taking Canasa with their doctor.
  • Canasa should not be used by pregnant women unless the benefits outweigh the potential risks.
  • Canasa may be excreted in breast milk, so patients who are breastfeeding should talk to their doctor before taking Canasa.
  • Canasa may worsen certain medical conditions, such as liver disease, blood disorders, or pancreatitis, so patients with these conditions should discuss the risks and benefits of taking Canasa with their doctor.
  • Canasa may cause dizziness or drowsiness, so patients should use caution when driving or operating heavy machinery until they know how the medication affects them.
  • Patients taking Canasa should avoid alcohol, as it can worsen some side effects of the medication.
  • Canasa may increase the risk of certain infections, so patients should be monitored closely for signs of infection and should report any symptoms to their doctor immediately.
  • Canasa should not be used in patients with abnormal kidney function or a history of kidney disease.
  • Patients taking other medications, especially those that affect the kidneys or the liver, should discuss the risks and benefits of taking Canasa with their doctor.

Frequently Asked Questions (FAQ)

Is Canasa safe?

Canasa is generally safe when used as directed by a doctor. However, like any medication, it can cause side effects in some people. If you experience any unusual side effects or allergic reactions, contact your doctor immediately.

Can I take Canasa if I'm pregnant or breastfeeding?

Take to your doctor before taking Canasa if you are pregnant or breastfeeding. Your doctor can help you weigh the potential risks and benefits of the medication.

Can Canasa be used to treat other conditions?

Canasa is only approved for the treatment of ulcerative proctitis. It should not be used to treat other medical conditions unless directed by a doctor.

Can I use Canasa if I am pregnant or breastfeeding?

Discuss the potential risks and benefits of using Canasa with your doctor if you are pregnant or breastfeeding.

How should I store Canasa?

Store Canasa suppositories at room temperature, away from moisture and heat.


It's important to purchase Canasa from verified Canadian pharmacy.

Additional information

Generic name:



Rectal Suppository


500mg, 1000mg

Quantities Available:

30, 90


Online Pharmacies Canada has provided information from third parties intended to increase awareness and does not contain all the information about Canasa (Mesalamine). Talk to your doctor or other qualified medical practitioners for medical attention or advice, or if you have any concerns about Canasa (Mesalamine).