Canasa (mesalamine) is a brand-name suppository that’s prescribed for ulcerative proctitis in adults. As with other drugs, Canasa can cause side effects, such as dizziness and rectal pain.

Canasa can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who used Canasa in clinical trials:

  • dizziness
  • rectal pain
  • fever
  • rash
  • acne

Mild side effects can occur with Canasa use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Canasa’s prescribing information.

Mild side effects that have been reported with Canasa include:

  • dizziness
  • headache
  • rectal pain
  • fever
  • rash
  • acne
  • colitis (inflammation in the colon)
  • abdominal pain
  • diarrhea
  • nausea

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Canasa and want to tell the FDA about it, visit MedWatch.

Canasa may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Canasa’s prescribing information.

If you develop serious side effects while taking Canasa, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • problems with kidney function, which may include symptoms such as:
    • urinating less than usual
    • swollen ankles
    • confusion
    • shortness of breath
  • severe skin reactions, which may include symptoms such as:
    • severe skin rash
    • skin blistering or peeling
    • fever
  • kidney stones*
  • increased sensitivity of the skin to sunlight*
  • acute intolerance syndrome*

* For more information about this side effect, see “Side effect specifics” below.

ALLERGIC REACTION

For some people, Canasa suppository can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Canasa suppository, your doctor may recommend taking a different medication instead.

Learn more about some of the side effects that Canasa may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Canasa.

Kidney stones

Canasa can sometimes cause kidney stones. It’s not known how often this side effect occurs, but it isn’t common.

Symptoms of kidney stones can include:

  • severe pain in your back or side
  • blood in your urine
  • nausea and vomiting
  • fever

What you can do

To help prevent kidney stones, it’s important to drink plenty of non-alcoholic fluids while using Canasa. Talk with your doctor about how much water you should drink each day.

If you have symptoms of kidney stones while using Canasa, talk with your doctor right away. They can determine whether you may need treatment.

If you have questions about the risk of kidney stones with Canasa, talk with your doctor or pharmacist.

Increased skin sensitivity to sunlight

While using Canasa, your skin may become more sensitive to sunlight. This is called photosensitivity. It’s not known how often this occurs, but you can prevent it by taking measures to protect your skin from the sun.

Symptoms of photosensitivity can include:

  • getting a sunburn more easily than usual
  • itching or rash on skin exposed to sunlight
  • severe sunburn or blistering

If you have a skin condition such as eczema, you are more likely to have a severe skin reaction with sun exposure while using Canasa.

What you can do

To prevent burning or other skin reactions in sunlight, you should protect your skin from the sun while using Canasa. For example, you should cover your skin with clothing, use sun cream with a high sun protection factor (SPF) on exposed skin, and wear a hat.

If you have a sunburn or other skin reaction after sun exposure, talk with your pharmacist about ways to ease this.

If you have questions about photosensitivity while using Canasa, talk with your doctor or pharmacist.

Acute intolerance syndrome

In some people, Canasa can cause acute intolerance syndrome. This can occur if your body can’t tolerate the medication. It’s not known how often this side effect occurs, but it isn’t common.

Acute intolerance syndrome can cause symptoms similar to a flare-up or worsening of your condition. You may also have symptoms similar to an allergic reaction.

Symptoms of acute intolerance syndrome can include:

  • abdominal cramping or pain
  • bloody diarrhea
  • fever
  • headache
  • feeling unwell
  • itching
  • rash
  • conjunctivitis (eye inflammation)

What you can do

If you have symptoms of acute intolerance syndrome while using Canasa, talk with your doctor right away. Your doctor may have you stop using the medication.

If you have questions about this side effect, talk with your doctor or pharmacist.

Below is important information you should consider before taking Canasa.

Other precautions

Before using Canasa, discuss your health history with your doctor. Canasa may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • kidney problems
  • liver problems
  • heart problems
  • skin problems
  • previous allergic reaction to this or a similar drug
  • pregnancy
  • breastfeeding
  • alcohol consumption

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.