Generic name: MesalamineBrand names: Rowasa, Asacol, Canasa, Pentasa

Why is Canasa prescribed?

Rowasa Suspension Enema, Pentasa, and Asacol are used to treat mild to moderate ulcerative colitis (inflammation of the large intestine and rectum). Rowasa Suspension Enema is also prescribed for inflammation of the lower colon, and inflammation of the rectum.

Rowasa Suppositories and Canasa Suppositories are used to treat inflammation of the rectum.

Most important fact about Canasa

Mesalamine, the active ingredient in these products, has been known to cause side effects such as:Bloody diarrheaCrampingFeverRashSevere headacheSudden, severe stomach pain

If you develop any of these symptoms, stop taking Rowasa and consult your doctor.

How should you take Canasa?

To Use Rowasa Suspension Enema

  1. Rowasa Suspension Enema comes in boxes of 7 bottles each. After the foil on the box has been unwrapped, all Rowasa Suspension Enemas should be used promptly, following your doctor's instructions. The Suspension Enema is normally off-white to tan in color, but may darken over time once its foil cover is unwrapped. You may still use the enema if it is slightly discolored, but do not use Rowasa Suspension Enema if it is dark brown. If you have any questions about using Rowasa Suspension Enema, contact your doctor.
  2. Use Rowasa Suspension Enema at bedtime.
  3. Shake the bottle thoroughly.
  4. Uncover the applicator tip.
  5. You may find it easier to use Rowasa Suspension Enema if you lie down on your left side, extending your left leg and bending your right leg forward for a comfortable balance. An alternative position is on your knees with your hips in the air and your head and shoulders down on the bed.
  6. Pointing the applicator tip slightly towards the navel, gently insert the tip into the rectum.
  7. Tilt the bottle slightly towards the back, then squeeze it slowly to discharge the contents.
  8. Remain in position for at least 30 minutes to allow thorough distribution of the medicine. Retain the enema all night (8 hours) for best results.

To Use Rowasa or Canasa Suppositories

  1. Rowasa suppositories should be used twice a day. Canasa suppositories can be used 2 or 3 times a day.
  2. You should handle the suppositories as little as possible, because they are designed to melt at body temperature.
  3. Remove one suppository from the strip of suppositories.
  4. While holding the suppository upright, carefully remove the wrapper.
  5. Using gentle pressure, insert the suppository (with the pointed end first) completely into the rectum. A small amount of lubricating gel may be used on the tip of the suppository to assist insertion.
  6. The suppository should be retained for 1 to 3 hours or longer for best results.

To take Pentasa or Asacol

Swallow the capsule or tablet whole. Do not break, crush, or chew it before swallowing.

You may notice what looks like small beads in your stool. These are just empty shells that are left after Rowasa has been absorbed into your body. However, if this continues, check with your doctor.

--If you miss a dose...

Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.

--Storage instructions...

Store these products at room temperature. Keep suppositories away from direct heat, light, and humidity. Do not refrigerate.

Canasa side effects

Side effects cannot be anticipated. If any side effects develop or change in intensity, tell your doctor immediately. Only your doctor can determine whether it is safe to continue using Rowasa.

  • Side effects generally include:Diarrhea, dizziness, flu-like symptoms, gas, headache, nausea, stomach pain

Other typical side effects may include:Abdominal pain, acne, back pain, belching, bloating, chest pain, chills, constipation, fever, hair loss, hemorrhoids, indigestion, insomnia, itching, joint pain, leg pain, liver disorders, menstrual problems, muscle pain, nasal inflammation, rash, rectal pain or bleeding, sore throat, stomach and intestinal bleeding, sweating, swelling of the arms and legs, tiredness, urinary burning, vomiting, weakness

Why should Canasa not be prescribed?

These products should not be used by anyone who is allergic or sensitive to mesalamine or their other ingredients.

Pentasa, Canasa, and Asacol should not be used if you are allergic or sensitive to salicylates (aspirin), foods, preservatives, or dyes.

Special warnings about Canasa

Your doctor should check your kidney function while you are taking mesalamine, especially if you have a history of kidney disease or you are using other anti-inflammatory drugs such as Dipentum.

Because older adults tend to have weaker kidneys, mesalamine is more likely to trigger side effects within this age group. The drug also seems more prone to cause blood disorders in older adults. If you are 65 or older, be sure to tell the doctor about any change in your health.

You should use mesalamine cautiously if you are allergic to sulfasalazine (Azulfidine). If you develop a rash or fever, you should stop using Rowasa and notify your doctor.

Canasa suppositories contain salicylates (including aspirin) and saturated vegetable fatty acids. If you are sensitive to one of these components, contact your doctor to discuss other options.

Some people using mesalamine have developed flare-ups of their colitis. Inflammation of the pancreas has also been reported.

Rare cases of pericarditis, in which the membrane surrounding the heart becomes inflamed, have been reported with products containing mesalamine. Symptoms may include chest, neck, and shoulder pain, and shortness of breath.

Rowasa Suspension Enema contains a sulfite that may cause allergic reactions in some people. These reactions may include shock and severe, possibly fatal asthma attacks. Most people aren't sensitive to sulfites. However, some people with asthma might be sensitive and should take any medication containing sulfites cautiously.

Rowasa Suspension Enema may stain clothes and fabrics. Canasa Suppositories can also stain surfaces, including marble, granite, plastic, and painted surfaces.

Possible food and drug interactions when taking Canasa

If these products are taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Rowasa Suspension Enema, Rowasa Suppositories, and Canasa Suppositories with sulfasalazine (Azulfidine).

Special information if you are pregnant or breastfeeding

Pregnant women should use mesalamine only if clearly needed. Mesalamine has been found in breast milk. If Rowasa is essential to your health your doctor may advise you to discontinue breastfeeding until your treatment is finished.

Recommended dosage for Canasa


Rowasa Suspension Enema

The usual dose is 1 rectal enema (60 milliliters) per day, preferably used at bedtime and retained for about 8 hours. Treatment time usually lasts from 3 to 6 weeks, although improvement may be seen within 3 to 21 days.

Rowasa Suppositories

The usual dose is one rectal suppository (500 milligrams) 2 times a day. To get the most benefit from the suppository, it should be retained for 1 to 3 hours or longer.

Canasa Suppositories

The recommended dose is 1 rectal suppository (500 milligrams) 2 times a day for 3 to 6 weeks. To get the most benefit from the suppository, it should be retained for 1 to 3 hours or longer. The dosage may be increased to 3 suppositories daily if response is unsatisfactory after 2 weeks of therapy. For the 1,000-milligram suppository, the recommended dose is 1 rectal suppository at bedtime for 3 to 6 weeks. Improvement may be seen within 3 to 21 days.

Pentasa Capsules

The usual dose is 1 gram (four 250-milligram or two 500-milligram capsules) 4 times per day for a total of 4 grams. Treatment usually lasts for up to 8 weeks.

Asacol Tablets

The recommended dose for the treatment of ulcerative colitis is 2 tablets 3 times a day for 6 weeks.

To prevent a relapse, the usual dosage is 4 tablets a day, taken in 2 or more smaller doses, for 6 months.


Safety and effectiveness in children have not been established.


There have been no proven reports of serious effects resulting from overdoses of Rowasa or Canasa. An overdose of Pentasa or Asacol could cause any of the following symptoms:

  • Confusion, diarrhea, drowsiness, headache, hyperventilation, ringing in the ears, sweating, vomiting

Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.

  • Canasa Oral, Rectal Advanced Consumer (Micromedex) - Includes Dosage Information
  • Canasa Suppositories MedFacts Consumer Leaflet (Wolters Kluwer)
  • Canasa Prescribing Information (FDA)
  • Mesalamine Prescribing Information (FDA)
  • Mesalamine Controlled-Release Capsules MedFacts Consumer Leaflet (Wolters Kluwer)
  • Apriso Prescribing Information (FDA)
  • Apriso Consumer Overview
  • Apriso Advanced Consumer (Micromedex) - Includes Dosage Information
  • Apriso Extended-Release Capsules MedFacts Consumer Leaflet (Wolters Kluwer)
  • Asacol Consumer Overview
  • Asacol Prescribing Information (FDA)
  • Asacol Delayed-Release Tablets MedFacts Consumer Leaflet (Wolters Kluwer)
  • Asacol HD Delayed-Release Tablets MedFacts Consumer Leaflet (Wolters Kluwer)
  • Asacol HD Prescribing Information (FDA)
  • Lialda Consumer Overview
  • Lialda Prescribing Information (FDA)
  • Pentasa Prescribing Information (FDA)
  • Pentasa Consumer Overview
  • Rowasa Prescribing Information (FDA)
  • Rowasa Enema MedFacts Consumer Leaflet (Wolters Kluwer)
  • Rowasa Advanced Consumer (Micromedex) - Includes Dosage Information