Canasa® (mesalamine) is a prescription medication widely used to treat inflammatory bowel disease (IBD), especially ulcerative proctitis (a mild form of ulcerative colitis limited to the rectum). It belongs to the aminosalicylate class of drugs and is designed to work locally in the lower rectum, where inflammation typically begins.
This guide explains everything you need to know about Canasa suppositories—how they work, proper usage, side effects, cost, and important precautions—so you can have a clear, trustworthy reference for your health.
Quick Disclaimer
This article is for educational purposes only and should not replace medical advice. Always follow your doctor’s instructions regarding Canasa or any other medication.
What Is Canasa?
Canasa is the brand name for mesalamine in suppository form. It is designed for rectal use only (not oral) and is absorbed locally at the site of inflammation.
- Canasa Suppository 1000 mg: The most commonly prescribed strength.
- Canasa 400 mg: A lower dose, sometimes used for specific treatment plans.
- Generic name: Mesalamine (also known as 5-aminosalicylic acid, or 5-ASA).
Unlike oral mesalamine (such as Asacol or Pentasa), Canasa directly targets the rectum and lower colon, making it highly effective for patients with localized disease.
How Does Canasa Work?
Canasa works by reducing inflammation in the lining of the colon and rectum. Mesalamine acts as an anti-inflammatory agent in the bowel by:
- Blocking the production of prostaglandins and leukotrienes (chemicals that trigger inflammation).
- Reducing redness, swelling, and irritation in the rectal tissue.
- Helping heal rectal bleeding, mucus, and pain caused by ulcerative colitis.
Unlike steroids, mesalamine is not immunosuppressive, making it safer for long-term use in many patients.
Common Uses of Canasa
Doctors prescribe Canasa primarily for:
- Ulcerative proctitis (inflammation limited to the rectum).
- Ulcerative colitis (mild to moderate) localized to the lower colon.
- Rectal bleeding, mucus, and pain due to IBD flare-ups.
- Maintenance therapy to keep inflammation under control after initial flare relief.
It is not used for Crohn’s disease, hemorrhoids, or infections unless specifically directed by your physician.
Canasa Suppository Dosage & Administration
Standard Dosage
- Adults: 1 suppository (1000 mg) inserted rectally once daily at bedtime, for 3 to 6 weeks.
- Pediatric patients: Use only if prescribed—dosing is carefully adjusted by the doctor.
Step-by-Step Instructions for Use
- Wash hands with soap and water.
- Unwrap the suppository carefully—avoid breaking or melting it in your hands.
- Lie on your side with your lower leg straight and your upper leg bent toward your stomach.
- Insert the suppository gently into the rectum, pointed end first, about 1 inch.
- Remain lying down for 15–20 minutes to prevent the suppository from slipping out.
- Best time to use: At bedtime, to maximize absorption.
Important Tips
- Do not swallow the suppository—it is only for rectal use.
- Try to empty your bowels before using it.
- Continue treatment for the full prescribed duration, even if symptoms improve earlier.
- If you miss a dose, use it as soon as you remember unless it’s close to the next scheduled dose.
Canasa Side Effects
Most people tolerate Canasa well, but side effects may occur.
Common (usually mild):
- Rectal discomfort or pain after insertion
- Gas, bloating, or abdominal cramps
- Diarrhea or mild nausea
- Headache
Less Common but Important:
- Rectal bleeding or worsening diarrhea
- Rash, itching, or allergic reactions
- Fever or flu-like symptoms
- Chest pain or shortness of breath (rare, but seek immediate help)
Rare but Serious:
- Kidney problems (mesalamine can sometimes affect kidney function)
- Pancreatitis or liver issues (very rare)
Tip: Always report new or worsening symptoms to your healthcare provider promptly.
Warnings and Precautions
- Kidney disease: Use with caution; regular monitoring may be required.
- Liver problems: Discuss with your doctor before starting.
- Allergies: If allergic to mesalamine, sulfasalazine, or aspirin-like drugs, Canasa may not be suitable.
- Pregnancy & breastfeeding: Generally considered safe, but always consult your doctor first.
- Children: Use only under specialist supervision.
Canasa vs. Other Mesalamine Treatments
| Form | Example Brands | Area of Action | Best For |
|---|---|---|---|
| Suppository | Canasa | Rectum | Ulcerative proctitis |
| Enema | Rowasa | Rectum + lower colon | Extensive distal colitis |
| Oral tablets | Asacol, Lialda, Pentasa | Entire colon | Extensive ulcerative colitis |
Key Point: Suppositories are often the first choice for ulcerative proctitis because they deliver medication exactly where it’s needed.
Cost of Canasa
- Canasa suppository price varies widely depending on location, insurance, and pharmacy.
- Without insurance, 30 suppositories (1000 mg) can cost $400–$700+.
- Generic mesalamine suppository is often cheaper, when available.
- Coupons and patient assistance programs may significantly reduce cost.
Tip: Ask your doctor about Canasa alternatives (like mesalamine enemas) if cost is a concern.
Canasa Interactions
Canasa has relatively few drug interactions but may interact with:
- NSAIDs (ibuprofen, aspirin) – may increase kidney side effect risk.
- Azathioprine or 6-mercaptopurine – may increase bone marrow toxicity.
- Other mesalamine products – avoid duplication unless prescribed.
Always share a full medication list with your healthcare provider.
Special Section: Canasa 1000 mg vs. 400 mg
- Canasa 1000 mg: Standard strength for most adult patients.
- Canasa 400 mg: Lower strength, sometimes used for maintenance or pediatric patients.
Both contain the same active ingredient—mesalamine—but differ in dosage and treatment duration.
Proper Care While Using Canasa
- Store suppositories in a cool, dry place (not in hot or humid areas).
- If they soften, refrigerating for a short time may help, but don’t freeze.
- Wash your hands before and after use.
- Keep out of reach of children.
Frequently Asked Questions (FAQs)
Q1. Is Canasa the same as mesalamine?
Yes. Canasa is a brand of mesalamine rectal suppositories.
Q2. How long does Canasa take to work?
Many patients notice improvement in 3–21 days, but full relief may take several weeks.
Q3. Can I use Canasa for hemorrhoids?
No. Canasa is not designed for hemorrhoids—it is for ulcerative proctitis/colitis.
Q4. Can I stop using Canasa if I feel better?
No. Always complete your prescribed course to prevent flare-ups.
Q5. Can I use Canasa during pregnancy?
Generally considered safe, but consult your doctor.
Q6. What if I miss a dose?
Insert as soon as possible, unless it’s almost time for the next dose.
Q7. Is there a generic for Canasa?
Yes, mesalamine suppositories are available as generics and may cost less.
Q8. How should I store Canasa?
Keep at room temperature, away from moisture and heat.
Q9. What is the difference between Canasa and Rowasa?
Canasa is a suppository (rectum only), Rowasa is an enema (rectum + lower colon).
Q10. Can children use Canasa?
Only under pediatric specialist supervision.
Q11. Can I drink alcohol while using Canasa?
Alcohol may worsen GI irritation; moderation is best.
Q12. Does Canasa cure ulcerative colitis?
No. It manages symptoms and helps maintain remission but is not a cure.
Final Thoughts
Canasa suppositories are a proven, targeted treatment for ulcerative proctitis and rectal inflammation in ulcerative colitis. By delivering mesalamine directly to the site of inflammation, they help control bleeding, pain, and mucus, and can maintain remission when used consistently.
To get the most from Canasa:
- Use it exactly as prescribed.
- Don’t stop early, even if symptoms improve.
- Store it properly and follow safe handling steps.
- Report any side effects promptly to your healthcare provider.
With proper use, Canasa can make a major difference in managing inflammatory bowel disease and improving quality of life.
