Understanding Mesalamine and Its Role in IBD
Mesalamine, also known as 5-aminosalicylic acid (5-ASA), is a first-line anti-inflammatory medication primarily used to treat and manage mild to moderate ulcerative colitis (UC). Ulcerative colitis is a form of inflammatory bowel disease (IBD) that causes swelling, inflammation, and sores (ulcers) in the lining of the large intestine (colon) and rectum. Mesalamine helps to reduce these symptoms and can also be used as a maintenance therapy to prevent flare-ups once the disease is in remission.
How Does Mesalamine Work?
The exact mechanism of action for mesalamine is not fully understood, but it is believed to work topically on the lining of the gut. It acts as an anti-inflammatory agent by stopping the body from producing certain substances, like prostaglandins and leukotrienes, that can cause inflammation. By inhibiting these inflammatory pathways directly at the site of the disease in the colon, mesalamine helps to heal the intestinal lining and alleviate symptoms such as diarrhea, rectal bleeding, and stomach pain.
Conditions Treated with Mesalamine
Ulcerative Colitis (UC): The primary use for mesalamine is for treating active, mild-to-moderate ulcerative colitis and for maintaining remission. Its effectiveness in inducing and maintaining remission in UC patients is well-established.
Crohn's Disease: While primarily used for UC, mesalamine is sometimes used for Crohn's disease, another type of IBD. However, its role in managing Crohn's disease is less clear and has produced mixed results in studies.
Formulations, Brands, and Administration
Mesalamine is available in various formulations designed to release the medication at different locations within the digestive tract. This targeted delivery ensures the drug acts where it is most needed. The choice of product depends on the specific location and extent of the inflammation in the colon.
Oral Formulations
Oral versions are designed with special coatings to delay the release of the medication until it reaches the intestine.
- Delayed-Release Tablets/Capsules: These are designed to release mesalamine in the colon. Brand names include Lialda, Asacol HD, and Delzicol.
- Extended-Release Capsules: These release the medication slowly throughout the digestive system. Brand names include Pentasa and Apriso.
Oral mesalamine is available in different strengths and can be prescribed for daily use to treat an active flare-up or to maintain remission. It's critical to take these medications as prescribed and not to crush or chew them, as that can damage their special coatings.
Rectal Formulations
Rectal therapies deliver the medication directly to the rectum and lower part of the colon and are effective for distal UC (inflammation in the lower colon and rectum).
- Suppositories: These are solid forms of medicine that are inserted into the rectum. The common brand name is Canasa. They are typically used as directed by a healthcare professional.
- Enemas: This is a liquid form of the medication administered into the rectum. The common brand name is Rowasa. It is also usually used as directed by a healthcare professional to allow the medicine to work.
Mesalamine vs. Sulfasalazine Comparison
Sulfasalazine is another medication used for ulcerative colitis. It is broken down by the body into two parts: mesalamine (5-ASA) and sulfapyridine. The sulfapyridine component is associated with more side effects than mesalamine alone.
| Feature | Mesalamine | Sulfasalazine |
|---|---|---|
| Mechanism | Acts directly as an anti-inflammatory (5-ASA) in the gut. | Breaks down into 5-ASA (the active part) and sulfapyridine (causes more side effects). |
| Primary Uses | Ulcerative colitis. | Ulcerative colitis, Rheumatoid Arthritis. |
| Common Side Effects | Headache, stomach pain, nausea, diarrhea. | Nausea, indigestion, headache; can cause low sperm count (reversible). |
| Administration Frequency | Varies by formulation. | Typically multiple times per day. |
| Allergy Concern | Allergy to salicylates (like aspirin). | Allergy to sulfa drugs and salicylates. |
Side Effects and Safety Precautions
While generally well-tolerated, mesalamine can cause side effects.
Common Side Effects
Most side effects are mild and may include:
- Headache
- Diarrhea
- Stomach pain and cramping
- Gas or burping
- Nausea and vomiting
- Runny nose or sore throat
Serious Side Effects
Though rare, serious side effects can occur and require immediate medical attention. These include:
- Kidney Problems: Mesalamine can, in rare cases, cause kidney inflammation or kidney stones. Symptoms include changes in urination, back or side pain, or blood in the urine. Drinking plenty of fluids can help prevent kidney stones.
- Acute Intolerance Syndrome: Some people experience a reaction with symptoms like cramping, bloody diarrhea, fever, and headache, which can be difficult to distinguish from a UC flare-up.
- Heart Inflammation: Myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the sac around the heart) have been reported rarely. Symptoms include chest pain and shortness of breath.
- Liver Problems: Rarely, liver issues can occur. Signs include yellowing of the skin or eyes (jaundice), dark urine, and upper stomach pain.
- Severe Skin Reactions: Serious skin reactions can happen. Any new rash should be reported to a doctor immediately.
Drug Interactions and Contraindications
Before taking mesalamine, tell your doctor about all other medications you use. Key interactions include:
- NSAIDs (Nonsteroidal anti-inflammatory drugs): Drugs like ibuprofen and naproxen may increase the risk of kidney side effects.
- Antacids: Certain antacids can interfere with the coating of delayed-release tablets and should not be taken at the same time.
- Azathioprine or Mercaptopurine: Using these with mesalamine can increase the risk of blood disorders.
People with a known allergy to salicylates (like aspirin) or sulfasalazine should not take mesalamine. It should be used with caution in patients with existing kidney or liver disease.
Conclusion
Mesalamine is a cornerstone therapy for inducing and maintaining remission in people with mild to moderate ulcerative colitis. With a variety of oral and rectal formulations available, treatment can be tailored to the location of the inflammation. While it is a safe and effective medication for most people, it's important to be aware of potential side effects and to maintain regular follow-up appointments with your healthcare provider to monitor for any issues, particularly with kidney function. Adherence to the prescribed regimen is crucial for preventing disease flares and managing this chronic condition long-term.
For more information, you can visit the Crohn's & Colitis Foundation.
