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Mesalamine

Generic name: mesalamine

Brand names: Apriso, Delzicol, Lialda, Pentasa, Asacol HD, Canasa, Rowasa

Last updated August 25, 2026 0 views Reviewed by Carmen Pope, Senior Medical Editor, B. Pharm
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What is mesalamine?

Mesalamine is used to treat mild to moderate ulcerative colitis and prevent the symptoms of ulcerative colitis from recurring. Mesalamine is a long-term treatment that relieves inflammation and may be one of the first treatment options considered for ulcerative colitis. Mesalamine does not suppress the immune system and is not an immunosuppressant.

Mesalamine, also known as 5-ASA (5-aminosalicylic acid), is an aminosalicylic acid chemically related to aspirin. The exact mechanism of action for mesalamine in ulcerative colitis is not known, but it is thought to reduce inflammation by modulating the response of the cyclooxygenase and lipooxygenase pathways, reducing the production of prostaglandins and leukotrienes.

Some brands of mesalamine are for use only in adults, and some brands are for use in children who are at least 5 years old, for example, the delayed-release (Asacol HD) is for adults, but another brand, Lialda, may be used in adults and children who weigh at least 53 to 77 pounds (24 to 35 kg). Mesalamine capsules and tablets are taken by mouth (orally) and rectal mesalamine preparations (such as Canasa suppositories or Rowasa enemas) are inserted directly into the lowest part of the bowel to relieve inflammation associated with conditions such as distal ulcerative colitis, proctosigmoiditis, and proctitis.

Mesalamine first gained FDA approval in December 1987 as sfRowasa and Rowasa enemas. Asacol delayed-release tablets were the first oral preparation approved on January 31, 1992. Brand names for mesalamine include Lialda, Pentasa, Apriso, and Delzicol.

How should I take mesalamine?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

  • Call your doctor if your ulcerative colitis symptoms do not improve, or if they get worse.
  • This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using mesalamine.
  • You may need frequent blood tests to check your blood cells or kidney function.
  • Your urine may appear reddish-brown if it comes into contact with bleach-treated water (such as in a toilet). This is normal. Tell your doctor if your urine is discolored before it leaves your body.

Oral mesalamine

Read the label on the container. Some mesalamine preparations are taken with food and others are taken on an empty stomach. For example:

Do not substitute two 400 mg delayed-release capsules for one 800 mg delayed-release tablet.

Drink plenty of liquids to help prevent kidney stones.

Swallow the capsule or tablet whole and do not crush, chew, or break it. Tell your doctor if you have trouble swallowing the pill.

  • If you cannot swallow a Pentasa capsule whole, open it and sprinkle the medicine into a spoonful of yogurt or applesauce. Swallow the mixture right away without chewing. Do not save it for later use.

Tell your doctor if you find undissolved mesalamine tablets in your stool.

Rectal mesalamine

The usual dosage of mesalamine rectal suppositories in adults is 1000 mg administered rectally once daily at bedtime for 3 to 6 weeks depending on symptoms and sigmoidoscopic findings.

  • Using mesalamine rectal suppositories beyond 6 weeks have not been established.
  • Do not cut or break mesalamine suppositories. Retain the suppository for one to three hours or longer, if possible.
  • Drink an adequate amount of fluids.
  • Mesalamine rectal products (such as suppositories and enemas) will cause staining of direct contact surfaces, including but not limited to fabrics, flooring, painted surfaces, marble, granite, vinyl, and enamel, and should be kept away from these surfaces to prevent staining.

Before taking this medicine

You should not use mesalamine if you are allergic to mesalamine, aspirin, sulfasalazine, salicylates (such as Disalcid, Doans Pills, Dolobid, Kaopectate, Nuprin Backache, Pepto-Bismol, Tricosal, Trilisate, and others), or sulfites.

Tell your doctor if you have ever had:

  • a kidney stone or kidney disease
  • liver disease
  • a blockage in your stomach or intestines (such as pyloric stenosis) or
  • a skin condition such as eczema
  • take iron supplements or are at risk for iron overload;
  • are pregnant or plan to become pregnant
  • are breastfeeding or plan to breastfeed.

Some forms of mesalamine contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. It is not known whether mesalamine will harm an unborn baby. However, having untreated or uncontrolled ulcerative colitis during pregnancy may cause complications such as low birth weight or premature birth. The benefit of treating ulcerative colitis may outweigh any risks to the baby.

Breastfeeding

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk. If you are breastfeeding, tell your doctor if you notice diarrhea in the nursing baby.

Mesalamine side effects

Common side effects of mesalamine may include:

  • burping, constipation, nausea, vomiting, stomach pain, diarrhea, gas;
  • dizziness;
  • cold symptoms such as stuffy nose, sneezing, sore throat;
  • back pain;
  • headache;
  • rash; or
  • abnormal liver function tests.

See What are 7 mesalamine side effects to be aware of? for more information.

Serious side effects and warnings

Mesalamine may cause hypersensitivity reactions, including anaphylaxis. Should not be taken by people with a known or suspected hypersensitivity to salicylates or aminosalicylates, mesalamine, or any of the inactive ingredients in the preparations. Some hypersensitivity reactions may present with heart inflammation, such as myocarditis and pericarditis. Stop taking mesalamine and call your healthcare provider right away if you have signs of an allergic reaction such as hives; difficulty breathing; or swelling of your face, lips, tongue, or throat.

Kidney problems have been reported in people taking mesalamine or products that are converted to mesalamine. Your healthcare provider will monitor your kidney function before starting treatment and then regularly thereafter. Mesalamine may not be suitable for people with pre-existing kidney disease or who are also taking other medications that can affect kidney function.

Mesalamine has been associated with an acute intolerance syndrome (AIS) that may be difficult to distinguish from an exacerbation of ulcerative colitis. Tell your healthcare provider if your symptoms worsen while on treatment, stop treatment, or if you suspect AIS.

May not be suitable for people with liver disease.

May cause blood disorders, and seniors or those taking other medicines, such as azathioprine or 6-mercaptopurine, are more at risk. Your healthcare provider will monitor you for these.

Do not give this medicine to a child without medical advice. Some brands of mesalamine are not approved for use in anyone younger than 18 years old. Delzicol should not be given to a child younger than 5 years old.

Stop using mesalamine and call your doctor at once if you have:

  • severe stomach pain, stomach cramping, bloody diarrhea;
  • fever, unusual headache or visual disturbances, general ill feeling;
  • rash, itching, eye redness, or signs of a severe skin reaction (such as skin pain, blisters, peeling skin, or mouth sores);
  • bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
  • low white blood cell counts--fever, chills, mouth sores, skin sores, sore throat, cough, feeling light-headed, trouble breathing;
  • signs of a kidney stone--severe pain in your side and back, frequent need to urinate, foul-smelling urine, dark or cloudy urine;
  • kidney problems--increased or decreased urination, swelling, weight gain; or
  • liver problems--loss of appetite, upper stomach pain, tiredness, easy bruising or bleeding, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Low white blood cell counts may be more likely in older adults.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

The cost of prescription drugs varies depending on your insurance plan and which pharmacy you use. Refer to our price guide page for more information about the cost of mesalamine.

You may also be eligible for a mesalamine coupon, or mesalamine copay card. Ask your doctor or pharmacist if you qualify. Brand names for mesalamine include Lialda, Pentasa, Apriso, and Delzicol.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

If you have a skin condition such as eczema, mesalamine could make you sunburn more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Ask your doctor before using an antacid, and use only the type your doctor recommends. Some antacids can make it harder for your body to absorb mesalamine.

What other drugs will affect mesalamine?

Mesalamine can harm your kidneys, especially if you also use certain medicines for infections, cancer, osteoporosis, organ transplant rejection, bowel disorders, high blood pressure, or pain or arthritis (including Advil, Motrin, and Aleve).

Tell your doctor about all your other medicines, especially:

  • azathioprine or 6-mercaptopurine.

This list is not complete. Other drugs may affect mesalamine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Storage

Store at room temperature away from moisture and heat.

Common questions about mesalamine

How long does it take for mesalamine to work?
Research studies looking at patients who received daily oral doses of 4 to 6 grams of mesalamine showed that 80% of patients achieved complete or significant clinical improvement within 4 weeks.
When is the best time to take mesalamine?
The best time to take or use mesalamine will depend on the specific product you are using and why you are using it (ulcerative colitis induction or maintenance, ulcerative proctitis). Some products may need to be taken with food while others are taken on an empty stomach. Check with your doctor.
Can I stop taking mesalamine?
Mesalamine is used in some patients with ulcerative colitis as a maintenance (long-term) treatment to help you stay in remission (without active symptoms). Other treatments for ulcerative colitis or proctitis are only taken short-term. Ask your doctor when you can stop taking treatment.
Why is mesalamine so expensive?
Brand name products of mesalamine may be more expensive than generic options. Some, but not all mesalamine products are available as generics. Your insurance should help pay for generics, or if you are paying out-of-pocket, ask your healthcare provider if there is a more affordable option.
What is the maximum dosage of mesalamine?
Mesalamine is available as delayed-release tablets or capsules, extended-release capsules, and rectal preparations like suppositories or enemas. The maximum dose will depend upon the specific product you are using and your diagnosis. Only use the dose prescribed by your doctor.
Is mesalamine an immunosuppressant?
Mesalamine is an antiinflammatory, not an immunosuppressant. It may be one of the first treatments used for ulcerative colitis (UC) to lessen symptoms like diarrhea, rectal bleeding, or stomach pain. Immunosuppression is not a listed side effect for mesalamine. Other medicines used for UC, like prednisone, can suppress the immune system.
How long can you take mesalamine?
Some forms of mesalamine are used long-term as a maintenance therapy in ulcerative colitis to help prevent symptoms from flaring up. Not all forms or brands of mesalamine are used long-term, so check with your doctor about your specific medicine. Call your doctor if your ulcerative colitis symptoms get worse after starting treatment.

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
General medicine information Consumer-friendly language Source: Drugs.com

Content is provided for education and is not medical advice. See our medical disclaimer. Source page medically reviewed by Carmen Pope, Senior Medical Editor, B. Pharm on August 25, 2026.