BMA Concise Guide to Medicine & Drugs


Brand names Asacol, Ipocol, Mesren MR, Mezavant XL, Octasa, Pentasa, Salofalk

Used in the following combined preparations None


Drug group Drug for inflammatory bowel disease

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic No


Mesalazine is prescribed for patients with ulcerative colitis and is sometimes used for Crohn’s disease, which affects the large intestine. The drug is given to relieve symptoms in an acute attack and is also taken as a preventive measure. When mesalazine is used to treat severe cases, it is often taken with other drugs such as corticosteroids.

When the drug is taken as tablets, the active component is released in the large intestine, where its local effect relieves the inflamed mucosa. Always stick to the same brand of tablet. Enemas and suppositories are also available and are particularly useful when the disease affects the rectum and lower colon.

This drug produces fewer side effects than some older treatments, such as sulfasalazine. Patients unable to tolerate sulfasalazine may be able to take mesalazine with no problem. Anyone hypersensitive to salicylates, such as aspirin, should not take mesalazine.


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, SR tablets, granules, suppositories, enema (foam or liquid).

Frequency and timing of doses 3 x daily, swallowed whole and not chewed (tablets); 3 x daily (suppositories); once daily at bedtime (enema).

Adult dosage range 2.4–4g daily (acute attack); 1.2–2.4g daily (maintenance dose). Dose varies with brand used.

Onset of effect Adverse effects may be noticed within a few days, but full beneficial effects may not be felt for a couple of weeks.

Duration of action Up to 12 hours.

Diet advice Your doctor may advise you, taking account of the condition affecting you.

Storage Keep in original container at room temperature out of the reach of children. Protect from light. Keep aerosol container out of direct sunlight.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop taking the drug without consulting your doctor; symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.


Gastrointestinal problems such as nausea, abdominal pain and diarrhoea are common; discuss with your doctor if they are severe. If your colitis worsens or you develop a rash, you should stop taking the drug and consult your doctor. If fever, wheezing, spontaneous bruising or bleeding, sore throat, or malaise occur, you should stop the drug and immediately contact your doctor, who may carry out a blood test to check for blood disorders.


Lactulose The release of mesalazine at its site of action may be reduced by lactulose.

Warfarin Mesalazine may reduce the effect of warfarin.

Azathioprine and mercaptopurine may increase the risk of blood problems with mesalazine.


Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have a blood disorder.

· You are allergic to aspirin.

· You are taking other medicines.

Pregnancy Negligible amounts of the drug cross the placenta. However, safety in pregnancy is not established. Discuss with your doctor.

Breast-feeding Negligible amounts of the drug pass into the breast milk. However, safety is not established. Discuss with your doctor.

Infants and children Not recommended under 15 years.

Over 60 Dosage reduction not normally necessary unless there is kidney impairment.

Driving and hazardous work No special problems.

Alcohol No special problems.


No problems expected.

Monitoring Regular blood tests and checks on kidney function are usually required.