Mesalazine works by reducing inflammation of the large intestine (colon and rectum) and therefore improves symptoms related to ulcerative proctitis and colitis. There are many different preparations and brands of mesalazine (Salofalk, Asacol, Pentasa, Mezavant, Colazide, Ipocol, Mesren). Some brands have proven advantages in certain patients but overall they are similar. I tend to recommend Salofalk granules first-line because of once daily dosing.

Does it work?

There is very good evidence from many clinical trials over more than 20 years that mesalazine is of significant benefit in patients with ulcerative procto-colitis. It works best in patients with mild to moderate exacerbations (or relapses) and in maintaining remission (keeping you well). It decreases the chance of a relapse from about 70% to 30% each year.

How long does it take to work?

The benefits of mesalazine treatment may not be evident for 4 weeks.

What are the common side effects?

Fortunately many patients do not suffer any side effects with this treatment. Nausea, headache, diarrhoea and abdominal pain are the most common (1:10) side effects. Rare side effects include: pancreatitis, kidney failure, unexplained bruising, bleeding, sore throat, fever or rashes. Should you develop any of these troublesome symptoms please tell either your GP or me. Mesalazine should be avoided in patients with aspirin hypersensitivity.

Mesalazine, pregnancy and breast feeding

Negligible amounts cross placenta or are found in breast milk; therefore it appears safe during pregnancy and breast feeding.

Keep all medicines out of the reach of children. Never give any medication prescribed for you to anyone else. It may harm them even if their symptoms are the same as yours.

How is it taken?

Mesalazine may be taken as tablets (or granules) by mouth (and must be swallowed whole and not chewed), or inserted into the bottom (rectum) as foam or liquid enemas or suppositories (for patients with proctitis only).

How long will I be taking it?

Patients who respond to mesalazine usually remain on it for many months and perhaps several years as long as the blood test monitoring remains satisfactory.

Special monitoring

You will need to have blood tests (full blood count, liver & kidney function) about 3 months after starting drug and then after each year because of the drug’s rare adverse effects on the bone marrow (it suppresses production of white cells & platelets) and kidney damage (interstitial nephritis). If the blood tests become abnormal, your doctor will advise you to stop the drug and normally, the test results return to normal.

At Digestive Health City & Docklands, we work hard to provide our patients with top-class care. You will enjoy friendly, fast and modern treatment by a highly experienced gastroenterologist. We carefully review patient satisfaction and feedback, and at Digestive Health we are continuously making improvements to our services, ensuring the highest level of care possible.

Get In Touch

Secretarial Hours

Monday – Friday
9am – 5pm

Call Us

0203 727 6179


@dradamharris - 2 weeks

Was pleased to organise and speak at the 3rd annual “Update in Medicine for GPs” event that took place on Saturday…

@dradamharris - 5 months

Listen to my podcast on Helicobacter pylori at

© 2021 Digestive Health City & Docklands. All Rights Reserved.

Designed and Developed By