Pentasa Slow release tablets 500 mg – patient leaflet, side effects, dosage

1. What Pentasa Tablet Is And What It Is Used For

Each Pentasa Slow Release Tablet contains mesalazine 500mg or 1g as the active ingredient. Mesalazine belongs to a group of medicines called salicylates.

Pentasa Tablets are used for the treatment of mild to moderate attacks of ulcerative colitis and to help maintain freedom from further attacks. Ulcerative colitis is an inflammatory bowel disease in which the lining of the intestine becomes inflamed and develops many tiny breaks in its surface (ulcers) which may bleed.

Pentasa tablets release the active ingredient slowly which then acts locally to reduce the inflammation and help relieve or stop the pain.

2. What You Need To Know Before You Take Pentasa Tablets

Do Not take Pentasa Tablet if you:

• are allergic (hypersensitive) to mesalazine or any of the

  other ingredients of this medicine (see section 6)

• are allergic to other salicylates e.g. acetylsalicylic acid
• have severe liver and/or kidney problems Warnings and precautions

Talk to your doctor or pharmacist before taking Pentasa Tablets if you:

• are allergic to sulphasalazine (risk of allergy to

  salicylates)

• currently have or have previously had liver or kidney

  disease

• have a medical condition that can make you prone to

  bleeding

• have an active peptic ulcer (stomach ulcer or duodenal

  ulcer)

• are on medication that may affect kidney function e.g.

  Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin

• have lung problems, in particular asthma

• suddenly develop abdominal cramps, abdominal pain,

  fever, severe headache and rash. In such circumstances you should stop taking Pentasa immediately.

• Kidney stones may develop with use of mesalazine.

  Symptoms may include pain in sides of abdomen and blood in urine. Take care to drink sufficient amount of liquid during treatment with mesalazine

• have ever developed a severe skin rash or skin peeling,

  blistering and/or mouth sores after using mesalazine. Mesalazine may produce red-brown urine discoloration after contact with sodium hypochlorite bleach in the toilet water. It concerns a chemical reaction between mesalazine and bleach and is harmless.

Take special care with mesalazine

Serious skin reactions including Drug reaction with eosinophilia

and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported in association with mesalazine treatment. Stop using Pentasa tablets and seek medical attention immediately if you notice any of the symptoms related to these serious skin reactions described in section 4.

If you experience strong or recurrent headache, disturbed vision, or ringing or buzzing in the ears contact your doctor immediately.

While you are on treatment with this medicine, your doctor will normally arrange blood and urine tests to check your kidney function especially at the beginning of treatment.

You should make sure that you don’t become dehydrated, while you are taking this medicine. This can occur after severe or prolonged attacks of vomiting and/or diarrhoea, high fever or heavy sweating. If this occurs, you should talk to your doctor or a pharmacist for advice as soon as possible.

Other medicines and Pentasa Tablets

Tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. This is especially important if you are taking any of the following :

• azathioprine (used after transplantations or to treat auto-immune diseases)
• 6-mercaptopurine or thioguanine (chemotherapy, used to treat leukaemia)

• certain agents that inhibit blood clotting (medicines for thrombosis or to thin your blood, e.g. warfarin) Pregnancy, Breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine. There is limited experience with the use of mesalazine during pregnancy and breast-feeding. Blood disorders have been reported in newborns of mothers being treated with this medicine. The newborn may develop allergic reactions after breast-feeding, e.g. diarrhoea. If the newborn develops diarrhoea, breast-feeding should be discontinued. Driving and using machines

This medicine is not known to affect the ability to drive and/or use machines.

3. How To Take Pentasa Tablets Always take Pentasa exactly as your doctor has told you.

You should check with your doctor or pharmacist if you are not sure.

Adults

To treat an attack of colitis, your doctor will usually prescribe a dose of up to 4g mesalazine a day to be taken as eight 500mg tablets or four 1g tablets, once a day or in two or three divided doses.

To help maintain freedom from further attacks, your doctor will usually prescribe a dose of 2g mesalazine a day, to be taken as four 500mg tablets or two 1g tablets, once a day.

Use in children and adolescents

Children 6 years of age and older:

The dose for children will be calculated by your doctor and depends on the child’s weight. It is generally recommended that half the adult dose is given to children up to 40 kg of body weight and the normal adult dose to children above 40 kg of body weight.

You should take the tablets orally (by mouth) either whole or broken up, they should not be crushed or chewed. If you have difficulty swallowing the tablets you can disperse them in a small quantity of cold water (approximately 50ml) then stir and drink immediately.

If you take more Pentasa than you should

If you have accidentally taken too many tablets, you should go to your nearest emergency department or contact your doctor immediately. Take the pack and any remaining tablets with you.

If you forget to take Pentasa

If you forget to take a dose, then take it as soon as you remember, unless it is less than 3 hours until your next dose. Do not take a double dose to make up for the forgotten one. If you have any further questions on the use of this product, ask your doctor or pharmacist.

4. Possible Side Effects

Like all medicines, Pentasa can cause side effects, although not everyone gets them.

STOP taking Pentasa Tablets and seek medical attention immediately if you notice any of the following symptoms:

• reddish non-elevated, target-like or circular patches on

  the trunk, often with central blisters, skin peeling, ulcers of mouth, throat, nose, genitals and eyes, widespread rash, fever and enlarged lymph nodes. These serious skin rashes can be preceded by fever and flu-like symptoms.

• itching, skin rashes, swelling of the face, lips or throat,

  difficulty in breathing or wheeziness (signs of an allergic reaction).

• unexplained bleeding, bruising, skin rashes, fever or sore

  throat (signs of a blood disorder).

• a change in the colour or amount of urine produced (signs

  of kidney problems).

If you experience any of the above side effects, you should contact your doctor or go to the nearest hospital emergency department immediately.

The following common side effects may affect up to 1 in 10 people:

• diarrhoea
• abdominal pain
• nausea
• vomiting
• headache
• rash
• flatulence (passing wind)

The following rare side effects may affect up to 1 in 1,000 people:

• inflammation of some areas of the heart (myocarditis and

  pericarditis) which can cause shortness of breath and chest pain or palpitations (rapid or irregular heartbeats)

• inflammation of the pancreas (symptoms include back

  and/or stomach pain).

• Increased amylase (enzyme that helps digest

  carbohydrates)

• dizziness

• Increased sensitivity of your skin to sun and ultraviolet

  light (photosensitivity).

The following very rare side effects may affect up to 1 in 10,000 people:

• anaemia and other blood disorders (decrease in the

  numbers of certain blood cells, which can cause unexplained bleeding, bruising, fever or sore throat)

• liver disorders (symptoms include jaundice (yellowing of

  the skin and/or eyes) and/or pale bowel motions)

• kidney disorders (symptoms include blood in the urine,

  and/or oedema (swelling due to build-up of fluid))

• peripheral neuropathy (a condition affecting the nerves

  of the hands and feet symptoms include tingling and numbness)

• allergic and fibrotic lung reactions, inflammation of the

  lining of the lungs or lung scarring (symptoms include coughing, bronchospasm, chest discomfort or pain on breathing, breathing difficulties, bloody and/or excessive phlegm)

• Pancolitis (a kind of inflammatory bowel disorder (IBD)

  that affects the entire internal lining of the large bowel)

• hair loss (this is reversible)
• muscle or joint pain

• inflammation which can affect different parts of the body

  such as joints, skin, kidneys, heart etc. (symptoms include painful joints, fatigue, fever, abnormal or

• unexplained bleeding (e.g. nose bleeds), bruising, purple

  discoloration of the skin (including severe skin erosions and severe blistering that may affect the skin as the protective barrier of the body))

• semen with a low concentration of sperm (oligospermia)

  (this is reversible)

• severe diarrhoea and abdominal pain because of an

  allergic reaction to this medicine within the bowel

• allergic reactions and fever may occasionally occur.

  Not known (frequency cannot be estimated from the available data)

  • kidney stones and associated kidney pain (see also section 2)
  • change in urine colour.
  • if you experience strong or recurrent headache, disturbed vision, or ringing or buzzing on the ears. These could be symptoms of increased pressure within your skull (idiopathic intracranial hypertension).

Reporting of side effects

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme, website: www.mhra.gov.uk/ yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects, you can help provide more information on the safety of this medicine.

5. How To Store Pentasa Tablets

Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the carton and blister. The expiry date refers to the last day of that month.

Do not store above 25ºC. Do not freeze.

Store in original packaging to protect from light. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Content Of The Pack And Other Information What Pentasa Tablets contain

The active substance is mesalazine

Each tablet contains 500mg or 1g of mesalazine. Other ingredients: povidone, ethylcellulose, microcrystalline cellulose, magnesium stearate and talc.

What Pentasa Tablets looks like and the contents of the pack

Pentasa Tablets 500mg

White/grey to pale brown, specked round tablets, scored and marked ‘500mg’ on one side and ‘PENTASA’ on the other side. Each carton contains 100 tablets presented in blister strips of 10 tablets per strip.

Pentasa Tablets 1g

White/grey to pale brown, specked oval tablets, marked with ‘PENTASA’ on both sides. Each carton contains 60 tablets presented in blister strips of 10 tablets per strip. Marketing Authorisation Holder:

Ferring Pharmaceuticals Ltd., Drayton Hall, Church Road, West Drayton, UB7 7PS, (UK))

Manufactured by:

Ferring GmbH, Wittland 11, D-24109 Kiel, Germany. This leaflet was last revised in May 2025.

PENTASA is a registered trademark.

Date: 04 Jun 2025