Mesalazine / mesalamine medicine card
Content date: 11 November 2026
An anti-inflammatory medicine that works inside the bowel, mainly for ulcerative colitis. It is not a usual substitute for effective Crohn’s disease treatments.
Your next step
Check your written prescription and monitoring plan. If anything is unclear, ask your care team before changing a dose.
Get urgent help: Severe rash or mouth ulcers, difficulty breathing or chest pain: seek urgent care before taking another dose. A severe headache with changed vision needs urgent assessment.
How do I use it?
- Available as tablets or granules, suppositories or enemas; your doctor may combine oral and rectal forms. Products differ in where they release the medicine and how they should be taken. Do not crush or switch products, open a capsule or dissolve a tablet unless your product leaflet allows it.
How do I store it?
- Keep in the original packaging away from heat and moisture, at the temperature stated on the pack. Instructions differ between tablets, suppositories and enemas. Do not leave it in a car.
What tests do I need?
- Kidney function before starting and regularly afterwards, with blood, liver and urine tests as appropriate. Tell your doctor about kidney disease and painkillers such as ibuprofen or diclofenac.
Possible side effects: what to expect
- Not everyone experiences side effects. Headache, nausea, wind or abdominal discomfort may occur. Report persistent symptoms; sudden worsening diarrhoea and cramps with fever after starting need assessment because a medicine reaction can resemble a flare.
- The Pentasa leaflet lists kidney disorders as very rare: up to 1 in 10,000 people. Kidney monitoring remains important to detect changes early. Other reactions include pancreatitis or allergy; see the warning signs below for when to seek help.
Important points
- Do not stop maintenance treatment when symptoms improve or double a missed dose. Pregnancy and breastfeeding plans are individualized with your doctor.
Brand / device: ........................ | Dose and how I take or use the medicine: ........................
Next dose: ........................ | Next blood tests: ........................
Team contact: ........................
When to get help
Severe rash or mouth ulcers, difficulty breathing or chest pain: seek urgent care before taking another dose. A severe headache with changed vision needs urgent assessment.
Sudden worsening diarrhea and cramps with fever after starting: seek same-day assessment and advice before the next dose; this may be a medicine reaction. Reduced urination needs prompt review, and a severe headache with altered vision needs urgent assessment.