1.5.1 Aminosalicylates

For guidance on the management of inflammatory bowel disease see Inflammatory Bowel Disease

Aminosalicylates may cause blood dyscrasias and patients should be told to report any unexplained bleeding, bruising, purpura, sore throat, fever or malaise that occurs during treatment. The BNF recommends a blood count should be performed and the drug stopped immediately if there is suspicion of a blood dyscrasia.

All aminosalicylates are classified as 'Specialist' drugs to reflect the need for specialist input but continuation supplies may be prescribed in primary care.



  • Tablets modified-release 400mg, 800mg (£37.68 = 2.4g daily, 800mg tablets)

Pentasa® (existing patients only)

  • Tablets modified-release 500mg, 1g (£34.43 = 2g daily)
  • Granules 1g, 2g sachets (£34.43 = 2g daily)
  • Retention enema (liquid) 1g/100mL (£17.73 = 7 enemas)
  • Suppositories 1g (£40.01 = 1g daily)


  • Retention enema (foam) 1g (£30.17 = 14 dose aerosol + applicators)
  • Retention enema (liquid) 2g/59mL (£29.92 = 7 enemas)
  • Suppositories 500mg, 1g (£29.62= 30 x 1g suppositories)



  • Octasa® tablets: Treatment of mild to moderate ulcerative colitis, acute attack 2.4g once daily, alternatively 2.4–4.8g daily in divided doses, dose over 2.4g daily in divided doses only. Maintenance of remission of ulcerative colitis and Crohn's ileo-colitis 1.2–2.4g once daily, alternatively daily in divided doses.
  • Pentasa® tablets and granules: Treatment of mild to moderate ulcerative colitis, acute attack up to 4g daily either as a single dose or in 2–3 divided doses (tablets), or 2-4 divided doses (granules). Maintenance of remission of ulcerative colitis 2g once daily.
  • Pentasa® liquid enema: Treatment of acute attack of mild to moderate ulcerative colitis or maintenance of remission 1g administered once daily at bedtime
  • Pentasa® suppositories: Treatment of acute attack, ulcerative proctitis 1g administered daily for 2–4 weeks. Maintenance, ulcerative proctitis 1g administered daily
  • Salofalk® foam enema: Treatment of mild ulcerative colitis affecting sigmoid colon and rectum 2g administered once daily at bedtime, alternatively 2g administered daily in 2 divided doses.
  • Salofalk® liquid enema: Treatment of acute attack of mild to moderate ulcerative colitis or maintenance of remission 2g administered once daily at bedtime
  • Salofalk® suppositories: Treatment of acute attack of mild to moderate ulcerative colitis affecting the rectum, sigmoid colon and descending colon 0.5–1g 2–3 times a day, adjusted according to response. Salofalk® suppositories are unlicensed for the maintenance of remission but use in practice is recognised.


  1. The BNF states that there is no evidence to show that any one oral preparation of mesalazine is more effective than another; however, the delivery characteristics of oral mesalazine preparations may vary. Oral Octasa® is recommended for use where release in the distal bowel is required. Oral Pentasa® is recommended for use where release in the proximal bowel is required.
  2. The choice of topical formulation should reflect the current disease activity, area of the gastrointestinal tract affected (e.g. proctitis, recto-sigmoid, or extensive), patient preference including ease of insertion or retention of enemas and adherence, which may also influence the dosing frequency chosen and cost. Suppositories are indicated for disease to the rectosigmoid junction because they deliver the drug more effectively to the rectum than enemas, whereas foam enemas usually treat up to the proximal sigmoid colon and liquid enemas can deliver medication as proximal as the splenic flexure in most patients. Foam and liquid enemas appear to be equally effective in treating patients with proximal ulcerative colitis, but generally foam enemas are preferred because they are easier to administer and retention is more comfortable. Suppositories are usually better tolerated than enemas.
  3. Salofalk® suppositories and foam enema are not licensed for use in maintenance of remission.
  4. If it is necessary to switch a patient to a different brand of mesalazine, the patient should be advised to report any changes in symptoms.
  5. Mesalazine intolerance occurs in up to 15% of patients, symptoms include diarrhoea, headache, nausea, thrombocytopenia and rash.
  6. Acute intolerance occurs in 3% of patients and may mimic an acute flare with bloody diarrhoea.
  7. Mesalazine-induced renal toxicity should be considered if renal function deteriorates during treatment. Renal impairment (including interstitial nephritis) is rare and idiosyncratic; it may be related to disease severity rather than dose or type of mesalazine.
  8. Renal function should be monitored every three months for the first year of treatment and annually thereafter (more frequently in renal impairment) as per BNF recommendation.
  9. Mesalazine is contra-indicated in severe renal impairment (eGFR<20mL/minute/1.73m2) and should be used with caution in less severe impairment.
  10. Patients need to remain well hydrated whilst taking mesalazine. If a patient develops dehydration while on treatment, normal electrolyte levels and fluid balance should be restored as soon as possible.
  11. Mesalazine Summary of Product Characteristics (SPCs) recommend blood tests (differential blood count, liver function parameters such as ALT or AST; serum creatinine) and urinary status (dip sticks) should be determined prior to and during treatment, at the discretion of the treating physician. As a guideline, follow-up tests are recommended 14 days after commencement of treatment and then every 4 weeks for 8-12 weeks. If the findings are normal, follow-up tests should be carried out every three months. If additional signs appear, these tests should be performed immediately. Local specialists will advise on monitoring requirements for individual patients.
  • Tablets EC 500mg (£8.43 = 500mg four times a day)



  1. See Shared Care Guideline Sulfasalazine for the treatment of inflammatory bowel disease


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