What are the differences between different brands of mesalazine tablets?

Tim Meadows, Medicines Information Pharmacist, Midlands and East Medicines Advice Service (East Anglia site)Published
Topics: Mesalazine

This updated Medicines Q&A discusses the differences between different brands of mesalazine tablets


  • Asacol MR, Mezavant XL, Octasa MR, Pentasa Slow Release, Salofalk and Zintasa are all licensed for treatment of mild to moderate ulcerative colitis and maintenance of remission in ulcerative colitis. Asacol MR and Octasa MR 400mg and 800mg tablets are also licensed for maintenance of remission in Crohn’s ileo-colitis, although the BSG advises against this.
  • Asacol MR and Octasa MR are available in 400mg and 800mg strengths. Octasa is also available in a 1,600mg strength. Mezavant XL contains 1200mg, Pentasa Slow Release contains 500mg and 1,000mg and Salofalk contains 250mg, 500mg and 1,000mg, and Zintasa contains 400mg mesalazine.
  • Different preparations recommend different doses (including frequency) based on both strength of tablet and indication of use. These are listed in Appendix 1.
  • Asacol MR, Octasa MR, and Zintasa are similar in terms of formulation, optimal pH for drug release and site of drug release. Mezavant XL, Pentasa Slow Release and Salofalk have slightly different formulations and optimal pH for drug release. Pentasa also has a slightly different site of drug release too.
  • Renal function should be measured prior to treatment starting and then periodically once treatment is commenced. The SPCs vary in their recommendations for frequency of testing.
  • Independent reviews have concluded that there is very little difference in terms of efficacy or safety between mesalazine MR preparations so choice should depend on factors that may aid adherence to therapy; for example, less frequent dosing has been shown for some preparations to be as effective as multiple daily dosing. NICE recommends considering once-daily dosing for maintenance of remission in ulcerative colitis, although this may result in more side-effects.
  • The British National Formulary 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. If it’s necessary to switch a patient to a different brand of mesalazine, the patient should be advised to report any changes in symptoms.
  • From a cost perspective, Octasa 400mg and 800mg tablets are preferred to Asacol or generic mesalazine 400mg and 800mg tablets. Any switch to Octasa needs to be tailored to the individual needs of the patient.