Early Oral & Topical Anti-inflammatory Therapies for IBD

Treatment Options Overview: 5-ASA

PRODUCT DETAILS / COMPANY (APPROVED BY HEALTH CANADA FOR IBD INDICATIONS)

Mesalamine / Ferring Inc. (Initial Approval 1994)

INDICATION

Treatment of mild to moderate active ulcerative colitis and for long-term maintenance therapy in order to maintain remission and prevent relapse of active disease.

           

Logistics and Monitoring: 5-ASA

METHOD OF ADMINISTRATION

Oral
Rectal suppository
Rectal enema

LOCATION

Oral 
Mild to moderate ulcerative colitis extending beyond proctitis.

Suppositories
Mild to moderate ulcerative proctitis.

Rectal suspension (enema)
Mild to moderate left-sided ulcerative colitis.

DOSING - ADULTS

Oral
Extended-release tablets (500 mg and 1 g).

Mild to moderative ulcerative colitis 2 g – 4 g daily dose.

Mild to moderate Crohn’s disease 4 g daily dose and 3 g daily dose when in remission.

Recommend taking medication reliably and consistently.  

Tablets should be swallowed whole before meals with plenty of fluid. May be dissolved in water if unable to swallow.  Do not crush. Prolonged treatment may be required.

Dosing 5-ASA once-daily can be considered for induction of remission and for maintenance. 

Rectal suppository
1 g suppository per rectum once daily at bedtime.

Rectal suspension (enema)
1 g enema or 4 g enema per rectum once daily at bedtime depending on disease activity.

DOSING - PEDIATRIC

Suggested dosing10: 
Oral mesalamine
60 to 80 mg/kg once daily to maximum 4.8 g daily

Rectal mesalamine
25 mg/kg up to 1 g daily

*Practice point: 500 mg Pentasa tabs may be dissolved in a teaspoon of water for children who cannot swallow tablets.

ROUTINE MONITORING

Not suitable for individuals with poor renal function and liver disease.

Comorbidities (i.e., hypertension, diabetes, chronic renal disease, use of nephrotoxic drugs, and concomitant steroid therapy) should be assessed prior to starting treatment.

Baseline renal function (serum creatinine, eGFR, +/- 24-hours proteinuria), 3 times in the first year and then twice per year there after.

           

5-ASA: 5 -aminosalicylic acid, CBC: complete blood count, LTF: liver function test, eGFR: estimated glomerular filtration rate

Side Effects: 5-ASA

SIDE EFFECTS

For more detailed information regarding side effects, please refer to the appropriate product monograph.

Common Side Effects
• Nausea/Vomiting
• Paradoxical diarrhea
• Allergic hypersensitivity reactions causing rash and mild fever
• Possible decreased sperm count

Serious Side Effects
• Pericarditis
• Allergic interstitial nephritis
• Cytopenia
• Pancreatitis
• Hepatitis

           

Special Populations: 5-ASA

PEDIATRICS

Data supporting the use of 5-ASA therapy in the pediatric population is limited. Health Canada has not authorized an indication for pediatric use. 


Turner D. et al. suggest10:

  • Oral 5-ASA compounds are recommended as first-line induction and maintenance therapy for mild-to-moderate ulcerative colitis.
  • Combined oral and rectal 5-ASA therapy is more effective than oral 5-ASA monotherapy.
  • Rectal monotherapy should be reserved for mild-to-moderate ulcerative proctitis, an uncommon pediatric phenotype.
  • When rectal therapy is used, 5-ASA is preferred over steroids.

ELDERLY

Data supporting the use of 5-ASA therapy in the elderly is limited. Health Canada has not authorized an indication for geriatric use.

Antanthakrishnan A. et al. suggest11: 

  • Their lack of systemic immunosuppressive effect has made them a frequently relied-on option for older patients.
  • Rare complication of interstitial nephritis may be pertinent in older patients because of age-related decline in renal function.
  • Careful monitoring is warranted.


Concern with the elderly12:

  • Polypharmacy and complex regimens that may impact adherence and drug interactions.
  • Sphincter incompetence and coordination skills to self-administer topical therapy.

PREGNANCY

For access to the full guidelines click here

The Global Consensus Statement on the management of Pregnancy in Inflammatory Bowel Disease by Mahadevan, U. et al suggest13:

For women with IBD who are pregnant or attempting conception, the guidelines recommend continuing maintenance 5-ASA therapy. There is low risk in pregnancy.

Considerations to address regarding the use of 5ASA in pregnancy include:

  • Poor adherence during pregnancy. Maintenance of remission is key and it has been shown that nearly 25% of women who were previously adherent are not during pregnancy. Non-adherence was an independent risk factor than relapse.
  • Current available 5-ASA formulations do not contain DBP which had been associated with higher odds of preterm birth in humans.
  • Rectal 5-ASA formulations can be utilized in pregnant individuals with UC, especially those with predominant rectal symptoms including urgency and tenesmus. There is no evidence to support that rectal therapy increases miscarriage rates.


In women with IBD who are pregnant, the guidelines suggest the continuing maintenance sulfasalazine therapy.

  • Mesalamine is better tolerated than sulfasalazine with intolerance likely related to the sulfapyridine component.
  • There is low risk in pregnancy.
  • Supplementation with folate 2mg/d is recommended as sulfasalazine impair folic acid absorption and metabolism.

BREASTFEEDING

For access to the full guidelines click here

The Global Consensus Statement on the management of Pregnancy in Inflammatory Bowel Disease by Mahadevan, U. et al suggest13:

  • Literature supports breastfeeding as a generally safe and beneficial practice for mothers with IBD
  • Mothers with IBD currently on 5-ASA/sulfasalazine may breastfeed.
           

5-ASA: 5- aminosalicylic acid, DBP: dibutyl phthalate, UC: ulcerative colitis

This tool is intended for Canadian Healthcare Professionals. Copyright © 2026 CANIBD Canadian IBD Nurses.

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CANIBD and Crohn's and Colitis Canada do not accept any responsibility or liability for the accuracy, content, completeness, legality, or reliability of the information contained in this Service. The content is not intended to diagnose, treat, cure or prevent disease. Content was developed in 2024 and is provided for informational purposes only.