5-ASA (Mesalamine, Sulfasalazine)

Aminosalicylates (5-aminosalicylic acid)

Mesalamine (also called mesalazine): Pentasa, Asacol, Salofalk, Mezavant, Lialda. Sulfasalazine (Salazopyrin) — older form, also treats joint disease but more side effects.

5-ASA is a topical anti-inflammatory drug for the bowel lining. Different formulations release in different parts of the GI tract — important for matching to the location of disease. Reduces inflammation directly without major systemic effects.

**Oral mesalamine** — many formulations and brands. Common: 2-4.8 g/day in 1-3 divided doses. Newer once-daily formulations (Mezavant) improve adherence.

**Mesalamine suppositories (1 g)** — for proctitis only; insert at bedtime.

**Mesalamine enemas (4 g/60 mL)** — for left-sided colitis; instill at bedtime, retain overnight.

**Sulfasalazine** — 2-4 g/day in divided doses; cheaper but more side effects.

Combination of oral + rectal therapy is more effective than either alone for left-sided UC.

• Severe abdominal pain or bloody diarrhea after starting — Possible mesalamine-induced colitis (paradoxical) — stop and see doctor.

• Severe rash, fever, mouth sores — Possible Stevens-Johnson syndrome — emergency.

• New shortness of breath or chest pain — Rare lung or heart inflammation — see your doctor.

• Significant kidney function decline — Mesalamine nephritis — stop and assess.

Sulfasalazine reduces folate absorption — supplement folate (especially in pregnancy planning). Limited interactions with most other drugs. Avoid combining mesalamine with other nephrotoxic drugs (NSAIDs, aminoglycosides) when possible.

Before starting: kidney function. During: kidney function every 6 months. CBC for sulfasalazine. Folate level for sulfasalazine. Periodic full liver function.

In ulcerative colitis: long-term maintenance recommended even when in remission — prevents relapse and reduces colon cancer risk. Don't stop without doctor advice.

Mesalamine is considered SAFE in pregnancy and breastfeeding. Sulfasalazine is also acceptable but may need higher folate supplementation (5 mg/day). Continue therapy in pregnancy — uncontrolled IBD is more dangerous to mother and baby than the medication.

All 5-ASA formulations are widely available and covered by insurance. Many Saudi IBD centers have pharmacist-led adherence programs.

• Should I add a rectal mesalamine to my oral form?

• Can I take mesalamine in pregnancy?

• Does long-term mesalamine reduce my colon cancer risk?

This guide comes from the Saudi Gastroenterology Association (SGA) patient library, prepared by the SGA Patient Education Panel. Last reviewed: 2026-04-24. It is for education and does not replace your doctor's advice.