Sulfasalazine

5-Aminosalicylic Acid Prodrug·Gastrointestinal - IBD & Antidiarrhoeals

Ulcerative Colitis, Rheumatoid Arthritis

Authority requiredPBSANTI-INFLAMMATORYSalazopyrin, Salazopyrin EN500 mg EC tablet+2

Max Dose

4 g/day

Half-life

6-14 h

Sulfa Allergy

CONTRAIND.

Folate Depletion

HIGH RISK

Rapid Summary

Overview

A prodrug combining 5-ASA (mesalazine) and sulfapyridine. Used for IBD and Rheumatoid Arthritis. Requires colonic bacteria for activation.

Maximum Dose

Max 4 g/day (given in divided doses).

Clinical Focus

The sulfapyridine component causes significant systemic toxicity (rash, marrow suppression). High rates of intolerance compared to pure Mesalazine.

Bottom Line

Sulfasalazine is a dual-action DMARD used in ulcerative colitis and rheumatoid arthritis, but causes significant GI intolerance, requires folate supplementation, and can cause blood dyscrasias.

Formulation & Access

Brand Names

Salazopyrin, Salazopyrin EN

Oral Routes

Tablets (500 mg), Enteric-coated tablets (500 mg).

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Ulcerative Colitis, Rheumatoid Arthritis.

Clinical Place

Excellent for UC patients with concurrent inflammatory arthropathy (as the sulfapyridine component treats the joints, while the 5-ASA treats the gut).

Quick reference

Class & Role

5-Aminosalicylic Acid Prodrug — A prodrug combining 5-ASA (mesalazine) and sulfapyridine.

Route / Formulation

Tablets (500 mg), Enteric-coated tablets (500 mg). (Salazopyrin, Salazopyrin EN)

Usual Dose & Max

PO 1-2 g QID (Max 4 g/day).

Key Indication Doses

Ulcerative Colitis (Flare): PO 1-2 g QID (Max 4 g/day). Rheumatoid Arthritis: Start PO 500 mg OD, titrate weekly to 1 g BD.

Best Uses

Sulfasalazine is a dual-action DMARD used in ulcerative colitis and rheumatoid arthritis, but causes significant GI intolerance, requires folate supplementation, and can cause blood dyscrasias.

Avoid / Cautions

Sulfonamide allergy, Aspirin allergy, Porphyria. Pregnancy Category A, but must prescribe high-dose Folic Acid (5 mg/day) as it interferes with folate absorption.

Key Risks

Haematological: Bone marrow suppression (leukopenia, agranulocytosis), megaloblastic anemia (due to folate inhibition). Dermatological: Rash, Stevens-Johnson Syndrome (SJS) due to the sulfa moiety. Genitourinary: Reversible oligospermia (reduced sperm count) in males.

Key Interactions

Inhibits absorption of Folic Acid (MANDATORY to prescribe concurrent oral folic acid). Can enhance the hypoglycemic effect of sulfonylureas (e.g., Gliclazide).

Monitoring

FBC and LFTs every 2 weeks for the first 3 months, then 3-monthly to catch bone marrow suppression early. Warn patients to report unexplained sore throat, fever, or rash immediately (signs of agranulocytosis/SJS).

Clinical Pearl

Sulfasalazine will stain bodily fluids (urine, sweat, tears) a bright yellow-orange color. It can permanently stain contact lenses. Warn the patient!

Access

Authority requiredSalazopyrin, Salazopyrin EN500 mg EC tablet

Brand: Salazopyrin, Salazopyrin EN
PBS status: Authority required
Formulation: Tablets (500 mg), Enteric-coated tablets (500 mg)

Sulfasalazine

5-Aminosalicylic Acid Prodrug·Gastrointestinal - IBD & Antidiarrhoeals

Ulcerative Colitis, Rheumatoid Arthritis

Authority requiredPBSANTI-INFLAMMATORYSalazopyrin, Salazopyrin EN500 mg EC tablet+2

Max Dose

4 g/day

Half-life

6-14 h

Sulfa Allergy

CONTRAIND.

Folate Depletion

HIGH RISK

Rapid Summary

Overview

A prodrug combining 5-ASA (mesalazine) and sulfapyridine. Used for IBD and Rheumatoid Arthritis. Requires colonic bacteria for activation.

Maximum Dose

Max 4 g/day (given in divided doses).

Clinical Focus

The sulfapyridine component causes significant systemic toxicity (rash, marrow suppression). High rates of intolerance compared to pure Mesalazine.

Bottom Line

Sulfasalazine is a dual-action DMARD used in ulcerative colitis and rheumatoid arthritis, but causes significant GI intolerance, requires folate supplementation, and can cause blood dyscrasias.

Formulation & Access

Brand Names

Salazopyrin, Salazopyrin EN

Oral Routes

Tablets (500 mg), Enteric-coated tablets (500 mg).

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Ulcerative Colitis, Rheumatoid Arthritis.

Clinical Place

Excellent for UC patients with concurrent inflammatory arthropathy (as the sulfapyridine component treats the joints, while the 5-ASA treats the gut).

Quick reference

Class & Role

5-Aminosalicylic Acid Prodrug — A prodrug combining 5-ASA (mesalazine) and sulfapyridine.

Route / Formulation

Tablets (500 mg), Enteric-coated tablets (500 mg). (Salazopyrin, Salazopyrin EN)

Usual Dose & Max

PO 1-2 g QID (Max 4 g/day).

Key Indication Doses

Ulcerative Colitis (Flare): PO 1-2 g QID (Max 4 g/day). Rheumatoid Arthritis: Start PO 500 mg OD, titrate weekly to 1 g BD.

Best Uses

Sulfasalazine is a dual-action DMARD used in ulcerative colitis and rheumatoid arthritis, but causes significant GI intolerance, requires folate supplementation, and can cause blood dyscrasias.

Avoid / Cautions

Sulfonamide allergy, Aspirin allergy, Porphyria. Pregnancy Category A, but must prescribe high-dose Folic Acid (5 mg/day) as it interferes with folate absorption.

Key Risks

Key Interactions

Inhibits absorption of Folic Acid (MANDATORY to prescribe concurrent oral folic acid). Can enhance the hypoglycemic effect of sulfonylureas (e.g., Gliclazide).

Monitoring

Clinical Pearl

Sulfasalazine will stain bodily fluids (urine, sweat, tears) a bright yellow-orange color. It can permanently stain contact lenses. Warn the patient!

Access

Authority requiredSalazopyrin, Salazopyrin EN500 mg EC tablet

Brand: Salazopyrin, Salazopyrin EN
PBS status: Authority required
Formulation: Tablets (500 mg), Enteric-coated tablets (500 mg)