Azulfidine (sulfasalazine) is a time-tested disease-modifying antirheumatic drug (DMARD) and anti-inflammatory agent, widely prescribed for the management of chronic autoimmune conditions. Its dual mechanism of action combines antibacterial and immunomodulatory effects, making it a cornerstone therapy in adult and pediatric gastroenterology and rheumatology. Composed of 5-aminosalicylic acid (5-ASA) linked to sulfapyridine, it remains a first-line treatment for mild to moderate ulcerative colitis and a foundational DMARD in rheumatoid arthritis protocols. This product card provides a comprehensive, evidence-based overview for healthcare professionals considering its therapeutic application.

Features

• Active Ingredient: Sulfasalazine 500 mg enteric-coated tablets
• Mechanism: Prodrug metabolized to 5-aminosalicylic acid (anti-inflammatory) and sulfapyridine (antibacterial/immunosuppressive)
• Formulation: Delayed-release to minimize gastric irritation and target colonic release
• Bioavailability: Poorly absorbed from the small intestine; colonic bacterial cleavage required for activation
• Half-life: 5–10 hours for sulfapyridine metabolite
• Excretion: Primarily renal; requires dose adjustment in renal impairment

Benefits

• Induces and maintains remission in ulcerative colitis, reducing mucosal inflammation and bleeding
• Modifies disease progression in rheumatoid arthritis by reducing joint swelling, pain, and structural damage
• Demonstrated efficacy in juvenile idiopathic arthritis and other seronegative spondyloarthropathies
• Cost-effective compared to biologic agents, with a well-established long-term safety profile
• May reduce systemic inflammation markers such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)
• Available in pediatric formulations for age-appropriate dosing in juvenile populations

Common use

Azulfidine is indicated for the treatment of mild to moderately active ulcerative colitis and for the maintenance of remission. In rheumatology, it is used as a first-line DMARD for rheumatoid arthritis, either as monotherapy or in combination with other agents such as methotrexate. It is also used off-label for conditions including Crohn’s disease, psoriatic arthritis, and ankylosing spondylitis. Its use is supported by decades of clinical evidence and inclusion in international treatment guidelines.

Dosage and direction

Dosing must be individualized based on indication, severity, and patient response. For ulcerative colitis in adults: initial dose is 1–2 g daily in divided doses, gradually increased to 3–6 g daily. Maintenance dose is typically 2 g daily. For rheumatoid arthritis: start with 500 mg daily, increasing weekly by 500 mg to a target of 2–3 g daily in divided doses. Tablets should be swallowed whole with a full glass of water, with or after food to minimize gastrointestinal upset. Regular monitoring of complete blood count, liver function, and renal function is required during therapy.

Precautions

Patients should be advised that urine and skin may develop an orange-yellow discoloration. Regular blood tests are essential to monitor for hematological toxicity (e.g., leukopenia, thrombocytopenia). Use with caution in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to risk of hemolysis. Hepatic and renal function should be assessed before and during treatment. Sun exposure should be limited due to photosensitivity risk. Patients should maintain adequate hydration to reduce risk of crystalluria.

Contraindications

Hypersensitivity to sulfonamides, salicylates, or any component of the formulation; intestinal or urinary obstruction; porphyria; severe renal or hepatic impairment; children under 2 years of age; pregnancy at term and during lactation (due to risk of kernicterus in neonates).

Possible side effect

Common: nausea, vomiting, headache, dizziness, anorexia, gastric distress. Less common: skin rash, fever, oligospermia (reversible), orange-yellow discoloration of urine/skin. Serious but rare: Stevens-Johnson syndrome, toxic epidermal necrolysis, agranulocytosis, aplastic anemia, hepatitis, pneumonitis, lupus-like syndrome. Most adverse effects are dose-related and often diminish with continued use or dose reduction.

Drug interaction

May enhance effects of oral hypoglycemics, warfarin, phenytoin, and methotrexate. Reduced absorption with iron supplements or antibiotics that affect gut flora. Increased risk of crystalluria with alkaline urine or other sulfonamides. Antacids may affect enteric coating. Live bacterial vaccines may have reduced efficacy.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose. Do not double the dose. Maintain regular dosing schedule to ensure consistent therapeutic effect.

Overdose

Symptoms may include nausea, vomiting, drowsiness, unconsciousness. Crystalluria with renal complications may occur. Management is supportive; gastric lavage may be considered if recent ingestion. Hemodialysis may remove sulfapyridine metabolite. Specific antidote is not available.

Storage

Store at room temperature (15–30°C) in original container, protected from light and moisture. Keep out of reach of children. Do not use after expiration date.

Disclaimer

This information is intended for healthcare professionals. Treatment decisions must be based on individual patient assessment, official prescribing information, and clinical judgment. Dosage and administration should follow local regulatory-approved labeling.

Reviews

Azulfidine maintains a strong reputation among rheumatologists and gastroenterologists for its efficacy, safety profile, and cost-effectiveness. Clinical studies consistently demonstrate its ability to induce remission in ulcerative colitis and improve symptoms and radiographic outcomes in rheumatoid arthritis. While newer biologics offer alternative mechanisms, Azulfidine remains a foundational therapy in treatment algorithms. Monitoring requirements and gastrointestinal side effects are noted considerations, but overall it is regarded as a valuable therapeutic option with decades of real-world evidence.