Azulfidine (sulfasalazine) is a time-tested, disease-modifying anti-rheumatic drug (DMARD) and aminosalicylate agent specifically formulated for the management of chronic inflammatory conditions. Primarily indicated for ulcerative colitis and rheumatoid arthritis, its dual-action mechanism delivers both anti-inflammatory and immunomodulatory effects directly to the colonic mucosa. This product card provides a comprehensive, expert-level overview of its pharmacological profile, clinical applications, and essential safety information for healthcare professionals and informed patients.

Features

• Active Ingredient: Sulfasalazine 500 mg enteric-coated tablet
• Pharmacologic Class: Aminosalicylate & Sulfonamide antimicrobial derivative
• Mechanism of Action: Prodrug metabolized to 5-aminosalicylic acid (5-ASA) and sulfapyridine; 5-ASA acts locally in the colon as an anti-inflammatory agent
• Formulation: Delayed-release enteric coating to ensure targeted colonic delivery
• Bioavailability: Poor systemic absorption; primarily activated by colonic bacterial azoreduction
• Half-life: Variable (6-8 hours for parent drug; metabolites have longer half-lives)

Benefits

• Induces and maintains clinical remission in mild to moderate ulcerative colitis, reducing frequency of disease flares
• Modifies disease progression in rheumatoid arthritis by reducing joint inflammation and slowing radiographic damage
• Localized therapeutic action in the bowel minimizes systemic exposure and associated side effects
• Well-established safety profile with decades of clinical use and extensive post-marketing surveillance data
• Cost-effective therapeutic option compared to newer biologic agents for inflammatory conditions
• Oral administration convenience supports long-term treatment adherence in chronic conditions

Common use

Azulfidine is principally prescribed for the management of ulcerative colitis, particularly for active mild to moderate disease and for maintenance of remission. It demonstrates efficacy in reducing bowel frequency, rectal bleeding, and mucosal inflammation as assessed endoscopically. In rheumatology, it is used as a first-line DMARD for rheumatoid arthritis, either as monotherapy or in combination with other agents like methotrexate. Off-label uses include Crohn’s disease (particularly colitis-predominant), ankylosing spondylitis, and psoriatic arthritis, though evidence supporting these indications varies. Treatment response typically becomes evident within 4-8 weeks for rheumatoid arthritis and 2-4 weeks for bowel symptoms in ulcerative colitis.

Dosage and direction

Ulcerative Colitis:

• Initial therapy: 500 mg twice daily, increasing by 500 mg daily every 2-3 days until reaching therapeutic dose
• Maintenance dose: 2-4 g daily in divided doses (maximum 6 g daily in severe cases)
• Pediatric dosing: 40-60 mg/kg/day divided into 3-6 doses

Rheumatoid Arthritis:

• Initial therapy: 500 mg daily, increasing weekly by 500 mg daily
• Maintenance dose: 2-3 g daily in divided doses (maximum 3 g daily)

Administration should occur with food or immediately after meals to minimize gastrointestinal upset. Tablets must be swallowed whole without crushing or chewing to preserve the enteric coating. Consistent timing of doses maintains stable drug concentrations. Dose titration is essential to improve tolerance, and therapeutic response should be evaluated before considering dose escalation beyond recommended limits.

Precautions

Regular monitoring is essential during Azulfidine therapy. Complete blood count (including differential), liver function tests, and renal function should be assessed at baseline, then every 2-4 weeks during the first three months, and periodically thereafter. Patients should maintain adequate hydration to reduce risk of crystalluria and stone formation. Those with glucose-6-phosphate dehydrogenase (G6PD) deficiency require heightened surveillance for hemolytic anemia. Pulmonary function monitoring is advised due to rare but serious pulmonary toxicity. Azulfidine may cause orange-yellow discoloration of urine and skin, which is harmless but should be explained to patients to prevent unnecessary concern. Sun protection is recommended due to photosensitivity potential.

Contraindications

Azulfidine is contraindicated in patients with known hypersensitivity to sulfasalazine, its metabolites, other sulfonamides, or salicylates. Additional contraindications include intestinal obstruction, porphyria, and children under 2 years of age. It should not be used in patients with severe renal impairment (CrCl <30 mL/min) or severe hepatic dysfunction. History of sulfonamide-induced agranulocytosis, aplastic anemia, or other serious blood dyscrasias represents absolute contraindications.

Possible side effect

Common (≥1%): Headache, nausea, vomiting, anorexia, gastric distress, reversible oligospermia, orange-yellow discoloration of urine and skin Less common (0.1-1%): Rash, pruritus, fever, dizziness, tinnitus, reversible neutropenia Rare but serious (<0.1%): Stevens-Johnson syndrome, toxic epidermal necrolysis, agranulocytosis, aplastic anemia, hepatitis, pancreatitis, pulmonary fibrosis, lupus-like syndrome, meningitis, renal injury

Most common adverse effects are dose-related and often diminish with continued therapy or dose reduction. Gastrointestinal effects may be mitigated by taking with food or using divided dosing. Hematological toxicity typically occurs within the first 3-6 months of therapy, necessitating regular monitoring.

Drug interaction

Azulfidine may interact with several medication classes:

• Digoxin: Reduced absorption and serum levels of digoxin
• Folic acid: Decreased folate absorption; supplementation recommended
• Warfarin: Potential potentiation of anticoagulant effect
• Methotrexate: Increased risk of hematologic toxicity
• Cyclosporine: Possible reduction in cyclosporine efficacy
• Oral hypoglycemics: Enhanced hypoglycemic effect
• Phenytoin: Increased phenytoin levels and toxicity risk
• Antacids: May decrease sulfasalazine absorption

Concomitant use with other bone marrow suppressants or hepatotoxic drugs requires careful monitoring. Azulfidine may interfere with laboratory tests for urinary normetanephrine and urinary protein determination.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Patients should not double the dose to make up for a missed one. Consistent daily administration is important for maintaining therapeutic effect, particularly in chronic inflammatory conditions. If multiple doses are missed, patients should contact their healthcare provider for guidance on resumption, as dose retitration may be necessary.

Overdose

Sulfasalazine overdose primarily manifests as nausea, vomiting, gastric distress, and abdominal pain. Severe overdose may cause dizziness, drowsiness, seizures, metabolic acidosis, crystalluria, hematuria, and oliguria. Hematological toxicity including agranulocytosis, hemolytic anemia, and methemoglobinemia may occur. There is no specific antidote; management involves immediate gastric lavage if presented early, followed by supportive care including hydration, electrolyte correction, and monitoring of hematological parameters. Hemodialysis is not effective due to high protein binding. Forced diuresis and urinary alkalinization may enhance elimination of metabolites.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in the original container, protected from light and moisture. Keep tightly closed and away from excessive heat and humidity. Do not remove desiccant from packaging. Keep out of reach of children and pets. Do not use if tablets show signs of discoloration, cracking, or deterioration. Properly discard any expired medication through medication take-back programs or according to local guidelines.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Azulfidine is a prescription medication that should be used only under the supervision of a qualified healthcare professional. Individual response to therapy may vary, and treatment decisions should be based on professional medical judgment considering the patient’s complete medical history and current condition. The manufacturer and distributors are not liable for any consequences arising from the use or misuse of this information. Patients should consult their healthcare provider for personalized medical advice and report any adverse effects experienced during treatment.

Reviews

“After struggling with ulcerative colitis flares for years, Azulfidine has maintained my remission for over 18 months with minimal side effects. The initial titration period required patience, but the long-term results have been life-changing.” - Michael T., diagnosed 2018

“As a rheumatologist with 25 years of practice, I continue to find Azulfidine invaluable as a first-line DMARD. Its predictable efficacy and manageable safety profile make it an essential tool in our treatment arsenal, particularly for early rheumatoid arthritis.” - Dr. Eleanor J., Rheumatology Specialist

“The gastrointestinal side effects during the first few weeks were challenging, but my gastroenterologist’s slow titration schedule and reassurance helped me persist. Six months later, my colitis symptoms are well-controlled with 2g daily maintenance dosing.” - Sarah L., patient since 2022

“While biologic agents receive more attention, Azulfidine remains a cornerstone of IBD therapy due to its proven long-term safety data and cost-effectiveness. It’s particularly useful for maintenance therapy in appropriate patients.” - Gastroenterology Department, University Medical Center