BSN Tracker

sulfasalazine

Brand: Azulfidine

Prototype Drug
Drug Class: anti-inflammatory (IBD/DMARD)
Drug Family: DMARD
Subclass: sulfonamide + 5-aminosalicylate prodrug
Organ Systems: gastrointestinalimmunologymusculoskeletal

Mechanism of Action

Prodrug cleaved by colonic bacteria to sulfapyridine (systemic antibacterial/immunomodulatory) and 5-ASA (local anti-inflammatory); 5-ASA inhibits prostaglandin synthesis and leukotriene formation in colonic mucosa.

5-aminosalicylic acid (5-ASA) — local anti-inflammatory in colon

Indications

  • ulcerative colitis
  • Crohn disease (colonic)
  • rheumatoid arthritis (DMARD)

Contraindications

  • sulfonamide or salicylate allergy
  • severe hepatic/renal impairment
  • porphyria
  • G6PD deficiency

Adverse Effects

Common

  • GI upset (nausea, vomiting — sulfapyridine component)
  • orange/yellow urine/skin discoloration
  • headache
  • reversible oligospermia

Serious

  • blood dyscrasias
  • severe allergic reactions (SJS, TEN)
  • hepatotoxicity
  • pulmonary toxicity

Pharmacokinetics (ADME)

Absorption 15-20% absorbed (rest cleaved in colon)
Distribution moderate
Metabolism colonic bacteria to 5-ASA + sulfapyridine; sulfapyridine hepatic acetylation
Excretion renal (sulfapyridine)
Half-life 6-10 hours
Onset 3-6 hours
Peak 3-6 hours
Duration 12 hours
Protein Binding 99% (sulfapyridine)
Vd moderate

Drug Interactions

Drug / Agent Mechanism Severity
folic acid inhibits DHFR — supplement folic acid moderate
digoxin reduces digoxin absorption moderate
cholestyramine reduces sulfasalazine absorption moderate

Nursing Considerations

  1. Take with food to reduce GI side effects
  2. Orange discoloration of urine and skin — not harmful; warn patients
  3. Supplement folic acid (folate antagonism)
  4. Reversible oligospermia: inform male patients of family planning
  5. CBC monitoring every 2-4 weeks first 3 months then q3 months

Clinical Pearls

  • Colonic bacteria cleave the azo bond releasing 5-ASA — effective only for colonic disease
  • Slow acetylators (NAT2 polymorphism) accumulate more sulfapyridine — more side effects in slow acetylators

Safety Profile

Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Anti-inflammatory (IBD/DMARD) Crohn Disease (colonic) Rheumatoid Arthritis (DMARD) Ulcerative Colitis
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