Sulfasalazine
AZULFIDINE
Pronunciation: sul-fa-SAL-a-zeen
“Surfer sailor scene”
What it isSulfapyridine linked to 5-ASA, split by colonic bacteria; ulcerative colitis and rheumatoid arthritis.
Why this oneIt treats both bowel and joint disease, which is useful in spondyloarthropathy.
What limits itThe sulfapyridine causes most of the toxicity: rash, hemolysis in G6PD deficiency, and reversible oligospermia. Folate supplementation is needed.
FDA-approved for
- ulcerative colitis/RA (~1950)
FDA label
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| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Ulcerative colitis — initial therapy | Adults | 1–2 g/day (to reduce GI intolerance) | 3–4 g/day in evenly divided doses (intervals ≤8 h) | >4 g/day increases toxicity risk |
| Ulcerative colitis — initial therapy | Children ≥6 yr | 40–60 mg/kg/day divided into 3–6 doses | ||
| Ulcerative colitis — maintenance | Adults | 2 g/day | ||
| Ulcerative colitis — maintenance | Children ≥6 yr | 30 mg/kg/day divided into 4 doses |
Renal Give only after critical appraisal in renal damage; discontinue if renal function deteriorates.
Hepatic Give only after critical appraisal in hepatic damage.
Instructions
- Take in evenly divided doses, preferably after meals
- Maintain adequate fluid intake to prevent crystalluria
- May cause orange-yellow discoloration of urine or skin
Available strengths
- tab 500 mg
- DR tab 500 mg
Contraindications
- Intestinal or urinary obstruction
- Porphyria
- Hypersensitivity to sulfonamides or salicylates
Cautions
- Hepatic, renal, and hematologic toxicity (deaths reported)
- Serious infections
- Oligospermia/infertility (reversible)
- Use caution in severe allergy/bronchial asthma
- G6PD deficiency (hemolytic anemia)
Adverse reactions
- Anorexia
- Headache
- Nausea
- Vomiting
- Gastric distress
- Reversible oligospermia
- Rash
Pregnancy No clear fetal harm in animals; inhibits folic acid absorption (may affect NTD-preventive supplementation).
Lactation Undefined.
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 500 mg | tab | per unit | $0.20/ea | offered |
Generic entry1983
NO BOXED WARNINGS
Principal riskHemolysis in G6PD deficiency; reversible oligospermia
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Active metabolites
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