Generic Name

Sulfasalazine

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Classification

FDA Approved Indications

• Ulcerative colitis
• Rheumatoid arthritis

Mechanism of Action

Sulfasalazine is metabolized in the colon to sulfapyridine and 5-aminosalicylic acid (5-ASA). The active metabolites exert anti-inflammatory effects by inhibiting prostaglandin synthesis and suppressing inflammatory mediators, leading to decreased inflammation in the colon and joints.

Dosage and Administration

Adult: Typically, 2-4 g/day in divided doses; dosage varies based on condition and response.

Pediatric: Use is based on weight and clinical response; consult specific guidelines.

Geriatric: Start at lower doses due to potential renal or hepatic impairments; monitor closely.

Renal Impairment: Adjust dose based on severity; monitor renal function.

Hepatic Impairment: Use with caution; monitor liver function.

Pharmacokinetics

Absorption: Moderate oral absorption, subject to variability.

Distribution: Widely distributed; crosses placental barrier but minimal into CSF.

Metabolism: Partially metabolized in the liver, with active metabolites.

Excretion: Excreted primarily in urine; some in feces.

Half Life: Approximately 10 hours.

Contraindications

• Hypersensitivity to sulfonamides or salicylates
• History of sulfa allergies
• Intestinal or urinary tract obstruction

Precautions

• Use with caution in patients with hepatic or renal impairment, blood dyscrasias, G6PD deficiency, or pregnancy/lactation. Regular blood counts and liver function tests are recommended.

Adverse Reactions - Common

• Nausea, vomiting (Common)
• Headache (Common)
• Rash (Common)

Adverse Reactions - Serious

• Hematologic reactions (e.g., agranulocytosis, aplastic anemia) (Rare)
• Liver toxicity, hepatitis (Rare)
• Uveitis, peripheral neuropathy (Rare)

Drug-Drug Interactions

• Methotrexate (risk of hematologic toxicity)
• Warfarin (increased anticoagulant effects)

Drug-Food Interactions

• Avoid Alcohol (may increase hepatotoxicity)

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Take medication with food to minimize GI discomfort.
• Report signs of allergic reactions, unusual bleeding, fatigue, or jaundice.
• Maintain regular lab monitoring appointments.

Special Considerations

Black Box Warnings:

• Hematologic reactions including agranulocytosis and aplastic anemia, which can be fatal.

Genetic Factors: G6PD deficiency can increase risk of hemolytic anemia. Consider screening before initiation.

Lab Test Interference: May cause false-positive tests for glucose or ketones in urine.

Overdose Management

Signs/Symptoms: Gastrointestinal distress, vomiting, dizziness, and hematologic abnormalities.

Treatment: Supportive care; hemodialysis may be considered in severe cases.

Storage and Handling

Storage: Store at room temperature away from moisture and heat.

Stability: Stable under proper storage conditions.