1. Introduction
Sulfasalazine is a disease-modifying anti-rheumatic drug (DMARD) and an anti-inflammatory agent used in the treatment of inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). It works by modulating the immune response and reducing inflammation in the gut and joints.
2. Indications
- Rheumatoid Arthritis (RA): Treatment of active and progressive RA in adults and juvenile idiopathic arthritis (JIA).
- Ulcerative Colitis (UC): Induction and maintenance of remission in mild to moderate cases.
- Crohn’s Disease (CD): Used in some cases for mild disease affecting the colon.
3. Dosage
Adults:
- Rheumatoid Arthritis:
- Start with 500 mg once daily, increasing by 500 mg weekly to a maintenance dose of 2,000–3,000 mg/day in divided doses.
- Ulcerative Colitis (Acute Phase):
- 1–2 g four times daily until remission.
- Maintenance: 2 g/day in divided doses.
- Crohn’s Disease (Mild to Moderate):
- 1–2 g twice daily, based on clinical response.
Children:
- Juvenile Idiopathic Arthritis (JIA):
- 30–50 mg/kg/day in divided doses, maximum 2 g/day.
Elderly:
- Use cautiously, starting at the lowest dose and titrating slowly.
Renal Impairment:
- Use with caution and monitor renal function closely.
Hepatic Impairment:
- Avoid in severe hepatic dysfunction.
4. Administration
- Take with food to reduce gastrointestinal side effects.
- Swallow tablets whole; do not crush or chew enteric-coated forms.
- Maintain adequate hydration to prevent crystalluria and kidney stones.
5. Forms Available
- Tablets: 500 mg (immediate and enteric-coated release).
- Oral Suspension (less common).
6. Side Effects
6.1 Common Side Effects:
- Nausea
- Headache
- Loss of appetite
- Abdominal pain
- Orange-yellow urine or skin discoloration
6.2 Less Common Side Effects:
- Skin rash
- Dizziness
- Fever
6.3 Rare but Serious Side Effects:
- Stevens-Johnson Syndrome (SJS)
- Agranulocytosis (low white blood cell count)
- Hepatotoxicity
- Haemolytic anaemia
- Pulmonary fibrosis
7. Warnings
- Severe Hypersensitivity Reactions: Discontinue immediately if signs of rash, fever, or blood dyscrasias occur.
- Hepatic Toxicity: Monitor liver function regularly.
- Bone Marrow Suppression: Regular blood counts required to detect agranulocytosis or anaemia.
- Male Infertility: May cause reversible oligospermia (low sperm count).
8. Precautions
- Avoid in patients with G6PD deficiency due to haemolytic anaemia risk.
- Use cautiously in patients with asthma or sulfa allergies.
- Avoid in patients with severe renal or hepatic impairment.
9. Interactions
- Methotrexate: Increased risk of bone marrow suppression.
- Warfarin: Enhances anticoagulant effects, increasing bleeding risk.
- Digoxin: May reduce digoxin absorption.
- Folic Acid: Sulfasalazine reduces folic acid absorption; supplementation is recommended.
10. Monitoring Parameters
- Complete Blood Count (CBC): Baseline, then every 2–4 weeks for 3 months, then every 3 months.
- Liver Function Tests (LFTs): Regular monitoring required.
- Renal Function: Serum creatinine and urine tests periodically.
- Signs of Infection or Bleeding: Due to potential bone marrow suppression.
11. Use in Children
- Approved for juvenile idiopathic arthritis (JIA).
- Requires close monitoring of blood counts and liver function.
12. Use in Pregnancy
- Category B: Can be used with caution, but folic acid supplementation is recommended to prevent deficiency.
- Considered safer than methotrexate for RA in pregnancy.
13. Use in Elderly
- Start with lower doses due to increased risk of side effects.
- Monitor kidney and liver function closely.
14. Use in Kidney Disease
- Use cautiously in mild to moderate renal impairment.
- Avoid in severe renal disease.
15. Use in Liver Disease
- Contraindicated in severe hepatic impairment due to hepatotoxicity risk.
16. Patient Counselling Points
- Take with food to reduce stomach upset.
- Expect urine and skin discoloration (yellow-orange); this is harmless.
- Maintain adequate hydration to prevent kidney stones.
- Report any unusual bruising, sore throat, or fever to a doctor immediately.
- Men should be aware of the potential for temporary infertility (reversible upon stopping).
- Folic acid supplementation is recommended to prevent deficiencies.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Azulfidine | Pfizer | 500 mg Tablet | $100 (60 tablets) |
Salazopyrin | Pfizer | 500 mg Enteric-Coated Tablet | $120 (60 tablets) |
Generic Sulfasalazine | Various | 500 mg Tablet | $30 (60 tablets) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Sulfasalazine used for?
It treats rheumatoid arthritis and inflammatory bowel disease (ulcerative colitis and Crohn’s disease).
2. How does Sulfasalazine work?
It reduces inflammation by inhibiting immune responses in the gut and joints.
3. Can Sulfasalazine cause urine discoloration?
Yes, it can turn urine or sweat orange-yellow, which is harmless.
4. Does Sulfasalazine cause weight gain?
No, weight gain is not a common side effect.
5. How long does Sulfasalazine take to work?
It may take several weeks to months for full effects in RA and IBD.
6. Can Sulfasalazine cause infertility?
Yes, it may cause reversible low sperm count in men.
7. Is Sulfasalazine safe in pregnancy?
Yes, but folic acid supplementation is needed to prevent deficiency.
8. Can Sulfasalazine cause liver damage?
Yes, liver function should be monitored regularly.
9. Can I drink alcohol while taking Sulfasalazine?
It’s best to limit alcohol, as both can affect the liver.
10. Does Sulfasalazine require blood tests?
Yes, regular blood counts and liver tests are necessary.
11. Can Sulfasalazine cause sun sensitivity?
Yes, it can increase sensitivity to sunlight; wear sun protection.
12. Can Sulfasalazine cause anaemia?
Yes, due to potential folic acid depletion. Supplementation is recommended.
13. Can Sulfasalazine be stopped suddenly?
No, stopping suddenly may worsen symptoms. Taper under medical supervision.
14. Can Sulfasalazine be taken with ibuprofen?
Yes, but monitor for stomach irritation and GI bleeding.
15. How should Sulfasalazine be stored?
Store at room temperature, away from moisture and heat.