Drug information of Sulfasalazine


Drug group:

A drug that is used in the management of inflammatory bowel diseases . Its activity is generally considered to lie in its metabolic breakdown product, 5-aminosalicylic acid (see mesalamine) released in the colon.

Mechanism of effect

Sulfasalazine is a prodrug that is metabolized to its active components, sulfapyridine and 5-aminosalicylic acid (5-ASA; mesalamine); beneficial effects are predominantly from the anti-inflammatory properties of 5-ASA, which inhibits leukotriene synthesis and lipoxygenase


Sulfasalazine is an anti-inflammatory indicated for the treatment of ulcerative colitis and rheumatoid arthritis .


• Bioavailability: <15% of parent drug; 60% (sulfapyridine); 10-30% (5-ASA)
• Peak plasma time: 6 hr; 10 hr (sulfapyridine and 5-ASA)
• Peak plasma concentration: 6 mcg/mL
Protein bound: >99% to albumin; 70% (sulfapyridine)
Vd: 7.5 L
Approximately 90% of sulfasalazine is converted by colon bacteria into its active components, sulfapyridine and mesalamine .
• Half-life: 10.4-14.8 hr (sulfapyridine)
• Renal clearance: 37%
• Excretion: Urine (systematically absorbed sulfapyridine and 5-ASA); feces (majority of 5-ASA)


Ulcerative Colitis
Mild to moderate cases, adjunctive therapy in severe cases, and prolongation of remission 3-4 g/day PO divided TID after meals; may start 1-2 g qDay
Rheumatoid Arthritis
Inadequate response or intolerance to salicylates or other NSAIDs
Enteric coated: 2-3 g/day PO divided TID after meals; may start 0.5-1 g qDay
Crohn Disease (Off-label)
3-6 g/day PO divided TID after meals


Sulfasalazine may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use sulfasalazine with caution . Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Sulfasalazine may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to sulfasalazine. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
Sulfasalazine may discolor the urine or skin to an orange-yellow color. This is normal and not a cause for concern.
• A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.
• Severe and sometimes fatal allergic reactions, infections, heart problems, kidney problems, liver problems, lung problems, blood problems, and permanent nerve or muscle problems have happened in patients taking sulfasalazine . Talk with your doctor for more information.
• Some men taking sulfasalazine have developed a decreased number of sperm and infertility. These effects usually went away after sulfasalazine was stopped. Discuss any questions or concerns with your doctor.
• Diabetes patients - Sulfasalazine may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
Sulfasalazine may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking sulfasalazine.
• LAB TESTS, including liver function, kidney function, complete blood cell counts, or urine tests, may be performed while you use sulfasalazine. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
Use sulfasalazine with caution in the ELDERLY ; they may be more sensitive to its effects.
Sulfasalazine should not be used in CHILDREN younger than 2 years old; safety and effectiveness in these children have not been confirmed.

Points of recommendation

• Take sulfasalazine by mouth after meals.
• Take sulfasalazine with a full glass of water (8 oz [240 mL]).
• Drinking extra fluids while you are taking sulfasalazine is recommended. Check with your doctor for instructions.
• Space your doses evenly over the hours you are awake. If possible, try not to space your doses more than 8 hours apart.
• Take sulfasalazine on a regular schedule to get the most benefit from it.
• Continue to take sulfasalazine even if you feel well. Do not miss any doses.

Pregnancy level


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