The reference site for Sulfasalazine

Sulfasalazine (SSZ), sold under the trade name Azulfidine among others, is a medication used to treat rheumatoid arthritis, ulcerative colitis, and Crohn’s disease.


Sulfasalazine is used to treat ulcerative colitis and to maintain remission. The delayed-release tablets, Azulfidine® (EN-tabs), are also used to treat rheumatoid arthritis and juvenile rheumatoid arthritis.

The exact way that sulfasalazine works is unknown, but it is believed to reduce the actions of substances in the body that cause inflammation, tissue damage, and diarrhea.

Sulfasalazine is sold under the brand name Azulfidine® in the United States.


Brand Name(s): Azulfidine; Azulfidine EN-tabs;

Salazopyrin; SAS-500
CAS nº: 599-79-1
(sul fa sal’ a zeen)


Product Info

The sections below will provide you with more specific information and guidelines related to sulfasalazine and its correct use. Please read them carefully.

FDA Information

Sulfasalazine was approved by the Food and Drug Administration in 1950.

Azulfidine EN-tabs
® is the only formulation of sulfasalazine approved by the FDA for the treatment of both juvenile and adult RA. The enteric-coated formulation of Azulfidine EN-tabs® was specifically designed to reduce the likelihood of nausea and stomach upset.

A prescription is required for this medicine.

Please visit the official site of the FDA for further information.

Why is this medication prescribed?

Sulfasalazine is used to treat a certain type of bowel disease called ulcerative colitis. This medication does not cure this condition, but it helps decrease symptoms such as fever, stomach pain, diarrhea, and rectal bleeding. After an attack is treated, sulfasalazine is also used to increase the amount of time between attacks. This medication works by reducing irritation and swelling in the large intestines.

In addition, delayed-release tablets of sulfasalazine are used to treat rheumatoid arthritis and juvenile rheumatoid arthritis. Sulfasalazine helps to reduce joint pain, swelling, and stiffness. Early treatment of rheumatoid arthritis with sulfasalazine helps to reduce and even prevent further joint damage so you can do more of your normal daily activities. This medication is used together with other drugs, rest, and physical therapy in patients who have not responded to other medications (such as salicylates and nonsteroidal anti-inflammatory drugs [NSAIDs]).

Other uses for this medicine

Sulfasalazine may also be used to treat stomach pain, rectal bleeding, diarrhea caused by Crohn’s disease, and back pains and inflammation (ankylosing spondylitis).

However, it is important that you talk to your doctor about the possible risks of using this drug for your particular condition

Dosage and using this medicine

Sulfasalazine comes as regular and delayed-release (enteric-coated) tablets. It is usually taken four times a day in evenly spaced doses throughout the day so that no more than 8 hours separates any two doses, if possible.

Take sulfasalazine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Each dose should be taken with a full glass of water, and usually after meals.

Do not crush, chew, or break the delayed-release tablets (Azulfidine EN-tabs®). Swallow them whole. They are specially formulated to release the medication after they have passed through your stomach.

Call your doctor if you find an undissolved delayed-release (Azulfidine EN-tabs®) tablet in your stool.

Do not stop taking sulfasalazine, even if you begin to feel better, without first talking to your doctor. It is very important to continue taking sulfasalazine to control your condition.

What special precautions should I follow?


Do not take sulfasalazine without first talking to your doctor if you have ever had an allergic reaction to sulfasalazine, a sulfa-based antibiotic, or aspirin; an obstruction (blockage) in your intestines or urinary tract; porphyria; liver disease; kidney disease; asthma; or glucose-6-phosphate dehydrogenase deficiency. You may not be able to take sulfasalazine, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Sulfasalazine may decrease the absorption of digoxin (Lanoxin®, Lanoxicaps®). Your doctor may want to monitor the digoxin levels in your blood if you are taking this medicine.

Sulfasalazine may also decrease folate (a natural vitamin) in your body. You may need to take folate supplements or eat folate-rich foods.

Drugs other than those listed here may also interact with sulfasalazine. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Sulfasalazine is in the FDA pregnancy category B. This means that it is not expected to harm an unborn baby. Do not take sulfasalazine without first talking to your doctor if you are pregnant.

Moreover, sulfasalazine passes into breast milk and the effects of sulfasalazine on a nursing infant are not known. Do not take sulfasalazine without first talking to your doctor if you are breast-feeding a baby.

The safety and effectiveness of sulfasalazine have not been established for children younger than 2 years of age.

What should I do if I forget a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose.

Please do not take a double dose of this medication.

What side effects can this medication cause?

If you experience any of the following serious side effects, stop taking sulfasalazine and seek emergency medical attention or notify your doctor immediately:

an allergic reaction (difficulty breathing, closing of your throat, swelling of your lips, tongue, or face, or hives)
worsening colitis (fever, abdominal pain, cramping, or bloody diarrhea)
sore throat
pale skin
yellow skin or eyes (may indicate a blood disorder)

Other, less serious side effects may be more likely to occur. Continue to take sulfasalazine and talk to your doctor if you experience:

nausea, vomiting, or decreased appetite
a rash, itching, or hives
decreased sperm production (uncommon and usually reversible)
orange-yellow discoloration of the skin or urine (not harmful)

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What storage conditions are needed for this medicine?

Always keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Please remember to throw away any medication that is outdated or no longer needed. If you have any questions, talk to your pharmacist about the proper disposal of your medication.

In case of an emergency/overdose

In the case of an overdose, call your local poison control center on 1-800-222-1222. However, if the victim has collapsed or is not breathing,  then please call the local emergency services immediately on 911.

Symptoms of overdose may include:

abdominal pain

Product Images


Below you will find images and specific information on the principal types of sulfasalazine that exist, including their respective brand name(s), strength, inscription codes, manufacturers and/or distributors.

The information below includes general information and guidelines for patients taking this medication and should never be used to substitute professional medical advice that can be provided by a qualified physician or family doctor.

Strength(s): 500 MG
Imprint: MP 91

Strength(s): 500 MG
Imprint: G 500
Manufacturer: GREENSTONE LTD.

Strength(s): 500 MG
Imprint: KPH | 101
Manufacturer: PHARMACIA / UPJHN.

Strength(s): 500 MG
Imprint: 104
Manufacturer: GREENSTONE LTD

Strength(s): 500 MG
Imprint: V | 5905
Manufacturer: QUALITEST

Strength(s): 500 MG
Imprint: KPH | 102
Manufacturer: PHARMACIA / UPJHN.

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