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Generic name: sulfasalazineSUL-fa-SAL-a-zeen ]
Brand names: Azulfidine, Azulfidine EN-tabs, Sulfazine
Drug classes: 5-aminosalicylates, Antirheumatics

Medically reviewed by on Aug 10, 2023. Written by Cerner Multum.

What is Azulfidine?

Azulfidine is used to treat ulcerative colitis (UC), and to decrease the frequency of UC attacks. This medicine will not cure ulcerative colitis, but it can reduce the number of attacks you have.

Azulfidine is also used to treat rheumatoid arthritis in children and adults who have used other arthritis medicines that did not work or have stopped working.

Azulfidine may also be used for purposes not listed in this medication guide.

Azulfidine side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

You may get infections more easily, even serious or fatal infections. Call your doctor right away if you have signs of infection such as:

  • fever, chills, sore throat;

  • mouth sores, red or swollen gums;

  • pale skin, easy bruising, unusual bleeding; or

  • chest discomfort, wheezing, dry cough or hack, rapid weight loss.

Also call your doctor at once if you have:

  • fever with headache, rash, and vomiting;

  • a skin rash, no matter how mild;

  • severe nausea or vomiting when you first start taking Azulfidine;

  • little or no urination, urine that looks foamy;

  • puffy eyes, swelling in your ankles or feet, weight gain; or

  • liver problems--loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes).

Common side effects of Azulfidine may include:

  • nausea, vomiting, upset stomach, loss of appetite;

  • headache;

  • rash; or

  • low sperm count in men.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


You should not use Azulfidine if you have porphyria, a blockage in your bladder or intestines, or if you are allergic to sulfa drugs, aspirin, or similar medicines called salicylates.

Before taking this medicine

You should not use Azulfidine if you are allergic to it, or if you have:

Tell your doctor if you have ever had:

  • frequent infections;

  • asthma;

  • low blood cell counts; or

  • liver or kidney disease.

Tell your doctor if you are pregnant. Taking Azulfidine can make it harder for your body to absorb folic acid, and folic acid helps prevent major birth defects of the baby's brain or spine. You may need to take folic acid supplements if you take this medicine during pregnancy. Follow your doctor's instructions.

Sulfasalazine can pass into breast milk and may cause diarrhea or bloody stools in a nursing baby. Tell your doctor if you are breast-feeding.

Azulfidine is not approved for use by anyone younger than 2 years old.

How should I take Azulfidine?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Take Azulfidine after a meal.

Swallow the tablet whole and do not crush, chew, or break it.

You will need frequent medical tests.

Drink plenty of liquids to keep your kidneys working properly while you are taking Azulfidine.

Azulfidine can affect the results of certain medical tests. Tell any doctor who treats you that you are using this medicine.

Azulfidine may cause your skin or urine to appear orange-yellow in color. Call your doctor if you also have yellowing of your eyes, brown urine, or stomach pain. These may be signs of liver problems.

If you are treating arthritis, do not stop using any of your other arthritis medicines until your doctor tells you to. Azulfidine may not improve your symptoms right away, and you may still need your other medicines for awhile.

Azulfidine is only part of a complete treatment for rheumatoid arthritis that may also include rest and physical therapy. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include vomiting, stomach pain, drowsiness, or seizure.

What should I avoid while taking Azulfidine?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect Azulfidine?

Other drugs may affect Azulfidine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

It can take up to two months before you feel the full effects of sulfasalazine, a disease-modifying anti-rheumatic drug (DMARD) used in the treatment of inflammatory conditions like rheumatoid arthritis, ulcerative colitis and Crohn's disease.

Cancer or malignancies are not listed as an oncology side effect in the product labeling for sulfasalazine, a conventional DMARD, but your doctor may suggest more frequent skin cancer monitoring.

You may not be eligible to use certain biologic DMARDs if you have a history of skin cancer (melanoma) or other cancers. Some biologic DMARDs, for example Humira or Enbrel, have been rarely associated with cancers such as lymphoma or melanoma.

Sulfasalazine may suppress your immune system by lowering white blood cell counts. Serious or fatal infections can occur. If you come down with signs or symptoms of an infection such as fever, chills, shortness of breath, cough, paleness, sore throat, mouth sores, redness or swelling, contact your doctor right away.

Sulfasalazine may cause kidney problems that lead to fluid build-up in your body and weight gain. You may have puffy eyes or swelling in your arms, ankles or feet, or little or no urination. Call your doctor right away if you have any of these side effects.

Long-term side effects with sulfasalazine may include serious allergic reactions, low blood cell counts, infections, heart, liver and kidney damage, nerve or muscle problems, low sperm count, sun sensitivity and severe skin reactions. Your urine or skin may turn orange colored but is usually harmless and goes away when medicine is stopped.

Oral sulfasalazine is mainly broken down in your intestines to the more active agent sulfapyridine. It takes 1.5 to 2 days to get sulfasalazine out of your system, and 2 to 3.5 days for sulfapyridine. Results can vary due to many factors, including your age, health, how fast you metabolize, and drug route and dose.

Hair loss (alopecia) has been reported with sulfasalazine in one case report of a severe allergic reaction (Drug Rash with Eosinophilia and Systemic Symptoms or “DRESS”), but is not a common side effect. Autoimmune conditions, such as rheumatoid arthritis (RA) and lupus, can be associated with hair loss.

No, sulfasalazine is not a steroid medication like prednisone or prednisolone, but can lower inflammation in certain diseases and help prevent the need for steroids. It is classified as an oral 5-aminosalicylate agent and is used for conditions like ulcerative colitis and rheumatoid arthritis.

Sulfasalazine has not been found to be associated with high blood pressure (hypertension) in a clinical research study. Also, the manufacturer’s product information does not list high blood pressure as a side effect. Common side effects with sulfasalazine include loss of appetite, headache, vomiting, and upset stomach.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.