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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Generic drug name: sulfasalazine (sul fa SAL a zeen)
Brand name(s): AZULFIDINE, AZULFIDINE EN-TABS
GENERIC: not available FAMILY: Other Gastrointestinal Drugs
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Sulfasalazine is excreted into breast milk. Because it can cause jaundice in the nursing infant, you should not take this drug while nursing. There have been five reports with limited data that shows that bloody stools or diarrhea occurred in breastfed infants of nursing mothers taking sulfasalazine.

Facts About This Drug [top]

Sulfasalazine is used to treat inflammatory bowel diseases. The two major diseases of this type are ulcerative colitis, which typically affects the colon, and Crohn’s disease, which can occur anywhere in the intestine. Crohn’s disease typically presents in young adulthood with weight loss, abdominal pain, anemia, and malnutrition. Ulcerative colitis typically occurs later in life. Both are associated with increased risk of colon cancer, although the risk is greater for ulcerative colitis....

Sulfasalazine is used to treat inflammatory bowel diseases. The two major diseases of this type are ulcerative colitis, which typically affects the colon, and Crohn’s disease, which can occur anywhere in the intestine. Crohn’s disease typically presents in young adulthood with weight loss, abdominal pain, anemia, and malnutrition. Ulcerative colitis typically occurs later in life. Both are associated with increased risk of colon cancer, although the risk is greater for ulcerative colitis. Sulfasalazine also is approved for the treatment of rheumatoid arthritis.

Because of the chronic nature of these conditions, sulfasalazine usually is taken for a long time. If your disease improves enough, you may be able to lower your dose to a maintenance level or even stop using the drug for periods of time. If you have impaired kidney function, you may need to take less than the usual adult dose. Kidney function should be monitored periodically while taking sulfasalazine, and the drug should be discontinued if kidney function deteriorates while using the drug.[1] The drug should not be used in children under the age of 2.[2]

In 2012, the drug product label for sulfasalazine was updated to include information concerning the use of sulfasalazine in nursing mothers. The update stated that there have been five reports with limited data that shows that bloody stools or diarrhea occurred in breastfed infants of nursing mothers taking sulfasalazine.[3]

In 2014, an FDA advisory stated that serious infections, including fatal sepsis and pneumonia, have been reported in patients taking sulfasalazine.[4]

Before You Use This Drug [top]

Do not use if you have or have had:

  • gastrointestinal tract obstruction
  • previous allergic reaction to sulfasalazine, sulfonamides, salicylates, furosemide, thiazide diuretics, sulfonylureas, or carbonic anhydrase inhibitors
  • urinary obstruction

Tell your doctor if you have or have had:

  • allergies that are severe
  • asthma
  • blood problems
  • glucose-6-phosphate dehydrogenase deficiency
  • kidney or liver problems
  • porphyria
  • stomach or intestinal blockage

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Check with your doctor to make certain your fluid intake is adequate and appropriate.
  • Call your doctor if your symptoms (including diarrhea) do not improve in a month or two, or if they get worse. Schedule regular visits to your doctor to check your progress.
  • Your skin or urine may turn orange-yellow in color. This is no cause for alarm.
  • Take all the sulfasalazine your doctor prescribed, even if you begin to feel better. If you stop too soon, your symptoms could come back.
  • Throw away outdated drugs.
  • Caution diabetics: see Diabetes Prevention and Treatment.
  • This drug makes you more sensitive to the sun. Stay out of the sun as much as possible, and call your doctor if you get a rash, hives, or any other skin reaction.
  • You may need more folic acid than usual while taking sulfasalazine. Ask your doctor about how to get more folic acid in your diet.
  • If you plan to have any surgery, including dental, tell your doctor that you take this drug.
  • Have regular checkups to check on blood counts if you are on long-term therapy.
  • Until you know how you react to this drug, do not drive or perform other activities requiring alertness.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Take with a full glass (eight ounces) of water. Sulfasalazine can be taken right after meals or with food to lessen stomach upset.
  • Swallow tablets whole.
  • Take the full course of therapy.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Do not let the liquid form freeze. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

digoxin, HIPREX, LANOXICAPS, LANOXIN, methenamine, potassium aminobenzoate, UREX.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • appetite loss
  • back, leg, or stomach pain
  • bleeding or bruising that is unusual
  • chest pain
  • chills
  • cough or difficulty breathing
  • diarrhea, bloody
  • eyes or skin yellow
  • feeling of discomfort or illness
  • fever
  • fingernails, lips, or skin bluish
  • headache
  • itching or skin rash
  • muscle or joint aches
  • nausea or vomiting
  • redness, blistering, peeling, or loosening of skin
  • skin pale
  • sore throat
  • sun sensitivity
  • swallowing difficulty
  • tiredness or weakness that is unusual

Call your doctor if these symptoms continue:

  • abdominal or stomach pain or upset
  • appetite loss
  • diarrhea
  • nausea or vomiting

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • complete blood count every two to three weeks for the first two to three months, then every three to six months.
  • liver function test every two weeks for the first three months, then monthly for the second three months and then once every three months.
  • proctoscopy and sigmoidoscopy
  • urine tests

last reviewed September 30, 2023