Sulfasalazine belongs to the class of medications called anti-inflammatories. It is used to treat inflammatory bowel disease such as ulcerative colitis, proctitis or distal ulcerative colitis, and Crohn's disease. It helps control symptoms by reducing chronic inflammation in the bowel. The enteric-coated tablets can be used to treat rheumatoid arthritis when treatment with other medications has not helped. It may take 1 to 2 months before you see any results.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The dose of sulfasalazine varies widely according to the condition being treated and the needs of the person. The dose is usually started at a low dose and increased to the dose that is most effective. 

Side effects are more likely to occur with total daily doses of 4 g (4,000 mg) daily or more. Doses of sulfasalazine should be taken at regular and even intervals over the 24 hour daily period. If you are taking sulfasalazine for an intestinal inflammatory disease, the night-time dose interval should not be longer than eight hours.

The uncoated tablets should be taken with a meal if possible. The enteric-coated tablets must not be chewed or crushed; they should be swallowed whole.

While taking sulfasalazine, drink an adequate amount of fluids to minimize the risk of crystals in the urine and the formation of kidney stones.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Tablets
Each yellow-orange, round, convex tablet, engraved with "KPh" on one side and "101" and a score on the other side, contains sulfasalazine 500 mg. Nonmedicinal ingredients: silicon dioxide, starch, and magnesium stearate.

Each yellow-orange, elliptical, convex, enteric-coated tablet, engraved with "KPh" on one side and "102" on the other side, contains sulfasalazine 500 mg. Nonmedicinal ingredients: beeswax, carnauba wax, cellulose acetate phthalate, glyceryl monostearate, polyethylene glycol, propylene glycol, and talc.

Do not take sulfasalazine if you:

• are allergic to sulfasalazine or any ingredients of the medication
• are allergic to sulfonamides or salicylates (e.g., ASA or aspirin)
• have a liver condition called porphyria as this type of medication has been reported to bring on an attack
• have had acute asthmatic attacks, hives, rhinitis, or other allergic symptoms that are brought on by ASA or other nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, naproxen)
• have an intestinal or urinary blockage
• have severely decreased kidney function
• have severely reduced liver function

Do not give this medication to children under 2 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• diarrhea
• dizziness
• headache
• increased sensitivity of skin to sunlight
• itchiness
• loss of appetite
• low sperm count (men)
• nausea
• orange-yellow urine
• upset stomach
• vomiting
• yellow stain on contact lenses

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• aching joints and muscles
• difficulty swallowing
• headache (continuing)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin rash, hives, fever
• symptoms of anemia (such as weakness, paleness, and fatigue)
• symptoms of arthritis (such as joint pain, stiffness)
• symptoms of infection (such as fever, chills, or a general feeling of being ill)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of interstitial lung disease (e.g., shortness of breath or difficulty breathing)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergies: Some people who are allergic to furosemide, thiazide water pills, or carbonic anhydrase inhibitors also experience allergic reactions to this medication. Before you take sulfasalazine, inform your doctor about any previous adverse reactions you have had to medications, especially water pills or sulfonamide antibiotics. Contact your doctor at once if you experience signs of an allergic reaction, such as skin rash, itching, difficulty breathing, or swelling of the face and throat.

Anemia: Sulfasalazine may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Asthma: Sulfasalazine can cause increased breathing difficulty for people with asthma. If you have asthma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Bleeding: Sulfasalazine may cause a reduced number of platelets in the blood, which can make it difficult to stop cuts from bleeding. If you notice any signs of bleeding, such as frequent nosebleeds, unexplained bruising, or black and tarry stools, notify your doctor as soon as possible. Your doctor will order routine blood tests to make sure potential problems are caught early.

Fertility: Some men taking sulfasalazine have experienced infertility. Stopping the medication appears to reverse these effects.

Glucose-6-phosphate dehydrogenase enzyme deficiency: People without the G6PD enzyme should discuss with their doctor how this medication may affect the dosing and effectiveness of this medication.

Hypersensitivity syndrome: A severe allergic reaction called hypersensitivity syndrome has occurred for some people who take sulfasalazine. This reaction involves a number of organs in the body and may be fatal if not treated quickly. It is most likely to occur during the first three months of taking sulfasalazine, but may happen at any point during treatment. Stop taking the medication and get immediate medical attention if you have symptoms of a severe allergic reaction, including fever, swollen glands, yellowing of the skin or eyes, or flu-like symptoms with skin rash or blistering.

Infection: Sulfasalazine can reduce the number of cells that fight infection in the body (white blood cells). Tell your doctor immediately if you notice more frequent signs of infections, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.

Kidney disease: This medication can reduce kidney function. If you have kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need to have regular tests while taking this medication to make sure that your kidneys are working properly. People who have severe kidney problems should not use this medication.

Liver disease: Sulfasalazine may reduce liver function and can cause liver failure. If you have liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need to have regular liver tests while taking this medication. People with severe liver disease or very poor liver function should not take sulfasalazine.

Staining: Sulfasalazine may produce an orange-yellow colour in the urine. Similar discoloration of the skin and yellow staining of soft contact lenses have occasionally been reported.

Tablets in stool: If you notice intact enteric-coated tablets in your stool, contact your doctor.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are breast-feeding and are taking sulfasalazine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: This medication is not recommended for children with juvenile rheumatoid arthritis.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.