Azulfidine, Sulfasalazine, Azulfidine En-tabs

Introduction

Written by Helen Marshall BPharm MRPharmS
Medically reviewed by Elizabeth Scheffel, PharmD
Updated on August 4, 2023

Sulfasalazine (sul fa SAL a zeen) is a generic medication prescribed for ulcerative colitis and rheumatoid arthritis. It’s used in adults and some children. Sulfasalazine belongs to a group of anti-inflammatory drugs called aminosalicylates.

Side effects of sulfasalazine

Sulfasalazine may cause mild or serious side effects. More common mild side effects of sulfasalazine and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about sulfasalazine’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for sulfasalazine listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of sulfasalazine are listed below. These side effects may differ based on the form of sulfasalazine you take.

This article doesn’t include all possible mild side effects of the drug. To learn more about sulfasalazine’s side effects based on the form, refer to the prescribing information for sulfasalazine listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Mild side effects of sulfasalazine oral tablet and delayed-release oral tablet include:

• nausea and vomiting
• indigestion
• headache
• reduced appetite
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for sulfasalazine” section.

Serious side effects

Serious side effects of sulfasalazine are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about sulfasalazine’s side effects, refer to the prescribing information for sulfasalazine listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, sulfasalazine’s serious side effects include:

• blood disorders, such as low levels of white blood cells, red blood cells, or platelets
• serious infections, such as pneumonia
• liver problems, such as liver inflammation
• kidney problems, such as kidney inflammation
• severe skin reactions
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for sulfasalazine” section.

Uses of sulfasalazine

The Food and Drug Administration (FDA) approves prescription drugs such as sulfasalazine for certain conditions. Approved uses for sulfasalazine are described below. These uses differ based on the form of sulfasalazine prescribed.

Use for rheumatoid arthritis

Doctors may prescribe sulfasalazine delayed-release* oral tablet for treating:

• rheumatoid arthritis (RA) in adults
• juvenile rheumatoid arthritis (JRA) in children ages 6 years and older who have five or more joints affected by JRA

It’s used for this purpose in people whose arthritis hasn’t improved enough with other medications called non-steroidal anti-inflammatory drugs (NSAIDs). It’s usually prescribed as a long-term treatment.

With rheumatoid arthritis, you have inflammation, pain, and stiffness in certain joints in your body. These symptoms can cause trouble with daily activities, such as washing, dressing, or walking.

Sulfasalazine reduces the inflammation, pain, and stiffness in your joints. This makes it easier to do your daily activities. When used for rheumatoid arthritis, sulfasalazine is known as a disease-modifying anti-rheumatic drug (DMARD).

Sulfasalazine is usually prescribed together with NSAIDs or other pain- relievers for at least the first few months of treatment.

* Delayed-release tablets don’t release the medication until after they’ve passed through your stomach.

Use for ulcerative colitis

Doctors may prescribe sulfasalazine oral tablet and delayed-release oral tablet for treating mild to severe ulcerative colitis. It’s used for this purpose in adults and children ages 6 years and older. It’s usually prescribed as a long-term treatment.

With ulcerative colitis, you have inflammation and ulcers (small sores) in the lower part of your intestines (colon and rectum). This causes symptoms such as belly pain or cramps, diarrhea, bloody stools, and weight loss.  

Your ulcerative colitis symptoms may vary over time. There may be times when the disease flares up and causes symptoms. There may be other times when the disease goes into remission and your symptoms improve.

Sulfasalazine reduces the inflammation in your intestines. It reduces the symptoms of ulcerative colitis flare-ups. It also helps lengthen periods of remission between flare-ups.

For severe ulcerative colitis, sulfasalazine is prescribed together with other medications.

Common questions about sulfasalazine

Below you’ll find answers to a few commonly asked questions about sulfasalazine.

What is sulfasalazine’s mechanism of action? How does the drug work?

Sulfasalazine treats rheumatoid arthritis (RA) and ulcerative colitis (UC). With RA, you have inflammation in your joints. With UC, you have inflammation in the lower part of your intestine.

Doctors don’t fully understand how sulfasalazine works. But it treats RA by reducing inflammation in your joints. It treats UC by reducing inflammation in your intestine. This lessens the symptoms of both of these conditions.

Sulfasalazine starts working soon after you start taking it. But it may take up to 3 months for your symptoms to get better.

If you’d like to know more about how sulfasalazine works, talk with your doctor or pharmacist.

Is sulfasalazine an antibiotic?

No, sulfasalazine is not an antibiotic. Antibiotics treat bacterial infections. Instead, sulfasalazine is a type of anti-inflammatory drug called an aminosalicylate. Anti-inflammatory drugs reduce discomfort and pain.

Sulfasalazine has a similar chemical structure to certain antibiotics called sulfonamides. But sulfasalazine doesn’t treat bacterial infections.

Interactions and warnings for sulfasalazine

Below, you’ll find information about sulfasalazine’s possible interactions and warnings.

Interactions of sulfasalazine

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take sulfasalazine, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for sulfasalazine” section below.

Warnings for sulfasalazine

Some people should not take sulfasalazine, and others should take it cautiously.

Sulfasalazine could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether sulfasalazine is a safe option for you. These warnings may differ based on the form of sulfasalazine you take.

Ask your doctor about specific warnings for sulfasalazine, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Sulfasalazine can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to sulfasalazine or any of its ingredients, your doctor will likely not prescribe sulfasalazine. And they’ll likely not prescribe it if you’ve had an allergic reaction to other drugs classed as sulfonamides or salicylates. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems
• reddening of the skin that results in peeling or blistering  

If you have an allergic reaction to sulfasalazine, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of sulfasalazine

You should not take more sulfasalazine than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken too much sulfasalazine, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and sulfasalazine

Information about sulfasalazine and pregnancy and breastfeeding is described below.

Sulfasalazine and pregnancy

There may be risks to taking sulfasalazine during pregnancy. But there are also risks with having unmanaged ulcerative colitis or rheumatoid arthritis while pregnant. (Keep in mind that sulfasalazine is used for treating ulcerative colitis and rheumatoid arthritis.)

If you’re planning a pregnancy or can become pregnant, talk with your doctor about treatment options for your condition during pregnancy. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take sulfasalazine during pregnancy. Your doctor may recommend additional folic acid, an important vitamin for proper fetal development while taking sulfasalazine.

Sulfasalazine and breastfeeding
There may be risks to taking sulfasalazine while breastfeeding. But there are also risks with having unmanaged ulcerative colitis or rheumatoid arthritis during this time. (Keep in mind that sulfasalazine is used for treating ulcerative colitis and rheumatoid arthritis.)

For instance, sulfasalazine may cause diarrhea or bloody stools in a breastfed child.

If you’re planning to breastfeed, talk with your doctor about treatment options for your condition. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take sulfasalazine during this time. Your doctor may recommend other healthy ways to feed your child.

What to ask your doctor

Let your doctor know if you have questions about sulfasalazine or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Is sulfasalazine safe for children?
• What form and dose of sulfasalazine will I need?
• Are there any alternative medications that I can take for my condition?
• What drug interactions should I avoid when taking sulfasalazine?

Resources

• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm
• Sulfasalazine delayed release oral tablet. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/257cee60-b68f-4c2b-b57d-8e4d73d17e09/spl-doc
• Sulfasalazine tablets. (2023). http//nctr-crs.fda.gov/fdalabel/services/spl/set-ids/8f5e8320-d972-453a-9b8c-bc4c5424aa4c/spl-doc

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.