Azulfidine and Azulfidine EN-tabs (sulfasalazine) are brand-name prescription medications. The Food and Drug Administration (FDA) has approved Azulfidine and Azulfidine EN-tabs for the following uses in adults and in children ages 6 years and older:

Azulfidine EN-tabs are FDA-approved to treat the following conditions that haven’t responded to other treatments:

Azulfidine and Azulfidine EN-tabs come as oral tablets. Azulfidine EN-tabs are delayed-release enteric-coated tablets (EN-tabs). These tablets help your intestines absorb the drug throughout the day. Your doctor may prescribe you Azulfidine EN-tabs if you have gastrointestinal (digestive system) side effects from Azulfidine.

Dosage summary

The following table summarizes the dosages of Azulfidine and Azulfidine EN-tabs. (For more details, see the “Azulfidine and Azulfidine EN-tabs dosage” section below.) Your doctor will determine the dosage that’s best for you.


Azulfidine and Azulfidine EN-tabs
UseDaily starting dosageDaily maintenance (long-term) dosage
UC in adults3 to 4 grams* (g), split into multiple doses2 g, split into two doses
UC in children ages 6 years and older40 to 60 milligrams per kilogram† (mg/kg) of body weight, split into three to six doses30 mg/kg of body weight, split into four doses

Azulfidine EN-tabs
UseDaily starting dosageDaily maintenance dosage
RA in adultsa dosage lower than your maintenance dosage‡2 g, split into two doses
polyarticular course juvenile RA in children ages 6 years and oldera dosage lower than the child’s maintenance dosage‡30 to 50 mg/kg of body weight, split into two doses

* 1 g equals 1,000 mg.
† 1 kg is about 2.2 pounds.
‡ Your doctor may prescribe a low dosage of Azulfidine EN-tabs to decrease the risk of gastrointestinal side effects from the drug. (To learn more about the side effects of Azulfidine and Azulfidine EN-tabs, see this article.)

For information about the dosages of Azulfidine and Azulfidine EN-tabs, including their strength and how to take the drugs, keep reading. For a comprehensive look at Azulfidine and Azulfidine EN-tabs, see this article.

This section describes the typical dosages of Azulfidine and Azulfidine EN-tabs.

Azulfidine and Azulfidine EN-tabs forms

Azulfidine and Azulfidine EN-tabs both come as oral tablets.

Azulfidine EN-tabs come as delayed-release enteric-coated tablets (EN-tabs). These tablets help your intestines absorb the drug throughout the day. Your doctor may prescribe you Azulfidine EN-tabs if you have gastrointestinal (digestive system) side effects from Azulfidine. (To learn more, about the side effects of Azulfidine and Azulfidine EN-tabs, see this article.)

Azulfidine and Azulfidine EN-tabs strength

Azulfidine and Azulfidine EN-tabs come in one strength: 500 milligrams (mg).

Typical dosages

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Dosages for ulcerative colitis (UC) in adults

To treat UC in adults, the typical starting dosage of Azulfidine or Azulfidine EN-tabs is 3 to 4 grams (g) daily. This is 3,000 to 4,000 mg per day. The typical maintenance (long-term) dosage for this use is 2 g (2,000 mg) daily.

Your dosage will be split into multiple doses throughout the day. For example, if your total daily dose is 3,000 mg, you’ll take 1,000 mg every 8 hours. Talk with your doctor about the best way to split your doses throughout the day.

Dosages for rheumatoid arthritis (RA) in adults

To treat RA in adults, your doctor may recommend starting Azulfidine EN-tabs treatment with a dosage lower than your maintenance dosage. This is to decrease the risk of gastrointestinal side effects from the drug. The starting dosage will be split into two doses throughout the day. Your doctor will recommend a dosing schedule that’s best for you. The table below shows an example dosing schedule.

Week of treatmentMorning doseEvening dose
1none500 milligrams (mg)
2500 mg500 mg
3500 mg1,000 mg
41,000 mg1,000 mg

The typical maintenance dosage of Azulfidine EN-tabs to treat RA in adults is 2 g (2,000 mg) daily. Your doctor will recommend dividing this dosage into two doses:

  • 1 g (1,000 mg) in the morning
  • 1 g (1,000 mg) in the evening

Note: The Food and Drug Administration (FDA) hasn’t approved Azulfidine to treat RA in adults.

Children’s dosages

Below is information about the children’s dosages of Azulfidine and Azulfidine EN-tabs.

Dosages for UC in children ages 6 years and older

To treat UC in children, the typical starting dosage of Azulfidine or Azulfidine EN-tabs is 40 to 60 milligrams per kilograms (mg/kg) of body weight daily. (One kg is about 2.2 pounds [lb].) Your child’s total daily dosage will be split into three to six doses throughout the day.

For example, if your child weighs 45 kg (about 99 lb), their total daily dose would likely be 1,800 mg to 2,700 mg. This dose would be split into three to six doses and given once every 4 to 8 hours.

The typical maintenance (long-term) dosage of Azulfidine or Azulfidine EN-tabs for UC in children is 30 mg/kg of body weight daily. This total daily dosage will be split into four doses throughout the day. Your child’s doctor will recommend when they should take their doses.

Dosages for polyarticular-course juvenile RA in children ages 6 years and older

To treat polyarticular-course juvenile RA in children, your child’s doctor will likely recommend starting Azulfidine EN-tabs treatment with a dosage lower than your child’s maintenance dosage. This is to decrease the risk of gastrointestinal side effects from the drug. The starting dosage will be split into two doses throughout the day. Your child’s doctor will recommend a dosing schedule that’s best for them.

The typical maintenance dosage of Azulfidine EN-tabs for this use is 30 to 50 mg/kg of body weight daily. Your child’s total daily dosage will be split into two doses throughout the day.

For example, if your child weighs 40 kg (about 88 pounds), their total daily dose would likely be 1,200 mg to 2,000 mg. This total daily dose would be split into two doses:

  • 500 mg or 1,000 mg in the morning
  • 1,000 mg in the evening

It’s important to note the maximum dosage of Azulfidine EN-tabs for this use is 2,000 mg daily.

Note: The Food and Drug Administration (FDA) hasn’t approved Azulfidine to treat polyarticular-course juvenile RA.

Long-term treatment

Azulfidine and Azulfidine EN-tabs are meant to be taken as a long-term treatment. If you and your doctor determine that Azulfidine or Azulfidine EN-tabs are safe and effective for you, you’ll likely take it long term.

The Azulfidine or Azulfidine EN-tabs dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re taking Azulfidine or Azulfidine EN-tabs to treat
  • your age
  • your body weight
  • other medical conditions you may have
  • how well you tolerate the drug

Dosage adjustments

Your doctor may adjust your dosage of Azulfidine or Azulfidine EN-tabs during your treatment. They may increase your dosage if your current dosage isn’t effective for your condition.

They may also adjust your dosage if you have gastrointestinal (digestive system) side effects* while taking Azulfidine for ulcerative colitis. These side effects may include nausea and vomiting.

To decrease the risk of these side effects, your doctor may prescribe you a lower dosage of Azulfidine. For example, they may recommend you start treatment by taking 1 to 2 grams (g) daily. This is 1,000 to 2,000 milligrams (mg) per day.

Your doctor may also prescribe you Azulfidine EN-tabs instead of Azulfidine. Azulfidine EN-tabs are designed to help ease gastrointestinal side effects due to Azulfidine treatment.

* To learn more about the side effects of Azulfidine or Azulfidine EN-tabs, see this article.

Azulfidine and Azulfidine EN-tabs are oral tablets that you’ll swallow. You should swallow the whole tablet after eating a meal.

If you have trouble swallowing tablets, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.

Accessible drug labels and containers

If you’re having trouble reading your prescription label, talk with your doctor or pharmacist. Some pharmacies offer labels with large print, Braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.

If you’re having trouble opening medication bottles, ask your pharmacist about putting Azulfidine or Azulfidine EN-tabs in an easy-open container. They also may recommend tools that can make it easier to open bottles.

If you miss a dose of Azulfidine or Azulfidine EN-tabs, call your doctor or pharmacist right away. They’ll advise if you should take the missed dose or skip it and resume your usual dosing schedule.

To help make sure that you don’t miss a dose, try using a medication reminder. This can include setting an alarm or using a timer. You could also download a reminder app on your phone.

If you take more Azulfidine or Azulfidine EN-tabs than your doctor prescribes, you may develop serious side effects.

It’s important that you don’t take more Azulfidine or Azulfidine EN-tabs than your doctor advises.

Symptoms of an overdose

Overdose symptoms of Azulfidine and Azulfidine EN-tabs can include:

Although it’s rare, you may also experience drowsiness or convulsions (involuntary muscle movements).

If you take more than the recommended amount of Azulfidine or Azulfidine EN-tabs

Call your doctor right away if you believe you’ve taken too much Azulfidine or Azulfidine EN-tabs. Another option is to call the American Association of Poison Control Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.

The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Azulfidine or Azulfidine EN-tabs for you, they’ll prescribe the dosage that’s right for you. Always follow the dosage that your doctor prescribes for you.

As with any drug, never change your dosage of Azulfidine or Azulfidine EN-tabs without your doctor’s recommendation. If you have questions about the dosage that’s right for you, talk with your doctor.

Besides learning about dosage, you may want other information about Azulfidine and Azulfidine EN-tabs. These additional articles might be helpful to you:

Disclaimer: Medical News Today 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.