Sulfasalazine for Ankylosing Spondylitis

Medically Reviewed by Tyler Wheeler, MD on August 02, 2022
4 min read

Doctors most often use NSAIDS (short for nonsteroidal anti-inflammatory drugs) like ibuprofen or naproxen to treat the pain and stiffness that comes with ankylosing spondylitis. If NSAIDS don’t work for you or you shouldn’t take NSAIDS, you might move on to other medicines. Sulfasalazine is one of many other options your doctor might prescribe. Your doctor might also choose sulfasalazine if you have ankylosing spondylitis and inflammatory bowel disease (IBD).

Sulfasalazine is a drug that fights inflammation. It does this by blocking your body from making prostaglandins, chemicals that play a role in pain and inflammation. It was originally approved for people with a type of IBD called ulcerative colitis.

But doctors also consider this drug a DMARD (short for disease-modifying antirheumatic drug). That means it can help with the pain and swelling of arthritis, including ankylosing spondylitis. In addition to helping with symptoms, sulfasalazine can protect your joints from damage. It also can help keep you from becoming disabled from your ankylosing spondylitis.

Ankylosing spondylitis primarily affects bones in your spine. Sulfasalazine will help you most if you have problems in your arm and leg joints, too. Sulfasalazine can help your spine loosen up and feel less stiff. It also can help other joints. But doctors haven’t shown that it helps your spine move better or that it will help you function better physically. It doesn’t help with inflammation in your tendons either.

A study that compared sulfasalazine to another drug called etanercept found that sulfasalazine helped significantly less. Etanercept is one of a few drugs approved for ankylosing spondylitis that work in a different way. They’re collectively called TNF-alpha inhibitors (short for tumor necrosis factor-alpha inhibitors). So other approved drugs might work better for you than sulfasalazine if you’ve already found that NSAID therapy doesn’t work or you can’t take NSAIDs. Ask your doctor what they recommend in your case and if it’s worth trying sulfasalazine to see how it works for you.

Sulfasalazine comes in a pill that you should take with food and water to avoid upsetting your stomach. You’ll probably start with 1 or 2 pills a day. Your doctor might increase your dose over time.

You’ll need to be sure to drink enough water or other liquids when you’re taking sulfasalazine. You shouldn’t take it when your stomach is empty or you’ve taken antacids. The drug can change how your body absorbs folate. So you should take folic acid along with it, especially if you are pregnant or think you may get pregnant.

If you miss a pill, take it when you remember. You shouldn’t take a double dose to make up for a missed one, though. If it’s time or almost time for the next pill, just skip the one you missed.

The most common side effects include:

  • Headache
  • Nausea
  • Fever
  • Rash
  • Infertility in men
  • Sun sensitivity
  • Turning skin and pee yellow

You’re more likely to have headaches if you take bigger doses of sulfasalazine. Some symptoms, including nausea, are more common at first. It can lower sperm count, but this will go away if you stop taking sulfasalazine.

Rare side effects include:

  • Liver inflammation (hepatitis)
  • Lung inflammation (pneumonitis)
  • Serious skin reaction (Stevens-Johnson syndrome)
  • Breakdown of red blood cells (hemolysis)
  • Kidney inflammation
  • A drop in number of white blood cells

Your doctor will monitor your blood counts while you take sulfasalazine. Blood tests also will make sure your kidneys are working well. You’ll need testing after the first 6 weeks and then every 6 months to make sure you aren’t having a rarer and potentially serious side effect. Contact your doctor if you have new symptoms and think you’re having a bad reaction to sulfasalazine.

You shouldn’t take sulfasalazine if you’re allergic to sulfa drugs. If you notice mild allergy symptoms when you take it but it’s working for your ankylosing spondylitis, ask your doctor if it’s OK to keep taking it. Your body might get used to the drug and stop reacting. You may need to start with a really low dose and increase it slowly.

If you have ankylosing spondylitis and NSAIDs aren’t helping you feel better, here are some questions to ask your doctor:

  • What’s causing my symptoms?
  • Do I need more tests?
  • What if NSAIDs don’t work?
  • What other treatments should I consider?
  • Are there other things I can do to help with pain, stiffness, and damage to my joints?
  • Should I see a specialist?