Azulfidine or Salazopyrin (Sulfasalazine) is a Disease Modifying Anti-Rheumatic Drug (DMARD) that is used in the treatment of rheumatoid arthritis, psoriatic arthritis, and many other types of arthritis.
Sulfasalazine may also be used to treat inflammatory bowel diseases like ulcerative colitis and Crohn’s disease.
Sulfasalazine is an old medicine that was first developed in the 1950s. It is a combination of a salicylate (a chemical like Aspirin) and a sulfa antibiotic.
Sulfasalazine is available in oral tablets.
Oral Tablets – Administration, Dose, and Frequency
Sulfasalazine is available in 500mg oral tablets. The dosage is decided by a doctor. It usually ranges from 2 tablets (1000 mg) twice a day to 3 tablets twice a day (1500 mg).
A common dose is 2 tablets in the morning, taken with breakfast, and two tablets at night, taken before bed. It is good to take Sulfasalazine with food.
Sulfasalazine is usually started slowly: either one tablet daily or one tablet twice daily. The dose is then increased by a tablet or two every week.
When Sulfasalazine works most patients start to feel improvement after 6-8 weeks. The maximum effect can take 6-12 months.
Doctors will determine if Sulfasalazine is working after 3 months. If it isn’t working at all after 3 months then it is usually stopped.
Important Tests and Risks
Patients starting Sulfasalazine should have their blood tested two weeks after starting the medicine, and then every month after that. It is important to make sure the medicine isn’t harming the liver, kidneys, or affecting blood counts.
How Sulfasalazine Works
The exact mechanism of how Sulfasalazine works to control arthritis is not understood, but it is believed that the sulfa portion of the medication is responsible for the benefits that are seen in patients taking the medication.
The Sulfasalazine molecule is made of two components: 5-aminosalicylate (5-ASA, also known as mesalamine) and sulfapyridine that are bonded together with a type of chemical bond called an azo bond.
5-ASA is an anti-inflammatory that specifically works in the bowels. It is a salicylate similar to aspirin (acetylsalicylic acid). This component and its effectiveness in the bowels helps explain why Sulfasalazine is useful in treating diseases like ulcerative colitis and Crohn’s disease.
Sulfapyridine is a type of sulfa antibiotic. It is thought that this sulfa component of the medication is responsible for the benefits seen in arthritis patients who take Sulfasalazine.
Sulfapyridine is thought to block NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) a protein complex that plays a role in the immune system response.
In blunting the immune system’s response, Sulfasalazine can help reduce the pain, joint swelling, and stiffness associated with types of arthritis that involve the immune system attacking the body’s own joints.
The most common side effect of Sulfasalazine is nausea and feeling unwell. This can get better over time as patients get used to the medication. It can be helpful for patients to drink lots of water while taking this medicine.
MORE COMMON side-effects include:
- Nausea, diarrhea, and abdominal pain
- Headaches or slight dizziness
- Rash – Patients should stop the medicine and let their doctor know if they develop a rash
RARE side-effects include:
- Sensitivity to the sun – Patients are advised to wear sunscreen
- Liver – Sulfasalazine can rarely irritate the liver. This does not usually cause symptoms but may be found on blood tests. Damage is rare and usually reversible when regularly monitored with monthly blood tests.
- Blood Counts – Sulfasalazine can cause a drop in the numbers of white blood cells (which are needed to fight infection), red blood cells (which carry oxygen), and platelets (which help to stop bleeding). With regular blood tests, it is unusual for this to be a serious problem.
- Fertility – Sulfasalazine may cause a drop in the sperm count resulting in temporary infertility. This reverses when the medication is stopped.
- Kidneys – Sulfasalazine may rarely irritate the kidneys.
- Urine may turn slightly orange
Patients should tell their doctor if they are concerned about any side effects.
Sulfasalazine can simply be stopped and doesn’t need to be weaned off. However, a patient’s arthritis may “flare” after they stop taking this medicine.
Who Shouldn’t Take Sulfasalazine
Patients who should NOT be taking Sulfasalazine include:
- Patients who have had a prior serious allergic reaction to Sulfasalazine
- Patients who have an allergy to medications containing Sulfa
- Patients who have an allergy to ASA (acetylsalicylic acid = Aspirin).
When to Call a Doctor
Patients should call their doctor if they feel sick and want to stop, or they you are concerned about any side effects.
Other reasons to call a doctor while taking Sulfasalazine include:
- Development of a rash
- Becoming pregnant or planning pregnancy
Watch rheumatologist Dr. Andy Thompson introduce Sulfasalazine in a short 1.5-minute video: