Sulfasalazine is a drug with an anti-inflammatory effect, used particularly in ulcerative colitis and some rheumatic diseases.
Related to the 5-aminosalicylate (5-ASA) group of drugs, sulfasalazine reduces inflammation in the bowel and helps bring the symptoms of the disease under control.
Sulfasalazine is not a steroid (cortisone). It is not addictive.
How does sulfasalazine work?
Sulfasalazine is made of two components: 5-aminosalicylic acid (5-ASA, mesalazine) and sulfapyridine.
When the drug reaches the large bowel, the bowel bacteria split it into these two components.
5-ASA helps reduce the inflammation on the bowel lining. Sulfapyridine is linked to some of the drug’s effects on the rest of the body and to its side effects.
For this reason, in some patients sulfasalazine can cause more side effects than drugs containing mesalazine alone.
What is it used for?
Ulcerative colitis
Ulcerative colitis is a chronic disease that causes inflammation of the inner lining of the large bowel.
Sulfasalazine can be used in some patients with mild to moderate ulcerative colitis to reduce the inflammation and keep the disease under control.
Once the disease has been brought under control, it can also be used in suitable patients to prevent further flare-ups.
However, in many patients today mesalazine is preferred to sulfasalazine because it is better tolerated.
In patients who benefit from sulfasalazine and tolerate it well, it may be appropriate to continue the treatment.
Crohn’s disease
Crohn’s disease is a chronic inflammatory bowel disease that can affect different parts of the digestive system.
Sulfasalazine was also used in Crohn’s disease in the past.
However, in current treatment approaches its role in Crohn’s disease is quite limited.
Particularly in moderate and severe Crohn’s disease, it is not routinely recommended for bringing the disease under control or for keeping it in long-term remission.
For this reason, sulfasalazine is not a suitable treatment for every patient with Crohn’s disease.
Rheumatoid arthritis
Sulfasalazine can also be used in the inflammatory joint disease called rheumatoid arthritis.
It helps reduce joint pain, swelling and inflammation.
In this disease the decision to treat is made by a rheumatologist.
Other rheumatic diseases
Sulfasalazine can be used in some patients with spondyloarthritis and involvement of the peripheral joints.
However, its effect is limited, particularly when the disease mainly affects the spine. It is not equally effective in every rheumatic disease.
How is sulfasalazine taken?
Sulfasalazine is taken by mouth as a tablet.
The dose and how often it is taken are decided according to the type and severity of the disease and how well the patient tolerates the drug.
In some patients, to reduce side effects, treatment is started at a low dose and the dose is increased step by step.
- Take the drug at the dose your doctor recommends.
- Taking it with or after food can usually reduce stomach complaints.
- It is recommended to take it with plenty of water.
- Enteric-coated tablets should not be broken or chewed.
- Do not take a double dose for a missed one.
- Regular blood tests should be done during treatment.
How long the drug is taken depends on the state of the disease. Some patients may need long-term treatment.
What are the side effects of sulfasalazine?
Sulfasalazine can cause side effects in some patients.
More common side effects
- Nausea
- Loss of appetite
- Abdominal pain
- Headache
- Indigestion
- Skin rash
These complaints can sometimes be related to the dose.
Rare but serious side effects
Fall in blood cells: Rarely, sulfasalazine can affect the bone marrow and cause a fall in white blood cells, red blood cells or platelets.
Liver damage: Raised liver enzymes and, rarely, serious liver problems can occur.
Severe skin reactions: Very rarely, serious reactions such as Stevens–Johnson syndrome or toxic epidermal necrolysis can develop.
Kidney problems: Rarely, kidney function can worsen.
Allergic reactions: Symptoms such as fever, a widespread rash, swelling of the face or difficulty breathing can develop.
Although these serious side effects are uncommon, it is important to recognise them early.
Which symptoms mean I should see a doctor urgently?
The following symptoms are important in patients taking sulfasalazine:
- High fever and sore throat
- Unexplained bruising or bleeding
- A widespread skin rash
- Sores in the mouth
- Yellowing of the eyes or skin
- Marked tiredness
- Passing less urine
- Blistering or peeling of the skin
Fever, sore throat, bruising or jaundice in particular can be signs of a serious problem with the blood cells or the liver.
In these situations, urgent medical assessment should be made before the next dose of the drug is taken.
Which blood tests are done while taking sulfasalazine?
Regular monitoring is important in sulfasalazine treatment.
Before and during treatment the following are usually assessed:
- Full blood count
- Liver function tests
- Kidney function tests
The checks are more frequent in the first months of treatment. After that, the intervals are arranged according to the patient’s condition.
Normal blood tests do not mean that side effects will not develop later.
Sulfasalazine and folic acid
Sulfasalazine can reduce the absorption of folic acid from the bowel and its use in the body.
Folic acid is a vitamin needed for making blood cells and for the normal working of cells.
For this reason, folic acid supplements are recommended for some patients taking sulfasalazine.
The need for folic acid should be assessed separately, particularly in women planning a pregnancy.
The dose of folic acid should be decided by the doctor.
Does sulfasalazine affect men’s ability to have children?
Yes. In some men sulfasalazine can reduce the number and movement of sperm.
This effect is mostly temporary.
After the drug is stopped, or another suitable treatment is started, the sperm usually return to normal within a few months.
Male patients planning to have children should discuss this with their doctor.
The drug should not be stopped without a doctor’s advice.
Can it be used in pregnancy and breastfeeding?
Sulfasalazine is not a drug that is strictly forbidden in pregnancy in every situation.
In women with ulcerative colitis or some rheumatic diseases, it can be used during pregnancy to keep the disease under control.
However, folic acid supplements are important and the treatment should be planned by a specialist.
It can also be used by some patients while breastfeeding. Even so, particular care is needed with babies who are premature, jaundiced or have G6PD deficiency.
Patients planning a pregnancy or breastfeeding should talk to their doctor.
Are sulfasalazine and mesalazine the same?
No.
Mesalazine is a drug that contains 5-ASA directly.
Sulfasalazine, on the other hand, is made of the components 5-ASA and sulfapyridine.
Both drugs can be used in ulcerative colitis.
However, because of the sulfapyridine component of sulfasalazine, nausea, headache and some other side effects can be more common.
For this reason, mesalazine is a better-tolerated option for many patients with ulcerative colitis.
Can my urine change colour while taking sulfasalazine?
Yes. In some patients sulfasalazine can make the urine or sweat look yellow-orange.
On its own this colour change is usually not dangerous.
However, if dark urine comes with jaundice, abdominal pain or marked tiredness, the liver needs to be assessed.
Does it interact with other medicines?
Sulfasalazine can interact with some medicines.
Care is needed particularly when it is used together with:
- Methotrexate
- Azathioprine
- Mercaptopurine
- Digoxin
- Some other drugs that affect the immune system
Using it together with azathioprine or mercaptopurine can increase the risk of a fall in blood cells in some patients.
For this reason, all the medicines you take should be reported to your doctor.
Frequently asked questions
Is sulfasalazine a steroid (cortisone)?
No. It is not cortisone. It is a different drug with an anti-inflammatory effect.
Is sulfasalazine an antibiotic?
Although it contains a component derived from a sulphonamide, it is not used as an antibiotic in ulcerative colitis.
Is sulfasalazine addictive?
No. It is not addictive. However, it may need to be taken for a long time to keep chronic diseases under control.
Is sulfasalazine given to every patient with ulcerative colitis?
No. The severity of the disease, how much of the bowel is involved, the drugs used before and how well the patient tolerates the treatment are taken into account.
Should I take folic acid while taking sulfasalazine?
Some patients need folic acid supplements. This is particularly important for women planning a pregnancy. The dose should be decided by the doctor.
Are regular blood tests needed while taking sulfasalazine?
Yes. Regular checks of the blood count and of liver and kidney function are important.
Are sulfasalazine and Asacol the same?
No. Asacol contains mesalazine. Sulfasalazine contains, alongside a 5-ASA component related to mesalazine, sulfapyridine as well. For this reason their effects and side effects are not exactly the same.
Important: This page has been prepared to inform patients. Sulfasalazine is a drug that needs regular follow-up by a doctor and blood tests. The dose should not be changed and the drug should not be stopped without a doctor’s advice.
Sources
- Prof. Ali Tüzün İnce, MD — personal endoscopy archive