Experiences with
Sulfasalazine

ContraindicationsHow it's used (previously Dosage and administration)Side effectsBreastfeedingInteractions

Sulfasalazine is not suitable for some people. For example, check with your doctor if you have asthma or problems with your liver or kidneys.

Sulfasalazine comes as tablets, liquid or suppositories. Your dose depends on your condition. Follow the instructions that come with your medicine.

Side effects of sulfasalazine include indigestion, heartburn and feeling sick. More serious side effects can happen in rare cases.

You may be able to take or use sulfasalazine while breastfeeding. Always check with your doctor.

It can cause problems to take sulfasalazine with some other medicines, such as digoxin, metformin or folic acid. Check with a pharmacist or doctor.

Who can take sulfasalazine

Most adults and children aged 2 years or over can take sulfasalazine.

Who may not be able to take sulfasalazine

Sulfasalazine is not suitable for some people. To make sure it's safe for you, tell your doctor if you:

have ever had an allergic reaction to sulfasalazine or any other sulfonamides, aspirin, or any other salicylates such as methyl salicylate or choline salicylate
have ever had an allergic reaction to any other medicine
have a rare blood condition called porphyria
have any problems with your kidneys or liver
are pregnant, trying to get pregnant or breastfeeding
have a genetic condition called glucose-6-dehydrogenase deficiency
have ever had asthma
often get infections or have a condition that makes you more likely to get infections

Dosage and strength

Sulfasalazine tablets and suppositories contain 500mg of sulfasalazine. The liquid contains 250mg in 5ml.

Your dose and how often you take or use sulfasalazine will depend on why you need it, the type you’re using and how severe your symptoms are.

For inflammatory bowel disease the usual dose at the start of your treatment is either:

2 to 4 tablets or 20ml to 40ml of liquid, 4 times a day
1 to 2 suppositories, twice a day

For rheumatoid arthritis, the usual dose at the start of your treatment is 1 tablet (500mg) taken once a day. This will increase by 1 tablet each week until you reach a dose of 1 tablet 4 times a day (2g a day), or 2 tablets 3 times a day (3g a day), depending on how it works for you.

For children, the dose may be lower. The doctor will usually prescribe a dose based on your child's weight.

Changes to your dose

When your symptoms start to get better, your doctor may reduce your dose. This lower dose, sometimes called a maintenance dose, will help keep your symptoms under control.

If your symptoms get worse again, your doctor may want to increase your dose.

Cautions with other medicines

There are some medicines that can affect how sulfasalazine works.

Tell your doctor or pharmacist before starting to take or use sulfasalazine if you're taking any other medicines, including:

digoxin, a medicine for heart problems
medicines for high blood sugar or diabetes, such as metformin or glibenclamide
methenamine, a type of antibiotic sometimes used for treating urinary tract infections (UTIs)
folic acid, often taken in first 12 weeks of pregnancy, as it may be less well absorbed so you may need to take a higher dose than usual
azathioprine or mercaptopurine, taken for rheumatoid arthritis or to prevent organ rejection after a transplant
methotrexate, which is usually used to treat rheumatoid arthritis

Sulfasalazine and pregnancy

There are no concerns that taking sulfasalazine in pregnancy can harm your baby.

Sulfasalazine can affect your folate levels. To help with this, take high dose folic acid (5mg a day), particularly in the 3 months before you start trying to get pregnant and during the first 12 weeks of pregnancy.

You can continue taking folic acid throughout your pregnancy.

Talk to your doctor or midwife if you're trying to get pregnant, or as soon as you become pregnant, so that high dose folic acid can be prescribed.

Sulfasalazine and breastfeeding

If your baby is healthy, you may be able to take or use sulfasalazine while breastfeeding. Your doctor can talk with you about your options.

It's important to keep treating your condition to keep you well. Breastfeeding will also benefit both you and your baby.

Small amounts of sulfasalazine pass into breast milk and it should not cause any side effects in your baby, although there have been some rare cases of diarrhoea in babies. It's important to keep monitoring your baby if you're taking any medicine while breastfeeding.

Contact your healthcare professional or call 111 as soon as possible if you notice that your baby:

has diarrhoea
is being sick (vomiting)
has a rash
is not sleeping as well as usual, or being irritable
has signs of jaundice – yellowing of the whites of the eyes and the skin (this may be less obvious on brown or black skin), dark pee and pale poo

If your baby has any symptoms that are not listed, or if you're worried about them, you can also call 111 or contact any healthcare professional.

Carry on taking the medicine, and keep breastfeeding as usual until you've got advice about your baby's symptoms.

Common side effects of sulfasalazine

Side effects of sulfasalazine can vary depending on whether you're taking it as a tablet, suppository or liquid. Check the leaflet that comes with your medicine before taking or using it.

These common side effects happen in more than 1 in 100 people. There are things you can do to help cope with them:

It might help to take your sulfasalazine a few minutes before or after a meal.

If you need something to ease the discomfort, try taking an antacid. However, if you take an antacid, take it at least 2 hours before or at least 2 hours after you take sulfasalazine.

Stick to simple meals and do not eat rich or spicy food. It might help to take your sulfasalazine after you've eaten.

Drink lots of fluids, such as water or squash, to avoid dehydration. Speak to a pharmacist if you have signs of dehydration such as peeing less than usual or having dark strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or the progestogen-only pill and you have severe, watery diarrhoea, or any diarrhoea that lasts for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Stick to simple meals and do not eat rich or spicy food. It might help to take your sulfasalazine after you've eaten.

Drink plenty of fluids, such as water or squash, to avoid dehydration. Take small frequent sips if you're being sick. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help. If you're in a lot of pain, speak to your pharmacist or doctor.

Sit down for a while until the feeling passes. Do not drive, cycle or use tools or machinery until you feel better.

Drink plenty of water and ask your pharmacist to recommend a painkiller. If the headache or pains continue or are severe, and taking a painkiller does not help, tell your doctor.

Try chewing sugar-free gum. If you're coughing try having frequent sips of water or other unsweetened drinks.

Avoid having a big meal, smoking, or drinking alcohol, tea or coffee in the evening. Try not to watch television or use your mobile phone before going to bed. Instead, try to relax for an hour before bedtime.

Speak to your doctor if this does not go away or lasts longer than 2 days.