Pharmacy Guide

Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.

Pharmacy Guide

Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.

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Salazopyrin En-Tabs 500 mg gastro-resistant tablets

⚠ This medicine appears to have been discontinued

The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.

If you were prescribed this medicine, other products containing Sulfasalazine may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.

Active substance: Sulfasalazine

Equivalent medicines (same active substance, strength and form)

Source: electronic medicines compendium (emc)
Official leaflet: Read the PIL on emc

What it is and what it is used for

for The active substance in Salazopyrin En-Tabs is sulfasalazine which is an anti-inflammatory drug and belongs to a group of medicines called aminosalicylates. Your doctor may give you Salazopyrin En-Tabs to treat and manage inflammatory bowel disease or to treat rheumatoid arthritis. Inflammatory bowel disease The main forms of inflammatory bowel disease are Ulcerative Colitis and Crohn's disease. Although the diseases have some features in common, there are some important differences. Ulcerative Colitis is an inflammatory disease which affects only the large bowel (colon and back passage). The lining of the bowel becomes inflamed (red and swollen) and symptoms include abdominal pain and diarrhoea (which may contain blood and mucus). Salazopyrin En-Tabs are used to control the flare-ups of ulcerative colitis. They may also be used at lower doses to prevent more flare-ups of ulcerative colitis. Crohn's disease is an inflammatory disease which may affect any part of the digestive system from the mouth to the anus, but it most commonly affects the last part of the small bowel and the first part of the large bowel. Symptoms include abdominal pain and diarrhoea (which may be bloody). Salazopyrin En-Tabs are used to control the flare-ups of Crohn's Disease. Rheumatoid arthritis Salazopyrin En-Tabs are usually given when a group of medicines known as non-steroidal antiinflammatory drugs (NSAIDs e.g., aspirin and ibuprofen) are not working. They help prevent damage to your joints and work slowly to reduce swelling and stiffness in your joints.

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You must talk to a doctor if you do not feel better or if you feel worse.

What you need to know before you take it

e Salazopyrin En-Tabs Your doctor will perform complete blood counts and liver function tests before starting Salazopyrin and every second week during the first three months of therapy. During the second three months, the same tests should be done once monthly and thereafter once every three months, and as clinically indicated. Urine analysis and an assessment of kidney function should also be done in all patients initiating treatment with Salazopyrin. For patients with baseline renal impairment, treatment with Salazopyrin should only be initiated if the benefits are considered to outweigh risk. Thereafter, periodic renal function monitoring, especially in the early months of treatment, should be conducted by your doctor during treatment with Salazopyrin. Treatment should be discontinued if renal function deteriorates. Do not take Salazopyrin En-Tabs:

  • if you are allergic to sulfasalazine or any of the other ingredients of this medicine (listed in section 6).
  • if you are allergic to salicylates (e.g., aspirin) or sulfonamides (e.g., a certain type of antibiotic).
  • if you have a disease known as porphyria (a rare blood pigment disorder). Your doctor will have already told you if you have this disease. Salazopyrin En-Tabs are not to be used in children under 2 years of age. Warnings and precautions Tell your doctor if you are taking or have recently taken Salazopyrin En-Tabs, or any other sulfasalazine containing products, because they may affect results of blood and urine tests. Talk to your doctor or pharmacist before taking Salazopyrin En-Tabs:
  • if you have ever had any problems with your liver or kidneys.
  • if you have been told by your doctor that you have an inherited condition in which the body doesn't have enough of an enzyme known as glucose-6-dehydrogenase which helps red blood cells function normally.
  • if you have ever had asthma.
  • if you are a child and have arthritis.
  • if you have a history of recurring chronic infections or an underlying condition which may predispose you to infections. Oral sulfasalazine inhibits the absorption and metabolism of folic acid and may cause folic acid deficiency potentially resulting in serious blood disorders (e.g., red blood cells that are larger than normal and lower-than-normal number of red and white blood cells and platelets in the blood), this can be normalised by administration of folic acid or folinic acid (leucovorin). Because sulfasalazine causes crystalluria and kidney stone formation, adequate fluid intake should be ensured during treatment. Potentially life-threatening skin rashes (exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported with the use of Salazopyrin En-Tabs, appearing initially as reddish target-like spots or circular patches often with central blisters on the trunk. Additional signs to look for include ulcers in the mouth, throat, nose, genitals and conjunctivitis (red and swollen eyes). These potentially life-threatening skin rashes are often accompanied by flu-like

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symptoms. The rash may progress to widespread blistering or peeling of the skin. The highest risk for occurrence of serious skin reactions is within the first weeks of treatment. If you have developed exfoliative dermatitis, Stevens-Johnson syndrome or toxic epidermal necrolysis with the use of Salazopyrin En-Tabs you must not be re-started on Salazopyrin EnTabs at any time. If you develop a rash or these skin symptoms, stop taking Salazopyrin En-Tabs, seek immediate advice from a doctor and tell your doctor that you are taking this medicine. Severe, life-threatening allergic reactions such as Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) have been reported in patients taking various drugs including Salazopyrin En-Tabs. It is important to note that early signs of severe allergy, such as fever or swollen lymph nodes, may be present even though rash is not evident. If such signs or symptoms are present, you should seek immediate advice from a doctor. Salazopyrin En-Tabs should be discontinued if an alternative cause for the signs or symptoms cannot be established. Children and adolescents Sulfasalazine is not recommended if you are a child and have systemic-onset juvenile rheumatoid arthritis (Stills disease). Tests on your blood, kidneys, liver and urine Your doctor will be taking blood tests to check your blood and your kidneys before you start treatment and regularly during treatment. They will also measure substances produced by your liver known as enzymes (liver function tests) before you start treatment and at regular intervals. They may also test your urine for protein and blood. Other medicines and Salazopyrin En-Tabs Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. In particular, the following medicines may interact with Salazopyrin En-Tabs:

  • any medicine for high blood sugar/diabetes.
  • methenamine, an antibiotic for treating urinary tract infections.
  • digoxin, used to treat heart failure.
  • folate, sometimes taken during the first few weeks of pregnancy to reduce the risk of birth defects of the brain, spine or spinal cord, e.g., Spina Bifida.
  • azathioprine and mercaptopurine – drugs used to help to suppress your body's immune response in organ transplantation and certain chronic inflammations such as rheumatoid arthritis.
  • methotrexate, used to treat rheumatoid arthritis. Pregnancy, breast-feeding and fertility If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, you MUST ask your doctor or pharmacist for advice before taking this medicine. You should avoid breast-feeding while taking this medicine. There have been reports of diarrhoea or blood in the stools of babies of breast-feeding mothers taking Salazopyrin En-Tabs. If this happens you must stop taking Salazopyrin En-Tabs and see your doctor as soon as possible. There have been reports of babies with birth defects of the brain, spine or spinal cord born to mothers who were exposed to sulfasalazine during pregnancy, although the role of sulfasalazine in these defects has not been established. Low sperm count and infertility may occur in men treated with sulfasalazine. Discontinuation of the medicine appears to reverse these effects within 2 to 3 months.

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Driving and using machines Salazopyrin En-Tabs is unlikely to affect your ability to drive or use machinery. Salazopyrin En-Tabs contains propylene glycol This medicine contains 5 mg propylene glycol in each tablet.

How to take it

Salazopyrin En-Tabs Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. The tablets should be taken with a glass of water and should be swallowed whole. Do not crush, break or chew the tablets. The recommended doses for the following conditions are: For Inflammatory bowel disease: Ulcerative Colitis

  • Adults and the Elderly
  • Severe Flare-Ups 2-4 tablets four times a day, with other medicines such as steroids. Do not leave more than 8 hours between the evening and following morning dose.
  • Mild/Moderate Flare-Ups 2-4 tablets four times a day, but not always with other medicines.
  • Maintenance dose to control your flare-ups – Once the flare-up is controlled the dose is slowly reduced to 4 tablets each day. Your doctor will tell you how to reduce your dose. This lower dose may be continued for some time to help stop other flare-ups.
  • Children 2 years of age and over Your doctor will tell you what dose your child will need to use. This will be based on your child's weight. Crohn's Disease
  • Adults and the Elderly
  • Severe Flare-Ups – 2-4 tablets four times a day, with other medicines such as steroids. Do not leave more than 8 hours between the evening and following morning dose.
  • Mild/Moderate Flare-Ups – 2-4 tablets four times a day, but not always with other medicines.
  • Children 2 years of age and over – Your doctor will tell you what dose your child will need to use. This will be based on your child's weight. For Rheumatoid arthritis
  • Adults and the Elderly – Start on one tablet each day for the first week. Then, increase the dose by one tablet a day each week to a maximum of 6 tablets daily as shown in table. 1st Week 2nd Week Morning 1 Evening 1 1 *etc., to a maximum of 6 tablets per day. Do not take more than 6 tablets a day.
  • Children and adolescents – No recommendations. Page 4 of 8

3rd Week 1 2

4th Week 2 2*

How long should you use these tablets? How long you use these tablets depends on how well the tablets suit you. For Inflammatory bowel disease (Ulcerative Colitis and Crohn's Disease)

  • The tablets should start to work in a few days.
  • If they work well, you may be using them for some time because inflammatory bowel disease may be a lifelong condition. For Rheumatoid arthritis
  • Salazopyrin En-Tabs may take some months to have a full effect, so you should keep taking them.
  • You may notice some effect after a few weeks.
  • When they start to work you will feel less stiffness in your joints, especially in the mornings.
  • If they work well, you may be using them for some time. Ensure that you drink adequate fluids whilst you are taking this medicine. This is to avoid problems with your kidneys. If you take more Salazopyrin En-Tabs than you should The most common symptoms of overdose are nausea and vomiting. If you experience any of these contact your nearest hospital casualty department or tell your doctor immediately, if you have taken too many tablets (an overdose) or if a child has taken your medicine. Please take this leaflet and these tablets with you to the hospital casualty department or to your doctor. If you forget to take Salazopyrin En-Tabs If you forget to take a dose, just take the next dose as usual. Do not take a double dose to make up for a forgotten tablet. If you stop taking Salazopyrin En-Tabs Do not stop taking this medicine or alter the dose you are currently taking without seeing your doctor first. If you have any further questions on the use of this medicine, ask your doctor or pharmacist. 4. Possible side effects Like all medicines, this medicine can cause side effects, although not everybody gets them. Stop taking Salazopyrin En-Tabs and tell your doctor immediately if you experience any of the following symptoms after taking this medicine. Although they are very rare, these symptoms can be serious.
  • An allergic reaction such as sudden wheeziness, difficulty in breathing, swelling of eyelids, face or lips, rash or itching (especially affecting the whole body).
  • If you develop a severe skin rash that causes blistering, (this can affect the mouth and tongue). Potentially life-threatening skin rashes (exfoliative dermatitis, Stevens Johnson Syndrome, or toxic epidermal necrolysis (TEN)) have been reported very rarely (see section 2 for a list of some of the possible symptoms). Your doctor will stop your treatment in these cases.

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  • If you have a serious skin condition with a rash (sometimes confined to the cheeks and bridge of the nose) peeling skin or blistering. It may be triggered or aggravated by sunlight. Should this occur, stop taking this medicine, avoid strong sunlight and contact your doctor promptly.
  • If you are generally feeling unwell, have a fever, have pains in your joints, hives, swollen glands, rash and itching. These may be signs of a condition known as serum sickness. Your doctor will stop your treatment in these cases.
  • If you are breast feeding stop taking this medicine, once you notice blood in stools or diarrhoea in newborn. Tell your doctor immediately if you experience any of the following symptoms after taking this medicine as they will stop treatment in these cases:
  • If you notice any unexplained bleeding.
  • If you notice bruising, fever, rash, pallor (paleness), a severe sore throat or tiredness. These may be the first signs of an abnormality of the blood, including decreases in the number of red cells, white cells or platelets. Your doctor may take regular blood samples to test for these effects. Discontinue treatment with Salazopyrin while awaiting the results of blood tests. Other side-effects that may occur are: Very common (may affect more than 1 in 10 people)
  • Indigestion, heartburn
  • Feeling sick (nausea) Common (may affect up to 1 in 10 people)
  • Dizziness
  • Difficulty sleeping
  • Headache
  • Changes in taste
  • Abdominal pains
  • Diarrhoea
  • Being sick
  • Ringing in the ears
  • Blood shot eyes
  • Inflamed mouth (stomatitis)
  • Cough
  • Itching of the skin
  • Purple discolourations on the skin
  • Joint pain
  • Protein in urine
  • Fever Uncommon (may affect up to 1 in 100 people)
  • Depression
  • Fits, jerky, uncontrolled movements
  • Loss of balance
  • Shortness of breath
  • Hair loss
  • Hives
  • Puffiness around the eyes and face

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•

Yellowing of the skin or whites of the eyes (jaundice)

Not known (frequency cannot be estimated from the available data)

  • Inflammation of the lining of the brain
  • Severe diarrhoea
  • Other blood disorders including anaemia, enlarged glands (lymph nodes), glandular fever, persistant sore throat
  • Blood vessel inflammation
  • Loss of appetite
  • Hallucinations
  • Changes in mental state
  • Changes in smell
  • Inflammation of the sac surrounding the heart (pericarditis)
  • Inflammation of the heart muscle (myocarditis)
  • Bluish tint or paleness to skin due to poor circulation
  • Lung complications with breathlessness
  • Inflammation of the salivary glands on either side of the face
  • Kidney inflammation and kidney pain, kidney stones
  • Liver disease (hepatitis)
  • Inflammation of pancreas, which causes severe pain in the abdomen and face
  • Rash, reddening or blistering of the skin, eczema, swelling of the skin
  • Tingling, numbness, pain in hands and feet
  • Blood and crystals in urine
  • Urine or motions may become a yellow/orange colour which is normal and harmless. (See section 6)
  • Temporary infertility in men. Fertility returns when treatment is stopped. Normal contraception should still be used.
  • Dryness of the mouth and eyes
  • Deficiency in folic acid (may cause fatigue) Very rarely sulfasalazine has caused permanent staining of extended wear soft contact lenses. See section 6. Reporting of side effects If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible

Possible side effects

not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

How to store it

Salazopyrin En-Tabs Keep this medicine out of the sight and reach of children. Do not use this medicine after the expiry date which is stated on the bottle after EXP. The expiry date refers to the last day of that month. Store in a dry place.

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Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

Contents of the pack and other information

What Salazopyrin En-Tabs contain The active substance is sulfasalazine. Each tablet contains 500 mg of sulfasalazine. Other ingredients are maize starch, povidone, magnesium stearate, colloidal silicon dioxide. The tablet enteric coating contains cellulose acetate phthalate, propylene glycol (E1520) (see section 2 Salazopyrin En-Tabs contains propylene glycol), macrogol 20,000, bees wax, carnauba wax, self-emulsifying glyceryl monostearate and talc. What Salazopyrin En-Tabs looks like and contents of the pack The tablets are yellow in colour, and are oval-shaped. They have "Kph" imprinted on one side and "102", on the other. They are coated with a film, which stops them breaking up until they leave the stomach. The tablets are the colour of the medicine itself. They contain no artificial colouring. Salazopyrin is supplied in bottles. Each bottle contains 112 tablets. Marketing Authorisation Holder and Manufacturer The marketing authorisation for this medicine is held by: Pfizer Limited, Ramsgate Road, Sandwich, Kent, CT13 9NJ, UK. The manufacturer of this medicine is: Recipharm Uppsala AB, Björkgatan 30, Uppsala Domkyrkofors, Uppsala, 753 23, Sweden. For any information about this medicine, please contact: Medical Information, Pfizer Limited, Walton Oaks, Dorking Road, Tadworth, Surrey, KT20 7NS. Telephone 01304 616161. General Advice Because the tablets are coloured yellow they may cause your urine or motions to become a yellow/orange colour. This is normal and harmless but can stain fabric. Any Salazopyrin soiled fabric should be put in to soak. Difficult stains may be removed with a solution of washing soda. Always test the effect of soda on a small piece of the fabric first. Then apply a mild acid such as white vinegar. Sulfasalazine has caused permanent staining of extended wear soft contact lenses. Although this happened very rarely. Daily-wear soft contact lenses and gas permeable lenses respond to standard cleaning if this happens. This leaflet was last revised in 04/2024 Ref: SZ 26_3

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Frequently asked questions about Salazopyrin En-Tabs 500 mg gastro-resistant tablets

How do I take Salazopyrin En-Tabs 500 mg gastro-resistant tablets?

Salazopyrin En-Tabs 500 mg gastro-resistant tablets comes as tablet containing 500mg. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.

What is the active substance in Salazopyrin En-Tabs 500 mg gastro-resistant tablets?

The active substance in Salazopyrin En-Tabs 500 mg gastro-resistant tablets is sulfasalazine.

Are there equivalent medicines to Salazopyrin En-Tabs 500 mg gastro-resistant tablets?

Medicines with the same active substance, strength and form include: Sulfasalazine 500 mg Tablets, Sulfasalazine 500 mg gastro-resistant tablets. They are interchangeable only if your prescriber or pharmacist says so.

Where does this information come from?

This leaflet reproduces the patient information leaflet approved for Salazopyrin En-Tabs 500 mg gastro-resistant tablets, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.

Can I get Salazopyrin En-Tabs 500 mg gastro-resistant tablets without a prescription?

Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.

About this leaflet

The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.

Medical disclaimer: This page is for information only and does not replace advice from your doctor or pharmacist. Always read the leaflet supplied with your medicine. If you are unwell, call NHS 111; in an emergency, call 999.

Medicines with the same active substance: Sulfasalazine (7 medicines)
See every medicine containing this substance, or browse the full A–Z of active substances.
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
Technical information intended for healthcare professionals (doctors and pharmacists). The Summary of Product Characteristics (SmPC) is the official document approved by the MHRA/EMA. It does not replace the patient leaflet or a doctor’s advice.

4.1. Therapeutic indications

a) Induction and maintenance of remission of ulcerative colitis; treatment of active Crohn's Disease.

b) Treatment of rheumatoid arthritis which has failed to respond to non-steroidal anti-inflammatory drugs (NSAIDs).

4.2. Posology and method of administration

This medicine should be used where there is gastro-intestinal intolerance of plain tablets. They should not be crushed or broken.

The dose is adjusted according to the severity of the disease and the patient's tolerance to the drug, as detailed below.

Elderly Patients: No special precautions are necessary.

a) Ulcerative colitis

Adults

Severe Attack: 2-4 tablets four times a day may be given in conjunction with steroids as part of an intensive management regime. Rapid passage of the tablets may reduce effect of the drug.

Night-time interval between doses should not exceed 8 hours.

Moderate Attack: 2-4 tablets four times a day may be given in conjunction with steroids.

Mild Attack: 2 tablets four times a day with or without steroids.

Maintenance Therapy: With induction of remission reduce the dose gradually to 4 tablets per day. This dosage should be continued indefinitely, since discontinuance even several years after an acute attack is associated with a fourfold increase in risk of relapse.

Paediatric population

The dose is reduced in proportion to body weight.

Acute Attack or relapse: 40- 60 mg/kg per day

Maintenance Dosage: 20 – 30 mg/kg per day

Suspension may provide a more flexible dosage form.

b) Crohn 's Disease

In active Crohn's Disease, this medicine should be administered as in attacks of ulcerative colitis (see above).

c) Rheumatoid Arthritis

Patients with rheumatoid arthritis, and those treated over a long period with NSAIDs, may have sensitive stomachs and for this reason enteric-coated sulfasalazine gastro-resistant tablets are recommended for this disease, as follows:

The patient should start with one tablet daily, increasing his dosage by a tablet a day each week until one tablet four times a day, or two three times a day are reached, according to tolerance and response. Onset of effect is slow and a marked effect may not be seen for six weeks. A reduction in ESR and C-reactive protein should accompany an improvement in joint mobility. NSAIDs may be taken concurrently with sulfasalazine.

4.3. Contraindications

Sulfasalazine is contraindicated in:

Infants under the age of 2 years.

Patients with a known hypersensitivity to sulfasalazine, its metabolites or any of the excipients as well as sulfonamides or salicylates.

Patients with porphyria.

4.4. Special warnings and precautions for use

Serious infections associated with myelosuppression, including sepsis and pneumonia, have been reported. Patients who develop a new infection while undergoing treatment with sulfasalazine should be monitored closely. Administration of sulfasalazine should be discontinued if a patient develops a serious infection. Caution should be exercised when considering the use of sulfasalazine in patients with a history of recurring or chronic infections or with underlying conditions which may predispose patients to infections.

Complete blood counts, including differential white cell count and liver function tests, should be performed before starting sulfasalazine, and every second week during the first three months of therapy. During the second three months, the same tests should be done once monthly and thereafter once every three months, and as clinically indicated. Baseline assessment of renal function (including urinalysis) is required to be performed in all patients initiating treatment with sulfasalazine. For patients with baseline renal impairment, treatment with sulfasalazine should only be initiated if the benefits are considered to outweigh risk. Thereafter, periodic renal function monitoring, especially in the early months of treatment, should be conducted based on clinical judgment taking baseline renal function into account. Treatment should be discontinued if renal function deteriorates. The patient should also be counselled to report immediately with any sore throat, fever, malaise, pallor, purpura, jaundice or unexpected non-specific illness during sulfasalazine treatment, this may indicate myelosuppression, haemolysis or hepatoxicity. Treatment should be stopped immediately while awaiting the results of blood tests. Please see section 4.4. “Interference with laboratory testing”.

Sulfasalazine should not be given to patients with impaired hepatic function or with blood dyscrasias, unless the potential benefit outweighs the risk.

Sulfasalazine should be given with caution to patients with severe allergy or bronchial asthma.

Severe hypersensitivity reactions may include internal organ involvement, such as hepatitis, nephritis, myocarditis, mononucleosis-like syndrome (i.e., pseudomononucleosis), haematological abnormalities (including hematophagic histiocytosis), and/or pneumonitis including eosinophilic infiltration.

Severe, life-threatening, systemic hypersensitivity reactions such as Drug rash with eosinophilia and systemic symptoms (DRESS) have been reported in patients taking various drugs including sulfasalazine. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately.

Serious skin reactions, some of them fatal, including exfoliative dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis, have been reported very rarely in association with the use of sulfasalazine. Patients appear to be at highest risk for these events early in the course of therapy, the onset of the event occurring in the majority of cases within the first month of treatment.

Sulfasalazine should be discontinued at the first appearance of skin rash, mucosal lesions, or any other sign of hypersensitivity.

Sulfasalazine should be discontinued if an alternative etiology for the signs or symptoms cannot be established.

Use in children with the concomitant condition systemic onset juvenile rheumatoid arthritis may result in a serum sickness like reaction; therefore sulfasalazine is not recommended in these patients.

Since sulfasalazine may cause haemolytic anaemia, it should be used with caution in patients with G-6-PD deficiency.

Oral sulfasalazine inhibits the absorption and metabolism of folic acid and may cause folic acid deficiency (see section 4.6), potentially resulting in serious blood disorders (e.g., macrocytosis and pancytopenia), this can be normalised by administration of folic acid or folinic acid (leucovorin).

Because sulfasalazine causes crystalluria and kidney stone formation, adequate fluid intake should be ensured during treatment.

Oligospermia and infertility may occur in men treated with sulfasalazine. Discontinuation of the drug appears to reverse these effects within 2 to 3 months.

Interference with laboratory testing

Several reports of possible interference with measurements, by liquid chromatography, of urinary normetanephrine causing a false-positive test result have been observed in patients exposed to sulfasalazine or its metabolite, mesalamine/ mesalazine.

Sulfasalazine or its metabolites may interfere with ultraviolet absorbance, particularly at 340 nm, and may cause interference with some laboratory assays that use NAD(H) or NADP(H) to measure ultraviolet absorbance around that wavelength. Examples of such assays may include urea, ammonia, LDH, α-HBDH and glucose. It is possible that alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase-muscle/brain (CK-MB), glutamate dehydrogenase (GLDH), or thyroxine may also show interference when sulfasalazine treatment is given at high doses. Consult with the testing laboratory regarding the methodology used. Caution should be exercised in the interpretation of these laboratory results in patients who are receiving sulfasalazine. Results should be interpreted in conjunction with clinical findings.

Excipient information

This medicine contains propylene glycol (see section 2).

Examples of propylene glycol exposure based on daily dose (see section 4.2) are as follows:

• 16 sulfasalazine 500 mg gastro-resistant tablets administered to an adult weighing 70 kg would result in a propylene glycol exposure of 1.14 mg/kg/day.

• 2 sulfasalazine 500 mg gastro-resistant tablets administered to a 6 year-old child weighing 20 kg would result in a propylene glycol exposure of 0.50 mg/kg/day.

4.5. Interaction with other medicinal products and other forms of interaction

Reduced absorption of digoxin, resulting in non-therapeutic serum levels, has been reported when used concomitantly with oral sulfasalazine.

Sulfonamides bear certain chemical similarities to some oral hypoglycaemic agents. Hypoglycaemia has occurred in patients receiving sulfonamides. Patients receiving sulfasalazine and hypoglycaemic agents should be closely monitored.

Due to inhibition of thiopurine methyltransferase by sulfasalazine, bone marrow suppression and leucopenia have been reported when the thiopurine 6-mercaptopurine or it's prodrug, azathioprine, and oral sulfasalazine were used concomitantly.

Coadministration of oral sulfasalazine and methotrexate to rheumatoid arthritis patients did not alter the pharmacokinetic disposition of the drugs. However, an increased incidence of gastrointestinal adverse events, especially nausea, was reported.

Several reports of possible interference with measurements, by liquid chromatography, of urinary normetanephrine causing a false-positive test result have been observed in patients exposed to sulfasalazine or its metabolite, mesalamine/mesalazine.

4.6. Fertility, pregnancy and lactation

Pregnancy

Reproduction studies in rats and rabbits have revealed no evidence of harm to the foetus. Oral sulfasalazine inhibits the absorption and metabolism of folic acid and may cause folic acid deficiency. There have been reports of babies with neural tube defects born to mothers who were exposed to sulfasalazine during pregnancy, although the role of sulfasalazine in these defects has not been established. Because the possibility of harm cannot be completely ruled out, sulfasalazine should be used during pregnancy only if clearly needed.

Breast-feeding

Sulfasalazine and sulfapyridine are found in low levels in breast milk. Patients should avoid breastfeeding while taking this medicine.

There have been reports of bloody stools or diarrhoea in infants who were breastfeeding from mothers on sulfasalazine. In cases where the outcome was reported, bloody stools or diarrhoea resolved in the infant after discontinuation of sulfasalazine in the mother.

4.7. Effects on ability to drive and use machines

Sulfasalazine has no influence on the ability to drive and use machines.

4.8. Undesirable effects

Overall, about 75% of ADRs occur within 3 months of starting therapy, and over 90% by 6 months. Some undesirable effects are dose-dependent and symptoms can often be alleviated by reduction of the dose.

General

Sulfasalazine is split by intestinal bacteria to sulfapyridine and 5-amino salicylate so ADRs to either sulfonamide or salicylate are possible. Patients with slow acetylator status are more likely to experience ADRs related to sulfapyridine. The most commonly encountered ADRs are nausea, headache, rash, loss of appetite and raised temperature.

Specific

The adverse reactions observed during clinical studies conducted with Sulfasalazine have been provided in a single list below by class and frequency (very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1000 to < 1/100); rare (1/10000 to <1/1000); very rare (<1/10000); not known (cannot be estimated from available data)). Where an adverse reaction was seen at different frequencies in clinical studies, it was assigned to the highest frequency reported.

Additional reactions reported from post-marketing experience are included as frequency Not known (cannot be estimated from the available data) in the table below.

MedDRA System Organ Class

Frequency

Adverse Drug Reaction

Infections and Infestations

Not known

aseptic meningitis, pseudomembranous colitis

Blood and lymphatic system disorders

Common

leukopenia

Uncommon

thrombocytopenia**

Not known

agranulocytosis, aplastic anaemia, haemolytic anaemia, heinz body anaemia, hypoprothrombinaemia, lymphadenopathy, macrocytosis, megaloblastic anaemia, methaemoglobinaemina, neutropenia, pancytopenia, pseudomononucleosis**

Immune system disorders

Not known

anaphylaxis*, polyarteritis nodosa, serum sickness

Metabolism and nutrition system disorders

Common

loss of appetite

Not known

folate deficiency**

Psychiatric disorders

Common

insomnia

Uncommon

depression

Not known

hallucinations

Nervous system disorders

Common

dizziness, headache, taste disorders

Uncommon

convulsions

Not known

aseptic meningitis, ataxia, encephalopathy, peripheral neuropathy, smell disorders

Ear and labyrinth disorders

Common

tinnitus

Uncommon

vertigo

Cardiac disorders

Not known

allergic myocarditis**, cyanosis, pericarditis

Vascular disorders

Uncommon

vasculitis

Not known

pallor**

Respiratory, thoracic and mediastinal disorders

Common

cough

Uncommon

dyspnoea

Not known

fibrosing alveolitis, eosinophilic infiltration, interstitial lung disease*, oropharyngeal pain**

Gastrointestinal disorders

Very common

gastric distress, nausea

Common

abdominal pain, diarrhoea*, vomiting*, stomatitis

Not known

aggravation of ulcerative colitis*, pancreatitis, parotitis

Hepatobiliary disorders

Uncommon

jaundice**

Not known

hepatic failure*, hepatitis fulminant*, hepatitis**, hepatitis cholestatic*, cholestasis*

Skin and subcutaneous tissue disorders

Common

pruritus, purpura**

Uncommon

alopecia, urticaria

Not known

drug rash with eosinophilia and systemic symptoms (DRESS)**, epidermal necrolysis (Lyell's syndrome)**, Stevens-Johnson syndrome** , exanthema, exfoliative dermatitis**, angioedema*, toxic pustuloderma, lichen planus, photosensitvity, erythema

Musculoskeletal and connective tissue disorders

Common

arthralgia

Not known

system lupus erythematosus, Sjogren's syndrome

Renal and urinary disorders

Common

proteinuria

Not known

nephrotic syndrome, interstitial nephritis, nephrolithiasis*, haematuria, crystalluria**

Reproductive system and breast disorders

Not known

reversible oligospermia**

General disorders and administration site conditions

Common

fever**

Uncommon

facial edema

Not known

yellow discoloration of skin and body fluids*

Investigations

Uncommon

elevation of liver enzymes

Not known

induction of autoantibodies

Frequency categories: Very common ≥1/10; Common ≥1/100 to <1/10; Uncommon ≥1/1000 to <1/100; Rare ≥1/10000 to <1/1000; Very rare <1/10000; Not known (cannot be estimated from available data)

* ADR identified post-marketing

** see section 4.4 Special warnings and precautions for use

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9. Overdose

The drug has low acute per oral toxicity in the absence of hypersensitivity. There is no specific antidote and treatment should be supportive.

💬 Ask about this leaflet

Ask anything about Salazopyrin En-Tabs 500 mg gastro-resistant tablets. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.

Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.

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