Zopirin 500

Zopirin 500

Zopirin 500

Sulfasalazine Enteric Coated Tablet 500 mg



Pharmaceutical Group: Anti-inflammatory drug belonging to aminosalicylate group

Therapeutic indications:Treat and manage rheumatoid arthritis, ulcerative colitis and active Crohn's Diseas

Dosage Form(s): Enteric coated tablet 

 Pregnancy Category: B   






The active substance of Zopirin tablet is sulfasalazine which is an anti-inflammatory drug and belongs to a group of medicines called aminosalicylates. It is used to Treat and manage rheumatoid arthritis, ulcerative colitis and active Crohn's Disease.


  •  Treatment of patients with rheumatoid arthritis who have responded inadequately to other non- Steroidal anti-inflammatory drugs 
  •  Treatment of  ulcerative colitis.
  •  Treatment of active Crohn's Disease



Enteric coated tablets 100


Dosage and direction

Rheumatoid arthritis

1) Initial therapy: Take 500mg once a day.
2) Maintain therapy: Depending on the clinical response and tolerability of the individual patient, the daily dosage should be titrated by 500 mg with an interval time of one week. Usually take 500 mg, 2~4 times a day.

Ulcerative colitis

Take 2 tablets 4~6 times a day.

According to improved symptoms, take 1 tablet 4 times a day.

The dosage can be increased or decreased according to symptoms or ages.


 Children over 2 years of age  

The dose is reduced in proportion to body weight. 

Acute Attack or relapse: 40-60 mg per Kg per day

Maintanance Dosage: 20-0 mg/kg per day



  •  Hypersensitivity to sulfasalazine, its metabolites, sulfonamides or salicylates.
  •  Patients with intestinal or urinary obstruction.
  •  Patients with porphyria, as the sulfonamides have been reported to precipitate an acute attack.


 Possible side 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.
  • 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.
  • The most common adverse reactions associated with sulfasalazine are anorexia, headache, nausea, vomiting, gastric distress, and apparently reversible oligospermia. These occur in about one-third of the patients.
  • Less frequent adverse reactions are pruritus, urticaria, rash, fever, Heinz body anemia, hemolytic anemia and cyanosis, which may occur at a frequency of 1 in 30 patients or less.
  • Other adverse reactions include nausea, dyspepsia, rash, headache , abdominal pain, vomiting, fever , dizziness, stomatitis, pruritis, abnormal liver function tests , leukopenia, and thrombocytopenia.



  Interaction with other medicinal products and other forms of interaction

Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription as they may interact with Zopirin tablets:

• 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 neural tube defects, 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



  •  ZOPIRIN tablets should be given with caution to patients with severe allergy or bronchial asthma. 
  •  Patients with glucose-6-phosphate dehydrogenase deficiency should be observed closely for signs of hemolytic anemia. This reaction is dose related. If toxic or hypersensitivity reactions occur, ZOPIRIN should be discontinued immediately.
  •  Patients should be advised that sulfasalazine may produce an orange-yellow discoloration of the urine or skin.
  • Patients should be aware that ulcerative colitis and Rheumatoid arthritis rarely remits completely, and that the risk of relapse can be substantially reduced by continued administration of ZOPIRIN at a maintenance dosage.
  •  Only after critical appraisal, should ZOPIRIN tablets be given to patients with hepatic or renal damage or blood dyscrasias. Should any of these occur, the patient should seek medical advice.
  •  Discontinue treatment with sulfasalazine while awaiting the results of blood tests. 
  •  Oligospermia and infertility have been observed in men treated with sulfasalazine; however, withdrawal of the drug appears to reverse these effects.



Stop taking Zopirin tablets and tell your doctor immediately if you experience any of the following symptoms after taking this medicine:

  •  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). These may be signs of a condition known as Stevens Johnson Syndrome, or toxic epidermal necrolysis (TEN). Your doctor will stop your treatment in these cases.
  •  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.
  •  The occurrence of sore throat, fever, pallor, purpura or jaundice may indicate a serious blood disorder. Should any of these occur, the patient should seek medical advice.
  •  The safety and effectiveness of ZOPIRIN in pediatric patients below the age of two years with ulcerative colitis have not been 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.