Medical Editor: John P. Cunha, DO, FACOEP
Azulfidine EN-tabs (sulfasalazine delayed release tablets) are indicated in the treatment of mild to moderate ulcerative colitis, and as adjunctive therapy in severe ulcerative colitis; for the prolongation of the remission period between acute attacks of ulcerative colitis; in the treatment of patients with rheumatoid arthritis who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., an insufficient therapeutic response to, or intolerance of, an adequate trial of full doses of one or more nonsteroidal anti-inflammatory drugs); and in the treatment of pediatric patients with polyarticular-course juvenile rheumatoid arthritis who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs. Common side effects of Azulfidine EN-tabs include:
- loss of appetite,
- upset stomach,
- low sperm count (reversible),
- Heinz body anemia,
- hemolytic anemia
- and blue-colored skin due to low oxygen.
The initial adult dose of Azulfidine EN-tabs is 3 to 4 g daily in evenly divided doses with dosage intervals not exceeding eight hours. The adult maintenance dose is 2 g daily. The initial dose of Azulfidine EN-tabs for children six years of age and older is 40 to 60 mg/kg of body weight in each 24-hour period, divided into 3 to 6 doses. The maintenance dose for children is 30 mg/kg of body weight in each 24-hour period, divided into 4 doses. Azulfidine EN-tabs may interact with folic acid, digoxin, and methotrexate. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant or plan to become pregnant before using Azulfidine EN-tabs; it is unknown how it would affect a fetus. Azulfidine EN-tabs pass into breast milk. Consult your doctor before breastfeeding.
Our Azulfidine EN-tabs (sulfasalazine delayed release tablets) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
The most common adverse reactions associated with sulfasalazine in ulcerative colitis 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. Experience suggests that with a daily dose of 4 g or more, or total serum sulfapyridine levels above 50 μg/mL, the incidence of adverse reactions tends to increase.
Similar adverse reactions are associated with sulfasalazine use in adult rheumatoid arthritis, although there was a greater incidence of some reactions. In rheumatoid arthritis studies, the following common adverse reactions were noted: nausea (19%), dyspepsia (13%), rash (13%), headache (9%), abdominal pain (8%), vomiting (8%), fever (5%), dizziness (4%), stomatitis (4%), pruritis (4%), abnormal liver function tests (4%), leukopenia (3%), and thrombocytopenia (1%). One report7 showed a 10% rate of immunoglobulin suppression, which was slowly reversible and rarely accompanied by clinical findings.
In general, the adverse reactions in juvenile rheumatoid arthritis patients are similar to those seen in patients with adult rheumatoid arthritis except for a high frequency of serum sickness-like syndrome in systemic-course juvenile rheumatoid arthritis (see PRECAUTIONS, Pediatric Use). One clinical trial showed an approximate 10% rate of immunoglobulin suppression.1
Although the listing which follows includes a few adverse reactions which have not been reported with this specific drug, the pharmacological similarities among the sulfonamides require that each of these reactions be considered when AZULFIDINE EN-tabs is administered.
Less common or rare adverse reactions include:
Hypersensitivity reactions: erythema multiforme (Stevens-Johnson syndrome), exfoliative dermatitis, epidermal necrolysis (Lyell's syndrome) with corneal damage, drug rash with eosinophilia and systemic symptoms (DRESS), anaphylaxis, serum sickness syndrome, interstitial lung disease, pneumonitis with or without eosinophilia, vasculitis, fibrosing alveolitis, pleuritis, pericarditis with or without tamponade, allergic myocarditis, polyarteritis nodosa, lupus erythematosus-like syndrome, hepatitis and hepatic necrosis with or without immune complexes, fulminant hepatitis, sometimes leading to liver transplantation, parapsoriasis varioliformis acuta (Mucha-Haberman syndrome), rhabdomyolysis, photosensitization, arthralgia, periorbital edema, conjunctival and scleral injection and alopecia.
Gastrointestinal reactions: hepatitis, hepatic failure, pancreatitis, bloody diarrhea, impaired folic acid absorption, impaired digoxin absorption, stomatitis, diarrhea, abdominal pains, and neutropenic enterocolitis.
Central Nervous System reactions: transverse myelitis, convulsions, meningitis, transient lesions of the posterior spinal column, cauda equina syndrome, Guillain-Barre syndrome, peripheral neuropathy, mental depression, vertigo, hearing loss, insomnia, ataxia, hallucinations, tinnitus and drowsiness.
Other reactions: urine discoloration and skin discoloration.
The sulfonamides bear certain chemical similarities to some goitrogens, diuretics (acetazolamide and the thiazides), and oral hypoglycemic agents. Goiter production, diuresis and hypoglycemia have occurred rarely in patients receiving sulfonamides.
Cross-sensitivity may exist with these agents. Rats appear to be especially susceptible to the goitrogenic effects of sulfonamides and long-term administration has produced thyroid malignancies in this species.
The following events have been identified during post-approval use of products which contain (or are metabolized to) mesalamine in clinical practice. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of seriousness, frequency of reporting, or potential causal connection to mesalamine:
Blood dyscrasias: pseudomononucleosis
Cardiac disorders: myocarditis
Hepatobiliary disorders: reports of hepatotoxicity, including elevated liver function tests (SGOT/AST, SGPT/ALT, GGT, LDH, alkaline phosphatase, bilirubin), jaundice, cholestatic jaundice, cirrhosis, hepatitis cholestatic, cholestasis and possible hepatocellular damage including liver necrosis and liver failure. Some of these cases were fatal. One case of Kawasaki-like syndrome, which included hepatic function changes, was also reported.
Immune system disorders: anaphylaxis
Metabolism and nutrition system disorders: folate deficiency
Renal and urinary disorders: nephrolithiasis
Respiratory, thoracic and mediastinal disorders: oropharyngeal pain
Skin and subcutaneous tissue disorders: angioedema, purpura
Vascular disorders: pallor
Drug Abuse And Dependence
Read the entire FDA prescribing information for Azulfidine EN-tabs (sulfasalazine Delayed Release Tablets)