Sulfasalazine

INDICATIONS AND USAGE Sulfasalazine delayed release tablets are indicated: a) in the treatment of mild to moderate ulcerative colitis, and as adjunctive therapy in severe ulcerative colitis; b) for the prolongation of the remission period between acute attacks of ulcerative colitis; c) in the treatment of patients with rheumatoid arthritis who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs (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 d) in the treatment of pediatric patients with polyarticular-course 1 juvenile rheumatoid arthritis who have responded inadequately to salicylates or other nonsteroidal anti-inflammatory drugs. Sulfasalazine delayed release tablets are particularly indicated in patients with ulcerative colitis who cannot take uncoated sulfasalazine tablets because of gastrointestinal intolerance, and in whom there is evidence that this intolerance is not primarily the result of high blood levels of sulfapyridine and its metabolites, e.g., patients experiencing nausea and vomiting with the first few doses of the drug, or patients in whom a reduction in dosage does not alleviate the adverse gastrointestinal effects. In patients with rheumatoid arthritis or juvenile rheumatoid arthritis, rest and physiotherapy as indicated should be continued. Unlike anti-inflammatory drugs, sulfasalazine delayed release tablets do not produce an immediate response. Concurrent treatment with analgesics and/or nonsteroidal anti-inflammatory drugs is recommended at least until the effect of sulfasalazine delayed release tablets is apparent.

DOSAGE AND ADMINISTRATION The dosage of sulfasalazine delayed release tablets should be adjusted to each individual's response and tolerance. Patients should be instructed to take sulfasalazine delayed release tablets in evenly divided doses, preferably after meals, and to swallow the tablets whole. Ulcerative Colitis Initial Therapy: Adults: 3 to 4 g daily in evenly divided doses with dosage intervals not exceeding eight hours. It may be advisable to initiate therapy with a lower dosage, e.g., 1 to 2 g daily, to reduce possible gastrointestinal intolerance. If daily doses exceeding 4 g are required to achieve the desired therapeutic effect, the increased risk of toxicity should be kept in mind. Children, six years of age and older: 40 to 60 mg/kg of body weight in each 24-hour period, divided into 3 to 6 doses. Maintenance Therapy: Adults: 2 g daily. Children, six years of age and older: 30 mg/kg of body weight in each 24-hour period, divided into 4 doses. The response of acute ulcerative colitis to sulfasalazine delayed release tablets can be evaluated by clinical criteria, including the presence of fever, weight changes, and degree and frequency of diarrhea and bleeding, as well as by sigmoidoscopy and the evaluation of biopsy samples. It is often necessary to continue medication even when clinical symptoms, including diarrhea, have been controlled. When endoscopic examination confirms satisfactory improvement, dosage of sulfasalazine delayed release tablets should be reduced to a maintenance level. If diarrhea recurs, dosage should be increased to previously effective levels. Sulfasalazine delayed release tablets are particularly indicated in patients who cannot take uncoated sulfasalazine tablets because of gastrointestinal intolerance (e.g., anorexia, nausea). If symptoms of gastric intolerance (anorexia, nausea, vomiting, etc.) occur after the first few doses of sulfasalazine delayed release tablets, they are probably due to increased serum levels of total sulfapyridine, and may be alleviated by halving the daily dose of sulfasalazine delayed release tablets and subsequently increasing it gradually over several days. If gastric intolerance continues, the drug should be stopped for 5 to 7 days, then reintroduced at a lower daily dose. Adult Rheumatoid Arthritis: 2 g daily in two evenly divided doses. It is advisable to initiate therapy with a lower dosage of sulfasalazine delayed release tablets, e.g., 0.5 to 1.0 g daily, to reduce possible gastrointestinal intolerance. A suggested dosing schedule is given below. In rheumatoid arthritis, the effect of sulfasalazine delayed release tablets can be assessed by the degree of improvement in the number and extent of actively inflamed joints. A therapeutic response has been observed as early as 4 weeks after starting treatment with sulfasalazine delayed release tablets, but treatment for 12 weeks may be required in some patients before clinical benefit is noted. Consideration can be given to increasing the daily dose of sulfasalazine delayed release tablets to 3 g if the clinical response after 12 weeks is inadequate. Careful monitoring is recommended for doses over 2 g per day. Suggested Dosing Schedule for Adult Rheumatoid Arthritis: Number of sulfasalazine delayed release tablets Week of Treatment Morning Evening 1 - One 2 One One 3 One Two 4 Two Two Juvenile Rheumatoid Arthritis - polyarticular course Children, six years of age and older: 30 to 50 mg/kg of body weight daily in two evenly divided doses. Typically, the maximum dose is 2 g per day. To reduce possible gastrointestinal intolerance, begin with a quarter to a third of the planned maintenance dose and increase weekly until reaching the maintenance dose at one month. Some patients may be sensitive to treatment with sulfasalazine. Various desensitization-like regimens have been reported to be effective in 34 of 53 patients, 8 7 of 8 patients, 9 and 19 of 20 patients. 10 These regimens suggest starting with a total daily dose of 50 to 250 mg sulfasalazine initially, and doubling it every 4 to 7 days until the desired therapeutic level is achieved. If the symptoms of sensitivity recur, sulfasalazine delayed release tablets should be discontinued. Desensitization should not be attempted in patients who have a history of agranulocytosis, or who have experienced an anaphylactoid reaction while previously receiving sulfasalazine.

CONTRAINDICATIONS Sulfasalazine delayed release tablets are contraindicated in: 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.

WARNINGS Hepatic, Renal, and Hematologic Toxicity or Other Conditions Only after critical appraisal should sulfasalazine delayed release tablets be given to patients with hepatic or renal damage or blood dyscrasias. Deaths associated with the administration of sulfasalazine have been reported from hypersensitivity reactions, agranulocytosis, aplastic anemia, other blood dyscrasias, renal and liver damage, irreversible neuromuscular and central nervous system changes, and fibrosing alveolitis. The presence of clinical signs such as sore throat, fever, pallor, purpura, or jaundice may be indications of serious blood disorders or hepatotoxicity. Complete blood counts, as well as urinalysis with careful microscopic examination, should be done frequently in patients receiving sulfasalazine delayed release tablets (see PRECAUTIONS, Laboratory Tests ). Discontinue treatment with sulfasalazine while awaiting the results of blood tests. Discontinue sulfasalazine delayed release tablets if renal function deteriorates while on therapy. Oligospermia and Infertility Oligospermia and infertility have been observed in men treated with sulfasalazine; however, withdrawal of the drug appears to reverse these effects. Serious Infections Serious infections, including fatal sepsis and pneumonia, have been reported. Some infections were associated with agranulocytosis, neutropenia, or myelosuppression. Discontinue sulfasalazine delayed release tablets if a patient develops a serious infection. Closely monitor patients for the development of signs and symptoms of infection during and after treatment with sulfasalazine delayed release tablets. For a patient who develops a new infection during treatment with sulfasalazine delayed release tablets, perform a prompt and complete diagnostic workup for infection and myelosuppression. Caution should be exercised when considering the use of sulfasalazine in patients with a history of recurring or chronic infections or with underlying conditions or concomitant drugs which may predispose patients to infections. Hypersensitivity Reactions Severe hypersensitivity reactions may include internal organ involvement, such as hepatitis, nephritis, myocarditis, mononucleosis-like syndrome (i.e., pseudomononucleosis), hematological abnormalities (including hematophagic histiocytosis), and/or pneumonitis including eosinophilic infiltration. Severe Cutaneous Adverse Reactions Drug Reactions with Eosinophilia and Systemic Symptoms (DRESS) Severe, life-threatening, systemic hypersensitivity reactions such as drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients taking sulfasalazine. 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, evaluate the patient immediately. Discontinue sulfasalazine delayed release tablets if an alternative etiology for the signs or symptoms cannot be established. Other Severe Cutaneous Adverse Reactions Other severe cutaneous adverse reactions, including exfoliative dermatitis, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP) have been reported in association with the use of sulfasalazine (see ADVERSE REACTIONS ). Severe cutaneous adverse reactions can be serious and are sometimes fatal. Patients are at highest risk for these events early in therapy, with most events occurring within the first month of treatment. Discontinue sulfasalazine delayed release tablets at the first appearance of signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation.

Drug Interactions: Reduced absorption of folic acid and digoxin have been reported when those agents were administered concomitantly with sulfasalazine. When daily doses of sulfasalazine 2 g and weekly doses of methotrexate 7.5 mg were coadministered to 15 rheumatoid arthritis patients in a drug-drug interaction study, the pharmacokinetic disposition of the drugs was not altered. Daily doses of sulfasalazine 2 g (maximum 3 g) and weekly doses of methotrexate 7.5 mg (maximum 15 mg) were administered alone or in combination to 310 rheumatoid arthritis patients in two controlled 52-week clinical studies. The overall toxicity profile of the combination revealed an increased incidence of gastrointestinal adverse events, especially nausea, when compared to the incidence associated with either drug administered alone.

ADVERSE REACTIONS 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 report 7 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 sulfasalazine delayed release tablets are administered. Less common or rare adverse reactions include: Blood dyscrasias: aplastic anemia, agranulocytosis, megaloblastic (macrocytic) anemia, purpura, hypoprothrombinemia, methemoglobinemia, congenital neutropenia, and myelodysplastic syndrome. Hypersensitivity reactions: erythema multiforme, epidermal necrolysis (SJS/TEN) with corneal damage, exfoliative dermatitis, DRESS, anaphylaxis, serum sickness syndrome, interstitial lung disease, pneumonitis with or without eosinophilia, vasculitis, fibrosing alveolitis, pleurisy/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. Renal reactions: toxic nephrosis with oliguria and anuria, nephritis, nephrotic syndrome, urinary tract infections, hematuria, crystalluria, proteinuria, and hemolytic-uremic syndrome. 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. Postmarketing Reports 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, SJS/TEN, DRESS, and AGEP Vascular disorders: pallor

Pregnancy: There are no adequate and well-controlled studies of sulfasalazine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 6 times the human maintenance dose of 2 g/day based on body surface area and have revealed no evidence of impaired female fertility or harm to the fetus due to sulfasalazine. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. There have been case reports of neural tube defects (NTDs) in infants born to mothers who were exposed to sulfasalazine during pregnancy, but the role of sulfasalazine in these defects has not been established. However, oral sulfasalazine inhibits the absorption and metabolism of folic acid which may interfere with folic acid supplementation (see Drug Interactions ) and diminish the effect of periconceptional folic acid supplementation that has been shown to decrease the risk of NTDs. A national survey evaluated the outcome of pregnancies associated with inflammatory bowel disease (IBD). In 186 pregnancies in women treated with sulfasalazine alone or sulfasalazine and concomitant steroid therapy, the incidence of fetal morbidity and mortality was comparable both to that of 245 untreated IBD pregnancies, and to pregnancies in the general population. 2 A study of 1455 pregnancies associated with exposure to sulfonamides including sulfasalazine, indicated that this group of drugs did not appear to be associated with fetal malformation. 3 A review of the medical literature covering 1155 pregnancies in women with ulcerative colitis suggested that the outcome was similar to that expected in the general population. 4 No clinical studies have been performed to evaluate the effect of sulfasalazine on the growth development and functional maturation of children whose mothers received the drug during pregnancy. Clinical Considerations: Sulfasalazine and its metabolite, sulfapyridine, pass through the placenta. Sulfasalazine and its metabolite are also present in human milk. In the newborn, sulfonamides compete with bilirubin for binding sites on the plasma proteins and may cause kernicterus. Although sulfapyridine has been shown to have poor bilirubin-displacing capacity, monitor the newborn for the potential for kernicterus. A case of agranulocytosis has been reported in an infant whose mother was taking both sulfasalazine and prednisone throughout pregnancy.