Sulfasalazine

A to Z Drug Facts

(SULL-fuh-SAL-uh-zeen)

Azulfidine, Azulfidine EN-tabs,  S.A.A.-500, Salazopyrin, Salazopyrin Desensitizing Kit, Salazopyrin EN-tabs, S.A.S. Enteric-500

Class: Anti-infective/Sulfonamide

 Action Competitively antagonizes PABA, an essential component in folic acid synthesis.

 Indications Treatment of ulcerative colitis; rheumatoid arthritis and juvenile rheumatoid arthritis (enteric-coated tablets). unlabeled use(s): Treatment of ankylosing spondylitis, collagenous colitis, Crohn disease, psoriasis, psoriatic arthritis.

 Contraindications Hypersensitivity to sulfonamides or chemically related drugs (eg, sulfonylureas, thiazide and loop diuretics, carbonic anhydrase inhibitors, sunscreens containing PABA, local anesthetics); pregnancy at term; lactation; infants < 2 mo; porphyria; hypersensitivity to salicylates; intestinal or urinary obstruction.

 Route/Dosage

Ulcerative colitis

ADULTS: PO 3 to 4 g/day in evenly divided doses. More than 4 g/day is associated with higher incidence of side effects. May begin with 1 to 2 g/day to lessen GI effects. Maintenance: 2 g/day in 4 divided doses. Children ³ 2 yrs: PO 40 to 60 mg/kg/24 hr initially in 3 to 6 divided doses. Maintenance: 20 to 30 mg/kg/day in 4 divided doses. Maximum 2 g/day.

Rheumatoid arthritis

ADULTS: PO Enteric-coated: 2 g/day in 2 evenly divided doses. May initiate therapy with a lower dosage (eg, 0.5 to 1 g/day) to reduce possible GI intolerance. Children ³ 6 yr: PO Enteric-coated 30 to 50 mg/kg/day in 2 evenly divided doses. Initiate therapy with 25% to 33% of the planned maintenance dose to lessen GI effects; increase weekly until reaching maintenance dose at 1 mo. Maximum 2 g/day.

 Interactions

Folic acid: Signs of folate deficiency have occurred, but specific symptoms related to deficiency have not been reported. Methotrexate: Risk of methotrexate-induced bone marrow suppression may be enhanced. Sulfonylureas: Increased sulfonylurea half-lives and hypoglycemia have occurred.

 Lab Test Interferences May produce false-positive urinary glucose tests when performed by Benedict method.

 Adverse Reactions

CNS: Headache; insomnia; peripheral neuropathy; depression; convulsions. DERM: Orange-yellow discoloration of skin. GI: Nausea; vomiting; abdominal pain; diarrhea; anorexia; pancreatitis; impaired folic acid absorption; pseudomembranous enterocolitis. GU: Orange-yellow urine; crystalluria; hematuria; proteinuria; elevated creatinine; nephrotic syndrome; toxic nephrosis with oliguria and anuria. HEMA: Agranulocytosis; aplastic anemia; thrombocytopenia; leukopenia; hemolytic anemia; purpura; hypoprothrombinemia; methemoglobinemia; megaloblastic (macrocytic) anemia; Heinz body anemia. hypersensitivity reactions: May present as erythema multiforme of Stevens-Johnson type; generalized skin eruptions; allergic myocarditis; epidermal necrolysis, with or without corneal damage; urticaria; serum sickness; pruritus; exfoliative dermatitis; anaphylactoid reactions; periorbital edema; photosensitization; arthralgia; transient pulmonary changes with eosinophilia and decreased pulmonary function. HEPA: Hepatitis; hepatocellular necrosis. RESP: Pulmonary infiltrates. OTHER: Drug fever; chills; pyrexia; arthralgia; myalgia; periarteritis nodosum; lupus erythematosus phenomenon.

 Precautions

Pregnancy: Category B. Lactation: Excreted in breast milk. Children: Do not use in infants < 2 mo. Allergy or asthma: Use drug with caution in patients with severe allergy or bronchial asthma. Hemolytic anemia may occur in G-6-PD deficient individuals. Contact lenses: May permanently stain soft contact lenses yellow. Porphyria: May precipitate acute attack of porphyria. Renal or hepatic impairment: Use drug with caution in patients with imparied renal or hepatic function. Severe reactions: Reactions, including deaths, have been associated with hypersensitivity reactions, agranulocytosis, aplastic anemia, other blood dyscrasias, and renal and hepatic damage. Irreversible neuromuscular and CNS changes and fibrosing alveolitis may occur. Sulfonamides: Bear chemical similarities to some goitrogens, diuretics (acetazolamide and thiazides), and oral hypoglycemic agents. Goiter production, diuresis, and hypoglycemia have occurred rarely in patients receiving sulfonamides. Cross-sensitivity may exist.

 Administration/Storage

• Have resuscitative equipment readily available during administration.
• Give after meals or with food (to minimize GI irritation and prolong intestinal passage). Administer around clock (q 6 to 8 hr) in evenly spaced doses.
• Give each dose with full glass of water; encourage fluids between meals up to 2000 mL/day (to maintain hydration and decrease crystallization in kidneys).
• Do not allow patient to chew or crush enteric-coated tablet.
• Shake oral suspension well prior to administration; measure dose accurately with calibrated device.
• Store tables in tight, light-resistant container at room temperature; refrigerate suspension after opening and discard unused portion after 14 days.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Assess results of CBC, hepatic function, and renal function studies (BUN, creatinine, urinalysis) prior to and during therapy if on long-term regimen.
• Assess stool pattern (eg, frequency, consistency [dose increased if diarrhea recurs/continues], quantity) and document abdominal pain prior to and during therapy; sigmoidoscopy and proctoscopy may be used to verify response or adjust dosage.
• Monitor I&O; note urine color, pH, and character (high urine acidity may require alkalinization).
• Assess skin for rash, bleeding, bruising, jaundice; note fever, sore throat, mouth sores, or joint pain. Report any of these symptoms to physician (may require discontinuation of medication).
• Enteric-coated tablets: Careful monitoring is recommended for doses > 2 g/day.

 Patient/Family Education

• Advise patient to take with or after meals if GI intolerance occurs.
• Instruct patient and family to adhere to around the clock schedule as directed. Explain that if dose is missed, patient should take it as soon as remembered. Emphasize that patient should not double up doses.
• Tell patient to notify other physicians/dentist of therapy prior to other treatments/surgery.
• Explain that medication may cause urine and skin to have yellow-orange discoloration (expected effect) and that it may permanently stain soft contact lenses yellow.
• Encourage medical follow-up to ensure success of therapy and to evaluate continuing symptoms.
• Advise patient to take each oral dose with full glass of water to prevent crystalluria.
• Instruct patient to report the following symptoms to physician immediately: Difficulty breathing, skin rash, fever, chills, mouth sores, sore throat, ringing in ears, or unusual bleeding/bruising.
• Advise patient that drug may cause dizziness and to use caution while driving or performing other activities requiring mental alertness.
• Caution patient to avoid exposure to sunlight and to wear protective clothing or use sunscreen to avoid photosensitivity reaction.
• Instruct patient not to take otc medications (even vitamins) without consulting physician.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts