warnings and cautions
5 WARNINGS AND PRECAUTIONS Hypersensitivity Reactions: Sulfite-related reactions (mesalamine rectal suspension enema contains potassium metabisulfite) and sulfasalazine -associated reactions (myocarditis and pericarditis) can occur; evaluate patients immediately and discontinue mesalamine rectal suspension enema if a hypersensitivity reaction is suspected. ( 5.3 ) Renal Impairment: Assess renal function at the beginning of treatment and periodically during treatment. Evaluate the risks and benefits of mesalamine rectal suspension enema in patients with known renal impairment or taking nephrotoxic drug. Discontinue mesalamine rectal suspension enema if renal function deteriorates while on therapy. ( 5.1 , 7.1 ) Mesalamine-Induced Acute Intolerance Syndrome : Discontinue treatment if acute intolerance syndrome (cramping, acute abdominal pain, bloody diarrhea, sometimes fever, headache and rash) is suspected. ( 5.2 ) Hepatic Failure: Evaluate the risks and benefits of using mesalamine rectal suspension enema in patients with known liver impairment. ( 5.4 ) Severe Cutaneous Adverse Reactions : Discontinue at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. ( 5.5) Photosensitivity: Avoid sun exposure if pre-existing skin conditions. ( 5.6 ) Nephrolithiasis: Cases of nephrolithiasis have been reported with the use of mesalamine. Mesalamine -containing stones are undetectable by standard radiography or computed tomography (CT). Ensure adequate hydration during treatment. ( 5.7 ) Interference with Laboratory Tests: Mesalamine may lead to elevated urinary normetanephrine test results. ( 5.8 ) 5.1 Hypersensitivity Reactions Sulfite-Related Reactions Mesalamine rectal suspension enema contains potassium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown but probably low. Sulfite sensitivity is seen more frequently in asthmatic or in atopic nonasthmatic persons. Epinephrine is the preferred treatment for serious allergic or emergency situations even though epinephrine injection contains sodium or potassium metabisulfite with the above-mentioned potential liabilities. The alternatives to using epinephrine in a life-threatening situation may not be satisfactory. The presence of a sulfite(s) in epinephrine injection should not deter the administration of the drug for treatment of serious allergic or other emergency situations. Sulfasalazine-Associated Reactions Hypersensitivity reactions have been reported in patients taking sulfasalazine. Some patients may have a similar reaction to mesalamine rectal suspension enema or to other compounds that contain or are converted to mesalamine. As with sulfasalazine, mesalamine - induced hypersensitivity reactions may present as internal organ involvement, including myocarditis, pericarditis, nephritis, hepatitis, pneumonitis and hematologic abnormalities. Evaluate patients immediately if signs or symptoms of a hypersensitivity reaction are present. Discontinue mesalamine rectal suspension enema if an alternative etiology for the signs and symptoms cannot be established. 5.2 Renal Impairment Renal impairment, including minimal change disease, acute and chronic interstitial nephritis, and renal failure have been reported in patients given mesalamine rectal suspension enema or other products that contain mesalamine or are converted to mesalamine. In animal studies, the kidney was the principal organ of mesalamine toxicity [see Nonclinical Toxicology (13.2) ] . Evaluate the risks and benefits of using mesalamine rectal suspension enema in patients with known renal impairment or a history of renal disease or taking concomitant nephrotoxic drugs. Evaluate renal function in all patients prior to initiation and periodically while on mesalamine rectal suspension enema therapy. Discontinue mesalamine rectal suspension enema if renal function deteriorates while on therapy [see Drug Interactions (7.1) , Use in Specific Populations (8.6) ] . 5.3 Mesalamine-Induced Acute Intolerance Syndrome Mesalamine has been associated with an acute intolerance syndrome that may be difficult to distinguish from a flare of inflammatory bowel disease. Although the exact frequency of occurrence cannot be ascertained, it has occurred in 3% of patients in controlled clinical trials of mesalamine or sulfasalazine. Symptoms include cramping, acute abdominal pain and bloody diarrhea, sometimes fever, headache, and rash. Monitor patients for worsening of these symptoms while on treatment. If acute intolerance syndrome is suspected, promptly discontinue treatment with mesalamine rectal suspension enema. 5.4 Hepatic Failure There have been reports of hepatic failure in patients with pre-existing liver disease who have been administered other products containing mesalamine. Evaluate the risks and benefits of using mesalamine rectal suspension enema in patients with known liver impairment. 5.5 Severe Cutaneous Adverse Reactions Severe cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) ,and acute generalized exanthematous pustulosis (AGEP) have been reported with the use of mesalamine [see Adverse Reactions (6) ] . Discontinue mesalamine rectal suspension enema at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation. 5.6 Photosensitivity Patients with pre-existing skin conditions such as atopic dermatitis and atopic eczema have reported more severe photosensitivity reactions. Advise patients to avoid sun exposure, wear protective clothing, and use a broad-spectrum sunscreen when outdoors. 5.7 Nephrolithiasis Cases of nephrolithiasis have been reported with the use of mesalamine, including stones with 100% mesalamine content. Mesalamine - containing stones are radiotransparent and undetectable by standard radiography or computed tomography (CT). Ensure adequate fluid intake during treatment. 5.8 Interference with Laboratory Tests Use of mesalamine may lead to spuriously elevated test results when measuring urinary normetanephrine by liquid chromatography with electrochemical detection because of the similarity in the chromatograms of normetanephrine and the main metabolite of mesalamine, N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA). Consider an alternative, selective assay for normetanephrine.