warnings and cautions
5 WARNINGS AND PRECAUTIONS • Renal Impairment : Assess renal function at the beginning of treatment and periodically during treatment. Evaluate the risks and benefits of mesalamine in patients with known renal impairment or taking nephrotoxic drugs. Discontinue mesalamine delayed-release tablets if renal function deteriorates while on therapy. (5.1, 7.1, 8.6) • Mesalamine-Induced Acute Intolerance Syndrome: Symptoms may be difficult to distinguish from an ulcerative colitis exacerbation. Monitor for worsening symptoms while on treatment. Discontinue treatment if acute intolerance syndrome is suspected. (5.2) • Hypersensitivity Reactions, including myocarditis and pericarditis : Evaluate patients immediately and discontinue mesalamine if a hypersensitivity reaction is suspected. (5.3) • Hepatic Failure : Evaluate the risks and benefits of using mesalamine 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) • Upper Gastrointestinal Tract Obstruction : Avoid in patients with pyloric stenosis or other organic or functional obstruction. (5.6) • Photosensitivity: Advise patients with pre-existing skin conditions 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. Mesalamine-containing stones are undetectable by standard radiography or computed tomography (CT). Ensure adequate hydration 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. (5.9) 5.1 Renal Impairment Renal impairment, including minimal change disease, acute and chronic interstitial nephritis, and, rarely, renal failure, has been reported in patients given products such as mesalamine delayed-release tablets that contain mesalamine or are converted to mesalamine. In animal studies, the kidney was the principal organ of mesalamine toxicity [see Adverse Reactions (6.2), Nonclinical Toxicology (13.2)]. Evaluate renal function prior to initiation of mesalamine therapy and periodically while on therapy. Evaluate the risks and benefits of using mesalamine in patients with known renal impairment, history of renal disease, or taking concomitant nephrotoxic drugs. Discontinue mesalamine delayed-release tablets if renal function deteriorates while on therapy. [see Drug Interactions (7.1), Use in Specific Populations (8.6)] . 5.2 Mesalamine-Induced Acute Intolerance Syndrome Mesalamine has been associated with an acute intolerance syndrome that may be difficult to distinguish from an exacerbation of ulcerative colitis. Although the exact frequency of occurrence has not been determined, it has occurred in 3% of patients in controlled clinical trials of mesalamine or sulfasalazine. Symptoms include cramping, acute abdominal pain, and bloody diarrhea, and sometimes fever, headache, and rash. Monitor patients closely for worsening of these symptoms while on treatment. If acute intolerance syndrome is suspected, promptly discontinue treatment with mesalamine delayed-release tablets. 5.3 Hypersensitivity Reactions Hypersensitivity reactions have been reported in patients taking sulfasalazine. Some of these patients may have a similar reaction to mesalamine delayed-release tablets 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 if an alternative etiology for the signs or symptoms cannot be established. 5.4 Hepatic Failure There have been reports of hepatic failure in patients with pre-existing liver disease who have been administered mesalamine. Evaluate the risks and benefits of using mesalamine in patients with known liver impairment. 5.5 Severe Cutaneous Adverse Reactions Severe cutaneous adverse reactions, such as 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 (6.2)] . Discontinue mesalamine at the first appearance of signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation . 5.6 Upper Gastrointestinal Tract Obstruction Pyloric stenosis or other organic or functional obstruction in the upper gastrointestinal tract may cause prolonged gastric retention of mesalamine delayed-release tablets, which would delay mesalamine release in the colon. Avoid mesalamine in patients at risk of upper gastrointestinal tract obstruction. 5.7 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. 5.8 Nephrolithiasis Cases of nephrolithiasis have been reported with the use of mesalamine, including stones with a 100% mesalamine content. Mesalamine-containing stones are radiotransparent and undetectable by standard radiography or computed tomography (CT). Ensure adequate hydration during treatment with mesalamine. 5.9 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.