Included as part of the PRECAUTIONS section.

Renal Impairment

Renal impairment, including minimal change nephropathy, acute and chronic interstitial nephritis, and, rarely, renal failure, has been reported in patients given products such as CANASA that contain mesalamine or are converted to mesalamine. It is recommended that patients have an evaluation of renal function prior to initiation of CANASA therapy and periodically while on therapy. Exercise caution when using CANASA in patients with known renal dysfunction or a history of renal disease. In animal studies, the kidney was the principal organ for toxicity [See DRUG INTERACTIONS and Nonclinical Toxicology].

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. Observe patients closely for worsening of these symptoms while on treatment. If acute intolerance syndrome is suspected, promptly discontinue treatment with CANASA.

Hypersensitivity Reactions

Some patients who have experienced a hypersensitivity reaction to sulfasalazine may have a similar reaction to CANASA tablets or to other compounds that contain or are converted to mesalamine.

Mesalamine-induced cardiac hypersensitivity reactions (myocarditis and pericarditis) have been reported with CANASA and other mesalamine medications. Caution should be taken in prescribing CANASA to patients with hypersensitivity to 5-ASA products.

Hepatic Impairment

There have been reports of hepatic failure in patients with pre-existing liver disease who have been administered other products containing mesalamine. Caution should be exercised when administering CANASA to patients with liver disease.

Patient Counseling Information

See FDA-approved patient labeling (PATIENT INFORMATION)

Instruct patients not to take CANASA if they have hypersensitivity to salicylates (e.g., aspirin) or other mesalamines.

Inform patients to let their physicians know all medications they are taking and if they:

• are allergic to sulfasalazine, salicylates or mesalamine;
• are taking non-steroidal anti-inflammatory drugs (NSAIDs) or other nephrotoxic agents;
• are taking azathioprine or 6-mercaptopurine;
• experience cramping, abdominal pain, bloody diarrhea, fever, headache or rash;
• have a history of myocarditis or pericarditis;
• have kidney or liver disease;
• have a history of stomach blockage;
• are pregnant, intend to become pregnant or are breast-feeding.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment of Fertility

Mesalamine caused no increase in the incidence of neoplastic lesions over controls in a two-year study of Wistar rats fed up to 320 mg/kg/day of mesalamine admixed with diet (about 1.7 times the recommended human intra-rectal dose, based on body surface area).

Mesalamine was not mutagenic in the Ames test, the mouse lymphoma cell (TK+/-) forward mutation test, or the mouse micronucleus test.

No effects on fertility or reproductive performance of the male and female rats were observed at oral mesalamine doses up to 320 mg/kg/day (about 1.7 times the recommended human intra-rectal dose, based on body surface area).

Use In Specific Populations

Pregnancy

Pregnancy Category B

Reproduction studies have been performed in rats at oral doses up to 320 mg/kg/day (about 1.7 times the recommended human intra-rectal dose, based on body surface area) and in rabbits at oral doses up to 495 mg/kg/day (about 5.4 times the recommended human intrarectal dose, based on body surface area) and have revealed no evidence of impaired fertility or harm to the fetus due to mesalamine. There are, however, no adequate and well controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used in pregnancy only if clearly needed.

Nursing Mothers

Mesalamine and its N-acetyl metabolite have been detected in human breast milk. The clinical significance of this has not been determined. Caution should be exercised when Canasa is administered to a nursing woman.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Geriatric Use

Reports from uncontrolled clinical studies and postmarketing reporting systems suggested a higher incidence of blood dyscrasias (i.e., neutropenia and pancytopenia) in patients who were 65 years or older who were taking mesalamine-containing products such as CANASA. Caution should be taken to closely monitor blood cell counts during mesalamine therapy.

Clinical trials of CANASA did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. Systemic exposures are increased in elderly subjects [See CLINICAL PHARMACOLOGY]. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concurrent disease or other drug therapy in elderly patients.

Last reviewed on RxList: 2/26/2013
This monograph has been modified to include the generic and brand name in many instances.