There have been no documented reports of serious toxicity in man resulting from massive overdosing with mesalamine suppository. Under ordinary circumstances, mesalamine absorption from the colon is limited.
CANASA is contraindicated in patients with known or suspected hypersensitivity to salicylates or aminosalicylates or to any ingredients in the suppository vehicle.
The most serious adverse reactions seen in CANASA clinical trials or with other products that contain or are metabolized to mesalamine are:
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The most common adverse reactions in adult patients with mildly to moderately active ulcerative proctitis in double-blind, placebo-controlled trials are summarized in the Table 1 below.
Table 1: Adverse Reactions Occurring In More Than 1% of Mesalamine Suppository Treated Patients (Comparison to Placebo)
| Symptom | Mesalamine (n = 177) |
Placebo (n = 84) |
||
| N | % | N | % | |
| Dizziness | 5 | 3 | 2 | 2.4 |
| Rectal Pain | 3 | 1.8 | 0 | 0 |
| Fever | 2 | 1.2 | 0 | 0 |
| Rash | 2 | 1.2 | 0 | 0 |
| Acne | 2 | 1.2 | 0 | 0 |
| Colitis | 2 | 1.2 | 0 | 0 |
In a multicenter, open-label, randomized, parallel group study in 99 patients comparing the CANASA 1000 mg suppository administered nightly to that of the mesalamine 500 mg suppository twice daily. The most common adverse reactions in both groups were headache (14%), flatulence (5%), abdominal pain (5%), diarrhea (3%), and nausea (3%). Three (3) patients discontinued medication because of an adverse reaction; one of these adverse reactions (headache) was deemed possibly related to study medication. The recommended dosage of CANASA is 1000 mg administered rectally once daily at bedtime.
Postmarketing ExperienceIn addition to the adverse reactions reported above in clinical trials involving CANASA, the adverse reactions listed below have been identified during post-approval use of CANASA and other mesalamine-containing products. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
CANASA is indicated in adults for the treatment of mildly to moderately active ulcerative proctitis.
Mesalamine (5-ASA) administered as a rectal suppository is variably absorbed. In patients with ulcerative colitis treated with mesalamine 500 mg rectal suppositories, administered once every eight hours for six days, the mean mesalamine peak plasma concentration (Cmax) was 353 ng/mL (CV=55%) following the initial dose and 361 ng/mL (CV=67%) at steady state. The mean minimum steady state plasma concentration (Cmin) was 89 ng/mL (CV=89%). Absorbed mesalamine does not accumulate in the plasma.
DistributionMesalamine administered as a rectal suppository distributes in rectal tissue to some extent.
EliminationIn patients with ulcerative proctitis treated with mesalamine 500 mg as a rectal suppository every 8 hours for 6 days, the mean elimination half-life was 5 hours (CV=73%) for 5-ASA and 5 hours (CV=63%) for N-acetyl-5-ASA, the active metabolite, following the initial dose. At steady state, the mean elimination half-life was 7 hours for both 5-ASA and N-acetyl-5-ASA (CV=102% for 5ASA and 82% for N-acetyl-5-ASA).
Metabolism
The absorbed mesalamine is extensively metabolized, mainly to N-acetyl-5-ASA in the liver and in the gut mucosal wall. In patients with ulcerative colitis treated with one mesalamine 500 mg rectal suppository every eight hours for six days, the peak concentration (Cmax) of N-acetyl-5-ASA ranged from 467 ng/mL to 1399 ng/mL following the initial dose and from 193 ng/mL to 1304 ng/mL at steady state.
Excretion
Mesalamine is eliminated from plasma mainly by urinary excretion, predominantly as N-acetyl-5-ASA. In patients with ulcerative proctitis treated with mesalamine 500 mg as a rectal suppository every 8 hours for 6 days, 12% or less of the dose was eliminated in urine as unchanged 5-ASA and 8% to 77% was eliminated as N-acetyl-5-ASA following the initial dose. At steady state, 11% or less of the dose was eliminated in the urine as unchanged 5-ASA and 3% to 35% was eliminated as N-acetyl-5-ASA.
Limited published data on mesalamine use in pregnant women are insufficient to inform a drug-associated risk. No evidence of teratogenicity was observed in rats or rabbits when treated during gestation with orally administered mesalamine at doses greater than the recommended human intra-rectal dose.
The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
DataAnimal Data
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 of CANASA, based on body surface area) and in rabbits at oral doses up to 495 mg/kg/day (about 5.4 times the recommended human intra-rectal dose of CANASA, based on body surface area) following administration during the period of organogenesis, and have revealed no evidence of impaired fertility or harm to the fetus due to mesalamine.
CANASA Suppository: 1000 mg mesalamine in a bullet shaped, light tan to grey suppository.
Storage And HandlingCANASA 1000 mg suppositories for rectal administration are available as bullet shaped, light tan to grey suppositories containing 1000 mg mesalamine supplied in boxes of 30 and 42 individually plastic wrapped suppositories (NDC 58914-501-56 and 58914-50142).
Store below 25°C (77°F), may be refrigerated. Keep away from direct heat, light or humidity.
Distributed by: Allergan USA, Inc. Irvine, CA 92612. Revised: Sep 2016
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS Renal ImpairmentRenal impairment, including minimal change nephropathy, acute and chronic interstitial nephritis, and renal failure, has been reported in patients given products such as CANASA that contain mesalamine or are converted to mesalamine.
Evaluate renal function prior to initiation of CANASA therapy and periodically while on therapy.
Evaluate the risks and benefits of using CANASA in patients with known renal impairment or a history of renal disease or taking concomitant nephrotoxic drugs. In animal studies, the kidney was the principal organ for toxicity.
Mesalamine-Induced Acute Intolerance SyndromeMesalamine 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 for worsening of these symptoms while on treatment. If acute intolerance syndrome is suspected, promptly discontinue treatment with CANASA.
Hypersensitivity ReactionsHypersensitivity reactions have been reported in patients taking sulfasalazine. Some patients may have a similar reaction to CANASA 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 CANASA if an alternative etiology for the signs and symptoms cannot be established.
Hepatic FailureThere 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 CANASA in patients with known liver impairment.
Interaction With Laboratory Test For Urinary NormetanephrineUse 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 mesalamine's main metabolite, N-acetylaminosalicylic acid. Consider an alternative, selective assay for normetanephrine.
Patient Counseling InformationAdvise patients to read the FDA-approved patient labeling (PATIENT INFORMATION)
Administration
Advise patients:
Inform patients that CANASA may decrease their renal function, especially if they have known renal impairment or are taking nephrotoxic drugs, including NSAIDs, and periodic monitoring of renal function will be performed while they are on therapy. Advise patients to complete all blood tests ordered by their healthcare provider.
Mesalamine-Induced Acute Intolerance Syndrome And Other Hypersensitivity ReactionsInform patients of the signs and symptoms of hypersensitivity reactions. Instruct patients to stop taking CANASA and report to their healthcare provider if they experience new or worsening symptoms Acute Intolerance Syndrome (cramping, abdominal pain, bloody diarrhea, fever, headache, and rash) or other symptoms suggestive of mesalamine-induced hypersensitivity.
Hepatic FailureInform patients with known liver disease of the signs and symptoms of worsening liver function and advise them to report to their healthcare provider if they experience such signs or symptoms.
Blood Disorders Inform elderly patients and those taking azathioprine or 6-mercaptopurine of the risk for blood disorders and the need for periodic monitoring of complete blood cell counts and platelet counts while on therapy. Advise patients to complete all blood tests ordered by their healthcare provider.
Nonclinical Toxicology Carcinogenesis, Mutagenesis, Impairment Of FertilityMesalamine 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 of CANASA, 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 of CANASA, based on body surface area).
Use In Specific Populations Pregnancy Risk SummaryLimited published data on mesalamine use in pregnant women are insufficient to inform a drug-associated risk. No evidence of teratogenicity was observed in rats or rabbits when treated during gestation with orally administered mesalamine at doses greater than the recommended human intra-rectal dose.
The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. Adverse outcomes in pregnancy occur regardless of the health of the mother or the use of medications. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
DataAnimal Data
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 of CANASA, based on body surface area) and in rabbits at oral doses up to 495 mg/kg/day (about 5.4 times the recommended human intra-rectal dose of CANASA, based on body surface area) following administration during the period of organogenesis, and have revealed no evidence of impaired fertility or harm to the fetus due to mesalamine.
Lactation Risk SummaryMesalamine and its N-acetyl metabolite are present in human milk in undetectable to small amounts. There are limited reports of diarrhea in breastfed infants. There is no information on the effects of the drug on milk production. The lack of clinical data during lactation precludes a clear determination of the risk of CANASA to an infant during lactation; therefore, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for CANASA and any potential adverse effects on the breastfed child from CANASA or from the underlying maternal conditions.
Clinical ConsiderationsMonitor breastfed infants for diarrhea.
DataIn published lactation studies, maternal mesalamine doses from various oral and rectal formulations and products ranged from 500 mg to 3 g daily. The concentration of mesalamine in milk ranged from non-detectable to 0.11 mg/L. The concentration of the N-acetyl-5aminosalicylic acid metabolite ranged from 5 to 18.1 mg/L. Based on these concentrations, estimated infant daily dosages for an exclusively breastfed infant are 0 to 0.017 mg/kg/day of mesalamine and 0.75 to 2.72 mg/kg/day of N-acetyl-5-aminosalicylic acid.
Pediatric UseThe safety and effectiveness of CANASA in pediatric patients for the treatment of mildly to moderately active ulcerative proctitis have not been established. CANASA was evaluated for the treatment of ulcerative proctitis in a 6-week, open-label, single-arm study in 49 patients 5 to 17 years of age, which only included 14 patients with histologically-confirmed cases of ulcerative proctitis. However, efficacy was not demonstrated. Adverse reactions seen in pediatric patients in this trial (abdominal pain, headache, pyrexia, pharyngolaryngeal pain, diarrhea and vomiting) were similar to those seen in adult patients.
Geriatric UseClinical trials of CANASA did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. Systemic exposures are increased in elderly subjects. Reports from uncontrolled clinical studies and postmarketing reporting systems suggested a higher incidence of blood dyscrasias (i.e., agranulocytosis, neutropenia and pancytopenia) in patients receiving mesalamine-containing products such as CANASA who were 65 years or older compared to younger patients. Monitor complete blood cell counts and platelet counts in elderly patients during treatment with CANASA. In general, the greater frequency of decreased hepatic, renal, or cardiac function, and of concurrent disease or other drug therapy in elderly patients should be considered when prescribing CANASA.
Renal ImpairmentMesalamine is known to be substantially excreted by the kidney, and the risk of adverse reactions may be greater in patients with impaired renal function. Evaluate renal function in all patients prior to initiation and periodically while on CANASA therapy. Monitor patients with known renal impairment or history of renal disease or taking nephrotoxic drugs for decreased renal function and mesalamine-related adverse reactions.
The recommended dosage of CANASA in adults is 1000 mg administered rectally once daily at bedtime for 3 to 6 weeks depending on symptoms and sigmoidoscopic findings. Safety and effectiveness of CANASA beyond 6 weeks have not been established.
Administration InstructionsThe most serious adverse reactions seen in CANASA clinical trials or with other products that contain or are metabolized to mesalamine are:
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The most common adverse reactions in adult patients with mildly to moderately active ulcerative proctitis in double-blind, placebo-controlled trials are summarized in the Table 1 below.
Table 1: Adverse Reactions Occurring In More Than 1% of Mesalamine Suppository Treated Patients (Comparison to Placebo)
| Symptom | Mesalamine (n = 177) |
Placebo (n = 84) |
||
| N | % | N | % | |
| Dizziness | 5 | 3 | 2 | 2.4 |
| Rectal Pain | 3 | 1.8 | 0 | 0 |
| Fever | 2 | 1.2 | 0 | 0 |
| Rash | 2 | 1.2 | 0 | 0 |
| Acne | 2 | 1.2 | 0 | 0 |
| Colitis | 2 | 1.2 | 0 | 0 |
In a multicenter, open-label, randomized, parallel group study in 99 patients comparing the CANASA 1000 mg suppository administered nightly to that of the mesalamine 500 mg suppository twice daily. The most common adverse reactions in both groups were headache (14%), flatulence (5%), abdominal pain (5%), diarrhea (3%), and nausea (3%). Three (3) patients discontinued medication because of an adverse reaction; one of these adverse reactions (headache) was deemed possibly related to study medication. The recommended dosage of CANASA is 1000 mg administered rectally once daily at bedtime.
Postmarketing ExperienceIn addition to the adverse reactions reported above in clinical trials involving CANASA, the adverse reactions listed below have been identified during post-approval use of CANASA and other mesalamine-containing products. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
The concurrent use of mesalamine with known nephrotoxic agents, including nonsteroidal anti-inflammatory drugs (NSAIDs) may increase the risk of nephrotoxicity. Monitor patients taking nephrotoxic drugs for changes in renal function and mesalaminerelated adverse reactions.
Azathioprine Or 6-MercaptopurineThe concurrent use of mesalamine with azathioprine or 6-mercaptopurine may increase the risk for blood disorders. If concomitant use of CANASA and azathioprine or 6-mercaptopurine cannot be avoided, monitor blood tests, including complete blood cell counts and platelet counts.
Urinary Normetanephrine MeasurementsUse 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 mesalamine's main metabolite, N-acetylaminosalicylic acid. Consider an alternative, selective assay for normetanephrine.
