Pentasa

Renal impairment, including minimal change disease, acute and chronic interstitial nephritis, and renal failure have been reported in patients given PENTASA or other products that contain mesalamine or are converted to mesalamine.

Evaluate the risks and benefits of using PENTASA 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 therapy with PENTASA. Discontinue PENTASA if renal function deteriorates while on therapy [see Drug Interactions (7.1), Use in Specific Populations (8.6)].

Mesalamine has been associated with an acute intolerance syndrome that may be difficult to distinguish from an exacerbation of ulcerative colitis. Symptoms include cramping, acute abdominal pain, 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 PENTASA.

Hypersensitivity reactions have been reported in patients taking sulfasalazine. Some patients may have a similar reaction to PENTASA 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 PENTASA if an alternative etiology for the signs and symptoms cannot be established.

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 PENTASA in patients with known liver impairment.

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 in with the use of mesalamine [see Adverse Reactions (6.2)]. Discontinue PENTASA at the first signs or symptoms of severe cutaneous adverse reactions or other signs of hypersensitivity and consider further evaluation.

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.

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 hydration during treatment with PENTASA.

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 mesalamine’s main metabolite, N-acetyl-5-aminosalicylic acid (N-Ac-5-ASA). Consider an alternative, selective assay for normetanephrine.

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.

More than 2100 patients were exposed to PENTASA in clinical trials of ulcerative colitis or another gastrointestinal condition. The most common adverse reactions (i.e., greater than or equal to 1%) were diarrhea (3%), headache (2%), nausea (2%), abdominal pain (2%), dyspepsia (2%), vomiting (2%), and rash (1%).

The safety of PENTASA was evaluated in two randomized, double-blind, placebo-controlled, dose-response trials (UC-1 and UC-2) of 624 patients with mildly to moderately active ulcerative colitis for up to 8 weeks of treatment [see Clinical Studies (14)]. The most common adverse reaction was nausea and vomiting: 1% in the PENTASA group (N=451) and 0% in the placebo group (N=173). Withdrawal from therapy due to adverse reactions was 7% in the PENTASA group and 4% in the placebo group.

The following adverse reactions, presented by body system, were reported in less than 1% of patients in UC-1, UC-2, and clinical trials for another gastrointestinal condition.

Blood and lymphatic system disorders: thrombocythemia, thrombocytopenia

Cardiac Disorders: palpitations, pericarditis, vasodilation

Gastrointestinal Disorders: abdominal distention, constipation, duodenal ulcer, dysphagia, eructation, esophageal ulcer, fecal incontinence, GI bleeding, mouth ulcer, pancreatitis, rectal bleeding, stool abnormalities (color or texture change)

General disorders and administration site conditions: fever, malaise

Infections and infestations: oral moniliasis, conjunctivitis

Investigations: GGTP increase, increased alkaline phosphatase, LDH increase, SGOT increase, SGPT increase, lipase increase, amylase increase

Metabolism and nutritional disorders: anorexia, edema, thirst

Musculoskeletal and connective tissue disorders: arthralgia, leg cramps, myalgia

Nervous System Disorders: dizziness, insomnia, somnolence, paresthesia

Psychiatric disorders: depression, asthenia

Renal and urinary disorders: albuminuria, hematuria, urinary frequency

Reproductive system and breast disorders: amenorrhea, breast pain, hypomenorrhea, menorrhagia, metrorrhagia

Respiratory, Thoracic and Mediastinal Disorders: pulmonary infiltrates, one week after completion of an 8-week ulcerative colitis study, a 72-year-old male, with no previous history of pulmonary problems, developed dyspnea. The patient was subsequently diagnosed with interstitial pulmonary fibrosis without eosinophilia by one physician and bronchiolitis obliterans with organizing pneumonitis by a second physician.

Skin and Subcutaneous Tissue Disorders: acne, alopecia, dry skin, eczema, erythema nodosum, nail disorder, photosensitivity, pruritus, sweating, urticaria, ecchymosis, lichen planus

The following adverse reactions have been identified during post-approval use of mesalamine. 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.

Cardiac Disorders: chest pain, fatal myocarditis, pericarditis, T-wave abnormalities

Hematologic Disorders: agranulocytosis, anemia, aplastic anemia, leukopenia, pancytopenia

Hepatic Disorders: cirrhosis, jaundice, including cholestatic jaundice; hepatotoxicity, hepatitis, and possible hepatocellular damage including liver necrosis and liver failure. Some of these cases were fatal. One case of Kawasaki-like syndrome which included hepatic function changes was also reported.

Immune System Disorders: anaphylactic reaction, angioedema, lupus-like syndrome, systemic lupus erythematosus

Nervous System Disorders: intracranial hypertension

Renal and Urinary Disorders: acute renal failure, chronic renal failure, interstitial nephritis, nephrogenic diabetes insipidus, nephrolithiasis, nephrotic syndrome [see Warnings and Precautions (5.1, 5.7)]

• Urine discoloration occurring ex-vivo caused by contact of mesalamine, including inactive metabolite, with surfaces or water treated with hypochlorite-containing bleach

Reproductive System and Breast Disorders: reversible oligospermia

Respiratory, Thoracic and Mediastinal Disorders: hypersensitivity pneumonitis (including interstitial pneumonitis, allergic alveolitis, eosinophilic pneumonitis), interstitial lung disease, pleurisy/pleuritis, pneumonitis

Skin and Subcutaneous Tissue Disorders: AGEP, DRESS, SJS/TEN [see Warnings and Precautions (5.5)]

The concurrent use of mesalamine with azathioprine or 6-mercaptopurine and/or any other drugs known to cause myelotoxicity may increase the risk for blood disorders, bone marrow failure, and associated complications. If concomitant use of PENTASA and azathioprine or 6-mercaptopurine cannot be avoided, monitor blood tests, including complete blood cell counts and platelet counts.

Use of PENTASA may lead to spuriously elevated test results when measuring urinary normetanephrine by liquid chromatography with electrochemical detection [see Warnings and Precautions (5.8)]. Consider an alternative, selective assay for normetanephrine.

Clinical Considerations

Advise the caregiver to monitor the breastfed infant for diarrhea.

Data

In published lactation studies, maternal mesalamine doses from various oral and rectal formulations and products ranged from 500 mg to 4.8 g daily. The average concentration of mesalamine in milk ranged from non-detectable to 0.5 mg/L. The average concentration of N-acetyl-5-aminosalicylic acid in milk ranged from 0.2 to 9.3 mg/L. Based on these concentrations, estimated infant daily dosages for an exclusively breastfed infant are 0 to 0.075 mg/kg/day of mesalamine (RID 0% to 0.1%) and 0.03 to 1.4 mg/kg/day of N-acetyl-5-aminosalicylic acid.

Safety and effectiveness in pediatric patients have not been established.

Clinical trials of PENTASA did not include sufficient numbers of patients aged 65 years and over to determine whether they respond differently from younger patients. 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 PENTASA who were 65 years or older compared to younger adult patients, which may also be associated with ulcerative colitis, use of interacting drugs, or reduced renal function. Monitor complete blood cell counts and platelet counts in patients 65 years and over during treatment with PENTASA.

In general, consider the greater frequency of decreased hepatic, renal, or cardiac function, and of concurrent disease or other drug therapy in patients 65 years and over when prescribing PENTASA.

Mesalamine is known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function. Evaluate renal function in all patients prior to initiation and periodically while on PENTASA 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. Discontinue PENTASA if renal function deteriorates while on therapy [see Warnings and Precautions (5.1), Adverse Reactions (6.2), Drug Interactions (7.1)].

The mechanism of action of mesalamine is not fully understood, but it appears to be a topical anti-inflammatory effect on colonic epithelial cells. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways (i.e., prostanoids) and through the lipoxygenase pathways (i.e., leukotrienes and hydroxyeicosatetraenoic acids), is increased in patients with ulcerative colitis, and it is possible that mesalamine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.

The exposure-response relationship and time course of pharmacodynamic response for the safety and effectiveness of mesalamine have not been fully characterized.

Carcinogenesis

In a 104-week dietary carcinogenicity study of mesalamine, CD-1 mice were administered doses up to 2500 mg/kg/day and it was not tumorigenic. The 2500 mg/kg/day dose represents approximately 2.5 times the maximum recommended human dose on a body surface area basis. In a 104-week dietary carcinogenicity study in Wistar rats, mesalamine up to a dose of 800 mg/kg/day was not tumorigenic. This dose represents approximately 1.5 times the maximum recommended human dose on a body surface area basis.

Mutagenesis

No evidence of mutagenicity was observed in an in vitro Ames test and in an in vivo mouse micronucleus test.

Impairment of Fertility

No effects on fertility or reproductive performance were observed in male or female rats at oral doses of mesalamine up to 400 mg/kg/day (0.8 times the maximum recommended human dose based on body surface area).

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

Renal Impairment

Inform patients that PENTASA may decrease their renal function, especially if they have known renal impairment or are taking nephrotoxic drugs, 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 [see Warnings and Precautions (5.1)].

Mesalamine-Induced Acute Intolerance Syndrome and Other Hypersensitivity Reactions

Instruct patients to stop taking PENTASA and report to their healthcare provider if they experience new or worsening symptoms of acute intolerance syndrome (cramping, abdominal pain, bloody diarrhea, fever, headache, and rash) or other symptoms suggestive of mesalamine-induced hypersensitivity [see Warnings and Precautions (5.2, 5.3)].

Hepatic Failure

Advise patients with known liver disease to contact their healthcare provider if they experience signs or symptoms of worsening liver function [see Warnings and Precautions (5.4)].

Severe Cutaneous Adverse Reactions

Inform patients of the signs and symptoms of severe cutaneous adverse reactions. Instruct patients to stop taking PENTASA and report to their healthcare provider at first appearance of a severe cutaneous adverse reaction or other sign of hypersensitivity [see Warnings and Precautions (5.5)].

Photosensitivity

Advise patients with pre-existing skin conditions to avoid sun exposure, wear protective clothing, and use a broad-spectrum sunscreen when outdoors [see Warnings and Precautions (5.6)].

Nephrolithiasis

Instruct patients to drink an adequate amount of fluids during treatment in order to minimize the risk of kidney stone formation and to contact their healthcare provider if they experience signs or symptoms of a kidney stone (e.g., severe side or back pain, blood in the urine) [see Warnings and Precautions (5.7)].

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 [see Drug Interactions (7.2), Use in Specific Populations (8.5)].

Administration

Instruct patients:

• Swallow PENTASA capsules whole; do not crush or chew.
• Alternatively, the capsule(s) may be opened and the contents sprinkled onto applesauce or yogurt.
• Urine may become discolored reddish-brown while taking PENTASA when it comes in contact with surfaces or water treated with hypochlorite-containing bleach. If discolored urine is observed, advise patients to observe their urine flow. Report to the healthcare provider only if urine is discolored on leaving the body, before contact with any surface or water (e.g., in the toilet).
• Drink an adequate amount of fluids [see Dosage and Administration (2), Warnings and Precautions (5.7)].