Canasa suppository for treatment of ulcerative proctitis in adults

Canasa is a rectal suppository containing mesalamine, used to treat mildly to moderately active ulcerative proctitis in adults. It delivers medication directly to the affected area in the rectum to help reduce inflammation and manage symptoms.

Approved use:

• Treatment of mildly to moderately active ulcerative proctitis in adults via rectal administration.

mesalamine

Canasa contains mesalamine, an aminosalicylate that works by reducing inflammation in the lining of the rectum. It inhibits inflammatory processes locally, helping to relieve symptoms of ulcerative proctitis.

Adults: The recommended dose is one 1000 mg suppository administered rectally once daily at bedtime for 3 to 6 weeks based on symptoms and sigmoidoscopic findings. The safety and effectiveness beyond 6 weeks are not established.

Administration instructions:

• Do not cut or break the suppository.
• Retain the suppository in the rectum for 1 to 3 hours or longer if possible.
• Drink an adequate amount of fluids during treatment.
• If a dose is missed, take it as soon as possible unless it is almost time for the next dose; do not use two suppositories at once.
• Keep Canasa away from contact surfaces to avoid staining (e.g., fabrics, flooring, painted surfaces).
• Evaluate renal function before starting therapy and periodically during treatment.

Canasa is contraindicated in patients with known or suspected hypersensitivity to salicylates, aminosalicylates, or any component of the suppository formulation.

Serious risks and precautions:

• Renal impairment: Monitor kidney function before and during treatment. Discontinue Canasa if renal function worsens.
• Acute intolerance syndrome: Mesalamine can cause symptoms resembling ulcerative colitis flare—cramping, abdominal pain, bloody diarrhea, fever, rash. If suspected, stop treatment promptly.
• Hypersensitivity reactions: May include myocarditis, pericarditis, nephritis, hepatitis, pneumonitis, hematologic abnormalities. Discontinue immediately if suspected.
• Hepatic failure: Use with caution in patients with liver impairment.
• Severe cutaneous adverse reactions: Stop Canasa at first sign of Stevens-Johnson syndrome, toxic epidermal necrolysis, DRESS, or AGEP.
• Photosensitivity: Patients with pre-existing skin conditions should avoid sun exposure and use sunscreen.
• Nephrolithiasis: Mesalamine-containing kidney stones have been reported; ensure adequate hydration.
• Laboratory test interference: Can cause falsely elevated urinary normetanephrine with certain tests; use alternative assays.

Common adverse reactions (≥1%):

• Dizziness (3%)
• Rectal pain (1.8%)
• Fever, rash, acne, and colitis (each about 1.2%)

Other reported side effects include:

• Headache, flatulence, abdominal pain, diarrhea, nausea
• Drug fever, fatigue, lupus-like syndrome
• Myocarditis, pericarditis, pericardial effusion
• Nephrogenic diabetes insipidus, eye swelling
• Gastrointestinal symptoms such as cramps, bleeding, painful defecation
• Hepatic disorders including jaundice and hepatic failure
• Hematologic effects like agranulocytosis, aplastic anemia, thrombocytopenia
• Immune system reactions such as vasculitis
• Neurologic conditions including Guillain-Barre syndrome and neuropathies
• Renal disorders including interstitial nephritis and nephrolithiasis
• Respiratory hypersensitivity pneumonitis and pleuritis
• Skin reactions including alopecia, erythema, psoriasis, urticaria, and severe cutaneous reactions
• Reversible oligospermia

Notable drug interactions:

• Nephrotoxic agents (including NSAIDs): Increased risk of kidney toxicity; monitor renal function closely.
• Azathioprine or 6-mercaptopurine: Higher risk of blood disorders; monitor blood counts if used together.
• Laboratory interference: Mesalamine may cause falsely elevated urinary normetanephrine levels with certain assays; use alternative tests.

Pregnancy: Limited data in humans; animal studies showed no evidence of harm at doses exceeding recommended human rectal doses. The background risk of birth defects or miscarriage is unknown.

Lactation: Mesalamine and its metabolites are present in human milk in low amounts. Limited reports suggest possible diarrhea in breastfed infants. Monitor infants for diarrhea and weigh benefits of breastfeeding against maternal clinical need.

Keep Canasa suppositories away from direct contact surfaces that can be stained, such as fabrics, flooring, painted surfaces, marble, granite, vinyl, and enamel. Specific storage temperature details are not provided in the label excerpt.