Mesalamine
(5-aminosalicylic acid)
Mesalamine (Asacol, Pentasa, Rowasa)
5-aminosalicylic acid (Asacol, Pentasa, Rowasa)
Mesalamine
(mes- AL-ah-meen)
Pregnancy Category: B Asacol Mesasal Novo-5 ASA Pentasa Quintasa Rowasa Salofalk (Rx)

Classification: Anti-inflammatory agent

Action/Kinetics: Chemically related to acetylsalicylic acid. Acts locally in the colon to inhibit cyclo-oxygenase and therefore prostaglandin synthesis, resulting in a reduction of inflammation of colitis. Following PR administration, between 10% and 30% is absorbed and is excreted through the urine as the N-acetyl-5-aminosalicylic acid metabolite; the remainder is excreted in the feces. PO tablets are coated with an acrylic-based resin that prevents release of mesalamine until it reaches the terminal ileum and beyond. Approximately 28% of the drug found in tablets is absorbed with the remaining drug available for action in the colon. Capsules are ethylcellulose coated, controlled release designed to release the drug throughout the GI tract; from 20% to 30% is absorbed. t 1/2, mesalamine: 0.5-1.5 hr; t 1/2, N-acetyl mesalamine: 5-10 hr. Time to reach maximum plasma levels: 4-12 hr for both mesalamine and metabolite. Excreted mainly through the kidneys.

Uses: PO: Maintaining remission and treatment of mild to moderate active ulcerative colitis. Rectal: Treatment of active mild to moderate distal ulcerative colitis, proctosigmoiditis, or proctitis.

Contraindications: Hypersensitivity to salicylates.

Special Concerns: Use with caution in clients with sulfasalazine sensitivity, in those with impaired renal function, and during lactation. Safety and efficacy have not been established in children. Pyloric stenosis may delay the drug in reaching the colon.

Side Effects: Sulfite sensitivity: Hives, wheezing, itching, anaphylaxis. Intolerance syndrome: Acute abdominal pain, cramping, bloody diarrhea, rash, fever, headache. GI: Abdominal pain or discomfort, flatulence, cramps, dyspepsia, nausea, diarrhea, hemorrhoids, rectal pain or burning, rectal urgency, constipation, bloating, worsening of colitis, eructation, pain following insertion of enema, vomiting (after PO use). CNS: Headache, dizziness, insomnia, fatigue, malaise, chills, fever, asthenia. Respiratory: Cold, sore throat; increased cough, pharyngitis, rhinitis following PO use. Dermatologic: Acne, pruritus, itching, rash. Musculoskeletal: Back pain, hypertonia, arthralgia, myalgia, leg and joint pain, arthritis. Miscellaneous: Flu-like symptoms, hair loss, anorexia, peripheral edema, urinary burning, sweating, pain, chest pain, conjunctivitis, dysmenorrhea, pancreatitis.
In addition to the preceding, PO use may result in the following side effects. GI: Anorexia, gastritis, gastroenteritis, cholecystitis, dry mouth, increased appetite, oral ulcers, tenesmus, perforated peptic ulcer, bloody diarrhea, duodenal ulcer, dysphagia, esophageal ulcer, fecal incontinence, GI bleeding, oral moniliasis, rectal bleeding, abnormal stool color and texture. CNS: Anxiety, depression, hyperesthesia, nervousness, confusion, peripheral neuropathy, somnolence, emotional lability, vertigo, paresthesia, migraine, tremor, transverse myelitis, Guillain-Barrè syndrome. Dermatologic: Dry skin, psoriasis, pyoderma gangrenosum, urticaria, erythema nodosum, eczema, photosensitivity, lichen planus, nail disorder. CV: Pericarditis, myocarditis, vasodilation, palpitations, fatal myocarditis chest pain, T-wave abnormalities. GU: Nephropathy, interstitial nephritis, urinary urgency, dysuria, hematuria, menorrhagia, epididymitis, amenorrhea, hypomenorrhea, metrorrhagia, nephrotic syndrome, urinary frequency, albuminuria, nephrotoxicity. Hematologic: Agranulocytosis anemia, eosinophilia, leukopenia, thrombocytopenia, lymphadenopathy, thrombocythemia, ecchymosis. Respiratory: Worsening of asthma, sinusitis, interstitial pneumonitis, pulmonary infiltrates, fibrosing alveolitis. Ophthalmologic: Eye pain, blurred vision. Miscellaneous: Ear pain, tinnitus, taste perversion, neck pain, enlargement of abdomen, facial edema, gout, hypersensitivity pneumonitis, breast pain, Kawasaki-like syndrome.

Laboratory Test Alterations: AST, ALT, BUN, LDH, alkaline phosphatase, serum creatinine, amylase, lipase, GTTP.

Overdose Management: Symptoms: Salicylate toxicity manifested by tinnitus, vertigo, headache, confusion, drowsiness, sweating, hyperventilation, vomiting, and diarrhea. Severe toxicity results in disruption of electrolyte balance and blood pH, hyperthermia, and dehydration. Treatment: Therapy to treat salicylate toxicity, including emesis, gastric lavage, fluid and electrolyte replacement (if necessary), maintenance of adequate renal function.

How Supplied: Capsule, Extended Release: 250 mg; Enema: 4 g/60 mL; Enteric Coated Tablet: 400 mg; Suppository: 500 mg

Dosage
?Suppository
One suppository (500 mg) b.i.d.
?Rectal Suspension Enema
4 g in 60 mL once daily for 3-6 weeks, usually given at bedtime. For maintenance, the drug can be given every other day or every third day at doses of 1-2 g.
?Capsules, Extended-Release
1 g (4 capsules) q.i.d. for a total daily dose of 4 g for up to 8 weeks.
?Tablets, Enteric-Coated
800 mg t.i.d. for a total dose of 2.4 g/day for 6 weeks.