General Information

Colazol (balsalazide disodium) is a locally acting aminosalicylate.

Colazol is specifically indicated for the treatment of mildly to moderately active ulcerative colitis in patients 5 years of age and older.

Colazol is supplied as capsules for oral administration. The recommended dose administration is as follows:

• Adult dose is three 750 mg Colazol capsules 3 times a day (6.75 g/day) with or without food for 8 weeks. Some adult patients required treatment for up to 12 weeks.
• Pediatric dose is EITHER: three 750 mg Colazol capsules 3 times a day (6.75 g/day) with or without food for 8 weeks OR one 750 mg Colazol capsule 3 times a day (2.25 g/day) with or without food for up to 8 weeks.

Capsules may be swallowed whole or may be opened and sprinkled on applesauce, then chewed or swallowed immediate

Mechanism of Action

Balsalazide disodium is delivered intact to the colon where it is cleaved by bacterial azoreduction to release equimolar quantities of mesalamine, which is the therapeutically active portion of the molecule, and 4-aminobenzoyl-B-alanine. The recommended dose of 6.75 grams/day, for the treatment of active disease, provides 2.4 grams of free 5-aminosalicyclic acid to the colon.

The 4-aminobenzoyl-B-alanine carrier moiety released when balsalazide disodium is cleaved is only minimally absorbed and largely inert. The mechanism of action of 5-aminosalicyclic acid is unknown, but appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, ie. prostenoids, and through the lipoxygenase pathways, ie. leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that 5-aminosalicyclic acid diminishes inflammation by blocking production of arachidonic acid metabolites in the colon. 

Side Effects

Common side effect reported included, but were not limited to:

• headaches
• nausea
• abdominal pain
• diarrhea
• vomiting
• repiratory infection

Clinical Trial Results

Two randomized, double-blind studies have been conducted using Colazol to determine its effectiveness in treating mild to moderate ulcerative colitis. The first study consisted of 103 subjects with active ulcerative colitis who showed evidence of spontaneously bleeding mucosa of the colon. These subjects were randomized and treated with either 6.75 grams/day of balsalazide or 2.25 grams/day. The efficacy endpoint of the trial was reduction in rectal bleeding, pain, stool frequency and other assessed symptoms. The study showed a statistically significant difference in efficacy between the high and low dose test groups.

The second study was conducted in Europe and showed similar findings.