Balsalazide

Balsalazide is a prescription drug used for the treatment of ulcerative colitis (UC). In UC, the large intestine (colon) develops open sores. The main symptoms of UC are diarrhea and bloody stools. The cause of UC is thought to be inflammation (see video). Balsalazide belongs to a family of anti-inflammatory drugs called salicylates. The most popular member of this family is acetylsalicylic acid (aspirin). In fact, balsalazide is a form of acetylsalicylic acid that is designed to specifically act in the large intestine. Acetylsalicylic acid itself begins to dissolve in the stomach; this limits the amount that reaches the large intestine. The Food and Drug Administration approved balsalazide in July 2000. Balsalazide is marketed under the trade names Colazal in the United States and Colazide in Europe. Salix Pharmaceuticals makes Colazal and Colazide, but the generic formulation balsalazide is marketed by numerous other manufacturers.

Uses

Balsalazide is indicated for the treatment of mildly to moderately active UC in people five years of age and older.

How Balsalazide is Taken

Balsalazide is available in 750 mg oral capsules. For adults, the standard dose is three 750 mg capsules taken three times a day for up to eight weeks. For children aged 5 years to 17 years, one of two dosage regimens are typically used:

• three 750 mg capsules three times a day for up to eight weeks
• one 750 mg capsule three times a day for up to eight weeks

How Balsalazide Works

UC is an autoimmune disease in which an inflammatory reaction is directed towards the large intestine. The sores (ulcers) of UC are caused by the breakdown of a molecule called arachidonic acid. Arachidonic acid is metabolized through two different pathways. One pathway, called cyclooxygenase, results in the production of prostaglandins. The other pathway, called lipoxygenase, results in the production of leukotrienes.

After ingestion, balsalazide is delivered to the large intestine where it is cleaved by bacteria to release its active form, called 5-aminosalicylic acid (5-ASA). The mechanism of action of 5-ASA is unknown, but may involve decreased prostaglandin and leukotriene production in the colon.

How the Body Affects Balsalazide

The amount of 5-ASA that enters the blood varies considerably among individuals. A minor portion of balsalazide is metabolized by an enzyme called N-acetyltransferase (NAT). Many breakdown products of balsalazide have been found in the bloodstream, urine, and feces.

Side Effects

The most common side effects of balsalazide include the following:

• headache
• abdominal pain
• diarrhea
• nausea
• vomiting
• respiratory infection
• muscle aches

Risks and Precautions

• Balsalazide could cause dangerous allergic or hypersensitivity reactions in people with allergies to salicylates (such as acetylsalicylic acid).

• Balsalazide has been shown not to cause kidney toxicity in clinical trials. However, the number of people treated in the trials was small compared to the population of patients that receive balsalazide, and other drugs like balsalazide may harm the kidney. Thus, balsalazide use may carry some risk to the kidney in people with impaired kidney function.

Drug Interactions

The potential for balsalazide to interact with other drugs is low. Some antibiotics could interfere with 5-ASA production in the colon, but to date this has not been shown to occur.

Research

One head-to-head study comparing balsalazide (6.75 g daily) to mesalamine (2.4 g daily) demonstrated that balsalazide was more effective and more rapid in onset than mesalamine in improving the signs and symptoms of UC.^[1]

References

1. ↑ Levine DS, Riff DS, Pruitt R, et al. A randomized, double blind, dose-response comparison of balsalazide (6.75 g), balsalazide (2.25 g), and mesalamine (2.4 g) in the treatment of active, mild-to-moderate ulcerative colitis. Am J Gastroenterol. 2002 Jun;97(6):1398-407. Abstract

External Links

FDA: Patient Information Sheet