Ursodiol, Ursodeoxycholic Acid 829
Ursodiol, Ursodeoxycholic Acid er-soe-dye’ole, er-soe-dee-oks-ih-koe-lik ass’id
Trade and other names: Actigall, Urso Functional classification: Laxative, choleretic
Pharmacology and Mechanism of Action Hydrophilic bile acid. Ursodiol has anticholelithic and choleretic properties. Ursodiol is the short name for ursodeoxycholic acid. This is a naturally occurring, water-soluble bile acid. Ursodiol, like other bile acids, can act as a choleretic and increase bile flow. In dogs, it may alter the pool of circulating bile acids, displacing the more hydrophobic bile acids or enhancing their secretion in liver and bile. By modulating the composition of biliary bile salts in favor of more hydrophilic bile salts, injury to the biliary epithelium, such as the cytotoxic potential of endogenous bile acids, is less likely than with hydrophobic bile salts. There is also evidence that for treating acute liver injury, it may have antioxidant properties.
Indications and Clinical Uses Ursodiol is used for treatment of liver diseases. It is used to treat primary biliary cirrhosis, cholestatic liver disorders, and chronic liver disease. Although experimental evidence exists for its benefit in dogs, there are no well-controlled clinical trials that demonstrate efficacy. In people, it has been used as a laxative and to prevent or treat gallstones. It has also been used to treat chronic constipation because it may increase water content of feces and stimulate colonic peristalsis.
Precautionary Information Adverse Reactions and Side Effects Loose feces and pruritus are the most common problems in people. In animals, ursodiol may cause diarrhea. Adverse effects can be decreased by gradually increasing the dose over 1-2 weeks. Contraindications and Precautions No contraindications are reported for animals. Drug Interactions No drug interactions have been identified for animals. In people, it interferes with some cholesterol-lowering drugs.
Instructions for Use Results of clinical studies in animals have not been reported. Use in animals (and doses) is based on experience in people or anecdotal experience in animals. The optimum dose in people is 13-15 mg/kg per day PO. Once or twice daily is as effective as three to four times per day. Administer with meals.
Patient Monitoring and Laboratory Tests Monitor bile acids and hepatic enzymes during treatment to monitor effects.
Formulations • Ursodiol is available in 300-mg capsules and 250- or 500-mg tablets.
830 Ursodiol, Ursodeoxycholic Acid
Stability and Storage Store in a tightly sealed container, protected from light, and at room temperature. Suspensions have been prepared in vehicles for oral use and found to be stable for 35-60 days.
Small Animal Dosage Dogs and Cats • 10-15 mg/kg q24h PO; animals with liver disease should receive 15 mg/kg.
Large Animal Dosage • No large animal doses are available.
Regulatory Information It is expected to pose little risk from residues in animals intended for food, and no withdrawal times are recommended.