Ursodeoxycholic acid, ursodiol is an oral, naturally occurring bile acid agent. Ursodiol is FDA-approved to solubilize radiolucent (cholesterol) gallstones, prevent gallstone formation in obese patients experiencing rapid weight loss, and for the treatment of patients with primary biliary cirrhosis. Gallstone dissolution requires months of therapy, and complete dissolution may not occur in all patients. The drug helps prevent gallstones during rapid weight loss. Ursodiol is used off-label as an adjunct in treating cholestatic hepatobiliary diseases in adults and pediatric patients. In treating hepatobiliary disorders, ursodiol reduces cholestasis, pruritus, and elevated hepatic enzymes, but slowing of disease progression to cirrhosis is not always evident. In clinical trials, ursodiol was not associated with hepatotoxicity; however, elevated hepatic enzymes and jaundice have been reported during post-marketing safety surveillance. Monitoring of liver enzymes and bilirubin is recommended during therapy. Actigall was originally approved by the FDA in 1987 for gallstone dissolution and was subsequently approved for preventing gallstones in obese patients during rapid weight-loss diets in 1997. Ursodiol (Urso) was approved for the treatment of primary biliary cirrhosis (PBC) in December 1997, and is designated an orphan drug for this indication. In 2000, a biliary lithotripsy device was FDA-approved for use along with Actigall for selected patients with a solitary radiolucent gallstone ranging 4-20 mm in diameter.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
-Administer ursodiol orally with food or milk; infants may receive ursodiol with milk, formula, or soft food.
Extemporaneous Compounding-Oral:
-Shake well before use. Administer using a calibrated oral syringe or dosage cup.
Extemporaneous preparation of oral suspensions* (not commercially available in the US):
-To prepare a 25 mg/ml suspension: Open ten 300-mg ursodiol capsules into a glass mortar and mix capsule contents with 10 ml Glycerin, USP until a smooth mixture is obtained. Add 60 ml Ora-Plus in proportions and continue to levigate until a smooth mixture is achieved. Transfer mixture to a light-resistant bottle; add a small amount of Orange Syrup, NF to wash remaining drug from the mortar to bottle. Add additional syrup to make a final volume of 120 ml. Label 'shake well'. The suspension is stable for 60 days at room temperature or refrigerated.
-To prepare a 60 mg/ml suspension: Open twelve 300-mg ursodiol capsules and wet with sufficient glycerin, USP. Triturate to make a fine paste. Gradually add Simple Syrup, USP to make a final volume of 60 ml. Label 'shake well'. The suspension is stable for 35 days in the refrigerator (at 4 degrees C).
Ursodeoxycholic acid, ursodiol is typically well-tolerated, in both the pediatric and adult populations. Side effects reported in >= 5% of patients taking ursodiol often occur at rates similar to placebo in controlled trials.
GI-related side effects have been reported with ursodiol, but the actual incidences are difficult to determine because the effects may reflect the underlying disease for which the patient is treated. Such effects include abdominal pain, constipation, diarrhea, dyspepsia, flatulence, nausea, and vomiting. Increased bilirubin (hyperbilirubinemia), elevated hepatic enzymes, and jaundice (or aggravation or preexisting jaundice) have been reported in postmarketing experience. Liver function tests (LFTs) and bilirubin levels should be monitored every month for 3 months after initiation of therapy and every 6 months thereafter. Consider treatment discontinuation if LFTs increase to a level of clinical concern in patients with stable LFTs at baseline. Caution should be exercised to maintain the bile flow of patients taking ursodiol. Data from a phase IV post-market study of 60 adults reported that 43 (71.7%) patients experienced treatment emergent adverse events. These included dyspepsia (10%), nausea (8.3%), and non-specified GI disorders (5%). Other reported side effects judged to be possibly drug related were anorexia and esophagitis reported by one patient each. Discontinuation of treatment occurred in one patient due to intractable nausea. All treatment emergent adverse events were observed in patients receiving ursodiol at a total dose of 1000 mg/day or greater.
Side effects reported in clinical trials at a slightly higher incidence with ursodeoxycholic acid, ursodiol than with placebo included arthralgia, (arthritis-type symptoms) and myalgia. The following events occurred more often in ursodiol groups than placebo in trials for biliary cirrhosis (PBC), but no assessment of causality is available: elevated serum creatinine, hyperglycemia, leukopenia, peptic ulcer, and skin rash (unspecified). Clinical studies report a similar incidence of CNS side effects for both ursodiol and placebo, including headache and dizziness. Malaise and pyrexia (fever) have been reported with postmarketing experience.
Respiratory side effects have been reported with ursodeoxycholic acid, ursodiol. They include bronchitis, cough, pharyngitis, rhinitis, sinusitis and upper respiratory tract infection. Of the side effects reported, only bronchitis, cough, and pharyngitis occurred more often with ursodiol than with placebo.
Very rarely, allergic reactions to bile acid agents may occur. Anaphylactoid reactions, skin rash (unspecified), urticaria, or other allergic-type symptoms have been reported. Alopecia has been reported with ursodeoxycholic acid, ursodiol use. Reported postmarketing drug hypersensitively reactions include facial edema, angioedema, and laryngeal edema.
In a phase IV post-marketing study, 60 adult patients with primary biliary cirrhosis were given ursodiol in varying regimens of a single or a daily divided dose. Four of the sixty patients (6.7%) experienced one serious event each, new onset diabetes mellitus, cyst, and two patients experienced a breast neoplasm. The causality of these findings is difficult to determine; however 43 (71.7%) patients did report side effects that were considered treatment emergent adverse events. These included asthenia (11.7%), peripheral edema (8.3%), hypertension (8.3%), chest pain (unspecified) (5%), and pruritus (5%). All treatment emergent adverse events were observed in patients receiving ursodiol at a dose of 1000 mg/day or greater.
In placebo controlled trials with ursodiol, thrombocytopenia was reported in 1 patient (1.32%) at the 24 month visit.
In adult clinical studies, dysmenorrhea, musculoskeletal pain, influenza-like symptoms, and viral infections were reported with ursodiol; the incidence was similar between ursodiol and placebo.
Ursodeoxycholic acid, ursodiol will not dissolve calcified cholesterol stones, radiopaque stones, or radiolucent bile pigment stones. Therefore, patients with these types of stones are not candidates for ursodeoxycholic acid, ursodiol therapy.
The safety and effectiveness of ursodiol for cholelithiasis in children have not been established. However, trials of ursodiol for the treatment of cholestatic liver diseases in children, infants, and neonates have not indicated problems that would limit the drug's usefulness for studied off-label indications.
Ursodeoxycholic acid, ursodiol is contraindicated for use in patients hypersensitive to ursodiol, the formulation, or with other bile acid agents hypersensitivity.
Ursodiol is contraindicated in patients with complete biliary obstruction. Patients with cholelithiasis or biliary tract disease and compelling reasons for cholecystectomy, including unremitting acute cholecystitis, cholangitis, gallstone pancreatitis, or biliary-GI fistula are not candidates for gallstone dissolution via use of ursodeoxycholic acid, ursodiol. Use with caution in patients with hepatobiliary disorders; jaundice, aggravation of pre-existing jaundice, and elevated hepatic enzymes have been reported in postmarketing safety surveillance. Measure LFTs and bilirubin at baseline, monthly for 3 months after start of therapy, and then every 6 months thereafter. If clinically significant increases in LFTs or bilirubin concentrations occur in patients with previously stable hepatic function, consider discontinuing ursodiol therapy. Patients with primary biliary cirrhosis or other cholestatic hepatic disease complicated with concomitant ascites, hepatic encephalopathy, variceal bleeding (e.g. bleeding esophageal varices), or with the need for an urgent organ transplant of the liver should receive appropriate specific treatment.
Available published data on the use of ursodiol during pregnancy, derived from randomized controlled trials, observational studies, and case series collected over several decades, have not identified a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Most of the reported exposures to ursodiol occurred in the second and third trimester of pregnancy. In animal reproduction studies, ursodiol had no adverse effects on embryo-fetal development when administered at doses greater than human therapeutic doses. Ursodiol has been used effectively and safely in women with intrahepatic cholestasis of pregnancy (ICP) in several clinical trials; current evidence is insufficient to definitively determine maternal or fetal safety; however, gastroenterology experts consider the drug low risk based on available data.
Ursodiol is naturally present in human milk. There are no reports of adverse effects of ursodiol on the breastfed child, but the reports are extremely limited. There are no data on the effects of ursodiol on milk production. Only small amounts of ursodiol reach the systemic maternal circulation, it is unlikely that clinically significant amounts would reach the breast-fed infant. Gastroenterology experts consider the drug to be "probably" compatible with breast-feeding. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition.
Roughly 14% of the subjects in ursodiol clinical trials were over 65 years of age (with 3% of these over the age of 75). In a subgroup analysis, no efficacy difference has been found in rates of dissolution of gallstones of patients older than 56 years of age vs. younger patients. However, it is recommended to dose ursodiol cautiously in geriatric patients, as small differences in efficacy and/or safety cannot be completely ruled out.
For treatment of radiolucent cholelithiasis:
Oral dosage (capsules):
Adults: 8 to 10 mg/kg/day PO in 2 to 3 divided doses. Obtain ultrasound images of the gallbladder at 6-month intervals for the first year of therapy to monitor gallstone response. If gallstones appear to have dissolved, continue ursodiol and confirm dissolution on a repeat ultrasound examination within 1 to 3 months. Most persons who eventually achieve complete stone dissolution will show partial or complete dissolution at the first on-treatment reevaluation. If partial stone dissolution is not seen by 12 months of therapy, the likelihood of success is greatly reduced.
For the treatment of primary biliary cirrhosis (PBC):
NOTE: Ursodiol is designated an orphan drug by the FDA for this indication.
Oral dosage:
Adults: 13 to 15 mg/kg/day PO administered in two to four divided doses with food. Ursodiol slows disease progression and reduces the need for liver transplantation. Predictive factors for ursodiol failures include high serum bilirubin, high total serum bile acid concentrations, low serum albumin, hepatomegaly, or splenomegaly.
For the treatment of metabolic dysfunction-associated steatohepatitis*:
Oral dosage:
Adults: Preliminary data suggest 13 to 15 mg/kg/day PO, given in divided doses, is clinically beneficial (i.e., improves LFTs and histologic status of NASH). Results need confirmation in controlled trials.
Children and Adolescents 4 to 17 years: One trial used 10 to 12.5 mg/kg/day PO given in two divided doses. However, ursodiol plus a weight-reducing diet and exercise was no more efficacious than weight loss alone.
For the treatment of primary sclerosing cholangitis (PSC)*:
Oral dosage:
Adults: 13 to 15 mg/kg/day PO, administered in divided doses, may improve LFTs and reduce fatigue and pruritus; however, histologic or survival benefits for PSC are uncertain.
For the treatment of intrahepatic cholestasis of pregnancy (ICP)*:
Oral dosage:
Adult pregnant females: Dosages range from 5 to 20 mg/kg/day PO. Also, 500 mg PO twice daily has been used in a controlled trial (roughly 16 mg/kg/day PO).
For the treatment of cholestasis* (e.g., cholestasis due to parenteral nutrition, biliary atresia, intestinal failure, cystic fibrosis):
Oral dosage:
Adolescents, Children, and Infants: 15 to 30 mg/kg/day is used in patients with TPN-associated cholestasis. Doses of 10 to 30 mg/kg/day are commonly used for cholestasis secondary to bliliary atresia or cystic fibrosis; however, doses up to 40 mg/kg/day have been reported in infants with cystic fibrosis.
Premature Neonates and Neonates: 10 to 30 mg/kg/day in 3 divided doses has been used in neonates with cholestasis due to primary intestinal failure and TPN-associated cholestasis. Doses of 20 to 40 mg/kg/day have been used for the treatment of neonatal hepatitis and in neonates with cystic fibrosis.
For gallstone prophylaxis during rapid weight loss:
Oral dosage (Actigall):
Adults: 300 mg PO twice daily.
Maximum Dosage Limits:
-Adults
Maximum dosage information is not available.
-Geriatric
Maximum dosage information is not available.
-Adolescents
Safety and efficacy have not been established; however doses up to 30 mg/kg/day PO have been used off-label.
-Children
Safety and efficacy have not been established; however doses up to 30 mg/kg/day PO have been used off-label.
-Infants
Safety and efficacy have not been established; however off-label doses of up to 30 mg/kg/day for most uses and 40 mg/kg/day PO for cystic fibrosis have been used.
-Neonates
Safety and efficacy have not been established; however off-label doses of up to 30 mg/kg/day have been used. For cystic fibrosis and neonatal hepatitis, doses up to 40 mg/kg/day PO have been used in term neonates.
Patients with Hepatic Impairment Dosing
Follow normal dosage. The amount of accumulation that might occur in severe hepatic disease does not appear to be clinically significant.
Patients with Renal Impairment Dosing
No dosage adjustments are needed.
*non-FDA-approved indication
Aluminum Hydroxide: (Moderate) Aluminum hydroxide based antacids have been shown to adsorb bile acids in vitro and are expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 2 hours after the aluminum-based antacid.
Aluminum Hydroxide; Magnesium Carbonate: (Moderate) Aluminum hydroxide based antacids have been shown to adsorb bile acids in vitro and are expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 2 hours after the aluminum-based antacid.
Aluminum Hydroxide; Magnesium Hydroxide: (Moderate) Aluminum hydroxide based antacids have been shown to adsorb bile acids in vitro and are expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 2 hours after the aluminum-based antacid.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Moderate) Aluminum hydroxide based antacids have been shown to adsorb bile acids in vitro and are expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 2 hours after the aluminum-based antacid.
Aluminum Hydroxide; Magnesium Trisilicate: (Moderate) Aluminum hydroxide based antacids have been shown to adsorb bile acids in vitro and are expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 2 hours after the aluminum-based antacid.
Charcoal: (Major) Activated charcoal, which is available in dietary supplements, has been shown to adsorb bile acids in vitro and is expected to interfere with the efficacy of ursodeoxycholic acid, ursodiol. Concurrent use is not recommended.
Cholestyramine: (Moderate) Cholestyramine may interfere with the action of ursodeoxycholic acid, ursodiol by reducing its absorption. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 4 to 6 hours after the bile acid sequestering agents.
Ciprofloxacin: (Moderate) There has been one case report of reduced serum concentrations of ciprofloxacin after the administration of ursodeoxycholic acid, ursodiol to a patient with hepatobiliary disease. The mechanism of the proposed interaction is uncertain.
Colesevelam: (Moderate) Colesevelam may interfere with the action of ursodeoxycholic acid, ursodiol by reducing its absorption. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 4 hours after the bile acid sequestering agents.
Colestipol: (Moderate) Colestipol may interfere with the action of ursodeoxycholic acid, ursodiol by reducing its absorption. To minimize drug interactions, administer ursodiol at least 1 hour before or at least 4 hours after the bile acid sequestering agents.
Conjugated Estrogens: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Conjugated Estrogens; Bazedoxifene: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Conjugated Estrogens; Medroxyprogesterone: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Desogestrel; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Dienogest; Estradiol valerate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Drospirenone; Estetrol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Drospirenone; Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Drospirenone; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Elagolix; Estradiol; Norethindrone acetate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Esterified Estrogens: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Esterified Estrogens; Methyltestosterone: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estradiol; Levonorgestrel: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estradiol; Norethindrone: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estradiol; Norgestimate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estradiol; Progesterone: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estrogens: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Estropipate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Ethinyl Estradiol; Norelgestromin: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Ethinyl Estradiol; Norethindrone Acetate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Ethinyl Estradiol; Norgestrel: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Ethynodiol Diacetate; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Etonogestrel; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Fenofibrate: (Major) Fibric acid derivatives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Fenofibric Acid: (Major) Fibric acid derivatives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Fibric acid derivatives: (Major) Fibric acid derivatives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Gemfibrozil: (Major) Fibric acid derivatives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Levonorgestrel; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Norethindrone; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Norgestimate; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Relugolix; Estradiol; Norethindrone acetate: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Segesterone Acetate; Ethinyl Estradiol: (Minor) Estrogens and combined hormonal and oral contraceptives increase hepatic cholesterol secretion, and encourage cholesterol gallstone formation, and hence may counteract the effectiveness of ursodeoxycholic acid, ursodiol.
Ursodiol's therapeutic sites of action are in the liver, bile, and gut lumen. At chronic doses of 13-15 mg/kg/day, ursodiol constitutes roughly 30-50% of the total biliary and plasma bile acids.
-Mechanism of gallstone dissolution: Ursodiol decreases the cholesterol content of bile and associated gallstones by reducing the hepatic synthesis and secretion of cholesterol and the fractional reabsorption of cholesterol by the intestine. Ursodiol does not inhibit the synthesis and secretion of endogenous bile acids or phospholipids into the bile. In addition to solubilizing cholesterol in micelles, ursodiol causes dispersion of cholesterol as liquid crystals in aqueous media. The actions of ursodiol change the nature of the bile from cholesterol-precipitating to cholesterol-solubilizing, thus resulting in an environment conducive to gallstone dissolution.
-Mechanism in primary biliary cirrhosis (PBC) and other cholestatic liver diseases: Retardation of disease progression has only been noted in clinical trials for PBC; further investigation is needed to prove ursodiol retards the progression to cirrhosis in other cholestatic liver diseases. Ursodiol's benefit to date in other hepatic diseases has been a reduction in LFTs and clinical symptoms (e.g., pruritus). The exact mechanism by which ursodiol retards progression of liver disease in patients with primary biliary cirrhosis is still unclear. Retention of high concentrations of hydrophobic bile acids within hepatocytes during cholestasis has been shown to damage the membranes of intracellular organelles. Improved hepatic bile flow, decreased bile viscosity, reduced ductular proliferation and reduced portal inflammation appear to be important effects of ursodiol. Ursodiol has been shown to reduce the intrahepatic concentration of hydrophobic bile acids within hepatocytes, and to increase the hydrophilicity of the bile acid pool. Ursodiol also interferes with the enterohepatic circulation of bile acids by inhibiting reuptake of endogenous bile acids in the terminal ileum. Studies have suggested that ursodiol may have an immunomodulatory effect and inhibit the production of certain cytotoxic cytokines, which may reduce lipid peroxidation in hepatocytes.
Pharmacokinetics:
Ursodiol is administered orally. Only small amounts of ursodiol appear in the systemic circulation and very small amounts are excreted into the urine. With repeated dosing, bile ursodiol concentrations reach a steady-state in about 3 weeks; ursodiol concentrations in the bile do not exceed 60% of the total bile acid pool. After ursodiol is discontinued, the concentration of the drug in bile falls exponentially, declining to roughly 5-10% of its steady-state level within 1 week.
Beyond conjugation, ursodiol is not catabolized appreciably by the liver or intestinal mucosa. A small proportion of the orally administered drug undergoes bacterial degradation in the intestine with each cycle of enterohepatic circulation. rsodiol can be both oxidized and reduced, yielding either 7-keto-lithocholic acid or lithocholic acid, respectively. Further, the conjugated glyco- or tauro-ursodiol may be deconjugated in the small bowel, yielding free ursodiol. All of these bacterial degradation products are relatively insoluble and large proportions of these products are excreted in the feces. Some free ursodiol is reabsorbed and reconjugated by the liver. Eighty-percent of the lithocholic acid formed in the small bowel is excreted in the feces, but 20% is reabsorbed and then sulfated by the liver to lithocholyl conjugates excreted in the bile and lost in the feces. Small amounts of 7-keto-lithocholic acid are reabsorbed and stereospecifically reduced by the liver to chenodiol.
-Route-Specific Pharmacokinetics
Oral Route
Following oral administration, ursodiol is absorbed via passive diffusion. Roughly 90% of a therapeutic dose is absorbed in the small intestine, after which it enters the portal vein and is extracted from the portal blood by the liver. In the liver, ursodiol is conjugated with either glycine or taurine, then is secreted into the hepatic bile ducts. Ursodiol is then concentrated into the bile in the gallbladder. Ursodiol and the other bile acids are expelled into the duodenum via the cystic and common bile ducts by gallbladder contractions induced by the physiologic response to oral ingestion of food.
-Special Populations
Hepatic Impairment
No dosage reductions appear needed in hepatic dysfunction. Lithocholic acid, when administered chronically to animals, causes serious liver injury in certain animal species unable to form sulfate conjugates. However, humans can readily sulfate lithocholic acid. Ursodiol is 7-dehydroxylated to lithocholic acid more slowly than chenodiol, and steady-state levels of lithocholic acid in biliary bile acids are lower during ursodiol treatment than with the use of chenodiol. While a reduced capacity to sulfate lithocholic acid may exist in some individuals, such a deficiency has not yet been clearly demonstrated and must be extremely rare. Liver injury has not been associated with ursodiol therapy in widespread clinical use.
Renal Impairment
No ursodiol dosage reductions appear needed in renal dysfunction.
Pediatrics
Pediatric clinical experience to date suggests no relevant pharmacokinetic issues with ursodiol when compared to adults.