Ursodeoxycholic acid (UDCA), is a naturally occurring bile acid used to treat specific liver and gallbladder conditions. It was initially discovered in bear bile, and its name is derived from the Latin word ursus, meaning bear. Ursodeoxycholic acid (UDCA) was first identified in the 1900s from bear bile and used in traditional medicine, with its chemical structure determined in the 1930s and successful synthesis in the 1950s.In humans, it is a minor component of the bile acid pool, but oral administration can significantly increase its concentration to provide therapeutic effects.
BRAND NAMES
Actigall, Urso 250, Urso Forte-is available in the oral dosage forms: capsules, tablets, and suspension.
Capsules are available in 200 mg, 250 mg, 300 mg, and 400 mg strengths.
Tablets Available in 250 mg and 500 mg
The oral suspension is available in concentrations such as 125 mg per 5 mL.
MECHANISM OF ACTION
Ursodeoxycholic acid (UDCA) has multiple, complementary mechanisms of action that protect liver cells, stimulate bile flow, and dissolve cholesterol-based gallstones. Its overall effect is to decrease the concentration of toxic, hydrophobic bile acids in the liver and replace them with less-toxic, hydrophilic ones.
PHARMACOKINETICS
Absorption
Ursodeoxycholic acid (UDCA) is absorbed in the small intestine and undergoes extensive first-pass metabolism in the liver before entering into enterohepatic circulation. Absorption can be incomplete, and its rate is influenced by factors like food intake and other medications.
Distribution
The volume of distribution for ursodeoxycholic acid (ursodiol) has not been definitively determined but is expected to be small. This is because of its high plasma protein binding and its primary distribution to the bile and small intestine, rather than throughout the entire body.
Metabolism
Upon oral intake, ursodeoxycholic acid (UDCA) is absorbed and travels to the liver, where it is conjugated primarily with glycine or taurine to increase water solubility. This conjugated form is then secreted into bile and undergoes enterohepatic circulation, where it is reabsorbed in the small intestine to aid in fat absorption. The primary route of elimination for UDCA and its metabolites is through the feces, though small amounts may be cleared by the kidneys in cases of severe liver disease.
Excretion
Urinary excretion of UDCA is minimal, accounting for less than 1% in most cases. Lithocholic acid is minimally absorbed and mostly eliminated through feces.
PHARMACODYNAMICS
Ursodeoxycholic acid (UDCA) is a bile acid with multiple pharmacodynamic actions that alter bile composition, protect liver cells, and modulate the immune system. These actions are employed to manage cholestatic liver diseases and dissolve cholesterol gallstones.
ADMINISTRATION
Ursodeoxycholic acid (UDCA), also known as ursodiol, is an oral medication used to treat several cholestatic (impaired bile flow) liver diseases and to dissolve certain types of gallstones. It should be taken with food, and the specific dosage and duration of treatment are determined by a doctor based on the medical condition being treated.
DOSAGE AND STRENGTH
Ursodeoxycholic acid is available in several oral dosage forms, including capsules, tablets, and oral suspension. Commonly available in 200 mg, 300 mg, and 400 mg capsules. Tablets are available in strengths such as 250 mg and 500 mg
DRUG INTERACTIONS
Ursodeoxycholic acid (UDCA) has several notable drug interactions that can reduce its effectiveness or alter the levels of other medications. The absorption of UDCA is inhibited by aluminum-containing antacids and bile acid sequestrants like cholestyramine and colestipol, so doses should be separated by several hours. The efficacy of UDCA is also reduced by estrogen-based oral contraceptives and cholesterol-lowering fibrates, which can increase the cholesterol in bile.
FOOD INTERACTIONS
It is best to take ursodeoxycholic acid (UDCA), also known as Ursodiol, with or immediately after food. Taking it with meals improves absorption and may help reduce the risk of stomach discomfort. While there are no specific foods that negatively interact with UDCA, your doctor may recommend a low-fat, low-cholesterol diet to support the treatment of your underlying condition, such as gallstones or liver disease.
CONTRAINDICATIONS
Contraindicated in patients with conditions that strongly indicate the need for cholecystectomy, such as persistent acute cholecystitis, cholangitis, biliary obstruction, gallstones, pancreatitis, or biliary-gastrointestinal fistula. Also contraindicated in patients with calcified cholesterol stones, radiopaque stones, or radiolucent bile pigment stones.
SIDE EFFECTS
Gastrointestinal issues.
Musculoskeletal problems.
Neurological problems.
Dermatological problems.
Hair loss or thinning.
Sore throat or other cold-like symptoms.
Weight gain or loss.
Signs of serious liver problems.
Allergic reaction.
Biliary obstruction.
OVER DOSE
An overdose of ursodeoxycholic acid (UDCA) primarily causes severe diarrhea, but due to decreased absorption at high doses, serious systemic toxicity is unlikely.
Some reports have described upper-right abdominal pain, especially in patients with pre-existing primary biliary cholangitis (PBC).
Nausea and vomiting are also possible.
TOXICITY
Ursodeoxycholic acid (UDCA) toxicity can range from common side effects like diarrhea to rare but serious adverse reactions, including severe liver damage, particularly with high or long-term use. In some conditions, a high dose can be more detrimental than therapeutic.
