Ursofalk: Formula, Presentation, Indications, Mechanism of Action, Dosage, Side Effects, Warnings, Contraindications and Interactions

It is a naturally-occurring bile acid found in small amounts in usual human bile.

Ursofalk chemical formula

  • The active ingredient is ursodeoxycholic acid  C24H40O4.
  • Inactive ingredients are microcrystalline cellulose, povidone, sodium starch glycolate, magnesium stearate, ethylcellulose, dibutyl sebacate, carnauba wax, hydroxypropylmethylcellulose, cetyl alcohol, sodium lauryl sulfate, and hydrogen peroxide.


Ursofalk is available as a 250 mg film-coated tablet for oral administration.

Ursofalk indications

Orally administered Ursofalk is indicated for the dissolution of cholesterol gallstones in selected patients with radiolucent gallstones and an uncomplicated (functional) gallbladder.

When the stones are small, less than 20 mm, and of the floating type, treatment with Ursofalk is more effective.

Mechanism of action

Depending on the pathophysiology of liver disease, the mechanism of action of ursodeoxycholic acid may be different.

Five mechanisms of action are recognized for ursodeoxycholic acid:

  • Reduction of hydrophobic and, therefore, toxic bile by substituting hydrophobic bile acids in the bile acid pool.
  • Cytoprotective effect of the membrane of the hepatocytes and the cuticular cells of the bile ducts.
  • Immunomodulatory action.
  • Stimulation of bile secretion.

In addition, Ursofalk has a choleretic action, converting lithogenic bile into non-lithogenic bile, preventing the formation and favoring the gradual dissolution of stones. Still, it differs from other hydroxylated bile acids by not presenting cytotoxic activity.



The recommended dose of Ursofalk for adults in gallstones treatment is 13 to 15 mg per kg per day, given in two to four divided doses with food.

The dosage regimen should be adjusted according to the needs of each patient at the discretion of the physician.

Ursofalk side effects

Hepatobiliary disorders

During treatment with Ursofalk, calcification of the stones and decompensation of liver cirrhosis were observed in sporadic cases.

Gastrointestinal disorders

Pasty stools or diarrhea have been reported as a common side effect during Ursofalk therapy.

And although very rarely, severe right upper abdominal pain has occurred during treatment.

Skin disorders

Hives have been reported, although it is an infrequent effect.

Warnings and Contraindications

Patients with variceal bleeding, hepatic encephalopathy, ascites, or who need an urgent liver transplant should receive the appropriate specific treatment.

Liver function tests (γ-GT, alkaline phosphatase, alanine transaminase, aspartate transaminase) and bilirubin levels should be monitored every month for three months after initiation of therapy and every six months after that.

This monitoring will allow the early detection of a possible deterioration in liver function.

Treatment discontinuation should be considered if the above parameters increase to a clinically significant level in patients with stable historical liver function test levels.

Caution should be exercised to maintain bile flow in patients taking Ursofalk.

It should not be used in patients with:

  • Acute inflammation of the gallbladder or biliary tract.
  • Biliary tract occlusion (occlusion of the common bile duct or a cystic duct).
  • Having frequent biliary colic.
  • Presence of calcified gallstones.
  • Impaired gallbladder contractility.
  • Hypersensitivity to bile acids or any excipient in the formulation.
  • In hepatobiliary disorders associated with cystic fibrosis in children 6 to 18 years of age.
  • Failed Portoenterostomy or no recovery of good bile flow in children with biliary atresia

Ursofalk should not be used during pregnancy unless necessary.

It should be used in patients taking Ursofalk, an effective non-hormonal contraceptive, since oral hormonal contraceptives can increase gallstones.

Ursofalk interactions

Bile acid sequestering agents such as cholestyramine and colestipol can interfere with the action of Ursofalk by reducing its absorption.

Aluminum-based antacids have been shown to adsorb bile acids in vitro and can be expected to interfere with Ursofalk in the same way as bile acid sequestering agents.

Some medications, such as estrogens, oral contraceptives, clofibrate, and other lipid-lowering drugs, can counteract the effectiveness of Ursofalk, as they increase the liver’s secretion of cholesterol and stimulate the formation of gallstones.

Ursofalk capsules may affect the absorption of cyclosporine from the intestine, and the doses should be adjusted according to the results of the cyclosporine blood concentration.

Ursofalk used concomitantly with ciprofloxacin can reduce its absorption.

Concomitant use of ursofalk and rosuvastatin may produce slightly elevated plasma levels of rosuvastatin. The clinical relevance of this interaction also concerning other statins is unknown.

Monitoring the effects of concurrent use of nitrendipine and ursodeoxycholic acid is recommended, as an increase in the dose of nitrendipine may be necessary.

A reduction in the effect of dapsone when interacting with ursofalk has been reported.

Estrogenic hormones and blood cholesterol-lowering agents, such as clofibrate, increase the secretion of hepatic cholesterol and, therefore, can stimulate gallstones, which is an opposite effect of the ursodeoxycholic acid used to dissolve stones. Biliary.