Gallstone-dissolving agents: Nursing pharmacology

Gallstone-dissolving agents are medications used to treat cholelithiasis, more commonly known as gallstones, as an alternative for clients who can’t or prefer not to undergo surgery to remove them, as well as for treatment of clients with primary biliary cirrhosis, and to prevent gallstones in obese clients who are rapidly losing weight, such as after bariatric surgery.

Gallstone-dissolving agents include ursodiol, also known as ursodeoxycholic acid, or UDCA for short, as well as chenodiol, also known as chenodeoxycholic acid, which are bile acids that can be taken orally.

Now, once gallstone-dissolving agents are administered, their mechanism of action is not totally clear, but they primarily seem to act on the intestines by reducing cholesterol absorption, as well as on the liver by reducing the secretion of cholesterol into bile.

As a result, gallstone-dissolving agents help change the composition of bile, which facilitates bile flow, and ultimately dissolves gallstones.

Unfortunately, the decreased intestinal absorption of cholesterol can cause gastrointestinal side effects, such as abdominal pain, dyspepsia, nausea, vomiting, and diarrhea.

In addition, clients taking gallstone-dissolving agents may experience headaches, dizziness, weakness, tachycardia, back pain, and may develop alopecia, a skin rash, or pruritus.

Some clients may present with respiratory side effects like infection or cough; as well as urinary side effects, such as a frequent urge to urinate, as well as difficult, burning, or painful urination, and even bloody or cloudy urine. Finally, chenodiol has a boxed warning for hepatotoxicity, so it requires monitoring for liver function.

As far as contraindications go, gallstone-dissolving agents should not be given to clients with calcified, radiopaque, or radiolucent gallstones, as well as in clients with complete biliary obstruction, unremitting acute cholecystitis, cholangitis, or gallstone pancreatitis. Finally, chenodiol is contraindicated during pregnancy.