A commonly used name is chenodeoxycholic acid.

• Anticholelithic

Chenodiol (kee-noe-DYE-ole) is used in the treatment of gallstone disease. It is taken by mouth to dissolve the gallstones.

Chenodiol is used in patients who do not need to have their gallbladder removed or in those in whom surgery is best avoided because of other medical problems. However, chenodiol works only in those patients who have a working gallbladder and whose gallstones are made of cholesterol. Chenodiol works best when these stones are small and of the ``floating'' type.

Chenodiol is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For chenodiol, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to chenodiol or to other bile acid products.

Diet—If you have gallstones, your doctor may prescribe chenodiol and a personal high-fiber diet for you. Some foods that are high in fiber are whole grain breads and cereals, bran, fruit, and green, leafy vegetables. It has been found that such a diet may help dissolve the stones faster and may keep new stones from forming.

It may also be important for you to go on a reducing diet. However, check with your doctor before going on any diet.

Pregnancy—Chenodiol is not recommended for use during pregnancy. It has been shown to cause liver and kidney problems in animals when given in doses many times the human dose. Be sure you have discussed this with your doctor.

Breast-feeding—It is not known whether chenodiol passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of chenodiol in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of chenodiol in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

• Biliary tract problems or
• Blood vessel disease or
• Pancreatitis (inflammation of pancreas)—These conditions may make it necessary to have surgery since treatment with chenodiol would take too long

• Liver disease—Liver disease may become worse with use of chenodiol

Take chenodiol with food or milk for best results, unless otherwise directed by your doctor.

Take chenodiol for the full time of treatment, even if you begin to feel better. If you stop taking this medicine too soon, the gallstones may not dissolve as fast or may not dissolve at all.

Dosing—

The dose of chenodiol will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of chenodiol. If your dose is different, do not change it unless your doctor tells you to do so:

• For oral dosage forms (tablets):
  • For gallstone disease:
    • Adults and children 12 years of age and older—250 milligrams (mg) a day for the first two weeks of treatment. Your doctor may then increase the dose by 250 mg a day until the proper treatment dose is reached. The treatment dose is based on body weight. It is usually 13 to 16 mg per kilogram (6 to 7 mg per pound) of body weight a day, divided into two doses, taken in the morning and at night. Each dose should be taken with food or milk.
    • Children up to 12 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Do not take aluminum-containing antacids (e.g., ALternaGel, Maalox) while taking chenodiol. To do so may keep the chenodiol from working properly.

It is important that your doctor check your progress at regular visits. Laboratory tests will have to be done every few months while you are taking this medicine to make sure that the gallstones are dissolving and your liver is working properly.

Check with your doctor immediately if severe abdominal or stomach pain, especially toward the upper right side, and severe nausea and vomiting occur. These symptoms may mean that you have other medical problems or that your gallstone condition needs your doctor's attention.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if the following side effect occurs:

• Less common or rare
  • Diarrhea (severe) 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Diarrhea (mild) 
  
  

• Less common or rare
  • Constipation;  frequent urge for bowel movement;  gas or indigestion (usually disappears within 2 to 4 weeks after the beginning of treatment);  loss of appetite;  nausea or vomiting;  stomach cramps or pain 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.