Frequently asked questions about PBD-ZSD, treatment, and more


What is peroxisomal biogenesis disorder-Zellweger spectrum disorder (PBD-ZSD)?

PBD-ZSD is a group of rare, genetic disorders, characterized by the loss of functioning peroxisomes.

Peroxisomes are the important parts of cells in charge of producing bile acids that help break down fats and eliminate waste from the body. In people with PBD-ZSD, these peroxisomes only partially work or do not work at all. This results in the buildup of abnormal bile acids, which can become toxic to the liver.

What are bile acids and why are they important?

Bile acids are a component of bile. Bile is a fluid made in the liver that contains substances the body needs to break down food and get proper nutrition. Bile helps the body:

  • Absorb dietary fats, fat-soluble vitamins, and other nutrients.
  • Get rid of excess cholesterol, waste, and toxins.

Two key bile acids necessary for proper digestion, absorption, and toxin removal are:

  • Cholic acid
  • Chenodeoxycholic acid

These 2 bile acids allow the liver to work normally by:

  • Promoting bile flow out of the liver.
  • Assisting in the absorption of fats and fat-soluble vitamins.
  • Eliminating cholesterol from the body.

Abnormal bile flow or production can result in:

  • Poor absorption of vital nutrients.
  • Accumulation of toxic materials in the body.


What liver involvement signs of PBD-ZSD should you watch for?

One of the most common symptoms of PBD-ZSD is poor growth (lower height and weight) compared to peers of the same age.

Other signs and symptoms of liver involvement include:

  • Vitamin deficiencies (a lack of vitamins A, D, E, or K).
  • Pale, foul-smelling stool.
  • Dark urine.
  • Enlarged liver or spleen.
  • Liver dysfunction.

How is PBD-ZSD diagnosed?

Your doctor can diagnose PBD-ZSD through genetic testing, which identifies specific PEX gene mutations that are associated with, or causing, PBD-ZSD. Learn more about testing for PBD-ZSD.

How is liver involvement detected in PBD-ZSD?

Your child’s doctor can run a simple blood test called an atypical bile acid test to detect the presence of atypical bile acids that are harmful to the liver.

How much does it cost to test for PBD-ZSD?

If you qualify, these tests are available at no cost to you and can be ordered through your child’s doctor. Talk to your doctor about these free testing programs, available to eligible patients.


How is PBD-ZSD treated?

Currently, there is no cure for patients with PBD-ZSD. However, there are ways to help support your child and manage his or her symptoms. Although current treatments can only help with symptoms and do not cure the disease, they may help improve comfort and quality of life for people with PBD-ZSD. Since PBD-ZSD is caused by a defect in one of the PEX genes where bile acids are not made correctly, bile acid replacement therapy may help people with PBD-ZSD who show signs of liver involvement.

CHOLBAM® (cholic acid) capsules is an adjunctive, replacement therapy that prevents the buildup of abnormal bile acids that occur in patients who have liver involvement in PBD-ZSD. Learn about treating PBD-ZSD.


What is CHOLBAM® (cholic acid) capsules?

CHOLBAM® is a bile replacement medication that is taken by mouth. CHOLBAM® is indicated for:

  • Patients with bile acid synthesis disorders due to single enzyme defects.
  • Adjunctive treatment of peroxisomal disorders, including Zellweger spectrum disorders, in patients who show signs and symptoms of liver disease, steatorrhea (fatty stools), or complications from decreased fat-soluble vitamin absorption (A, D, E, K).

The safety and effectiveness of CHOLBAM® on symptoms outside the liver have not been studied.


How is CHOLBAM® taken?

CHOLBAM® is taken by mouth each day. It is recommended to take CHOLBAM® with food. Do not crush or chew capsules. If your child or loved one is unable to swallow capsules, talk to your doctor for instructions on how to take CHOLBAM®. CHOLBAM® is available in 50 mg and 250 mg capsules.


Is CHOLBAM® safe?

As with any medication, there is a possibility of side effects. In clinical studies, the most common side effect in about 2% of patients taking CHOLBAM® was diarrhea. All other side effects were less than or equal to 1% of patients.

Call your doctor right away if there is:

  • Yellowing of the skin or whites of the eyes.
  • Dark or brown (tea-colored) urine.
  • Pain on the right side of the stomach.
  • Bleeding or bruising that occurs more easily than normal.
  • Increased tiredness.

Discuss any side effects that concern you with your doctor.

Why is it important to take CHOLBAM® every day?

It’s important to take CHOLBAM® every day to help keep the normal balance of bile acids in the liver. Avoid missing doses and do not stop therapy without talking with your doctor.

How often should people taking CHOLBAM® see their doctor?

People taking CHOLBAM® should see their doctor regularly to be sure CHOLBAM® is working properly. Your child’s or loved one’s doctor will monitor liver function with appropriate tests every month for the first 3 months, every 3 months for the next 9 months, every 6 months for the next 3 years, and annually thereafter. The doctor may discontinue CHOLBAM® therapy if liver function does not improve within 3 months of starting treatment, if complete biliary obstruction develops, or if signs or symptoms worsening liver function or cholestasis appear.

Why does the dosage change?

The amount of medication may change as weight changes. Be sure to monitor this carefully and have your child’s or loved one’s doctor adjust as needed, particularly during periods of rapid growth.

Patient Support

What is the CHOLBAM® Total Care HUB?

The CHOLBAM® Total Care HUB is a comprehensive support program for patients who have been prescribed CHOLBAM® (cholic acid) capsules and their caregivers.


What does the CHOLBAM® Total Care HUB offer?

Once enrolled in the program, you will be assigned a dedicated team of professionals to assist you with financial support, home delivery options, and answer questions you may have about the disease or treatment.


Do I have to be enrolled in the CHOLBAM® Total Care HUB to receive CHOLBAM®?

In order to receive CHOLBAM®, your child or loved one needs to enroll in the CHOLBAM® Total Care HUB. This allows us to verify your child’s or loved one’s insurance, see if you qualify for any additional assistance programs, as well as deliver CHOLBAM® to your home and refill prescriptions. Learn more about how to enroll in the CHOLBAM® Total Care HUB or call 1-844-CHOLBAM (1-844-246-5226).


What financial support does the CHOLBAM® Total Care HUB provide?

The CHOLBAM® Total Care HUB provides financial support by working with your child’s or loved one’s insurance company on benefit verification, prior authorizations, and appeals. The program also partners with your doctor’s staff to help organize relevant documentation throughout your child’s or loved one’s treatment and informs you about any copay assistance or other financial support available.


What if I can’t afford CHOLBAM®?

If you are privately or publicly insured, and have difficulty paying your copay, co-insurance or monthly premiums, the Total Care HUB (your exclusive pharmacy provider) may refer you to a copay assistance foundation that supports patients with PBD-ZSD with liver involvement.

The financial assistance program will provide you direct access to a team of Case Managers in order to assist you in applying for financial assistance with your out-of-pocket expenses or health insurance premiums.

For any questions about financial assistance, call 1-844-CHOLBAM (1-844-246-5226).


Besides financial support, what else does CHOLBAM® Total Care HUB offer?

The CHOLBAM® Total Care HUB offers live, on-demand support, available 24/7, to answer questions about treatment and set up appointment reminders to help you stay on track. We also offer educational resources so you can learn about managing PBD-ZSD and treatment.


Can I get CHOLBAM® delivered to my house?

Yes. The CHOLBAM® Total Care HUB provides convenient home delivery and prescription refills, so you can save on trips to the pharmacy and stay on schedule with medication.

WHAT IS CHOLBAM® (cholic acid) capsules?

CHOLBAM is a prescription medicine. It is a bile acid used for

  • Treatment of bile acid synthesis disorders (malfunction in the production of bile acid in the liver) due to a lack of a single enzyme responsible for bile acid production
  • Treatment (in addition to other treatments) of peroxisomal disorders (a loss of function in important parts of the cell), including Zellweger spectrum disorders, in patients who show signs or symptoms of liver disease, pale stools due to too much fat, or problems resulting from not absorbing certain vitamins (A, D, E, K)

The safety and effectiveness of CHOLBAM on symptoms outside of the liver have not been studied.


CHOLBAM may not be right for you. Before taking CHOLBAM, tell your doctor about:

  • All health conditions you may have and any medications you may be taking
  • If you are pregnant or plan to become pregnant. Women who become pregnant during CHOLBAM treatment are encouraged to call 1-844-202-6262
  • If you are breastfeeding or plan to breastfeed


What are the possible side effects of CHOLBAM?

  • Serious Side Effects: You will need to undergo laboratory testing periodically while on treatment to assess liver function. CHOLBAM may worsen liver function. Tell your doctor right away if you experience symptoms associated with worsening of liver function (e.g., skin or the whites of eyes turn yellow, urine turns dark or brown [tea colored], pain on the right side of stomach, bleeding or bruising occurs more easily than normal, or increased lethargy). Your doctor will decide if you need to discontinue treatment with CHOLBAM.
  • Most Common Side Effects: Diarrhea, acid reflux that damages the lining of the esophagus, discomfort and fatigue, yellowing of skin or eyes, skin lesion, nausea, abdominal pain, formation of growths in the intestinal tract, urinary tract infection, nerve damage causing change in sensation in extremities.

These are not all the possible side effects of CHOLBAM. Tell your doctor if you have any side effect that bothers you or that does not go away.

You may report negative side effects to Travere Medical Information at 1-877-659-5518, or to the FDA at 1-800-FDA-1088 or

Please see accompanying full Prescribing Information for additional Important Safety Information.