You have questions. We have answers.

Take a look at some common questions that many other patients and caregivers have asked about Horizon UCD Support Services.

What is a case manager?

A case manager helps with access to urea cycle disorder medication, insurance benefits, financial assistance, and working with specialty pharmacies, to name just a few important roles they play.

What is a clinical nurse educator?

A clinical nurse educator plays an important role in helping you. They provide urea cycle disorder medication information, tips to manage side effects, ongoing telephone support, and much more. They'll also work closely with your doctor to ensure you get the care you need.

My insurance company says my UCD medication must be provided by a specialty pharmacy. What is a specialty pharmacy?

Many insurance providers require that special medicines, such as your urea cycle disorder (UCD) medication, be delivered through a specialty pharmacy rather than your local pharmacist. Specialty pharmacies focus on delivering medications for unique and rare diseases, including UCDs. A specialty pharmacy can provide:

  • Convenient deliveries to home, office, or other location
  • Refills of medication before you run out
  • Shipment of medication supplies, such as caps or syringes
  • 24/7 on-call pharmacist support
  • Specialized UCD training and support

There is a problem with my UCD medication shipment from the specialty pharmacy. Can Horizon UCD Support Services help?

Yes. Whether something is missing or broken, your shipment is late, or you have a question about what you received, Horizon UCD Support Services will work closely with the specialty pharmacy to get you what you need. Call your patient advocate with any concerns related to your urea cycle disorder medication shipments.

What is a UCD Mentor?

UCD Mentors are patients and caregivers who know what you’re going through because they live with a urea cycle disorder every day too. They’re available to talk, listen, and share their stories with you so that you know you’re not alone.

What are some online resources about UCDs?

These groups are part of the growing urea cycle disorder (UCD) community and are available to support you.

  • The National Urea Cycle Disorders Foundation's mission is to "save and improve the lives of all those affected by urea cycle disorders." This nonprofit offers membership to help people with UCDs stay informed about "all things UCD"
  • The Urea Cycle Disorders Consortium is a team of doctors, nurses, and researchers who are working together to improve the lives of people with UCDs. To learn more about UCDs, they encourage greater participation in research studies
  • The National Organization for Rare Disorders strives to raise awareness and recognition for all rare diseases. It works to help forward scientific discovery for rare diseases through education, advocacy, research, and service
  • Global Genes is one of the leading rare disease patient advocacy organizations in the world. Their mission is to build awareness, educate the global community, and provide critical connections and resources that equip advocates to become activists for their disease

I have just been diagnosed with a UCD, and I want to understand the process to start taking a UCD medication. Can Horizon UCD Support Services help?

A Horizon UCD Support Services representative is ready to answer your questions about your urea cycle disorder and will walk you through the process of starting medication. Call 1-855-UCD-SUPT (1-855-823-7878) between 9 AM and 8 PM (EST), Monday through Friday.

I am not currently taking a UCD medication. Can I still contact Horizon UCD Support Services and access your available resources?

Yes. You can still contact Horizon UCD Support Services with questions about managing your urea cycle disorder.

I am not sure if my UCD medication will be covered by insurance. Can a member of the Horizon UCD Support Services team help me find out?

Horizon UCD Support Services regularly works with doctors’ offices and insurance companies to verify UCD medication coverage for individuals. Speak with Horizon UCD Support Services directly, or ask your doctor to call to learn more about your coverage options.

Is there any financial help available to cover insurance copays?

Yes. There are several patient assistance programs available to help people pay for their insurance copays. Horizon UCD Support Services can find out if you are eligible for any assistance and may be able to help you get that assistance. Our team is dedicated to helping you in every way to make sure that finances don’t get in the way of you receiving your urea cycle disorder medication.

What should I do if I forget to order my urea cycle disorder medication before it runs out?

If you would like assistance with remembering to schedule your urea cycle disorder medication shipments in advance, your Horizon UCD Support Services patient advocate can help. Call your patient advocate to set up scheduled reminders to make sure you always have the medication you need.

If you have not worked with a patient advocate or have lost or forgotten his or her contact information, just call Horizon UCD Support Services for assistance.

We're only a phone call away!

Call Horizon UCD Support Services
Monday to Friday 9 AM to 8 PM (EST)

Important Safety information

Ravicti® (glycerol phenylbutyrate) oral liquid indications and usage

Approved Uses for RAVICTI® (glycerol phenylbutyrate) Oral Liquid

RAVICTI is a prescription medicine used in adults and children 2 years of age and older for long-term management of high blood levels of ammonia (hyperammonemia) caused by a condition called a urea cycle disorder (UCD). RAVICTI should only be used if the UCD cannot be managed with a low-protein diet and dietary supplements alone. RAVICTI must be used along with a low-protein diet and, in some cases, dietary supplements.

RAVICTI is not used for the treatment of acute hyperammonemia in people with UCDs.

It is not known if RAVICTI is safe and effective for the treatment of N-acetylglutamate synthase (NAGS) deficiency.

It is not known if RAVICTI is safe and effective in children 2 months to less than 2 years of age.

Detailed Important Safety Information

Who should not take RAVICTI:

  • Children less than 2 months of age should not take RAVICTI because it may not be digested in babies less than 2 months of age.
  • Do not take RAVICTI if you are allergic to phenylbutyrate. Call your doctor or go to the nearest hospital emergency room if you get wheezing, shortness of breath, cough, low blood pressure, flushing, nausea, or a rash while taking RAVICTI.

RAVICTI may cause serious side effects:

Phenylacetate, a breakdown product of RAVICTI, may cause nervous system side effects. Call your doctor or get medical help right away if you experience any of these symptoms while taking RAVICTI: sleepiness, weakness, lightheadedness, change in taste, problems with hearing, confusion, problems with memory, worsening neuropathy (numbness, tingling, or burning in your hands or feet), or headache.

What are the possible side effects of RAVICTI?

The most common side effects of RAVICTI in adults include diarrhea, gas, headache, nausea, vomiting, tiredness, decreased appetite, high blood levels of ammonia, and dizziness.

The most common side effects of RAVICTI in children include upper abdomen (stomach) pain, nausea, vomiting, diarrhea, decreased appetite, high blood levels of ammonia, and headache.

Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all of the possible side effects of RAVICTI. Call your doctor for medical advice about side effects.

Before you take RAVICTI:

Tell your doctor if you have liver or kidney problems, pancreas or bowel (intestine) problems, or any other medical conditions. Tell your doctor if you are pregnant or plan to become pregnant. It is not known if RAVICTI will harm your unborn baby. Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if RAVICTI passes into your breast milk. RAVICTI may harm your baby, so you and your doctor should decide if you will take RAVICTI or breastfeed.

Talk to your doctor about participating in a UCD registry. The purpose of this registry is to collect information about people with UCDs to improve care. For more information about the registry program, call 1-855-823-7878 or visit

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

This information is not comprehensive. To learn more, talk to your health care provider or pharmacist. For more information about RAVICTI, please see the full Prescribing Information (PDF) and Medication Guide (PDF) for RAVICTI.