Ornithine Transcarbamylase (OTC) Deficiency

How OTC is inherited

If your child has OTC deficiency, you could have it too. OTC deficiency is most commonly passed from a mother to her child through an X chromosome. A mother who is an OTC carrier has one unaffected gene and one OTC gene. These mothers may not know they carry the OTC gene until their child is diagnosed. Someone with OTC deficiency may also have symptoms and need treatment. In rare cases, OTC deficiency can be passed from a father to his daughter.

How OTC can be inherited from the mother

Insert AltDiagram showing how OTC can be inherited from the mother. Text here Insert AltDiagram showing how OTC can be inherited from the mother. Text here Insert AltDiagram showing how OTC can be inherited from the mother. Text here
Patricia lives with OTC.Patricia lives with OTC.

PATRICIA

lives with OTC

PATRICIA lives with OTC

If you experience these symptoms, you may need a doctor who understands UCDs. Our UCD Specialist Finder may help! 

Learn more about RAVICTI for most types of UCDs.*


RAVICTI is a liquid medicine that you can take by mouth, as few as 3 times a day. It is nearly tasteless and nearly odorless, and there are no pills to swallow or powders to mix.


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

Use and Important Safety Information

What is the most important safety information I should know about RAVICTI?

RAVICTI may cause serious side effects, including: Nervous system side effects (Neurotoxicity) Phenylacetate (PAA), a breakdown product of RAVICTI, may cause nervous system side effects.

Use and Important Safety Information


What is the most important safety information I should know about RAVICTI?
RAVICTI may cause serious side effects, including:
Nervous system side effects (Neurotoxicity) Phenylacetate (PAA), a breakdown product of RAVICTI, may cause nervous system side effects. Call your doctor or get medical help right away if you have any of these symptoms while taking RAVICTI:

  • sleepiness
  • lightheadedness
  • change in taste
  • problems with hearing
  • confusion
  • problems with memory
  • worsening of numbness, tingling, or burning in your hands or feet
  • headache
  • feeling very tired (fatigue)
  • nausea
  • vomiting

Your doctor may do blood tests to measure the amount of PAA in your blood during your treatment with RAVICTI.

What is RAVICTI?

  • RAVICTI (glycerol phenylbutyrate) Oral Liquid is a prescription medicine used for long-term management of high blood levels of ammonia (hyperammonemia) caused by a condition called a urea cycle disorder (UCD). RAVICTI should 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 acute treatment of hyperammonemia in people with UCD.
  • It is not known if RAVICTI is safe and effective for the treatment of N-acetylglutamate synthase (NAGS) deficiency.

Do not take RAVICTI if you are allergic to phenylbutyrate. Call your doctor or go to the nearest hospital emergency room if you have wheezing, shortness of breath, cough, low blood pressure, flushing, nausea or a rash while taking RAVICTI.

Before taking RAVICTI, tell your doctor about all of your medical conditions, including if you:

  • have liver or kidney problems.
  • have pancreas or bowel (intestine) problems.
  • are pregnant or plan to become pregnant. It is not known if RAVICTI will harm your unborn baby. If you become pregnant during treatment with RAVICTI, call Horizon at 1‐866‐479‐6742 to report the pregnancy.
  • are breastfeeding or plan to breastfeed. It is not known if RAVICTI passes into your breast milk. Breastfeeding is not recommended during treatment with RAVICTI. Talk to your doctor about the best way to feed your baby if you take RAVICTI.

What are possible side effects of RAVICTI?

RAVICTI may cause serious side effects, including:

  • See "What is the most important information I should know about RAVICTI?"

The most common side effects of RAVICTI in adults include:

  • diarrhea
  • gas
  • headache
  • abdomen (stomach) pain
  • vomiting
  • tiredness
  • decreased appetite
  • indigestion or heartburn

The most common side effects of RAVICTI in children 2 years to 17 years of age include:

  • upper abdomen (stomach) pain
  • rash
  • nausea
  • vomiting
  • diarrhea
  • decreased appetite
  • headache

The most common side effects of RAVICTI in children 2 months to less than 2 years of age include:

  • low white blood cell count (neutropenia)
  • vomiting
  • constipation
  • diarrhea
  • fever
  • reduced food intake
  • cough
  • stuffy nose
  • runny nose
  • skin rash
  • small round bumps on the skin

The most common side effects of RAVICTI in children less than 2 months of age include:

  • vomiting
  • rash
  • gastroesophageal reflux
  • increased levels of liver enzymes in the blood
  • decreased appetite and reduced food intake
  • low red blood cell count (anemia)
  • cough
  • loss of too much body fluid (dehydration)
  • too much acid in the blood (acidosis)
  • high blood platelet count (thrombocytosis)
  • low blood platelet count (thrombocytopenia)
  • low blood neutrophil count (type of white blood cell) (neutropenia)
  • high white blood cell count (lymphocytosis)
  • diarrhea
  • gas
  • constipation
  • fever
  • drowsiness (lethargy)
  • irritability
  • agitation

These are not all of the possible side effects of RAVICTI. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

For additional Important Safety Information, click here for the Medication Guide and discuss with your doctor.

Use and Important Safety Information

What is the most important safety information I should know about RAVICTI?

RAVICTI may cause serious side effects, including: Nervous system side effects (Neurotoxicity) Phenylacetate (PAA), a breakdown product of RAVICTI, may cause nervous system side effects.

Use and Important Safety Information


What is the most important safety information I should know about RAVICTI?
RAVICTI may cause serious side effects, including:
Nervous system side effects (Neurotoxicity) Phenylacetate (PAA), a breakdown product of RAVICTI, may cause nervous system side effects. Call your doctor or get medical help right away if you have any of these symptoms while taking RAVICTI:

  • sleepiness
  • lightheadedness
  • change in taste
  • problems with hearing
  • confusion
  • problems with memory
  • worsening of numbness, tingling, or burning in your hands or feet
  • headache
  • feeling very tired (fatigue)
  • nausea
  • vomiting

Your doctor may do blood tests to measure the amount of PAA in your blood during your treatment with RAVICTI.

What is RAVICTI?

  • RAVICTI (glycerol phenylbutyrate) Oral Liquid is a prescription medicine used for long-term management of high blood levels of ammonia (hyperammonemia) caused by a condition called a urea cycle disorder (UCD). RAVICTI should 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 acute treatment of hyperammonemia in people with UCD.
  • It is not known if RAVICTI is safe and effective for the treatment of N-acetylglutamate synthase (NAGS) deficiency.

Do not take RAVICTI if you are allergic to phenylbutyrate. Call your doctor or go to the nearest hospital emergency room if you have wheezing, shortness of breath, cough, low blood pressure, flushing, nausea or a rash while taking RAVICTI.

Before taking RAVICTI, tell your doctor about all of your medical conditions, including if you:

  • have liver or kidney problems.
  • have pancreas or bowel (intestine) problems.
  • are pregnant or plan to become pregnant. It is not known if RAVICTI will harm your unborn baby. If you become pregnant during treatment with RAVICTI, call Horizon at 1‐866‐479‐6742 to report the pregnancy.
  • are breastfeeding or plan to breastfeed. It is not known if RAVICTI passes into your breast milk. Breastfeeding is not recommended during treatment with RAVICTI. Talk to your doctor about the best way to feed your baby if you take RAVICTI.

What are possible side effects of RAVICTI?

RAVICTI may cause serious side effects, including:

  • See "What is the most important information I should know about RAVICTI?"

The most common side effects of RAVICTI in adults include:

  • diarrhea
  • gas
  • headache
  • abdomen (stomach) pain
  • vomiting
  • tiredness
  • decreased appetite
  • indigestion or heartburn

The most common side effects of RAVICTI in children 2 years to 17 years of age include:

  • upper abdomen (stomach) pain
  • rash
  • nausea
  • vomiting
  • diarrhea
  • decreased appetite
  • headache

The most common side effects of RAVICTI in children 2 months to less than 2 years of age include:

  • low white blood cell count (neutropenia)
  • vomiting
  • constipation
  • diarrhea
  • fever
  • reduced food intake
  • cough
  • stuffy nose
  • runny nose
  • skin rash
  • small round bumps on the skin

The most common side effects of RAVICTI in children less than 2 months of age include:

  • vomiting
  • rash
  • gastroesophageal reflux
  • increased levels of liver enzymes in the blood
  • decreased appetite and reduced food intake
  • low red blood cell count (anemia)
  • cough
  • loss of too much body fluid (dehydration)
  • too much acid in the blood (acidosis)
  • high blood platelet count (thrombocytosis)
  • low blood platelet count (thrombocytopenia)
  • low blood neutrophil count (type of white blood cell) (neutropenia)
  • high white blood cell count (lymphocytosis)
  • diarrhea
  • gas
  • constipation
  • fever
  • drowsiness (lethargy)
  • irritability
  • agitation

These are not all of the possible side effects of RAVICTI. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

For additional Important Safety Information, click here for the Medication Guide and discuss with your doctor.