Treating and managing urea cycle disorders

Living with a urea cycle disorder (UCD) can be difficult. If you or a loved one has a UCD, you know firsthand the day-to-day struggles of managing the disorder, the pressure to stick to specific diet and lifestyle changes, the stress that comes with trying to maintain normal levels of ammonia, and the constant fear of what will happen if those ammonia levels increase. Although it can be overwhelming and emotionally draining, there are tools that can help. Treatments to help prevent harmful buildup of ammonia and the resulting consequences include:

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Sticking to a low-
protein diet

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Medicines that manage ammonia levels

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Amino acid supplements, such as L-arginine or L-citrulline

It is important to work with a healthcare team to decide what treatment approach is right for you or your loved one. Your team may include any or all of the following types of healthcare professionals:

Registered dietitians are key

Dietary treatment is a cornerstone of UCD therapy, and working with a dietary specialist should be part of creating the treatment plan.

Registered dietitians are key

Dietary treatment is a cornerstone of UCD therapy, and working with a dietary specialist should be part of creating the treatment plan.

Keeping UCDs in check for the long term

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The overall goal of UCD treatment is to help people maintain normal development and brain function by preventing elevated ammonia levels. However, this can sound easier than it is. Having to juggle the strict low-protein diet, medicines, and the constant stress of what might happen if treatment goals are not met can be extremely taxing.

Currently, available treatments include:

  • Protein-restricted diets—Aimed at lowering protein intake without interfering with growth. Not eating enough protein can get in the way of a child’s growth, development, and well-being. In order to determine the right amount of protein for you or your loved one, it is important to work with a dietitian who can tailor a diet to your or their needs. Physical activity levels, body weight, and other factors can affect the amount of protein needed. The doctor may have you or your loved one take nutritional supplements with essential amino acids
  • Sodium phenylbutyrate—Prescribed as tablets or as powder that you can mix with foods or liquids. Both are taken with meals. Speak with a doctor to determine if this treatment is right for you or your loved one
  • Glycerol phenylbutyrate—Liquid that is measured and is taken with or after meals. Speak with a doctor to determine if this treatment is right for you or your loved one
  • Sodium benzoate—Approved in the US only in a medication with sodium phenylacetate for injection through a catheter placed in a central vein
  • Hemodialysis—Sometimes used to reduce ammonia levels during acute hyperammonemia

It is important to work with a doctor to determine the best treatment plan for you or your loved one.

While a long-term goal of treatment is to prevent hyperammonemic crises (HACs), another focus should be preventing any increase in ammonia levels, as even mild increases can result in behavior changes, learning and developmental delays, and even brain damage. Sometimes the symptoms of increased ammonia might not appear immediately, which can be just as dangerous as when you see them. For people living with UCDs and their families, the main goals are to manage their UCD and avoid hospitalizations, while trying to maintain quality of life.

Getting treatment and ensuring that it is taken as prescribed is important to managing ammonia levels.

If you or a loved one is experiencing symptoms or needs help managing a UCD, talk to a doctor as soon as possible.

The overall goal of UCD treatment is to help people maintain normal development and brain function by preventing elevated ammonia levels.

The overall goal of UCD treatment is to help people maintain normal development and brain function by preventing elevated ammonia levels.

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Sources

  1. Gerstein MT, Markus AR, Gianattasio KZ, et al. Choosing between medical management and liver transplant in urea cycle disorders: a conceptual framework for parental treatment decision-making in rare disease. J Inherit Metab Dis. 2020;43(3):438-458.
  2. Häberle J, Burlina A, Chakrapani A, et al. Suggested guidelines for the diagnosis and management of urea cycle disorders: first revision. J Inherit Metab Dis. 2019;42(6):1192-1230.
  3. Häberle J, Boddaert N, Burlina A, et al. Suggested guidelines for the diagnosis and management of urea cycle disorders. Orphanet J Rare Dis. 2012;7:32.
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  5. BUPHENYL® (sodium phenylbutyrate). Prescribing information. Lake Forest, IL: Horizon Therapeutics.
  6. RAVICTI® (glycerol phenylbutyrate) oral liquid. Prescribing information. Deerfield, IL: Horizon Therapeutics.
  7. AMMUNOL® (sodium phenylacetate and sodium benzoate). Prescribing information. Scottsdale, AZ: Ucyclyd Pharma, Inc.
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