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The goal of phenylketonuria (PKU) management is to lower blood phenylalanine (Phe) to protect brain function.



Management of PKU

The goal of PKU management is lifelong Phe control to protect brain function.1,2 Dietary restriction to reduce natural Phe intake is the mainstay of PKU management, and can be used together with pharmalogical treatments such as KUVAN® that increase Phe metabolism.1,2

Dietary management:

  • Avoidance of natural proteins in food such as meat, fish, eggs, nuts, and cheese.3

  • Substitution of regular bread, pasta, rice and flour-based products with specialised low protein foods.2

  • Administration of Phe-free amino acid supplements to meet the nutritional needs.2

It can be challenging for patients to follow and remain compliant with a PKU diet.3 Even with early and continuous dietary intervention, PKU individuals can still experience cognitive, behavioural and emotional problems.4 This can result in a vicious cycle, with symptoms of PKU making it more difficult for patients to adhere to treatment which requires executive functioning abilities like planning, organisation and impulse control.4,5

It can be challenging for people with PKU to maintain recommended blood Phe goals throughout life, and average levels tend to rise with age.4 Therefore, lifelong and systematic follow-up in specialised metabolic clinics is important to support patients with PKU.1,2

Pharmacologic treatment:

The low-Phe diet is challenging, and so is consistently keeping patient’s blood Phe level low. A low-Phe diet still allows a certain amount of Phe to pass from the food your patient eats into his bloodstream. KUVAN®, together with a low-Phe diet, helps your patient lower the blood Phe level and keep it low day after day. KUVAN® addresses the problem from a different angle than diet does. KUVAN® works by stimulating the PAH enzyme to break down the Phe in the patient’s body, thereby lowering the blood Phe levels.

KUVAN® is a synthetic version of BH4, which is the naturally occurring cofactor essential for PAH enzyme function. In responsive patients, KUVAN® helps lower and maintain blood Phe levels, which may prevent neurotoxicity.

Click for more information about KUVAN®


  1. van Spronsen FJ et al. Key European guidelines for the diagnosis and management of patients with phenylketonuria. Lancet Diabetes Endocrinol 2017;5(9):743-56.
  2. Australasian consensus guidelines for the management of maternal phenylketonuria (PKU) 2015. Available at Accessed March 2023.
  3. Blau N et al. Phenylketonuria. Lancet 2010;376(9750):1417-27.
  4. Enns GM et al. Suboptimal outcomes in patients with PKU treated early with diet alone: revisiting the evidence. Mol Genet Metab 2010;101:99-109.
  5. Vockley J et al. Phenylalanine hydroxylase deficiency: diagnosis and management guideline. Genet Med 2014;16(2):188-200.
  6. KUVAN® Product Information.