Treatment Guidelines: New Patients

 

Objective 1: Establish diagnosis and initiate contact with metabolic team.

  1. Referral from Newborn Screening Coordinator is received by metabolic clinic.
  2. Quantitative blood phenylalanine and tyrosine levels are measured to confirm diagnosis.
  3. Urine is collected for biopterin assay and blood for dihydropteridine reductase determination. (Samples are sent to an outside lab.)
  4. Initial appointment with metabolic team is made.
  5. Use the Checklist for Families New to the PKU Clinic to guide initial visits.

 

Objective 2: Obtain baseline data at first clinic visit.

  1. Document birth weight, length, OFC.
  2. Measure weight length, OFC; plot on appropriate growth charts.
  3. Draw blood for phenylalanine, tyrosine.
  4. Document feeding history, e.g., formula, breastmilk, and baseline intakes.
  5. If studies not complete, collect urine for biopterin assay and blood for dihydropteridine reductase determination.

 

Objective 3: Initiate treatment at first clinic visit. Adjust blood phenylalanine levels to achieve treatment goal of phenylalanine concentrations of 1-6 mg/dL.

  1. If phenylalanine level >20 mg/dl:
    • Phenylalanine-free formula alone until blood phenylalanine level <10 mg/dL, regardless of previous manner of feeding.
    • Monitor blood phenylalanine levels every other day.
  2. If phenylalanine level 10-20 mg/dL:
    • Phenylalanine-free formula alone (for 2-5 days) to bring level to <10 mg/dL, regardless of previous manner of feeding.
    • After level is <10 mg/dL, negotiate with breast-feeding mother about her wishes regarding continuing breast-feeding with supplemental phenylalanine-free formula or bottle feeding only.
  3. If phenylalanine level 6-10 mg/dL and mother is breast-feeding, support breast-feeding and introduce phenylalanine-free formula to bring level to 1-6 mg/dL If phenylalanine level 6-10 mg/dL and infant is on standard formula, introduce phenylalanine-free formula to bring level to 1-6 mg/dL

 

Objective 4: Monitor blood phenylalanine levels until treatment goal (1-6 mg/dL) is reached.

  1. While blood level is decreasing, measure blood phenylalanine and tyrosine every other day.
  2. Establish baseline intake of 100-120 kcal/kg and 2.0-3.5 g protein/kg.

 

Objective 5: Continue to monitor when blood phenylalanine levels reach treatment goal (1-6 mg/dL).

  1. Establish baseline intake of 100-120 kcal/kg, 2.0-3.5 g protein/kg, and 35-60 mg phenylalanine/kg. Introduce breastmilk or infant formula as needed to stabilize blood phenylalanine levels.
  2. Monitor blood phenylalanine and tyrosine weekly.
  3. Measure weight weekly. Monitor growth rate.
  4. Monitor intake: daily log of formula/breastmilk intake. Monitor phenylalanine, protein, and energy intakes.
  5. Document state of health and wellness.

 

Objective 6: Continue to monitor when blood phenylalanine levels have stabilized (4 serial determinations) at treatment goal (1-6 mg/dL).

  1. Measure blood phenylalanine and tyrosine levels monthly.
  2. Measure weight and length monthly. Monitor growth rate.
  3. Monitor intake: daily log of formula/breastmilk intake. Monitor phenylalanine, protein, and energy intakes.
  4. Document state of health and wellness.

 

Objective 7: Adjust treatment as necessary during illness.

  1. Adjust phenylalanine intake as necessary.
  2. Monitor blood phenylalanine levels more frequently until levels are stabilized.