Initiating Pancreatic Enzyme Replacement Therapy (PERT) — Clinical Examples for PERT Dosing — Clinical Pathway: All Settings

Clinical Pathway for Pancreatic Enzyme Replacement Therapy (PERT) in Children with or at Risk for Exocrine Pancreatic Insufficiency (EPI)

Clinical Examples for PERT Dosing

Case 1: Infant s/p surgery starting on tube feeds

Infant is a 3.7 kg, 25 day old male with cystic fibrosis, pancreatic insufficiency, homozygous F508del CFTR mutation, meconium ileus and jejunal atresia at birth requiring exploratory laparotomy, evacuation of meconium, resection of small bowel atresia, stapled anastomosis and appendectomy. Initially started on parenteral nutrition due to NPO status and was started on continuous NG feeds of human milk at 5ml per hr. The feeds have been titrated up to 15 ml/hr this morning.

PERT: continuous feeds

For this infant, we use a non-enteric coated enzyme, Viokace, crushed and added to the formula or breast milk before infusing into the child. PERT would be required when the infusion rate is 15 ml/hr and would be dosed based on the amount of fat in the enteral formula. At this flow rate, typically, 4 hrs of breast milk or formula would be placed in a syringe pump, and the calculation would be based on the amount infused over 4 hrs.

  • Breast milk contains an estimated average of 3.5 g fat/100 mL
    60 ml breast milk contains 2.1 g fat
  • Viokace starting dose range 1800-2200 lipase units/g fat
    Multiply 2.1 g fat x 2000 lipase units/g fat = 4200 lipase units
  • Viokace comes in 10,440 lipase unit tablet (half a tablet = 5220 lipase units and provides 2485 lipase units/gram fat, which is within dosing range of 500-4000 lipase units/g fat)
  • Order a half tablet, crushed and added to 60 mL breast milk; Viokace Patient Instructions
  • Start skin precautions; barrier cream to perianal area and monitor for irritation

PERT: oral feeding

PERT would be recommended when volume of oral breast milk feeding reaches 60 mL.

  • Starting dose would be 3000 lipase units/feed
  • 3000 lipase units/kg/feed divided by 3.7 kg = 810 lipase units/kg which is within starting dose range of 500-2500 lipase units/kg/feed
  • Start skin precautions; barrier cream to perianal area and monitor for irritation

PERT: oral feeds and continuous enteral feeding

If infant starts oral feeds while on continuous enteral feeding, child would need to start additional PERT to cover fat consumed orally. The Viokace used with the enteral formula will not cover oral feeding. PERT would be initiated at 3000 lipase units/feed starting at 60 mL of breast milk or formula as in the oral feeding example.

Case 2: Toddler on oral feeds who needs dose titration

Fourteen-month-old female with cystic fibrosis, pancreatic insufficiency, GER, history of meconium ileus and current weight of 9.2 kg. She has been taking pancrelipase consistently with meals, but her rate of weight gain has slowed, and she has had some intermittent malodorous stools between clinic visits. She takes Creon 6000, 2 capsules with meals and 1 capsule with snacks. She eats 3 meals and 2 snacks daily and gets a total of 8 Creon 6000 capsules daily. Enzymes are being administered and stored according to instructions. It is recommended to increase her pancrelipase dose to improve absorption.

  • Current meal dose: 1304 lipase units/kg/meal (dose range 500-2500 lipase units/kg/meal)
  • Current daily dose: 5217 lipase units/kg/day (within max dose range of 10,000 lipase units/kg/day)

Recommended first titrate dose increase by one capsule per meal to 3 capsules. Based on her current intake pattern, she would then receive 11 capsules daily.

  • New meal dose: 1956 lipase units/kg/meal (dose range 500-2500 lipase units/kg/meal)
  • New daily dose: 7173 lipase units/kg/day (within max dose range of 10,000 lipase units/kg/day)
  • Max daily dose: 15 Creon 6000 capsules total daily (10,000 lipase units/kg/day)
  • If diet history indicates high-fat snack or if weight gain is suboptimal, she might require an additional Creon 6000 capsule with each snack. Pancreatic Enzymes for Infants and Children

Case 3: Child on oral and enteral feeds dose calculation

6 yr old male with Shwachman–Diamond syndrome, pancreatic insufficiency, feeding problems, on g-tube overnight supplemental feeding with a weight of 19 kg. Determine enzyme dosing for both oral and enteral feeds. Current meal pattern is 3 meals and 2 snacks. Current enteral feeding regimen is Peptamen Junior. 1.5 at 98 mL/hr for 7.6 hrs, provides a total of 750 mL daily.

Oral enzyme dose will be based on weight. He can swallow capsules and his insurance formulary prefers he use the Zenpep brand. The Zenpep 5,000 capsule would be easy for him to swallow and allow flexible dosing for meals and snacks if needed.

  • Starting dose would be 500 lipase units/kg/meal. 19 kg x 500 lipase units/kg/meal = 9,500 divide by 5,000 lipase unit capsule = 2 capsules/meal. Snack dose would be half of the meal dose or 1 capsule.
  • Meal dose: 526 lipase units/kg/meal (dose range 500-2500 lipase units/kg/meal)
  • Daily dose based on potential 3 meals and 2 snacks = 8 capsules: 2105 lipase units/kg/day (within max dose range of less than 10,000 lipase units/kg/day)
  • Max daily dose: 38 capsules Zenpep 5,000 daily (10,000 lipase units/kg/day)
  • Titrate dose by 5,000 lipase unit capsules as needed based diet history, growth and signs and symptoms of malabsorption.

Enteral feeds

There are 3 methods of delivering enzymes for enteral feeding.

  1. The preferred method for children aged 2 yrs and older would be the RELiZORB in line lipase cartridge. Child receives 750 mL, the dose would be 2 cartridges (1 lipase cartridge for every 500 mL of formula). The cartridges would be connected end to end in tandem and would not have to be changed after 500 mL. RELiZORB (Immobilized Lipase) Cartridge Patient Instructions
  2. If RELiZORB is not available, the second preferred method would be to crush Viokace and add to the entire volume of tube feeding before enteral infusion. The dose would be calculated based on grams of fat in the formula. This child does not have cystic fibrosis and thus can be started at the lower range of dosing of Viokace.
    To calculate dose:
    Peptamen Jr 1.5 contains 17 g fat/250 mL. 750 mL Peptamen Jr. 1.5 contains 51 grams fat. 51 grams fat x 500 lipase units/gram fat = 25,500 lipase units divided by 20,880 lipase unit tablet of Viokace = 1.2 tablets, which would be rounded to 1.5 tablets crushed and added to volume of tube feeding. Viokace Patient Instructions
    Neither Viokace or RELiZORB are calculated into the total lipase units allowed for the day.
  3. If parents are unable to get RELiZORB or to crush Viokace and add to tube feeds, the last option would be to give him a meal enzyme dose (2 capsules of Zenpep 5,000) at the start of his tube feeds and if weight gain poor, then to add 1 capsules of Zenpep 5,000 at the end of the tube feeds.