The Challenges of Introducing Triheptanoin in a Child with Carnitine Acylcarnitine Translocase Deficiency (CACT)

Background: Triheptanoin is a synthetic medium chain triglyceride (MCT) used in long-chain fatty acid oxidation defects to reduce episodes of hyperammonia and rhabdomyolysis, requirements for high carbohydrate feeds and long-term risks of cardiomyopathy. We report our experience in modular feeding with added triheptanoin and ketones in a child with carnitine acylcarnitine translocase deficiency (CACT).
Aim: To introduce triheptanoin into modular feeds at 25-35% of estimated total energy intake.
Methods: Triheptanoin was initially introduced mixed into an oral modular formula at 10% total energy intake, without success due to refusal. An admission was required where a nasogastric tube was placed and Triheptanoin was introduced initially at 10% of total energy intake and gradually increased by 5% increments to a maximum tolerated amount of 23% total energy intake.
Results: Before introduction of triheptanoin, the patient had persistently elevated ammonia levels outside of illness, high total carbohydrate intake and was requiring 115-150% of estimated energy requirements which was resulting in rapid weight gain. After introduction of triheptanoin, average ammonia levels were lower outside illness, intake of carbohydrate was reduced, calories were able to be decreased to 100% of estimated energy requirements and with this weight stabilised.
Conclusion:
Triheptanoin was incorporated into modular feeds providing 23% of total energy intake. Since the addition of triheptanoin into this patient’s feeds, we have observed lower average ammonia levels outside of illness compared to pre-triheptanoin use and prevention of overfeeding. Total energy intake has reduced we have also observed a reduction in total intake of carbohydrate. We continue to work toward the original goal of 25-30% energy from triheptanoin.