How Trientine and Penicillamine Work: Cool Visual Study

FT Kirk et al. Hepatology 2024; 79: 1065-1074. Open Access! Effects of trientine and penicillamine on intestinal copper uptake: A mechanistic ⁶⁴Cu PET/CT study in healthy humans

Background: Trientine (TRI) and D-penicillamine (PEN) are used to treat copper overload in Wilson disease. Their main mode of action is thought to be through the facilitation of urinary copper excretion. In a recent study, TRI was noninferior to PEN despite lower 24-hour urinary copper excretion than PEN.

Key findings and conclusions:

• “TRI inhibits intestinal copper absorption, in addition to its cupriuretic effect. In contrast, PEN has modest effects on the intestinal copper absorption. This may explain why TRI and PEN are equally effective although urinary copper excretion is lower with TRI.”
• ” TRI (n=8) reduced hepatic ⁶⁴Cu activity 1 hour after ⁶⁴Cu dose from 6.17 (4.73) to 1.47 (2.97) standard uptake value, p<0.02, and after 15 hours from 14.24 (3.09) to 6.19 (3.43), p<0.02, indicating strong inhibition of intestinal ⁶⁴Cu absorption.”
• “PEN (n=8) slightly reduced hepatic standard uptake value at 15 hours, from 16.30 (5.63) to 12.17 (1.44), p<0.04.”
• “The study questions whether the same therapeutic targets for 24-hour urinary excretion apply to both drugs.”

My take: This is a cool study!

Related blog post: Practice Guidance on Wilson Disease (AASLD) (2023)