Comparison of the Pharmacokinetic Profiles of Trientine Tetrahydrochloride and Trientine Dihydrochloride in Healthy Subjects

Abstract

Background and objective: Wilson disease (WD) is an autosomal recessive inherited disorder of copper metabolism. Chelation of excessive copper is recommended but data on the pharmacokinetics of trientine are limited. The aim of this study was to compare the pharmacokinetics of a new trientine tetrahydrochloride formulation (TETA 4HCl) with those of an established trientine dihydrochloride (TETA 2HCl) salt.

Methods: A randomised single-centre crossover study to evaluate the pharmacokinetics, safety and tolerability of two different oral formulations of trientine (TETA 4HCl tablets vs TETA 2HCl capsules) in 23 healthy adult subjects receiving a single dose equivalent to 600 mg of trientine base was performed.

Results: Following oral administration, the median time to reach maximum plasma concentration (T_max) was 2.00 h (TETA 4HCl) and 3.00 h (TETA 2HCl). The rate (maximum plasma concentration [C_max]) and extent (area under the plasma concentration-time curve from time zero to infinity [AUC_0-∞]) of absorption of the active moiety, trientine, were greater (by approximately 68% and 56%, respectively) for TETA 4HCl than for the TETA 2HCl formulation. The two formulations presented a similar terminal elimination rate (λ_z) and a similar terminal half-life (t_½) for trientine. Differences between TETA 4HCl and TETA 2HCl in the levels of the two main mono- and diacetylated metabolites were less than seen for trientine. For both tested formulations, healthy male volunteers demonstrated higher trientine plasma levels but lower mono- and diacetylated metabolite levels compared with females, with no sex differences in terminal half-life (t_½) observed. Single oral doses of both formulations were safe and well tolerated.

Conclusions: Compared with an identical dose of a TETA 2HCl formulation, the TETA 4HCl formulation provided more rapid absorption of trientine and greater systemic exposure in healthy subjects. Clinical Trials Number EudraCT # 2015-002199-25.