Efficacy and Safety of Two Salts of Trientine in the Treatment of Wilson's Disease.

BACKGROUND

Wilson's disease (WD) is one of the few genetic disorders that can be successfully treated with pharmacological agents. Copper-chelating agents (D-penicillamine and Trientine salts) and zinc salts have been demonstrated to be effective. There are two salts of trientine. Trientine dihydrochloride salt (TETA 2HCL) is unstable at room temperature and requires storage at 2-8 °C. Trientine tetrahydrochloride (TETA 4HCL) is a more stable salt of trientine that can be stored at room temperature. No comparative study between both of the salts of trientine has been performed to date. As the two chemical forms were available in France between 1970 and 2009, we conducted a study to evaluate their efficacy and safety profiles.

METHODS

This retrospective cohort study was conducted by reviewing data from the national WD registry in France. Forty-three WD patients who received TETA 2HCL or TETA 4HCL monotherapy for at least one year until 2010 were included. The primary endpoints were hepatic and neurological outcomes. Secondary endpoints were the events leading to a discontinuation of medication.

RESULTS

Changes in medication were common, leading to the analysis of 57 treatment sequences of TETA 4HCL or TETA 2HCL. The mean duration of treatment sequence was significantly longer in the TETA 4 HCL group (12.6 years) than in the TETA 2HCL group (7.6 years) ( = 0.011). Ten patients experienced both trientine salts: eight stopped TETA 4 HCL (six had a hepatologic phenotype and two had a neurological phenotype) because this treatment was not available anymore (mean duration 7.4 years). Three of these patients already experienced TETA 2 HCL before the sequence. Two patients with a hepatologic phenotype (one had a previous sequence of TETA 4 HCL before) stopped TETA 2 HCL because of cold storage issues (mean duration 42.8 years). The total number of sequences was 57. All of the patients were clinically stable. No difference in efficacy was detected. Both treatments were well tolerated, except for a case of recurrence of lupus erythematosus-like syndrome in the TETA 2HCL group. The major reason for interruption of TETA 4HCL was due to a discontinuation in production of this salt. The reasons for stopping TETA 2HCL were mainly due to adherence issues largely attributed to the cold storage requirement.

CONCLUSIONS

The two salts of trientine were effective in treating patients with WD. However, interruption of TETA 2HCL was frequent, linked to the cold storage requirement. As adherence to treatment is a key factor in the successful management of WD, physicians need to be even more vigilant in detecting adherence difficulties in patients receiving treatment with TETA 2HCL.