Published: November 2017 in Journal of Inherited Metabolic Diseases
Article: Daily variation of blood NTBC concentrations and formation of succinylacetone
Authors: NS Kienstra, HE van Reemst, WG van Ginkel, A Daly, A MacDonald, JGM Burgerhof, P de Blaauw, PJ McKiernan, MR Heiner-Fokkema, FJ van Spronsen
Contact: Nienke Kienstra en Hannah van Reemst
Link to article: ncbi.nlm.nih.gov
Aside from tyrosine and phenylalanine, the previously mentioned study of van Dam et al also included measurements of blood NTBC and succinylacetone concentrations. NTBC is a drug that blocks the tyrosine degradation and thus prevents the formation of toxic metabolites such as succinylacetone.
Previous research suggested that NTBC degraded very slowly. Therefore it was thought that NTBC could be given once a day instead of twice daily. In this research project we investigated changes in NTBC concentrations during the day and its association with the presence of succinylacetone. This project was financed and made possible by the Tyrosinemia Foundation (previously known as Stichting Joris). We compared patients taking NTBC once and twice daily.
We were interested in whether NTBC concentrations stayed high enough during the day in both treatment groups in order to supress formation of succinylacetone adequately. We found that NTBC concentrations were more stable when NTBC was given twice daily instead of once a day. In addition, there is no detectable succinylacetone in the blood dwhen NTBC is given twice daily. These findings need to be investigated further as a prior study has shown that patients have adequate NTBC concentrations when it is taken once daily.