Akademik Veri Yönetim Sistemi
SSIEM Annual Symposium, Freiburg, Almanya, 30 Ağustos - 02 Eylül 2022, cilt.45, sa.222288, ss.99
Background: Nitisinone is the potent inhibitor of 4-hydroxyphenylpyruvic acid dioxygenase and is the only effective therapy of tyrosinemia type I with tyrosine restricted diet. The use of nitisinone provides a rapid decrease in succinylacetone concentrations, an increase in tyrosine, and a marked clinical improvement in most patients. Treatment should be started as early as possible and to improve the prognosis, it should be continued in an uninterrupted and continuous dose range. Considering its toxic effects, it is recommended to measure the nitisinone level continuously and adjust the dose with therapeutic drug monitoring. The aim of the treatment is to determine and follow the dose of nitisinone that will suppress the formation of succinylacetone. Case Study / Methods: Dried blood samples for succinylacetone and nitisinone were obtained from patients with tyrosinemia type I during treatment follow-up. succinylacetone and nitisinone analyses were performed by LC-MS/MS with Waters Xevo TQD.Results: When simultaneous succinylacetone and nitisinone levels are evaluated, it is seen that the nitisinone level is at an effective dose in 95.6% (109/114) of the cases and succinylacetone is suppressed (<1 nmol/L). 57.1% (65/114) of the patients were within the recommended range of 20-40 μmol/L for nitisinone in terms of side effects, while 42.9% (49/114) had values above 40 μmol/L. Conclusion / Discussion: Simultaneous monitoring of succinylacetone and nitisinone levels and therapeutic drug monitoring for nitisinone is recommended in the treatment follow-up of type 1 tyrosinemia. The data in our clinic show that nitisinone is used effectively and succinylacetone is suppressed in the vast majority of cases. However, in 42.9% of the cases, where the nitisinone level is higher than the recommendations in the literature and dose adjustment may be considered.Keywords: Tyrosinemia, succinylacetone, nitisinone, therapeutic drug monitoring