Bestimmung von Amifostin im Serum mittels eines einfachen Phosphat Tests: Anwendung für drug-monitoring in der Chemotherapie

摘要

The thiophosphoric ester amifostine represents the prodrug of the cytoprotective agent ethiol, which is considered to protect normal cells in contrary to tumor cells due to higher activity of alkaline phosphatase inside the cells. A simple phosphate kit was used for the determination of ethiol by measuring the amount of inorganic phosphate in serum during a 15 min infusion of amifostine. Analysis of serum samples of 24 patients (collected before, 10 and 15 min during administration) showed an increase of phosphate from 0.628 ± 0.155 mmol to 1.160 ± 0.264 mmol after 10 min (p < 0.001) and to 1.081 ± 0.248 mmol after 15 min of infusion (p < 0.0001). This increase of phosphate represents the concentration of ethiol in serum, as 1 mmol of amifostine contains 1 mmol inorganic phosphate. This simple and rapid method can be used for monitoring ethiol indirectly in human blood samples during infusion.