摘要 |
The invention relates to therapeutic drug monitoring (TDM) by mass spectrometry, particularly to the monitoring of immunosuppressant levels in blood of patients with transplanted organs. A liquid phase extraction procedure reproducibly extracts the therapeutic drug molecules from whole blood and mass spectrometric analysis on MALDI instruments, with a matrix substance for highest sensitivity and special sample deposition procedure for a reproducible ionization of the therapeutic drug molecules. Suitable internal standard substances added to the blood in exact amounts ensure a correct absolute quantification. The method is particularly suitable for immunosuppressants belonging to the class of macrocyclic lactones (sirolimus, tacrolimus, everolimus) and cyclic polypeptides (cyclosporin A), and even works as a multiplex method for all four immunosuppressants simultaneously. |