Cardiovascular Medication Stability in Urine for Non-Adherence Screening by LC-MS-MS

Abstract

Biochemical testing in urine is a powerful new tool in the investigation of non-adherence to cardiovascular medications Drug testing using liquid chromatography tandem mass spectrometry (LC-MS-MS) is the mainstay of the laboratory test but may be subject to pre-analytical factors that could impact on test results. The stability of cardiovascular medications in urine is one such factor that has not been fully explored in non-adherence testing and has the potential to result in patients appearing falsely non-adherent to their therapy. The stability of 29 cardiovascular medications in patients' urine samples were assessed at room temperature (RT) and at -80°C using a LC-MS-MS screening method. All drugs and drug metabolites were found to be stable under the storage conditions studied. The findings imply that the medication stability in urine samples does not have any impact on non-adherence results and thus allowing samples to be taken and transported without the need for specialist sample handling procedures. The stability of cardiovascular drugs in urine samples will allow adherence testing to be utilized more widely into routine clinics and research.