Through extensive pharmacological development, we have developed and validated a new method to measure the concentration of atorvastatin and all primary metabolites using modern mass spectrometry directly in blood. For the first time, we demonstrated that the sum of the parent compound and metabolites remained stable at room temperature for several days. This, combined with documented short analysis time and valid pilot results, indicates that the method can be used to measure statin levels in blood samples in clinical practice, such as in a doctor’s office or during hospital follow-up. We have developed a similar method for simvastatin.
To study adherence to statin therapy using the new method, we conducted a pharmacokinetics study (48 coronary patients), STAT-MON 1, where we defined clinical decision limits based on statin concentrations in blood. These limits distinguish patients with high adherence (i.e., taking the medication as prescribed) from those with reduced adherence (i.e., inconsistent tablet intake) and those who do not take the medication at all (very low/no adherence). The principle used to develop clinical decision limits for adherence has potential applicability to other medications.
In spring 2021, we conducted a new pharmacokinetics study (60 patients), STAT-MON 2, where we validated the decision limits we developed.