Toxicologic analysis of 35 drugs in post mortem human blood samples with focus on antihypertensive and antiarrhythmic drugs

Antiarrhythmic and antihypertensive drugs are frequently encountered in post mortem analysis, and the question may arise as to whether they were administered in therapeutic doses, and if they were taken in accidental, intentional, or suicidal overdose scenarios. Therefore, a novel analytical method was developed and validated for the quantification of 35 drugs with toxicological relevance, including antihypertensive and antiarrhythmic drugs (ajmaline, amlodipine, amiodarone, atenolol, bisoprolol, carvedilol, clonidine, desethylamiodarone, diltiazem, donepezil, doxazosin, dronedarone, esmolol, flecainide, lercanidipine, lidocaine, metoprolol, nebivolol, nimodipine, pindolol, prajmaline, propafenone, propranolol, sotalol, urapidil, and verapamil), as well as other medications commonly found in combination (sildenafil, tadalafil, atorvastatin, clopidogrel, dapoxetine, memantine, pentoxifylline, rivastigmine, and ivabradine). The method enables simultaneous identification and quantification in blood samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Validation exhibited excellent linearity across the concentration range for all analytes. Precision and accuracy were within acceptable limits, with bias and relative standard deviation (RSD) values consistently below 9 % and 10 %, respectively. Selectivity and specificity assessments confirmed the absence of any interference from contaminants or co-extracted drugs. The method demonstrated very high sensitivity, with limits of detection (LOD) as low as 0.01 ng/ml and limits of quantification (LOQ) as low as 0.04 ng/ml. Extraction recovery exceeded 57.5 % for all analytes except atenolol, and matrix effects were <17 % for all analytes except pindolol. Processed sample stability evaluations revealed consistent results with acceptable deviations for all analytes. In addition, the method was specifically tested for the use in post mortem analysis. The applicability of our method was demonstrated by the analysis of two authentic human autopsy blood samples.