Interpretation of Post Mortem Serum Levels of Cardiac Glycosides after Suspected Overdosage

Post mortem serum concentrations of cardiac glycosides have been measured in 13 patients who had suddenly died from suspected overdosage of cardiac glycosides. With digoxin, the highest level observed was 71 ng/ml after an intramuscular injection to an infant, whilst levels of 7.2 to 24 ng/ml were found after oral administration to adults. These levels are much higher than the mean therapeutic levels, which were 1.34 ng/ml for optimally digitalised patients and 3.11 ng/ml for those showing evidence of toxicity, although some overlap did occur. Other cardiac glycosides (digitoxin, lanatoside C and deslanoside) showed a similar relationship between concentrations found during therapy and after overdosage.