Plasma digoxin concentrations and digoxin toxicity in hospital patients.

Studies were made on io8 subjects on routine oral maintenance digoxin therapy. Twenty-two were found to have eidene of digoxin toxicity. The range of plasma digoxin concentrations in these subjects is recorded (1.38 SD+oO77 ng/ml). The subjects with evidence of toxicity are shown to have significantly higher plasma digoxin concentrations (3.36 SD I2o ng/ml) though there is some overlap with the non-toxic group. The subjects with toxicity are shown to be sub- stantially older and to have a much higher incidence of raised blood urea. The implications of these observations are discussed.