Digoxin concentrations in serum and saliva.

Serum and mixed saliva concentrations of digoxin were measured in 34 hospitalized patients. The mean saliva:serum concentration ratio of digoxin was 1.14 (plus or minus 0.48). Of 20 patients with saliva digoxin concentrations in the range of 0.7 to 1.5 ng/ml, 18 patients had serum concentrations which were within the same range. Saliva offers a convenient and noninvasive means of monitoring the digoxin status of patients.