TRANSITION FROM LANOXIN CAPSULES TO LANOXIN TABLETS IN THE DEBILITATED ELDERLY

Lanoxin capsules are more rapidly absorbed than tablets, with less contact by intestinal bacteria capable of metabolizing digoxin to an inactive form. The manufacturer states that the doses of a 0.25-mg tablet and a 0.20-mg capsule are approximately equivalent. Thirty-nine patients had digoxin concentrations determined within three months of the transition from Lanoxin capsules to Lanoxin tablets, and again one month after starting the tablets. Patients were excluded if confounding medications had been changed before the two blood draws or if they had an acute disease exacerbation. The mean digoxin concentration on capsules was 0.92 ± 26 ng/mL. The mean concentration on comparable doses of tablets was 1.03 ± 29 ng/mL, with a mean difference of 0.11 ng/mL. Paired comparisons were significantly higher on the tablets (t = 3.203, p = 0.0028).