Comparison of action of beta-methyldigoxin and digoxin utilizing systolic time intervals

The temporal course of orally and parenterally administered beta-methyldigoxin and orally administered digoxin was studied in a series of twenty patients who suffered from congestive heart failure due to a variety of causes. The parameters studied mainly were systolic time intervals. The incontrovertible conclusion was that beta-methyldigoxin acts almost immediately when administered intravenously and after 20 minutes when given by mouth. The peak action, however, by either route of administration was evident at the end of 45 minutes. Viewed in comparison, digoxin after oral administration acted after 2 hours, reaching its peak action after 8 hours. It must be admitted, however, that the magnitude of the response to both drugs, as measured by significant reduction in PEP/LVET ratio and increase in ejection fraction, was the same. Our study suggests that beta-methyldigoxin is as effective an inotropic agent as digoxin, with an additional characteristic of total and rapid gastrointestinal absorption, predictable and rapid onset and much shorter time interval for its peak action.