Distribution of lidocaine and digoxin in heart tissues and aorta following intrapericardial administration.

The distribution of lidocaine and digoxin in myocardial and aorta tissues of open chest anesthetized dogs was studied, following the administration of 30 ml phosphate buffer solution of the drugs in the pericardial cavity where it was kept for increasing time intervals. Transfer of lidocaine (15 or 30 mg) from the solution to myocardium was almost complete within 60 min, while only 50% of digoxin (2 or 50 micrograms) was removed, and this occurred during the first 30 min. Accordingly, the absorption rate of lidocaine by heart tissues increased with time up to 60 min while that of digoxin decreased with time.