Effect of phenobarbital on serum digoxin concentration during administration of liposome-entrapped digoxin: an examination of possible drug interactions.

The effect of concomitant administration in normal dogs of phenobarbital with either oral free digoxin, oral liposome-entrapped digoxin were examined. Phenobarbital induced a transient rise in serum digoxin concentrations during concomitant administration of oral free digoxin. Phenobarbital did not affect serum concentrations of either oral or intravenous liposome-entrapped digoxin. The results suggest that liposome-entrapped digoxin may be protected against transient fluctuations in serum concentrations during concomitant administration of phenobarbital. The protective liposome encapsulation of digoxin may prevent digoxin toxicosis in dogs induced by elevations in serum digoxin concentrations during concomitant administration of phenobarbital.