Therapeutic digoxin level in chylous drainage with no detectable plasma digoxin level.

A patient receiving digoxin for long-standing congestive heart failure developed a chylothorax following removal of an infected aortic graft. Drainage of the chylothorax resulted in plasma digoxin concentrations which were near zero while the digoxin levels in the chylous drainage fluid were therapeutic. The sequestration of even low lipid-soluble drugs, such as digoxin, in chyle should be recognized to prevent subtherapeutic plasma levels in patients undergoing chylothorax drainage.