title: Digoxin-interactions in man: spironolactone reduces renal but not biliary digoxin clearance.
abstract: The possibility of an inhibitory effect of spironolactone on the biliary clearance of digoxin has been investigated in 6 healthy subjects. Plasma clearance and the renal and biliary clearance of digoxin were determined twice at steady state (digoxin 0.5 to 1 mg.d-1 p.o. for 6 days), alone or in combination with spironolactone 200 mg daily, after an intravenous dose of digoxin (0.7 x oral dose) on Day 7. Plasma and urine were collected for 48 h. Biliary clearance of digoxin was determined on Day 8 by a duodenal perfusion technique. During spironolactone treatment plasma digoxin clearance tended to be lower (255 vs 224 ml/min; P = 0.057) and renal clearance significantly lower (166 vs 144 ml/min), while the biliary clearance of digoxin remained unchanged (106 vs 103 ml/min). Thus, spironolactone reduced the renal clearance of digoxin by an average of 13%, without affecting its biliary clearance.
authors.affiliation: Department of Clinical Pharmacology, Huddinge University Hospital, Karolinska Institute, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Hedman
authors.forename: B
authors.initials: B
authors.lastname: Angelin
authors.forename: A
authors.initials: A
authors.lastname: Arvidsson
authors.forename: R
authors.initials: R
authors.lastname: Dahlqvist
mesh_terms: D000328:Adult; D001646:Bile / Q000378:metabolism; D004077:Digoxin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D004347:Drug Interactions; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate / Q000187:drug effects; D013148:Spironolactone / Q000494:pharmacology*
chemical_list: D013148:Spironolactone; D004077:Digoxin