title: Apparent quinidine-induced digoxin toxicity after withdrawal of pentobarbital: a case of sequential drug interactions.
abstract: Accelerated quinidine metabolism was observed in a 94-year-old woman also receiving daily doses of digoxin and pentobarbital sodium. Discontinuation of pentobarbital produced a sharp increase in serum digoxin concentrations coupled with symptoms highly suggestive of digoxin toxicity. Associated with these findings was 3.8-fold increase in quinidine half-life. These data seemed consistent with an interaction between quinidine and digoxin that was precipitated by pentobarbital withdrawal.
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy; D004077:Digoxin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D004347:Drug Interactions; D005260:Female; D006207:Half-Life; D006801:Humans; D008099:Liver / Q000378:metabolism; D010424:Pentobarbital / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D011802:Quinidine / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism* / Q000627:therapeutic use; D012893:Sleep Wake Disorders / Q000188:drug therapy
chemical_list: D004077:Digoxin; D010424:Pentobarbital; D011802:Quinidine