RT Journal Article SR Electronic T1 Effect of quinidine on the renal clearance of digoxin in the presence of low and high serum digoxin concentrations. JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 49 OP 51 VO 222 IS 1 A1 D R Clohisy A1 A P Quintanilla A1 T P Gibson YR 1982 UL http://jpet.aspetjournals.org/content/222/1/49.abstract AB The effect of an infusion of quinidine, 180 micrograms/kg/Min (base) on the fractional clearance of digoxin (CDIG/Cin) was studied in saline volume-expanded dogs given a constant infusion of digoxin of either 0.0067 micrograms/kg/min (low dose) or 0.120 micrograms/kg/min (high dose). CDIG/CIN decreased 28% from 1.42 +/- 0.36 during control periods to 1.01 +/- 0.03 (P less than .05) with quinidine in dogs given the low dose. In dogs given the high dose of digoxin, CDIG/CIN decreased 22% from 0.76 +/- 0.17 to 0.59 +/- 0.05 (p less than .05) with quinidine. It is concluded that quinidine reduces CDIG/CIN. High doses of digoxin also reduce CDIG/CIN. Inasmuch as quinidine reduces CDIG/CIN to the same extent in the presence of low or high dose digoxin, the effect of quinidine would appear to be mediated through a mechanism different from that of digoxin.