Lethal quercetin-digoxin interaction in pigs.
Digoxin is a popular cardiac glycoside with very narrow therapeutic range. Quercetin is an ubiquitous antioxidant flavonoid. Digoxin is a substrate of P-glycoprotein (P-gp), a multi-drug efflux transporter, and quercetin was reported to be a modulator of P-gp. The aim of this study was to investigate the effect of quercetin on the absorption and disposition of digoxin in pigs. Pigs were orally given digoxin (0.02 mg/kg) with and without quercetin in crossover designs. The blood was collected via jugular vein and fluorescence polarization immunoassay was used to determine the serum concentration of digoxin. The pharmacokinetic parameters were calculated using WINNONLIN. The paired Student's t-test was used for statistical comparison. The coadministration of 50 mg/kg quercetin unexpectedly resulted in sudden death of two among three pigs within 30 min after digoxin administration. The coadministration of 40 mg/kg quercetin significantly elevated the Cmax of digoxin by 413% and increased the AUC0-t by 170%. The results indicated that a very serious pharmacokinetic interaction occurred between quercetin and digoxin. The concomitant administration of digoxin and quercetin or quercetin-containing herbs and dietary supplement should be avoided.
Wang
Yao-Horng
YH
Institute of Pharmaceutical Chemistry, China Medical University, Taichung, Taiwan.
Chao
Pei-Dawn L
PD
Hsiu
Su Lan
SL
Wen
Kuo-Ching
KC
Hou
Yu-Chi
YC
D000818:Animals; D019540:Area Under Curve; D001711:Biotransformation; D002316:Cardiotonic Agents / Q000097:blood / Q000493:pharmacokinetics / Q000633:toxicity*; D004077:Digoxin / Q000097:blood / Q000493:pharmacokinetics / Q000633:toxicity*; D007202:Indicators and Reagents; D007408:Intestinal Absorption; D008297:Male; D011794:Quercetin / Q000494:pharmacology*; D013552:Swine; D014018:Tissue Distribution
D002316:Cardiotonic Agents; D007202:Indicators and Reagents; D004077:Digoxin; D011794:Quercetin