Possible Interaction: Fentanyl and Quinidine

“ Quinidine increased oral fentanyl plasma C(max) (0.55 +/- 0.19 vs. 0.21 +/- 0.1 ng/mL) and AUC (1.9 +/- 0.5 vs. 0.7 +/- 0.3 ng*h*mL(-1)) (both p < 0.05) but had no effect on apparent elimination.”

“ Quinidine … oral fentanyl (3.4 +/- 1.3 vs. 2.3 +/- 1.3 mm, p< 0.05), commensurate with increases in plasma concentrations, but concentration-effect relationships … transfer between plasma and effect compartment (k(e0)) (1.9 +/- 1.0 vs. 3.6 +/- 2.6 h(-1)) were not significantly different.”