hexamethonium , ouabain , caffeine and isoproterenol had no effect on this rate , while alprenolol , metoprolol , oxprenolol , propranolol , timolol , pindolol , lidocaine , mexiletine , 17-n-pentyl-sparteine , tolazoline , quinine , quinidine , cinchonine and cinchonidine inhibited the in vitro reaction competitively .
C0034417
quinine
C0034414
quinidine