VerapamilCalcium Channel BlockersDiltiazemP-GlycoproteinDrug ResistanceCalciumNitrendipineAnti-Arrhythmia AgentsNicardipineDrug InteractionsDaunorubicinCinnarizineQuinidineDogsDose-Response Relationship, DrugFlunarizineDrug Resistance, MultipleRhodamine 123Anesthesia, IntratrachealBepridilCalcium ChlorideCalcium ChannelsStereoisomerism