Dichlorobenzamil (3',4'-Dichlorobenzamil; L-594881) is an effective Na/Ca exchange inhibitor. Dichlorobenzamil significantly inhibits 45 Ca uptake mediated by reverse Na/Ca exchange in pancreatic islet cells ( IC 50 = 18 μM). Dichlorobenzamil can also block K + channels and voltage-sensitive Ca 2+ channels.