The Influence of Verapamil on Cardiac Uptake of I-123 Labelled Anthracyclines in Rabbits

Since verapamil has been shown to increase cellular concentrations of anthracyclines in resistant tumor cells, this study was designed to investigate the impact of verapamil on myocardial accumulation of I-123 labelled doxorubicin (DOX) and iodo-doxorubicin (IDOX) in rabbits and to estimate the risk of increasing anthracycline-related cardiotoxicity. Cardiac accumulation of both DOX and IDOX, calculated by scintigraphic means, neither confirmed major differences due to prior administration of verapamil nor an increased risk of cardiotoxicity of DOX and IDOX in combination with verapamil, respectively.