Does combined single intravenous injection of doxorubicin and verapamil have any influence on hemodynamic parameters in rabbits?

The hemodynamic effects of a single intravenous injection of doxorubicin (DXR) in a dose of 3 mg/kg, verapamil (Vp) in a dose of 0.2 mg/kg and combined administration of the same doses of both drugs in rabbits were investigated. Cardiac output (CO), stroke volume (SV), heart rate (HR), mean arterial pressure (MAP) and total peripheral resistance (TPR) were estimated before and repeated in the 1st, 15th, 30th, 45th, 60th, 90th and 120th minute after injection of the drugs. It was found that administration of Vp after DXR or DXR after Vp produced significant decrease of MAP. However, no significant changes of CO, SV, HR and TPR in rabbits treated with DXR and Vp were noted. Rhythm disturbances occurred in animals receiving DXR or DXR with Vp. The obtained results indicate the need for further experimental studies before the introduction of combined treatment with DXR and Vp to cancer patients.