CAFFEINE ENHANCES ADRIAMYCIN ANTITUMOR-ACTIVITY IN EHRLICH ASCITES CARCINOMA-BEARING MICE

We examined whether caffeine enhances the antitumor activity of adriam ycin (ADR), in terms of prolonging survival in Ehrlich ascites carcino ma(ascites-type)-bearing mice. After administration of ADR at a dose o f 0.5 mg/kg/d for 5 d together with caffeine (100 mg/kg/d x 5 d), the survival period was increased by 39%. However, caffeine had little eff ect on this ADR induced-prolongation of survival following administrat ion of ADR at 2.0 mg/kg/d for 4 d. Although a significant increase in ADR concentration in the ascites tumor was seen after administration o f ADR at a dose of 0.5 mg/kg, caffeine failed to increase ADR concentr ation in the ascites tumor after administration of ADR at a dose of 2. 0 mg/kg. The effect of caffeine thus appears to be due to its effect o n the tumor distribution of ADR.