REDUCTION OF ADRIAMYCIN CARDIOTOXICITY BY ENOXIMONE

Several non catecholamine, non glycoside cardiotonic drugs have been d escribed recently. New compounds include amrinone, sulmazole, milrinon e and pimobendan. In an attempt to alleviate or prevent anthracycline toxicity, we have reported that these compounds reduce the negative ef fects of adriamycin, 4-epiadriamycin and esorubicin in isolated guinea pig atria. The present study reports the effects of a new cardiotonic agent:enoximone. Enoximone was administered after adriamycin (100 mu g/ml) on the isolated and spontaneously beating atria, and on electric ally driven left atria of guinea pig-in normodynamic and hypodynamic c onditions. Exposure for 60 minutes to the antitumor drug causes a depr ession of contractile force (g) and its derivative versus time (dF/dt, as maximal rate of contractile force). The negative effects of adriam ycin are antagonised by enoximone (100, 200 mu g/ml).