Distribution and metabolism of daunomycin, adriamycin, and N-acetyldaunomycin in the Syrian golden hamster

After intravenous administration, daunomycin (50 mg/kg), adriamycin (25 mg/kg), or N-acetyldaunomycin (50 mg/kg) disappeared rapidly from the blood of Syrian golden hamsters. The plasma half-life was determined to be 12.5 minutes for adriamycin, 15.0 minutes for daunomycin, and 22.0 minutes for N-acetyldaunomycin. Urinary excretion of the three compounds was detected within 5 minutes of injection. A significant proportion of the total dose of each compound was rapidly taken up in the heart, lung, liver, and kidney tissues. Between 55 and 69% of the daunomycin and 80–85% of the N-acetyldaunomycin total dose was recovered unchanged from these tissues for up to 30 minutes. During the first 15 minutes after administration of adriamycin 56–74% of the parent compound was recovered from the heart, lung, liver, and kidney tissues; however, after 30 minutes only 10–12% of the total injected dose could be accounted for in these tissues. Formation of an aglycone metabolic product was detected in the heart, lung, liver, kidney, and urine within 5 minutes after injection of adriamycin or daunomycin. Both compounds were metabolized to the same extent (10–15%), but a significantly higher percentage of the total recovered adriamycin rather than the daunomycin aglycone was found in heart and lung tissue at all time intervals. In contrast, only 2% of the injected dose of N-acetyldaunomycin was converted to the aglycone within 30–60 minutes.