Pharmacokinetic and myocardial enzyme profiles of two administration routes of epirubicin in breast cancer patients.

Abstract

To evaluate the changes in myocardial enzymes and plasma epirubicin concentration following administration by micro-pump (MP) and intravenous drip (ID) in breast cancer patients.11 self-controlled breast cancer patients were recruited for a trial with epirubicin administration by MP for 48 h and by ID for 1 h during 2 cycles of treatment. Plasma concentration of epirubicin at different time points was determined using LC-MS/MS. The levels of myocardial enzymes before and after chemotherapy were compared. Another group of patients receiving epirubicin by ID (n=4) or MP (n=9) were monitored for 4 months.8 patients completed the self-controlled study. The peak concentration of epirubicin in the MP group and the ID group were 21.84±18.85 ng/mL and 294.80±225.54 ng/mL, respectively. The MP group had a longer duration (54~60 h) of plasma concentration of epirubicin not less than 10 ng/mL than that of the ID group (8~14 h). There was significant difference for the alteration of myocardial enzymes before and after chemotherapy (p<0.05) in the ID group, whereas the MP group showed no significant difference (p>0.05). The increased range of myocardial enzymes after chemotherapy in the ID group was larger than that of the MP group and the difference was significant (p<0.05). There is an increased cardiotoxicity in patients receiving epirubicin by ID during the 4-month trial.Administration of epirubicin by MP maintained an effective drug concentration for a longer period of time than by ID. The higher peak plasma concentration observed following epirubicin administration by ID may lead to cardiac toxicity.