Comparison of pharmacokinetics of M1, M2, M3, and M4 after intravenous administration of DA-125 or ME2303 to mice and rats. New adriamycin analogues containing fluorine

Pharmacokinetic changes in drugs during protein-calorie malnutrition: correlation between drug metabolism and hepatic microsomal cytochrome p450 isozymes

The rats with protein-calorie malnutrition (PCM, 5% casein diet for a period of 4-week) were reported to exhibit 60 and 80% suppression in the hepatic microsomal cytochrome P450 (CYP) 1A2 and CYP2C11 levels, respectively, and 40-50% decreases in CYP2E1 and CYP3A1/2 levels compared to control (23% casein diet for a period of 4-week) based on Western blot analysis. In addition, Northern blot analysis showed that CYP1A2, CYP2E1, CYP2C11, and CYP3A1/2 mRNAs decreased in the state of PCM as well. Hence, pharmacokinetic changes of the drugs in rats with PCM [especially the area under the plasma concentration-time curve from time zero to time infinity (AUC) changes of metabolite(s)] reported from literatures were tried to explain in terms of CYP isozyme changes in the rats. Otherwise, the time-averaged nonrenal clearance (CL NR) of parent drug was compared. Pharmacokinetic changes of the drugs in other types of malnutritional state, such as kwashiorkor and marasmus, in both human and animal models were also compared. The drugs reviewed are as follows: diuretics, antibiotics, anticancer agents, antiepileptics, antiarrythmics, analgesics, xanthines, antimalarials, and miscellaneous.

Pharmacokinetics of four metabolites of DA-125, a new anthracycline antineoplastic agent after single and multiple intravenous administration to rats

The tissue distribution, and biliary and urinary excretion of four metabolites (M1-M4) of a new anthracycline antineoplastic agent (DA-125) were compared after single and multiple (7 consecutive days) intravenous (i.v.) administration to rats. The mean pharmacokinetic parameters of M1, such as area under the plasma concentration-time curve (AUC: 56.4 micrograms/ml vs. 69.0 micrograms min/ml), terminal half-life (t1/2: 3.51 h vs. 3.01 h), total body clearance (Cl: 70.9 ml/min/kg vs. 58.0 ml/min/kg), renal clearance (ClR: 0.193 ml/min/kg vs. 0.336 ml/min/kg) and nonrenal clearance (ClNR: 70.7 ml/min/kg vs. 57.7 ml/min/kg); of M2, such as plasma AUC (39.4 micrograms min/ml vs. 41.9 micrograms min/ ml), t1/2 (6.15 h vs. 7.34 h) and ClR (10.5 ml/min/ kg vs. 13.8 ml/min/kg); and of M4, such as plasma AUC (4.82 micrograms min/ml vs. 6.54 micrograms min/ml) and t1/2 (3.33 h vs 4.02 h), were comparable between single and multiple administrations of DA-125. M3 was detected in plasma for up to 1-5 min, and M3 and M4 were below the detection limit in 24-h urine after both single and multiple administrations of DA-125. M2 was the main metabolite of DA-125 excreted (among M1-M4) in 24-h urine after both single and multiple administrations of DA-125; approximately 12.3% and 20.1% (P < 0.01) of i.v. dosage (expressed in terms of DA-125) was excreted as M2 after single and multiple administrations of DA-125, respectively. Corresponding values for M1 were 0.326% and 0.694% (P < 0.05). The mean levels of M1 (229 micrograms vs. 175 micrograms) and M2 (1330 micrograms vs. 1120 micrograms) excreted in 24-h bile after single and multiple administrations of DA-125 were not significantly different; the percentages of i.v. dosage excreted in 24-h bile as M1 (expressed in terms of DA-125) were 4.83% and 3.58% after single and multiple administrations, respectively. The corresponding values for M2 were 27.8% and 22.5%. M3 and M4 were below the detection limit in 24-h bile after both single and multiple administrations of DA-125. Mean AUAts (area under the amount-time curves from time zero to last measurement time t) (or AUCts-area under the plasma concentration-time curves from time zero until the last measurement time t) of M1-M4 in each tissue after single and multiple administrations of DA-125 were also comparable except in the bone marrow and thymus. The data suggest that 7 consecutive days of i.v. administration of DA-125 (4 mg/kg) to rats does not lead to considerable accumulation of M1-M4 in the tissues, except in the bone marrow and thymus.