[Irritability study of paclitaxel in rabbit ear vein]

The vascular irritability of paclitaxel at concentrations of 0.6 and 1.2 mg/ml was examined using the rabbit ear vein by a single intravenous drip in comparison with its vehicle consisting of ethanol and Cremophor, and physiological saline. The results were as follows: 1. Slight to moderate congestion was macroscopically observed around some injection sites of the retroauricular veins infused by paclitaxel, the vehicle and saline. Its incidence and severity caused by paclitaxel was not so much different from that caused by the vehicle or saline. 2. Histopathological findings at the injection sites of the rabbits treated with paclitaxel consisted of vascular and perivascular changes, as well as alterations of the dermis and epidermis. These changes were severer than those brought by saline, and dose-dependent in their incidence and severity. Moreover, the lesions caused by paclitaxel at a concentration of 1.2 mg/ml were correspondent to those caused by the vehicle. Based on these results, the microscopic examinations suggested that the vascular irritability of paclitaxel might be attributable to administration of the vehicle.