PHARMACOKINETICS OF ALCURONIUM IN ELDERLY PATIENTS UNDERGOING TOTAL HIP REPLACEMENT OR AORTIC RECONSTRUCTIVE SURGERY

The pharmacokinetic behaviour of alcuronium was studied in threepatients undergoing resection of an aortic aneurysm, and inanother two patients undergoing total hip replacement (groupI). A control group of five elderly patients undergoing relativelyminor surgery was included (group II). In group I patients,the values of the pharmacokinetic parameters such as plasmaclearance, elimination half-life and the apparent volume ofdistribution of the drug were found to be comparable to thoseobtained in normal young patients in previous studies. The groupII patients, however, were found to have a prolonged eliminationhalf-life as a result of reduced plasma clearance, possiblyan age-related effect. The differences between these two groupsof patients may be explained by the differences in the extentof haemorrhage and fluid replacement or changes in blood circulation,or both. However, alcuronium must still be used cautiously inboth groups of patients, especially in the light of a recentfinding that patients undergoing aortic reconstructive surgeryhave a high frequency of functional renal failure after operation.