Pharmacokinetics of dicloxacillin in serum and aortic wall during aneurysmal surgery

Twenty-one patients undergoing elective surgery for abdominal aortic aneurysm were randomly assigned to receive 2 grams of dicloxacillin as an intravenous infusion either at the induction of anaesthesia, 3 hours or approximately 6 hours before surgery. Samples from serum and aortic tissue were simultaneously obtained so that antibiotic levels could be compared as a function of time. High concentrations of dicloxacillin in serum and aortic tissue were present already shortly after infusion and active levels were maintained in aortic tissue for approximately six hours. The kinetics of dicloxacillin was similar in serum and aortic tissue. These results support the need for antibiotic administration shortly before surgery to ensure adequate tissue levels of antibiotics.