PHARMACOKINETICS OF SYSTEMICALLY ADMINISTERED ANTIBIOTICS IN PATIENTS WITH THERMAL-INJURY

Patients who sustain thermal injury may require adjustments of antibiotic dosing because of pharmacokinetic alterations and pathological changes that occur in this patient subset. In general, studies of gentamicin, tobramycin, and amikacin have demonstrated lower elimination half-lives in burn patients than in nonburn patients and healthy volunteers. Other studies have shown a strong correlation between vancomycin clearance and creatinine clearance and the need for higher vancomycin dosages for burn patients than for nonburn patients. Studies of ceftazidime, ticarcillin, enoxacin, and aztreonam have shown increases in the volume of distribution or decreases in the maximum concentration achieved. Total and renal drug clearance of aztreonam was highly correlated with creatinine clearance. With imipenem, the half-life, clearance, and volume of distribution observed in burn patients were not significantly different from those in nonburn patients, although substantial interpatient variability existed. Imipenem clearance was significantly correlated with creatinine clearance. Individualization of antibiotic therapy for burn patients is recommended with use of measured serum concentrations of the antibiotic or creatinine clearance as an estimate of renal function.