Longstanding post-therapeutic gentamicin serum and urine concentrations in patients with unimpaired renal function. A pharmacokinetic evaluation

Abstract

Sixteen patients with various infections were treated with gentamicin for 5 to 76 days. Fourteen patients received intramuscular and 2 patients intravenous therapy. Using a radioimmunoassay sensitive to 0.008 μg/ml, gentamicin could be detected in serum and urine for weeks after end of therapy. Post-therapeutic concentration curves in serum exhibited a terminal phase with a mean half-life of 11.8 days. Roughly parallel curves were seen in urine with a mean terminal half-life of 9.5 days. The results indicated that the two-compartment open model hitherto used for describing the pharmacokinetics of gentamicin is inadequate.