[Further pharmacokinetical observations on gentamicin (author's transl)]

Applying a single i.m. dose of 80 mg (41 patients) and 120 mg (23 patients) of gentamicin, respectively, investigations in females have shown that, although the bulk of the antibiotic is excreted with the urine within the first 24 hours after injection, slow excretion is maintained at a very low level. According to the dose administered gentamicin remains detectable in the urine for many days. Thus, after injection of 120 mg in two patients gentamicin was detectable in the urine for a period of up to 20 days. Peak serum levels one hour after i.m. injection of 120 mg did not exceed 8.2 mug/ml, the mean concentration was 5.76 mug/ml. Serum half life was 2 hours. Studies of distribution in animal and human tissues have shown that gentamicin is accumulated almost exclusively in the kidneys, mainly in the cortex.