The detection of doxycycline activity in human bone.

Measurements of antibacterial activity in bone from 25 patients undergoing orthopaedic surgery were performed after preoperative treatment with doxycycline in a single dose of 200 mg. The antibiotic was given by intravenous infusion during 30-40 minutes, and the operation was performed 2-6 hours after administration of the dose. Using the agar diffusion method, the concentrations ranged from 0.05-0.6 mug/g. Using the electrophoretic method, higher levels of doxycycline were found, possibly as a consequence of a diminution in the binding capacity of the bone.