Investigation of clindamycin concentrations in human plasma and jawbone tissue in patients with osteonecrosis of the jaw: A prospective trial

The aim of this study was to investigate the jawbone concentration of clindamycin (CLI) in patients with an osteonecrosis of the jaw (ONJ). Patients with medication-related ONJ (MRONJ) and osteoradionecrosis (ORN) with an antibiotic treatment with CLI were included. Plasma, vital and necrotic bone samples were collected. Plasma and jawbone samples were analyzed by liquid chromatography-tandem mass spectrometry. Patients with MRONJ exhibited a mean plasma CLI concentration of 9.6 mu g/mL (SD +/- 3.6 mu g/mL) and mean concentrations 2.3 mu g/g CLI (SD +/- 1.4 mu g/g) and 2.1 mu g/g CLI (SD +/- 2.4 mu g/g) in vital and necrotic bone samples, without statistical significance (p = 0.79). In patients with ORN, mean concentration in plasma was 12.0 mu g/mL (SD 2.6 mu g/mL), in vital bone 2.1 mu g/g (SD +/- 1.5 mu g/g), and in necrotic bone 1.7 mu g/g (SD +/- 1.2 mu g/g). Vital and necrotic bone concentrations did not differ significantly (p = 0.88). The results demonstrate that CLI concentrations are considerably lower than in plasma, but sufficient for most bacteria present in ONJ. Within the limitations of the study, it seems that CLI is a relevant alternative to other antibiotics in the treatment of ONJ because it reaches adequate concentrations in jawbone.