 Linezolid has low plasma protein binding ( approximately 31 % , but highly variable ) and an apparent volume of distribution at steady state of around 40 – 50 liters . Peak serum concentrations ( <unk> ) are reached one to two hours after administration of the drug . Linezolid is readily distributed to all tissues in the body apart from bone matrix and white adipose tissue . Notably , the concentration of linezolid in the epithelial lining fluid of the lower respiratory tract is at least equal to , and often higher than , that achieved in serum ( some authors have reported bronchial fluid concentrations up to four times higher than serum concentrations ) , which may account for its efficacy in treating pneumonia . Cerebrospinal fluid ( CSF ) concentrations vary ; peak CSF concentrations are lower than serum ones , due to slow diffusion across the blood – brain barrier , and trough concentrations in the CSF are higher for the same reason . The average half @-@ life is three hours in children , four hours in teenagers , and five hours in adults . 
