Nafcillin entry into human cerebrospinal fluid.

The entry of nafcillin into the cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twenty studies were performed in 18 patients receiving 40 mg of sodium nafcillin per kg intravenously over 30 min. The CSF specimens were obtained at 1, 2, 3, and 4 h postinfusion, and sera were obtained at 5 min and 1, 2, 3, and 4 h. Nafcillin was uniformly detected in the lumbar CSF at 1 h, peaked at 2 h postinfusion, and was still detectable in the CSF of three of four patients studied at 4 h.