Penetration of aztreonam into cerebrospinal fluid of patients with bacterial meningitis.

The penetration of aztreonam into the cerebrospinal fluid was determined in 16 patients with bacterial meningitis undergoing treatment with other antibiotics. Three aztreonam doses of 30 mg/kg were infused intravenously over 30 to 45 min at 8-h intervals, first between days 2 and 4 and again between days 11 and 20 after onset of the disease. Concentrations of aztreonam in serum and cerebrospinal fluid samples obtained at 60, 90, 120, and 240 min after the third aztreonam dose were measured by high-pressure liquid chromatography. The concentrations of aztreonam in cerebrospinal fluid ranged from 3.5 to 62 micrograms/ml, depending on the sampling time and the time elapsed since the onset of the disease. These concentrations were equal to or higher than the MICs for most of the gram-negative bacilli (including Pseudomonas aeruginosa).