Penetration of aztreonam into human cerebrospinal fluid in the presence of meningeal inflammation

Cerebrospinal fluid of aztreonam were measured in 11 patients with meningeal inflammation. Two to eight hours after a single 2 gin intravenous dose, CSF aztreonam levels ranged from 0·76 to 16·6 mg/l. The mean CSF concentration in four patients with viral meningitis was 1·28 mg/l, which was lower than the mean con centration of 7·2 mg/l in the five with bacterial, cryptococcal or carcinomatous meningitis. Two patients with infected subdural drains were also sampled serially and had CSF levels greater than 1 mg/l between 1 and 8 h post dose. Penetration of aztreonam into the CSF in the presence of meningeal inflammation appears adequate to warrant therapeutic trials in patients infected with susceptible organisms.