A Comparative Experimental Study of the Circulation of Amoxycillin and Penicillin G in the Cerebro-Spinal Fluid of Dogs as a Function of the Type of Intravenous Administration

Abstract

The circulation of amoxycillin in the cerebrospinal fluid when the antibiotic is administered by the intravenous route has been investigated in dogs—animals generally used as the model for experimental meningitis—following two procedures: by rapid intravenous injection ( 1 g in 10 ml within one minute) or by slow intravenous infusion for one hour ( 1 g in 120 ml of isotonic glucose solution). Results were compared with those obtained with benzyl penicillin given by the same procedure and at an equivalent dose ( 1 g amoxycillin: 2 000 000 IU benzyl penicillin). Assays were carried out, in cerebrospinal fluid and blood, using the standard micro-biological technique. Comparison of the results obtained after the two procedures shows that after slow intravenous infusion, concentrations of the two antibiotics in cerebrospinal fluid and blood are higher after administration by slow infusion. Furthermore the concentrations of amoxycillin obtained in cerebrospinal fluid by slow infusion are significantly higher than those of penicillin; but in blood the reverse occurs. This study would suggest that amoxycillin possesses a greater ability to permeate into meningeal regions.