[Neurotoxicity of carbenicillin (author's transl)]

[Central nervous system side effects of different antibacterial substances]

This review concerns central nervous system side effects of different antibacterial agents. Special attention is focussed on the new quinolone derivatives, penicillins and cephalosporins. As far as possible, mechanisms of action are discussed as well as therapeutic regimens.

High-pressure liquid chromatographic assays for ticarcillin in serum and urine

Rapid and sensitive high-pressure liquid chromatographic (HPLC) assays for ticarcillin in serum and urine have been developed. Sample pretreatment and optimized chromatographic conditions are presented for a C-18-bonded reversed-phase column used in an internal standard assay method. Ticarcillin has a retention time of or approximately 5.3 min at a flow rate of 1.5 ml/min for a mobile phase of acetonitrile-aqueous 0.06 M sodium biphosphate, pH 2.05, (50.5:100). In a two-step extraction procedure, the ticarcillin extraction efficiencies from serum and urine were 76.1 +/- 4.7 and 80.9 +/- 3.2% respectively. The assay sensitivity limit for ticarcillin in these fluids is approximately 1.0 microgram/ml. A comparison is made of the HPLC and microbiological assay results for ticarcillin in 20 different but equally divided serum samples obtained from two volunteers.

Cerebral toxicity of penicillins in relation to their hydrophobic character

The neurotoxic effects of ticarcillin, methicillin, phenthicillin, oxacillin, cloxacillin and dicloxacillin were studied in the conscious rabbit. During and after intravenous administration of 1.2 and 2.4 g/kg, resp., over 50 min the blood concentrations of the drugs were determined and the neurotoxicity assessed by continuous recording of the electroencephalogram. The hydrophobia of the penicillins was characterized by determination of their partition coefficients between isobutanol and buffer solution pH 7.4. The penicillins showed quite different neurotoxic properties. A close correlation (r = 0.928) was found between the neurotoxic potency of the penicillins and their partition coefficients. With increasing hydrophobia the neurotoxic potency increased in the following sequence: Ticarcillin, methicillin, oxacillin, phenethicillin, cloxacillin, dicloxacillin. It can be concluded, therefore, that determination of the partition coefficient of a penicillin gives valuable information on the neurotoxicity to be expected. The introduction of a neurotoxicity quotient revealed that penicillins may be divided into two groups: less neurotoxic penicillins with a partition coefficient below 1.0 and highly neurotoxic penicillins with a partition coefficient above 1.0.