RESUMO
In two groups of patients undergoing coronary artery bypass grafting (CABG), two different regimens of antibiotic prophylaxis with cefamandole nafate were compared. In Group 1, 30 mg per kilogram of body weight was administered intravenously during induction of anesthesia. In Group 2, a second dose of 15 mg/kg was administered intravenously shortly before cannulation. Serum and tissue levels in the right atrium, the pericardium, and the sternum were determined using high-pressure liquid chromatography. The results showed that in Group 2 the serum levels were significantly higher from 48 minutes onward after induction and remained at an acceptable level during CABG. The tissue levels in the sternum and pericardium were also significantly higher in Group 2 compared with Group 1. It is concluded that a second dose of cefamandole (15 mg/kg) shortly before the beginning of cardiopulmonary bypass is recommended, particularly for high-risk patients.
Assuntos
Cefamandol/administração & dosagem , Ponte de Artéria Coronária , Pré-Medicação , Cefamandol/sangue , Cefamandol/farmacocinética , Esquema de Medicação , Meia-Vida , Humanos , Infusões Intravenosas , Estudos Prospectivos , Distribuição Aleatória , Distribuição TecidualRESUMO
The renal excretion rate of beta 2-microglobulin in man is 127 +/- 98 ng/min at alkaline urine pH (pH 7). Tobramycin, up to intravenous doses of 160 mg (2 mg/kg) does not increase the renal excretion rate of beta 2-microglobulin. Tobramycin must have less affinity than gentamicin for the tubular system for active reabsorption of amino groups containing organic compounds. Due to this reduced affinity tobramycin will be absorbed less by the proximal tubular cells, which may be one of the reasons for tobramycin being less toxic than gentamicin. beta 2-Microglobulin excretion can be used as a parameter for the relative binding affinity of aminoglycosides.
Assuntos
Tobramicina/urina , Microglobulina beta-2/urina , Adulto , Creatinina/urina , Feminino , Gentamicinas/urina , Meia-Vida , Humanos , Cinética , Masculino , Tobramicina/sangue , Tobramicina/farmacologiaRESUMO
The influence of oral administration of cefaclor, phenethicillin, co-trimoxazole and doxycycline on colonization resistance (CR) of the oropharynx and colon in healthy volunteers was studied. Antimicrobial agents were administered in a randomized cross-over design. No effect on CR of the oropharynx could be demonstrated. Phenethicillin decreased CR of the colon against Enterobacteriaceae (P = 0.001). Co-trimoxazole significantly decreased the concentration of Enterobacteriaceae in faeces (P = 0.03) but the decrease caused by cefaclor and doxycycline did not reach statistical significance. Administration of antimicrobial agents increased the appearance of secondary colonization by Enterobacteriaceae in faeces, especially when Escherichia coli was eliminated. During administration of phenethicillin, secondary colonization occurred at a concentration exceeding 10(7)/g in some volunteers. Following administration of cefaclor, co-trimoxazole and doxycycline, elimination of E. coli may result in the substitution by resistant Gram-negative bacilli in low concentrations.