Concentration of cefadroxil in kidney tissue and serum after oral administration in patients with normal and impaired renal function

In 17 patients (7 with normal renal function, 10 with impaired renal function) who underwent renal surgery, renal tissue samples and blood samples were taken 3-4 h following the administration of a single oral dose of 1000 mg cefadroxil. It was demonstrated that the concentrations in renal tissue were within the range from 14.2 to 115 micrograms/g tissue, while the serum levels varied from 11.6 to 63.3 micrograms/ml serum. A statistically significant correlation between serum levels and renal tissue levels can be demonstrated. The correlation of the distribution ratio: serum level/tissue level to serum creatinine level proved to be a linear regression, i.e. the distribution quotient decreased if the serum creatinine level increased. This means that the renal tissue level of cefadroxil in comparison to serum level will be lower in patients with renal impairment. However, even with much impaired renal function the renal tissue level exceeded the minimum inhibitory concentration for the most relevant pathogens.