Renal handling and lymph concentration of two cephalosporin analogues, cephacetrile and cephaloridine: an experimental study in dogs.

Cephacetrile (CIBA 36' 278-Ba) and cephaloridine (both cephalosporin derivatives) were compared in dogs with regard to their possible nephrotoxicity, renal handling, and concentration in the renal lymph. No adverse acute effect of either drug on the glomerular filtration rate and effective renal plasma flow was found at very high concentrations in the plasma, with or without concomitant administration of a potent diuretic (furosemide). Cephaloridine was filtered only by the kidney, whereas there was evidence that cephacetrile was also excreted by tubular secretion at low concentrations. The renal lymph concentration of the two antibiotics (in the hilar as well as the capsular lymph vessels) was found to be significantly lower than the simultaneous arterial plasma concentrations. When concentrations in the plasma were high, the relative lymph concentrations of cephaloridine and cephacetrile were in the same range as those of iothalamate (70 to 90% of the arterial plasma level), whereas at low plasma concentrations the lymph concentration of cephacetrile was markedly lower, a finding possibly explained by the active tubular secretion of cephacetrile.