Interaction between cephaloridine and furosemide in man.

The effect of a moderate oral dose of furosemide (80 mg daily) on the serum half-life of cephaloridine was studied. In 14 patients not previously treated with diuretics this dose was found to prolong the half-life significantly. A corresponding decrease of the half-life of cephaloridine was observed when furosemide was withdrawn from 2 patients who were treated with diuretics at admission to hospital. The concurrent treatment with furosemide and cephaloridine did not affect the renal function of the patients studied. From the results obtained it seems possible that even moderate doses of a potent diuretic increase the nephrotoxicity of a cephalosporin.