Effects on renal function of treatment with cefoxitin alone or in combination with furosemide

The glomerular filtration rate measured by 51Chrome-EDTA and serum half life of cefoxitin were followed in patients with preexisting moderate renal impairment. The patients were treated with cefoxitin for two to three weeks because of chronic serious infections. The dose used in patients with an initial clearance of more than 40 mg/ml was 1 g three times daily giving a mean peak concentration of 100 microgram/ml. Seven patients were treated with cefoxitin alone and twelve with cefoxitin and furosemide (80 mg daily orally). The glomerular filtration rate did not change significantly during treatment time. There were no signs of accumulation of cefoxitin as serum half life of the drug remained unchanged both in patients treated with and without furosemide concurrently.