Interference of cefoxitin in the creatinine estimation and its clinical relevance.

Serum creatinine and creatinine clearance were measured in 10 healthy volunteers before and after an intravenous injection of 2 g cefoxitin sodium. Results were compared with in vitro work which demonstrated a positive interference by cefoxitin in the Jaffé reaction, the routine laboratory method of creatinine measurement. The serum creatinine estimation should be delayed until at least 2 hours after cefoxitin administration. The creatinine clearance may appear to be falsely high.