The protocol entitled Absorption Kinetics of Subcutaneous Tumescent Cefazolin and Metronidazole is a Phase I dose ranging clinical study designed to document the concentration-time profile of cefazolin and lidocaine after subcutaneous infiltration of cefazolin in tumescent local anesthesia (TLA). The antibiotic cefazolin is routinely given intravenously (IV) for the prophylaxis of surgical site infections (SSI).