... cefotaxime, rifampin, and clarithromycin, have bioactive metabolites that may contribute to their overall efficacy. Chapter 127. Treatment and Prophylaxis of Bacterial Infections (Part 7) Distribution ... elimination), by renal excretion of the unchanged or metabolized form, or by a combination of the two processes. For most of the antibacterial drugs, metabolism leads to loss of in vitro activity, although ... information on the mode of excretion of an antibacterial agent is in adjusting dosage when elimination capability is impaired (Table 127- 3). Direct, nonidiosyncratic toxicity from antibacterial drugs...