A compendium of proven experimental approaches and strategies for studying the bioactivation, detoxification, tissue distribution, and elimination of xenobiotics in the metabolism and/or transport of various chemicals. The authors address several of the major drug metabolizing systems, including the cyhrome P450 family, flavin-containing monooxygenases, glutathione, S-transferase, glucuronidation, N-acetylation, and sulfotransferases. Additional chapters present novel approaches to the study of: signaling pathways in the regulation of drug metabolism enzymes, how the modulation of thiols and other low molecular-weight cofactors can alter drug metabolism, and how modulation of drug metabolism pathways can influence antiviral therapy.