A drug interaction is a situation in which a substance (usually another drug) affects the activity of a drug when both are administered together. This action can be synergistic (when the drug’s effect is increased) or antagonistic (when the drug’s effect is decreased) or a new effect can be produced that neither produces on its own. Typically, interactions between drugs come to mind (drug-drug interaction). However, interactions may also exist between drugs and foods (drug-food interactions), as well as drugs and medicinal plants or herbs (drug-plant interactions). People taking antidepressant drugs such as monoamine oxidase inhibitors should not take food containing tyramine as hypertensive crisis may occur (an example of a drug-food interaction). These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances.

In the present book, fifteen typical literatures about drug interaction published on international authoritative journals were selected to introduce the worldwide newest progress, which contains reviews or original researches on medical science, clinical pharmacology, pharmacokinetics, drug misuse ect. We hope this book can demonstrate advances in drug interaction as well as give references to the researchers, students and other related people.