Drug Toxicology is a interdisciplinary course which has close relationship with many other medical disciplines, such as physiology, biochemistry, immunology, pharmacology, pharmacotherapeutics and pharmacology. As well, it is a bridge between the pharmacology and clinical medicines. This course is intended to introduce the basic knowledge about adverse drug reaction, what we presently understand regarding the adverse reactions that caused by improper use of drugs and the damage to the body caused by the drugs. The emphasis is put on the mechanisms of adverse drug reaction and results caused by the drugs.