Answer:
Drugs may be defined as the chemicals substance that might cause change in the physiology of an organisms. Drugs are used legally to treat the particular disease. Excess dose of drugs might cause hallucinations and addiction in the individual.
The pharmaceutical drugs include the combination of the different fields of chemistry to make the new active compound. The pharmacogenomics is newly advanced field including personalized medicine. The chiral chemistry of the drug is quite important for the development of new small molecule design of drug.