ABSTRACT
Drugs are chemical substances which, by interaction with biological targets, can alter the biochemical systems of the body. The branch of science investigating drug action is known as pharmacology. These interactions may be mediated through a variety of target tissues within the body. For example, effects on cardiac muscle by drugs such as ephedrine can lead to an increase in the force and rate of beating of the heart; stimulation of nerve endings in the central nervous system by drugs such as amphetamine can produce changes in mood and behaviour; interaction with metabolic processes, with drugs such as insulin, can be used in the treatment of disorders such as diabetes.
