A drug can be defined as a substance use for medical purpose either alone or in mixture. It can be defined as any substance that modifies biological, psychological and social behavior. Drugs contain chemical that Interacts with the functions of the body. This interacts with the functions of the body. This interaction can enhance, inhibit or distort the biological psychological as well as social function of the body. Drug abuse is the routine use of a drug in which the user consumes the substance in amounts or with methods neither approved nor supervised by medical professional.
According to NAFDAC Drug abuse means the excessive and persistent self administration of a drug without regard to numerical or cultural accepted patterns.