It may be due to accidental intake or it is taken for suicidal purpose. It is purposefully given in case of homicides. The normal dose becomes over dose if the patient has got kidney failure for some drugs. Unlike overdose toxicity is usually associated with damage to the bodily organs and consequently functions. Poisoning Poison occurs when a drug is taken in large doses for the same reasons described under toxicity.
Drug becomes poison when taken in large doses or for prolonged period.
This is the condition where in the individual develops a liking for the drug either physically or psychologically. This is different from drug abuse where a person uses the drug not warranted or necessary and drug addiction wherein a person develops compulsive requirement of the drug. This occurs when a patient is too sensitive for a drug at normal dose. The individual may be sensitive only to a particular or particular group of drugs. It is very difficult to predict who is sensitive to which drug.