Often, the effects of withdrawing a drug are the opposite of the drug itself. Again, this is not a true withdrawal. However, as discussed in the text it is the situation where, after a long period of abstinence, the former user experience and unpleasant sensation upon some stimulus that is associated with the drug use. This may represent a component of the psychological withdrawal that a user may experience. Once a drug is absorbed, the body immediately begins to rid itself of the compound.
Numerous pathways exist to eliminate the drug from the body.
This has an effect in drug abuse in shortening the action of the drug. Therefore continued use or polydrug abuse could affect the duration and extent of a particular drugs effect. They often produce a wide range of side effects that, in non-abusing individuals, would be considered bothersome, but that the abuser will tolerate to achieve the desired effect. Also recall that many additional actions of the drug may be detrimental to the health of the abuser. In the drug abuse arena, there are many levels of use.