Abuse, drug:

Any use of an illegal drug, or the intentional self-administration of a medication for a non-medical
purpose such as altering one’s state of consciousness, e.g., “getting high.” (Canadian Guideline for
Safe and Effective Use of Opioids for Chronic Non-cancer Pain 2010)


Self-administration of any drug in a culturally disapproved manner that causes adverse consequences.


A behavioral pattern of drug abuse characterized by overwhelming involvement with the use of a drug (compulsive use) despite harm, the securing of its supply and a high tendency to relapse after discontinuation.  Addiction to a drug may or may not be associated with dependence on the drug. A hallmark of addiction is the euphoria (or high) experienced by the user.  The stronger and faster the euphoria from a drug via a certain route is experienced, the more addictive potential it has.

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A substance that acts at a neuronal receptor to produce effects similar to those of a reference psychoactive substance, e.g. methadone is an agonist at the opioid receptors.

Drugs that interact with receptor sites to cause the same effect that natural chemicals would case at these sites. Karch, A, M. (2008). Focus on nursing in pharmacology. (4th ed.). Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.


Drugs that interact with receptor sites to cause the same effect that natural chemicals would case at these sites. Karch, A, M. (2008). Focus on nursing in pharmacology. (4th ed.). Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.

A substance that counteracts the effects of a reference psychoactive substance by inhibiting or reversing its effects at a neuronal receptor site, e.g. naltrexone acts as an antagonist at the opioid receptor. (Adopted Canadian Society of Addiction Medicine October 14, 1999)

Concurrent Disorders:

The presence of one or more primary, physical and/or psychiatric disorders that have an interactive effect on the course of Substance Dependence and require specific diagnosis and treatment in order to achieve stabilization and/or recovery. (Adopted Canadian Society of Addiction Medicine October 14, 1999)

Controlled Substance:

There are many controlled substances listed under the Controlled Substance Act. These drugs are grouped under schedules. Below are examples of some of the better known drugs within each Schedule:

  • Schedule I contains drugs made from the opium poppy such as heroin, codeine; drugs made from coca such as cocaine; and synthetically derived drugs such as methadone.
  • Schedule II contains cannabis (marijuana) and its derivatives.
  • Schedule III contains drugs such as amphetamines and lysergic acid diethylamide (LDS). 
  • Schedule IV contains drugs such as benzodiazepines and barbiturates.
  • Schedule V and VI contain precursors required to produce controlled substances (NationalAssociation of Pharmacy Regulatory Authorities, 2002-2004).


The physiological state of neuroadaptation produced by repeated administration of a drug, necessitating continued administration to prevent the appearance of the withdrawal syndrome.  Dependence may be accompanied by addiction to the drug.


Methadone (also known as Symoron, Dolophine, Amidone, Methadose, Physeptone, Heptadon and many other names) is a synthetic opioid. It is used medically as an analgesic and a maintenance anti-addictive and reductive preparation for use by patients with opioid dependency. It was developed in Germany in 1937, mainly because Germany required a reliable internal source of opiates. Because it is an acyclic analog of morphine, methadone acts on the same opioid receptors and thus has many of the same effects. Methadone is also used in managing severe chronic pain, owing to its long duration of action, extremely powerful effects, and very low cost. Methadone was introduced into the United States in 1947 by Eli Lilly and Company


Opioids are a family of drugs used to relieve pain. Some opioids, such as morphine and codeine are made from the opium poppy plant. Heroin is a highly addictive, illegal opioid also made from morphine by adding via a chemical process. Those opiods derived from the poppy plant such as morphine, heroin, or oxycodone are refered to as "opiates".  Other opioids such as methadone or buprenorphine are synthetically made from chemicals.

Commonly misused prescription drugs include:

  • oxycodone (e.g., Percodan, Percocet, OxyContin)
  • hydrocodone (e.g., Tussionex)
  • codeine (e.g., Tylenol 1, Tylenol 3)
  • morphine
  • hydromorphone (e.g., Dilaudid)
  • meperidine (e.g., Demerol)

Opioids are effective painkillers. They can also create feelings of intense pleasure or euphoria. People who misuse or abuse opioids can easily become addicted to them.


The exaggerated expression of the original condition sometimes experienced by patients immediately after cessation of an effective treatment.  Rebound is not the same as withdrawl.


The reoccurrence on discontinuation of an effective medical treatment of the original condition from which the patient suffered.


Tolerance has developed when after repeated administration, a given dose of a drug produces decreased effect, or conversely, when increasingly larger doses must be administered to obtain the effects observed with the original use.


The psychologic and physiologic reactions to abrupt cessation of a dependence-producing drug.