Physical dependence
Tolerance
Substance abuse
Addiction

Substance abuse is very uncommon among patients with cancer. The number of known patients with cancer who are substance abusers may be small because these patients do not seek medical help in hospitals, or they may not acknowledge to health care providers that they have a substance abuse problem.

Physical dependence is defined as the occurrence of withdrawal symptoms when a drug is abruptly stopped, the dose is significantly reduced, or when a second drug is given that counteracts the actions of the drug to which the patient has developed a dependence. The dependence is not apparent until one of these actions occurs. When a patient with cancer is receiving an opioid drug for cancer pain, care is taken to avoid stopping the drug abruptly or prescribing other drugs that decrease or negate the effect of the opioid. Physical dependence on opioid pain medications does not seem to occur in patients with cancer. In these patients, once the pain disappears (usually through the effective treatment of the cancer), the pain medicine can be stopped without difficulty.

Tolerance to opioid pain medications may develop. Tolerance is the need to take increasingly larger doses of medication to relieve pain symptoms. Among patients taking opioid drugs for medical reasons, tolerance has not been shown to lead to drug addiction or drug abuse problems.

Substance abuse is the use of a drug in any manner that does not conform to the physician's orders or the use of any illegal drug.

Addiction is the use of a substance in a manner that is out of control, compulsive, used in increasing amounts, and is continued despite the risk of harm. A patient who uses opioids to relieve cancer pain may become physically dependent on the drugs, but is not described as being addicted to them.

These terms are generally used in association with people who do not have a medical illness. The terms are not entirely appropriate to use to describe medically ill people who are using drugs therapeutically.

Glossary Terms

Uncontrollable craving, seeking, and use of a substance such as a drug or alcohol.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

An uncontrollable urge to say or do something without an obvious reason. A person may repeat a behavior, such as hand-washing, over and over.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

The use of illegal drugs or the use of prescription or over-the-counter drugs for purposes other than those for which they are meant to be used, or in large amounts. Drug abuse may lead to social, physical, emotional, and job-related problems.

A legal drug that is used to prevent, treat, or relieve symptoms of a disease or abnormal condition.

Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.

A substance used to treat moderate to severe pain. Opioids are like opiates, such as morphine and codeine, but are not made from opium. Opioids bind to opioid receptors in the central nervous system. Opioids used to be called narcotics. An opioid is a type of alkaloid.

A condition in which a person takes a drug over time, and unpleasant physical symptoms occur if the drug is suddenly stopped or taken in smaller doses.

Medical doctor.

A doctor's order for medicine or another intervention.

The use of illegal drugs or the use of prescription or over-the-counter drugs or alcohol for purposes other than those for which they are meant to be used, or in excessive amounts. Substance abuse may lead to social, physical, emotional, and job-related problems.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Having to do with treating disease and helping healing take place.