Substance Abuse In Cancer

by National Cancer Institute

Introduction

This patient summary on substance abuse issues in cancer is adapted from the summary written for health professionals by cancer experts. This and other credible information about cancer treatment, screening, prevention, supportive care, and ongoing clinical trials, is available from the National Cancer Institute. Substance abuse rarely develops in people who have cancer who do not have a history of drug or alcohol abuse. This brief summary describes substance abuse issues in patients with cancer who have a history of substance abuse, and addresses the use of opioid drugs to control cancer pain.

Overview

People with cancer very rarely develop substance abuse problems unless they abused drugs and alcohol before cancer was diagnosed. Generally, people without a history of substance abuse can take opioids and other drugs to control cancer pain without developing substance abuse problems. People with a history of substance abuse, however, are at risk for developing problems when drugs are prescribed to control cancer symptoms.

Patients who have a history of substance abuse may find that illegal drug and alcohol use interfere with their ability to receive cancer therapy. The use of drugs may interfere with the effectiveness of anticancer therapy and may cause patients to become even sicker.

Patients with cancer who are current substance abusers, or who have been substance abusers in the past, may find it difficult to develop a trusting relationship with a network of friends and family members and with the cancer treatment team. The lack of trust may compromise cancer treatment and follow-up care and may worsen the patient's quality of life.

Prevalance Among the Physically Ill

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

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

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

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

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.

Defining Terms for the Medically Ill

The following issues make assessing substance abuse among patients who are receiving treatment for medical illness more difficult.

Undertreatment

If cancer pain is not adequately treated, a patient may use drugs recklessly in an attempt to seek relief. Many patients may not receive effective treatment for their pain. When the prescribed treatment is adjusted and pain is controlled, the patient's need to use drugs in a manner in which they were not prescribed disappears.

People who have a history of drug abuse may revert to the use of an illegal drug when their pain is not adequately treated. Some of these patients may develop an addiction to prescribed drugs.

Sociocultural influences

Because the terminology used to describe drug abuse is not intended to include people without a history of drug abuse who are using medications therapeutically, many questions have yet to be answered. For example, while it is clear that a patient who forges a prescription, or injects a drug that was meant to be taken by mouth, is displaying deviant behavior, it is not clear if the same may be said about a patient who increases the dosage to control unrelieved pain, or takes a pain medication to fall asleep at night.

Health care professionals may make assumptions about the risk of drug abuse based on a patient's social group. If the patient belongs to a social group in which there is a high incidence of drug abuse, or if the patient has a history of drug abuse, it may be incorrectly assumed that the patient is at risk for abusing drugs prescribed for therapeutic purposes.

About the Author

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