Introduction
This patient summary on pain 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. Pain associated with cancer can be controlled
in most patients but is frequently undertreated. This brief summary
describes the management of cancer pain with the use of medication,
physical methods, and psychological intervention.
Overview
Cancer pain can be managed effectively in most patients with cancer
or with a history of cancer. Although cancer pain cannot always
be relieved completely, therapy can lessen pain in most patients.
Pain management improves the patient's quality of life throughout
all stages of the disease.
Flexibility is important in managing
cancer pain. As patients vary in diagnosis, stage of disease,
responses to pain and treatments, and personal likes and dislikes,
management of cancer pain must be individualized. Patients, their
families, and their health care providers must work together closely
to manage a patient's pain effectively.
Assessment
To treat pain, it must be measured. The patient and the doctor
should measure pain levels at regular intervals after starting
cancer treatment, at each new report of pain, and after starting
any type of treatment for pain. The cause of the pain must be
identified and treated promptly.
Patient
Self-Report
To help the health care provider determine the type and extent
of the pain, cancer patients can describe the location and intensity
of their pain, any aggravating or relieving factors, and their
goals for pain control. The family/caregiver may be asked to report
for a patient who has communication problems such as a speech,
language, or thinking impairment.
|
•
|
Pain: The
patient can describe the pain, when it started, how long
it lasts, and whether it is worse during certain times of
the day or night.
|
|
•
|
Location:
The patient can show exactly where the pain is on his or
her body or on a drawing of a body and where the pain goes
if it travels.
|
|
•
|
Intensity or
severity: The patient can keep a diary of the degree
or severity of pain.
|
|
•
|
Aggravating
and relieving factors: The patient can identify factors
that increase or decrease the pain.
|
|
•
|
Behavioral
response to pain: The health care provider and/or caregivers
can note behaviors that may suggest pain in patients who
have communication problems.
|
|
•
|
Goals for pain
control: With the health care provider, the patient
can decide how much pain he or she can tolerate and how
much improvement he or she may achieve. The patient can
use a daily pain diary to increase awareness of pain, gain
a sense of control of the pain, and receive guidance from
health care providers on ways to manage the pain. |
Assessment
of the Outcomes of Pain Management
The results of pain management should be measured by monitoring
for a decrease in the severity of pain and improvement in thinking
ability, emotional well-being, and social functioning. The results
of taking pain medication should also be monitored. Drug addiction
is rare in cancer patients. Developing a higher tolerance for
a drug and becoming physically dependent on the drug for pain
relief does not mean that the patient is addicted. Patients should
take pain medication as prescribed by the doctor. Patients who
have a history of drug abuse may tolerate higher doses of medication
to control pain.
Management
With Drugs
Basic Principles of Cancer Pain
Management
The World Health Organization (WHO) developed a 3-step approach
for pain management based on the severity of the pain:
|
•
|
For mild to moderate
pain, the doctor may prescribe a Step 1 pain medication
such as aspirin, acetaminophen, or a nonsteroidal anti-inflammatory
drug (NSAID). Patients should be monitored for side effects,
especially those caused by NSAIDs such as kidney or stomach
and intestinal problems.
|
|
•
|
When pain lasts
or increases, the doctor may change the prescription to
a Step 2 or Step 3 pain medication. Most patients with cancer-related
pain will need a Step 2 or Step 3 medication. The doctor
may skip Step 1 medications if the patient initially has
moderate to severe pain.
|
|
•
|
At each step the
doctor may prescribe additional drugs or treatments (for
example, radiation therapy).
|
|
•
|
The patient should
take doses regularly, "by mouth, by the clock"
(at scheduled times), to maintain a constant level of the
drug in the body; this will help prevent recurrence of pain.
If the patient is unable to swallow, the drugs are given
by other routes (for example, by infusion or injection).
|
|
•
|
The doctor may
prescribe additional doses of drug that can be taken as
needed for pain that occurs between scheduled doses of drug.
|
|
•
|
The doctor will
adjust the pain medication regimen for each patient's individual
circumstances and physical condition. |
Acetaminophen
and NSAIDs
NSAIDs are effective for relief of mild pain. They may be given
with opioids for the relief of moderate to severe pain. Acetaminophen
also relieves pain, although it does not have the anti-inflammatory
effect that aspirin and NSAIDs do. Patients, especially older
patients, who are taking acetaminophen or NSAIDs should be closely
monitored for side effects.
Opioids
Opioids are very effective for the relief of moderate to severe
pain. Undertreatment results when concerns about addiction (psychological
dependence) to these drugs is confused with tolerance and physical
dependence. Many patients with cancer pain become tolerant to
opioids during long-term therapy. Therefore, increasing doses
are necessary to continue to relieve pain, even at the risk of
side effects.
Types of
Opioids
There are several types of opioids. Morphine is the most commonly
used opioid in cancer pain management. Other commonly used opioids
include hydromorphone, oxycodone, methadone, and fentanyl. The
availability of several different opioids allows the doctor flexibility
in prescribing a medication regimen that will meet individual
patient needs.
Guidelines
for Giving Opioids
Most patients with cancer pain will need to receive pain medication
on a fixed schedule to manage the pain and prevent it from getting
worse. The doctor will prescribe a dose of the opioid medication
that can be taken as-needed along with the regular fixed-schedule
opioid to control pain that occurs between the scheduled doses.
The amount of time between doses depends on which opioid the doctor
prescribes. The correct dose is the amount of opioid that controls
pain with the fewest side effects. The goal is to achieve a good
balance between pain relief and side effects by gradually adjusting
the dose. If opioid tolerance does occur, it can be overcome by
increasing the dose or changing to another opioid, especially
if higher doses are needed.
Occasionally, doses may need to be
decreased or stopped. This may occur when patients become pain
free because of cancer treatments such as nerve blocks or radiation
therapy. The doctor may also decrease the dose when the patient
experiences opioid-related sedation along with good pain control.
Medications for pain may be given
in several ways. The preferred method is by mouth, since medications
given orally are convenient and usually inexpensive. When patients
cannot take medications by mouth, other less invasive methods
may be used, such as rectally or through medication patches placed
on the skin. Intravenous methods are used only when simpler, less
demanding, and less costly methods are inappropriate, ineffective,
or unacceptable to the patient. Patient-controlled analgesia (PCA)
pumps may be used to determine the opioid dose when starting opioid
therapy. Once the pain is controlled, the doctor may prescribe
regular opioid doses based on the amount the patient required
when using the PCA pump. Intraspinal administration of opioids
combined with a local anesthetic may be helpful for some patients
who have uncontrollable pain.
Side Effects
of Opioids
Patients should be watched closely for side effects of opioids.
The most common side effects of opioids include nausea, sleepiness,
and constipation. The doctor should discuss the side effects with
patients before starting opioid treatment. Sleepiness and nausea
are usually experienced when opioid treatment is started and tends
to improve within a few days. Other side effects of opioid treatment
include vomiting, difficulty in thinking clearly, problems with
breathing, gradual overdose, and problems with sexual function.
Opioids slow down the muscle contractions
and movement in the stomach and intestines resulting in hard stools.
The key to effective prevention of constipation is to be sure
the patient receives plenty of fluids to keep the stool soft.
The doctor should prescribe a regular stool softener at the beginning
of opioid treatment. If the patient does not respond to the stool
softener, the doctor may prescribe additional laxatives.
Patients should talk to their doctor
about side effects that become too bothersome or severe. Because
there are differences between individual patients in the degree
to which opioids may cause side effects, severe or continuing
problems should be reported to the doctor. The doctor may decrease
the dose of the opioid, switch to a different opioid, or switch
the way the opioid is given (for example intravenous or injection
rather than by mouth) to attempt to decrease the side effects.
(Refer to the PDQ summaries on Gastrointestinal Complications,
Nausea and Vomiting, Nutrition in Cancer Care, and Sexuality and
Reproductive Issues for more information about coping with these
side effects.)
Drugs Used
With Pain Medications
Other drugs may be given at the same time as the pain medication.
This is done to increase the effectiveness of the pain medication,
treat symptoms, and relieve specific types of pain. These drugs
include antidepressants, anticonvulsants, local anesthetics, corticosteroids,
and stimulants. There are great differences in how patients respond
to these drugs. Side effects are common and should be reported
to the doctor.
Physical
and Psychosocial Interventions
Noninvasive physical and psychological methods can be used along
with drugs and other treatments to manage pain during all phases
of cancer treatment. The effectiveness of the pain interventions
depends on the patient's participation in treatment and his or
her ability to tell the health care provider which methods work
best to relieve pain.
Physical
Interventions
Weakness, muscle wasting, and muscle/bone pain may be treated
with heat (hot pack or heating pad); cold (flexible ice packs);
massage, pressure, and vibration (to improve relaxation); exercise
(to strengthen weak muscles, loosen stiff joints, help restore
coordination and balance, and strengthen the heart); changing
the position of the patient; restricting the movement of painful
areas or broken bones; stimulation; controlled low-voltage electrical
stimulation; or acupuncture.
Thinking
and Behavioral Interventions
Thinking and behavior interventions are also important in treating
pain. These interventions help give patients a sense of control
and help them develop coping skills to deal with the disease and
its symptoms. Beginning these interventions early in the course
of the disease is useful so that patients can learn and practice
the skills while they have enough strength and energy. Several
methods should be tried, and one or more should be used regularly.
|
•
|
Relaxation
and imagery: Simple relaxation techniques may be used
for episodes of brief pain (for example, during cancer treatment
procedures). Brief, simple techniques are suitable for periods
when the patient's ability to concentrate is limited by
severe pain, high anxiety, or fatigue. (See Relaxation exercises
below)
|
|
•
|
Hypnosis:
Hypnotic techniques may be used to encourage relaxation
and may be combined with other thinking/behavior methods.
Hypnosis is effective in relieving pain in people who are
able to concentrate and use imagery and who are willing
to practice the technique.
|
|
•
|
Redirecting
thinking: Focusing attention on triggers other than
pain or negative emotions that come with pain may involve
distractions that are internal (for example, counting, praying,
or saying things like "I can cope") or external
(for example, music, television, talking, listening to someone
read, or looking at something specific). Patients can also
learn to monitor and evaluate negative thoughts and replace
them with more positive thoughts and images.
|
|
•
|
Patient education:
Health care providers can give patients information and
instructions about pain and pain management and assure them
that most pain can be controlled effectively. Health care
providers should also discuss the major barriers that interfere
with effective pain management.
|
|
•
|
Psychological
support: Short-term psychological therapy helps some
patients. Patients who develop clinical depression or adjustment
disorder may see a psychiatrist for diagnosis.
|
|
•
|
Support groups
and religious counseling: Support groups help many patients.
Religious counseling may also help by providing spiritual
care and social support. |
Anticancer
Interventions
Radiation Therapy
Local or whole-body radiation therapy may increase the effectiveness
of pain medication and other noninvasive therapies by directly
affecting the cause of the pain (for example, by reducing tumor
size). A single injection of a radioactive agent may relieve pain
when cancer spreads extensively to the bones.
Surgery
Surgery may be used to remove part or all of a tumor to reduce
pain directly, relieve symptoms of obstruction or compression,
and improve outcome, even increasing long-term survival.
Invasive
Interventions
Less invasive methods should be used for relieving pain before
trying invasive treatment, however, some patients may need this
type of therapy.
Nerve Blocks
A nerve block is the injection of either a local anesthetic or
a drug that inactivates nerves to control otherwise uncontrollable
pain. Nerve blocks can be used to determine the source of pain,
to treat painful conditions that respond to nerve blocks, to predict
how the pain will respond to long-term treatments, and to prevent
pain following procedures.
Neurologic
Interventions
Surgery can be performed to implant devices that deliver drugs
or electrically stimulate the nerves. In rare cases, surgery may
be done to destroy a nerve or nerves that are part of the pain
pathway.
Management
of Procedural Pain
Many diagnostic and treatment procedures are painful. Pain related
to procedures may be treated before it occurs. Local anesthetics
and short-acting opioids can be used to manage procedure-related
pain, if enough time is allowed for the drug to work. Anti-anxiety
drugs and sedatives may be used to reduce anxiety or to sedate
the patient. Treatments such as imagery or relaxation are useful
in managing procedure-related pain and anxiety.
Patients usually tolerate procedures
better when they know what to expect. Having a relative or friend
stay with the patient during the procedure may help reduce anxiety.
Patients and family members should
receive written instructions for managing the pain at home. They
should receive information regarding who to contact for questions
related to pain management.
Treating
Elderly Patients
Older patients are at risk for under-treatment of pain because
their sensitivity to pain may be underestimated, they may be expected
to tolerate pain well, and misconceptions may exist about their
ability to benefit from opioids. Issues in assessing and treating
cancer pain in older patients include the following:
|
•
|
Multiple chronic
diseases and sources of pain: Age and complicated medication
regimens put older patients at increased risk for interactions
between drugs and between drugs and the chronic diseases.
|
|
•
|
Visual, hearing,
movement, and thinking impairments may require simpler tests
and more frequent monitoring to determine the extent of
pain in the older patient.
|
|
•
|
Nonsteroidal anti-inflammatory
drug (NSAID) side effects, such as stomach and kidney toxicity,
thinking problems, constipation, and headaches, are more
likely to occur in older patients.
|
|
•
|
Opioid effectiveness:
Older patients may be more sensitive to the pain-relieving
and central nervous system effects of opioids resulting
in longer periods of pain relief.
|
|
•
|
Patient-controlled
analgesia must be used cautiously in older patients, since
drugs are slower to leave the body and older patients are
more sensitive to the side effects.
|
|
•
|
Other methods
of administration, such as rectal administration, may not
be useful in older patients since they may be physically
unable to insert the medication.
|
|
•
|
Pain control after
surgery requires frequent direct contact with health care
providers to monitor pain management. |
Reassessment of pain management
and required changes should be made whenever the older patient
moves (for example, from hospital to home or nursing home).
