Last Modified : 2006-08-28
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.
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.
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.
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 a communication problem involving speech, language, or a thinking impairment. The health care provider should help the patient describe the following:
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.
The World Health Organization developed a 3-step approach for pain management based on the severity of the pain:
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. Aspirin should not be given to children to treat pain.
Opioids are very effective for the relief of moderate to severe pain. Many patients with cancer pain, however, become tolerant to opioids during long-term therapy. Therefore, increasing doses may be needed to continue to relieve pain. A patient's tolerance of an opioid or physical dependence on it is not the same as addiction (psychological dependence). Mistaken concerns about addiction can result in undertreating pain.
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.
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. When the patient has a working stomach and intestines, 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.
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 tend 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.)
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, bisphosphonates, and stimulants. There are great differences in how patients respond to these drugs. Side effects are common and should be reported to the doctor. Certain bisphosphonates given for bone pain are linked to a risk of bone loss after dental work. Patients taking bisphosphonates should check with their doctor before having dental work done.
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.
Weakness, muscle wasting, and muscle/bone pain may be treated with heat (a 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 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.
The following relaxation exercises may be helpful in relieving pain.
Exercise 1. Slow rhythmic breathing for relaxation *Especially for the elderly person, a back rub that effectively produces relaxation may consist of no more than 3 minutes of slow, rhythmic stroking (about 60 strokes per minute) on both sides of the spine, from the crown of the head to the lower back. Continuous hand contact is maintained by starting one hand down the back as the other hand stops at the lower back and is raised. Set aside a regular time for the massage. This gives the patient something pleasant to anticipate.
Exercise 3. Peaceful past experiences *Additional points: Some of the things that may comfort you, such as your favorite music or a prayer, can probably be recorded for you. Then you can listen to the tape whenever you wish. Or, if your memory is strong, you may simply close your eyes and recall the events or words.
Exercise 4. Active listening to recorded music *Additional points: Many patients have found this technique to be helpful. It tends to be very popular, probably because the equipment is usually readily available and is a part of daily life. Other advantages are that it is easy to learn and not physically or mentally demanding. If you are very tired, you may simply listen to the music and omit marking time or focusing on a spot.
*[注: Adapted and reprinted with permission from McCaffery M, Beebe A: Pain: Clinical Manual for Nursing Practice. St. Louis, Mo: CV Mosby: 1989.]
Radiation therapy, radiofrequency ablation, and surgery may be used for pain relief rather than as treatment for primary cancer. Certain chemotherapy drugs may also be used to manage cancer-related pain.
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.
Radiofrequency ablation uses a needle electrode to heat tumors and destroy them. This minimally invasive procedure may provide significant pain relief in patients who have cancer that has spread to the bones.
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.
Less invasive methods should be used for relieving pain before trying invasive treatment. Some patients, however, may need invasive therapy.
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.
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.
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 whom to contact for questions related to pain management.
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: