Thursday, March 19, 2009

Myths about Narcotics and Cancer Pain Control















A lot of cancer patients want to avoid taking opioids. Many fear that they will become addicted to these medications, and some feel that narcotics should be used only as a last resort for fear that they will not be effective when they are really needed. Doctors may also share some of the myths about opioid medications. These myths form barriers to good and effective relief of cancer pain. These myths need to be understood and addressed by patients and their caregivers.
Myth 1. People given opioids for pain control are always doing worse or are near death.
Just because a person is placed on a narcotic does not mean that he or she is gravely ill. Opioids are highly effective medications that can be used at any stage in the disease when severe pain requires strong medication.



Myth 2. All patients getting morphine or other opioids will become addicts.
Addiction is a psychological need for a drug and rarely, if ever, develops in people using narcotics for pain control. Physical dependence, however, always occurs in patients taking narcotics for a long time. Physical dependence is a problem only when a patient is suddenly taken off the drug. If this happens, a physical reaction, called withdrawal syndrome, takes place. If a disease becomes cured during therapy and opioid medications are no longer needed, they can be withdrawn slowly so that the withdrawal syndrome does not develop. (However, sometimes chronic opioid medications are still needed, because of the previous tissue destruction that the tumor or therapy caused.) The bottom line is that physical dependence does not equal addiction.



Myth 3. Patients who take opioid medications develop tolerance and always need more and more medicine.
There are many reasons behind the need for increased doses of an opioid medication. One is spreading disease or a change in the type of pain, such as a new neuropathic pain problem developing with tumor spread. Another reason is tolerance, which means the need for an increasing dose of a drug in order to achieve a desired result. Tolerance, if it develops at all, does not develop suddenly, and doctors can respond to its development by increasing the dose. Opioid medications are safe even at very high doses if given correctly. If a patient no longer experiences pain relief at one dose level, the dose can be safely increased again and again.



Myth 4. Opioids are dangerous because they can make breathing harder for a terminally ill patient.



Morphine and other opioid drugs are not dangerous respiratory depressants in patients with cancer and pain. Doses are gradually increased and tolerance to the respiratory-depressant effects of these drugs usually develops before tolerance to their pain-relieving effects.



Myth 5. People taking opioids must get it by injection since opioids are poorly absorbed by mouth.



Most opioids are absorbed very well when taken orally. However, a fair amount of the dose taken by mouth is ``lost'' to nontarget body tissues and therefore wasted, so larger dosages of the drug are required than the doses needed for shots. The pain equivalency between oral and intramuscular (shots) or intravenous morphine is 3 to 1 when taken over time, meaning that 30 mg of oral morphine is equivalent to 10 mg of intramuscular or intravenous morphine.










Treating and controlling pain is a primary concern for all members of the health care team, including your doctors, nurses and the hospital and home care team. According to the World Health Organization committee on cancer pain, 90 to 95 percent of all cancer pain can be well controlled using a special set of guidelines. These guidelines separate pain into levels of intensity and suggest tailoring the strength and potency of prescribed pain-relieving medications to the intensity. Not all cancer pain requires strong narcotics. But strong pain requires strong medications.




The guidelines suggest that mild pain be treated with nonnarcotic medications such as aspirin, acetaminophen (Tylenol) or other aspirin-like drugs called nonsteroidal anti-inflammatory drugs (NSAIDs);
moderate pain be treated with a combination of NSAIDs and weak narcotics such as codeine (Tylenol with codeine), hydrocodone (Vicodin or Lortab), Percocet, Percodan or propoxyphene (Darvon), and
severe pain be treated with strong opioids such as morphine, Demerol, Dilaudid, fentanyl (duragesic patches) or methadone in combination with an NSAID.
The guidelines also suggest adding an adjuvant medication to these narcotic and nonnarcotic medications when appropriate. These medications--which include steroids, bone-forming, antidepressant and anticonvulsant medications, antihistamines and sedatives--are often useful in treating opioid-resistant pain. For whatever reason, they do relieve pain, although they are not usually labeled as pain relievers.



Simple measures such as aspirin or Tylenol, with or without codeine, or ibuprofen may do the job well enough. But when pain is severe, the dosage has to be increased or the drug has to be taken more frequently. If these simple measures don't help, then it is important to increase the strength or potency of the medication. Sometimes, just the addition of an adjuvant medication is all that is needed.



Side Effects of Pain MedicationsBack to the Table of Contents
Not all people tolerate all drugs equally. Some people are allergic to various medications. Some develop side effects from medications that others taking the same drugs do not share. Some people tolerate one specific drug in a class of drugs but do not tolerate others in the same class. Some do not tolerate any drugs in a particular class. Everyone is an individual.
While 90 to 95 percent of patients receive adequate pain control using the WHO guidelines, there are still 5 to 10 percent of patients who do not achieve adequate pain control. Certain direct interventions by specialists can modify or block pain information from reaching the central nervous system.






These interventions include nerve blocks with local anesthetics or nerve-destroying agents, alternative delivery systems such as administering narcotics under the skin (subcutaneous) or into the spine, spinal local anesthetics or other therapies that destroy nerves causing the pain.






These invasive, interventional therapies require the expertise and skills of a pain specialist. Morphine remains the gold standard of medical practice. Morphine and other options can be taken in a variety of ways. Most methods control pain very effectively.









Many patients with cancer fear that they will suffer pain. In fact, at some point during the course of the disease, 60 to 90 percent of patients will require a pain-relieving therapy. But not all cancers produce pain equally, and some cancers, even when advanced, may not cause pain at all. Cancers that are more typically painful include tumors of the bone (either primary or through spread) and the organs of the abdomen. Cancers of the blood system, such as leukemias or lymphomas, often never cause pain.




Pain can have a terrible effect on a cancer patient's life. It can lead to depression, loss of appetite, irritability, and withdrawal from social interaction, anger, loss of sleep and an inability to cope. If uncontrolled, pain can destroy relationships with loved ones and the will to live. Fortunately, pain can almost always be controlled. What is needed is an understanding by caregivers of the nature of the pain, of what causes it and of the appropriate treatments for the type of pain involved, as well as a commitment to relieving it. The oncologist is usually well equipped to handle most types of pain. For more unremitting pains, patients may be referred by their doctor to a specialist who will help to sort out the cause and treatments for symptoms.
Pain is a complex phenomenon. It has physical, emotional and psychological components. How each person responds to pain is also complex.






The extent of disease and the nature of the discomfort contribute to a person's experience of pain. But pain is also modified by remembrances of past painful episodes, the special meaning of pain to each individual, the expectations of family and friends, religious upbringing and personal coping skills and strategies. Cultural beliefs also influence the pain experience. Certain cultures teach tolerance of pain or that the outward expression of pain is inappropriate. People from these cultures bear their pain without complaining or even expressing their needs. Externally, they may appear to have a higher threshold or tolerance to pain while in fact suffering quietly. Other cultures readily and outwardly express painful experiences, and people from those cultures may appear to have a lower threshold or tolerance.Types of PainBack to the Table of Contents
Somatic Pain from the cancer itself may come from a bone broken because of tumor invasion or from an obstruction in the intestine or urinary tract. Pain from bone involvement is often described as achy, dull, localized and brought about by activity of the surrounding muscle groups or movement of the limb or spine. Obstructions in the intestine or urinary tract typically are described as crampy and more diffuse. They may be associated with inability to eat or to pass stool or urine.




Neuropathic Pain from nerve involvement is either related to direct tumor spread, such as the spread of colon cancer into the pelvis where the nerves to the legs or pelvic structures reside, or is secondary to irritating substances that tumors secrete near nerves. Neuropathic pain may also result from pressure on the nerves, as when spinal tumors pinch or press on nerves to the arms or legs. Neuropathic pain is often described as sharp, burning, electrical, shooting or buzzing. It typically occurs in the area that the injured nerves serve.
Surgery may cause both somatic and neuropathic pain. Pain from direct surgical injury is somatic and usually responds to opioid medications. Surgical injury to nerves may respond to opioids, antiseizure or antidepressant medications.




Chemotherapeutic drugs act like poisons to tumors and may act the same way on some vulnerable nerves. Drugs such as antiviral agents or vincristine, cisplatin, carboplatin, Taxol and Navelbine can cause peripheral neuropathy, which is often felt as a burning in the hands and feet. This requires drugs specific for neuropathic pain or some other intervention for relief. The sore mouth (mucositis) that is sometimes a side effect of these drugs is one example of somatic pain from chemotherapy.




After radiation therapy, pain may be due to skin reactions to the radiation, breakdown of mucous membranes or even scarring of the nerves (fibrosis), which can produce a neuropathic pain.




Emotional SourcesBack to the Table of Contents
Pain is made worse by worry and fear of death, suffering, deformity, financial disability or isolation. The onset of pain or a new pain may trigger fears about the spread of the disease or of impending death. All these fears can be magnified when a kind of spiritual pain accompanies the fear. This might be triggered by surroundings, low levels of emotional support or feelings of loneliness and desperation. How one approaches the problems of life makes a big difference to the perception of pain. Also, whether pain is adequately controlled makes a big difference.

1 comment:

  1. Thanks for the great tutorial. It is nice to go through the process at a high level.
    Work Related Injury

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