Pain is defined as an unpleasant experience resulting from actual or potential damage to tissues of the body. Most patients experience pain at sometime during their lives. Pain involves injury or disease of skin, bone, muscles, nerves, blood vessels, brain, or internal organs. Studies show that as many as 80% of patients with cancer have pain sometime during the course of their illness. Adequate pain control is possible more than 90% of the time using medications that can be taken by mouth. With the use of surgical techniques and sedation, pain can almost always be controlled. Return to Top
Pain can be described as acute or chronic. Acute pain is usually related to an easily identified event or condition. For example, a child falling off his bike and breaking a leg will experience acute pain. Acute pain usually resolves within a period of days to weeks. In contrast, chronic pain may be present all the time. It is usually easy to tell if someone is in acute pain. They may be sweaty and be breathing quickly. Their pulse is often fast. There maybe facial signs of grimacing or moaning, and the patient may be holding the painful body part in a protective fashion. On the other hand, it may be very hard to tell if someone is experiencing chronic pain. The patient's body has become accustomed to the pain, and there may be no signs visible to someone else of the patient's level of pain. Patients with cancer often may experience chronic pain.
Pain is said to be nociceptive pain if it involves the direct stimulation of nerve endings and nerves. Nociceptive pain may involve the skin, muscles, bone, and internal organs. Patients typically describe nociceptive pain as sharp, aching, dull, or throbbing. Nociceptive pain generally responds well to acetaminophen, nonsteroidal anti-inflammatory drugs, and medication such as morphine that is in the opioid family.
Neuropathic pain results from injury to one's nerves. People describe neuropathic pain as burning, tingling, numbness, shooting, stabbing, or electric-like feelings. Unlike nociceptive pain, neuropathic pain can be treated with medication used for seizures or depression. Occasionally, medicines in the opioid family are also used to treat neuropathic pain. Return to Top
Acetaminophen (known as the medication in Tylenol) is a medication used for mild pain of any kind. Acetaminophen does not usually cause severe side effects. No more than 4,000 mg should be taken in a day to avoid liver damage. Persons consuming heavy amounts of alcohol should limit their intake of acetaminophen.
Aspirin can also be used for mild pain, but aspirin has more side effects than acetaminophen, including bleeding, nausea, heartburn, ringing in the ears, and irritation of the lining of the stomach.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are helpful for mild to moderate pain. Familiar medicines in this category include ibuprofen and naproxen. NSAIDs have significant side effects, including bleeding, kidney failure, nausea, rash, fluid retention, and stomach ulcers.
Opioids is the general name for a family of drugs. The name is derived from opium. The juice of the opium poppy is used to make some but not all of the drugs in this family. Opioids are medications for patients to take when they are experiencing moderate to severe pain. Medications in the opioid family include morphine, hydromorphone, methadone, oxycodone, fentanyl, and meperidine. Opioids have a common set of side effects that, in most cases, disappear within several days. The most common of these effects include nausea, vomiting, and sedation. Constipation is also a common side effect of opioids, but constipation usually does not resolve. At the same time that patients start opioids, they should start a stimulative laxative such as senna or casanthranol to counteract the constipating effect. These medications are available over the counter at your local pharmacy. Rare side effects of opioids include bad dreams, jerking, itching, rashes, slowing of breathing, and inability to urinate. If a patient is experiencing any of these side effects, the patient should contact a doctor. Return to Top
Doctors and nurses will assess the type (acute or chronic and nociceptive or neuropathic) and the severity of pain before prescribing pain medication. Frequently, doctors or nurses will ask patients to rate their pain on a scale from 0 (no pain at all) to 10 (the worst pain imaginable). Patients who rate their pain as mild (1-4 on the 10-point scale) are usually treated with aspirin, acetaminophen, nonsteroidal anti-inflammatory drugs such as ibuprofen, and other medications depending upon the cause of pain. For example, if the pain was neuropathic, an antiseizure or antidepressant medication might be used. If the patient rates the pain as moderate (5-6 on a 10-point scale), doctors will usually prescribe acetaminophen with codeine, acetaminophen with hydrocodone, acetaminophen with oxycodone, or tramadol. If the patient describes the pain as severe (7-10 on a 10-point scale), doctors use stronger pain medications such as morphine, hydromorphone, methadone, fentanyl, and oxycodone. Return to Top
If medications are given by mouth, relief from pain is usually experienced within 30-60 minutes. If pain medications are given as a shot into the muscle or under the skin, pain relief usually occurs within 30 minutes. If pain medications are given directly into the vein (intravenously), pain relief usually occurs within 10-15 minutes. Return to Top
Patients who have chronic pain are best treated with medications given on a regular basis throughout the day. Usually doctors prescribe long-acting pain medicines that work for 8 to 12 hours. Research has shown that treating chronic pain with doses around the clock prevents the pain from building up to the point in which it is much more difficult to control. Return to Top
Patients frequently do not want to take stronger medications such as opioids (morphine and similar medications) because of a concern that they will become addicted. In fact, addiction is an uncommon occurrence for most patients. Research has shown that fewer than 1 in 1,000 cancer patients become addicted. Fewer than 1 in 10,000 patients with acute pain from orthopedic injuries become addicted. The patients who are most prone to develop addiction are those who have problems with substance abuse. Patients who are addicted to pain medicine take pain medications for reasons other than pain relief and are characterized by compulsive drug use and continued use of the medications despite harmful negative consequences. Return to Top
Tolerance may develop to pain medication if it is taken over a long period of time. A sign of tolerance is if the same dose of a pain medication becomes less effective in reducing a patient's pain. Recent research has indicated that tolerance is not as common as previously thought. If tolerance does develop, the dose of the medication can be increased or a new medication can be started. Return to Top
Physical dependence describes the changes in the body that occur over time when a person takes opioids. After 1 or more weeks of taking opioids, the body may develop a physical dependence such that the opioids cannot be stopped abruptly. Physical dependence can occur for other substances such as caffeine and steroid medications. Just like people who are used to drinking large amounts of coffee each day might experience a caffeine withdrawal headache if they stop drinking coffee, patients who have been taking opioids on a daily bases for longer than a week may experience symptoms of drug withdrawal if they stop taking the opioids abruptly. To prevent drug withdrawal symptoms, patients should be weaned from opioid medications. The best approach is to decrease the amount of medication by 25% every two days until the medication is completely stopped. Return to Top
Information based on the Pain Management module in the American Medical Association's Education Program for Physicians on End-of-Life Care. www.epec.net