brain, spinal cord, and nerve disorders
Treatment of Pain
Nonopioid Pain Relievers
A variety of nonopioid pain relievers are available. They are often effective for mild to moderate pain and sometimes for severe pain. These drugs are often preferred for treating pain. People do not become physically dependent on these drugs or tolerant of their pain-relieving effects. Aspirinandacetaminophenare available without a prescription (over-the-counter, or OTC). Several other nonopioid analgesics (such asibuprofen,ketoprofen, andnaproxen) are available OTC, but higher doses may require a prescription. OTC pain relievers are reasonably safe to take for short periods of time. People should follow the instructions on the label for the maximum dose, frequency, and length of time the drug should be taken. A doctor should be consulted if symptoms worsen or do not go away. Many of the most commonly used nonopioid pain relievers are classified as nonsteroidal anti-inflammatory drugs (NSAIDs).Aspirin,ibuprofen, andnaproxenare examples. These drugs are usually used to treat mild to moderate pain. NSAIDs not only relieve pain, but they may also reduce the inflammation that often accompanies and worsens pain. NSAIDs are often taken by mouth. Some NSAIDs (ketorolacdiclofenac, andibuprofen) can also be given by injection into a vein (intravenously) or muscle (intramuscularly).Indomethacincan be given as a rectal suppository.Diclofenacis also available as a cream. Although widely used, NSAIDs can have side effects, sometimes serious ones. All NSAIDs tend to irritate the stomach’s lining and cause digestive upset (such as heartburn, indigestion, nausea, bloating, diarrhea, and stomach pain), Peptic Ulcer Disease , and bleeding in the digestive tract ( Bleeding problems:All NSAIDs interfere with the clotting tendency of platelets (cell-like particles in the blood that help stop bleeding when blood vessels are injured). Consequently, NSAIDs increase the risk of bleeding, especially in the digestive tract if they irritate the stomach’s lining. Coxibs are less likely to cause bleeding than other NSAIDs. Fluid retention or kidney problems:NSAIDs sometimes cause fluid retention and swelling. Regular use of NSAIDs may also increase the risk of developing a kidney disorder, sometimes resulting in kidney failure (a disorder called analgesic nephropathy). Increased risk of heart and blood vessel disorders:Studies suggest that with all NSAIDs exceptaspirin, the risk of heart attack, stroke, and blood clots in the legs may be increased. The risk appears to be higher with higher doses and longer use of the drug. The risk is also higher with some NSAIDs than with others. These problems may be related directly to the drug’s effect on clotting or indirectly to a small but persistent increase in blood pressure caused by the drug. People who take NSAIDs for a long time are more likely to have these problems. Such people need to have regular appointments with their doctor to check for high blood pressure, kidney failure, and ulcers or bleeding in the digestive tract and to evaluate their risk of heart disease and stroke. Taking NSAIDs for a short time is unlikely to cause serious problems. The risk of side effects may be increased for some groups of people, such as the following: Older people People who drink alcoholic beverages regularly People with coronary artery disease, other heart and blood vessel (cardiovascular) disorders, or risk factors for these disorders Older people and people who have heart failure, high blood pressure, or a kidney or liver disorder require a doctor’s supervision when they take NSAIDs. Some prescription heart and blood pressure drugs may not work as well when taken with NSAIDs. If taken for a long time, NSAIDs, including those available without a prescription, can have serious side effects. NSAIDs vary in how quickly they work and how long they relieve pain. Although NSAIDs are about equally effective, people respond to them differently. One person may find a particular drug to be more effective or to have fewer side effects than another. Aspirin(acetylsalicylic acid) has been used for about 100 years.Aspirinis taken by mouth and provides 4 to 6 hours of moderate pain relief. Becauseaspirincan irritate the stomach, it may be combined with an antacid (called buffered) or coated so that it passes quickly through the stomach and dissolves when it reaches the small intestine (called enteric coated). These products are intended to reduce stomach irritation. However, buffered or enteric-coatedaspirincan still irritate the stomach becauseaspirinalso reduces the production of substances that help protect the stomach’s lining. These substances are called prostaglandins. Aspirinincreases the risk of bleeding throughout the body because it makes platelets less able to function. Platelets are cell fragments in the blood that help blood clot. Anyone who has an increased tendency to bleed (a bleeding disorder such as hemophilia) or uncontrolled high blood pressure should not takeaspirinexcept under a doctor’s supervision. People who takeaspirinand anticoagulants (drugs that make blood less likely to clot), such aswarfarin, are closely monitored to avoid life-threatening bleeding. Usually,aspirinshould not be taken in the week before scheduled surgery. , may have a severe allergic reaction ( Anaphylactic Reactions ), leading to a rash, itching, severe breathing problems, or can have serious side effects such as abnormal breathing, fever, or confusion. One of the first signs of an overdose may be noise in the ears ( Ear Ringing or Buzzing ). because they could develop Reye Syndrome if they have or have just gotten over influenza or chickenpox. Although rare, Reye syndrome can have serious consequences, including death. gel can be applied to a joint to relieve pain due to Osteoarthritis (OA) and help improve movement. NSAIDs such asibuprofen,ketoprofen, andnaproxenare generally believed to be gentler on the stomach thanaspirin, although few studies have compared the drugs. Likeaspirin, these drugs can cause digestive upset, ulcers, and gastrointestinal bleeding. They can make asthma worse and increase blood pressure. Taking one of these drugs probably slightly increases the risk of stroke, heart attack, and blood clots in the arteries of the legs. The risk may be lower withnaproxenthan with other NSAIDs. Thus,naproxenmay be a better choice when people with a high risk of these disorders require NSAIDs. Althoughibuprofen,ketoprofen, andnaproxengenerally interfere with blood clotting less thanaspirindoes, people should not take these drugs with anticoagulants (such aswarfarin) except under a doctor’s close supervision. People who are allergic toaspirinmay also be allergic toibuprofen,ketoprofen, andnaproxen. If a rash, itching, breathing problems, or shock develops, medical attention is required immediately. Coxibs, such ascelecoxib, are a group of drugs that differ from other NSAIDs. Other NSAIDs block the following two enzymes: COX-1, which is involved in the production of prostaglandins that protect the stomach and play a crucial role in blood clotting COX-2, which is involved in the production of prostaglandins that promote inflammation Coxibs tend to block mainly COX-2 enzymes. Thus, coxibs are as effective as other NSAIDs in the treatment of pain and inflammation. But coxibs are less likely to damage the stomach and to cause nausea, bloating, heartburn, bleeding, and peptic ulcers. They are also less likely to interfere with clotting than are other NSAIDs. Because of these differences, coxibs may be useful for people who cannot tolerate other NSAIDs and for people who are at high risk of certain complications (such as gastrointestinal bleeding) from use of other NSAIDs. Such people include the following: Older people People taking anticoagulants People with a history of ulcers People taking an analgesic for a long time However, coxibs, like other NSAIDs, appear to increase the risk of heart attack, stroke, and blood clots in the legs. As a result, before people with certain conditions are given a coxib, they are told about the risk and the need to be closely monitored. These conditions include Cardiovascular disorders (such as coronary artery disease) Strokes Risk factors for these disorders Coxibs, like other NSAIDs, are not appropriate for people who have heart failure or who are at increased risk of heart failure (such as those who have had a heart attack). Nonsteroidal anti-inflammatory drugs (NSAIDs) work in two ways: They reduce the sensation of pain. At higher doses, they reduce the inflammation that often accompanies and worsens pain. NSAIDs have these effects because they reduce the production of hormone-like substances called prostaglandins. Different prostaglandins have different functions, such as making nerve cells more likely to respond to pain signals and causing blood vessels to widen (dilate). Most NSAIDs reduce prostaglandin production by blocking both cyclooxygenase (COX) enzymes (COX-1 and COX-2), which are crucial to the formation of prostaglandins. One type of NSAID, the coxibs (COX-2 inhibitors), tend to block mainly COX-2 enzymes. Only COX-2 enzymes are involved in the production of prostaglandins that promote Molecules and the resulting pain. These prostaglandins are released in response to an injury—burn, break, sprain, strain, or invasion by a microorganism. The result is inflammation, which is a protective response: The blood supply to the injured area increases, bringing in fluids and white blood cells to wall off the damaged tissue and remove any invading microorganisms. Prostaglandins that are formed through the action of COX-1 enzymes help protect the digestive tract from stomach acid and play a crucial role in blood clotting. Because most NSAIDs block COX-1 enzymes and thus reduce the production of these prostaglandins, they may irritate the stomach’s lining. Such irritation can cause digestive upset, peptic ulcers, and bleeding in the digestive tract. Because coxibs block mainly COX-2 enzymes, they are less likely to cause problems due to stomach irritation. However, coxibs block some COX-1 enzymes, so even coxibs may slightly increase the risk of these problems. Acetaminophenis roughly comparable toaspirinin its potential to relieve pain and lower a fever. But unlike NSAIDs,acetaminophenhas the following characteristics: Has virtually no useful anti-inflammatory activity Does not affect the blood’s ability to clot Has almost no adverse effects on the stomach Howacetaminophenworks is not clearly understood. Acetaminophenis taken by mouth or a suppository inserted into the rectum, and its effects generally last 4 to 6 hours. appears to be a very safe drug. However, high doses can lead to liver damage, which may be irreversible (see Acetaminophen Poisoning ). People with a liver disorder should use lower doses than those usually prescribed. Whether lower doses taken for a long time can harm the liver is less certain. People who regularly consume large amounts of alcohol are probably at highest risk of liver damage from overuse of 