Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain relievers are effective for nociceptive pain (due to injury) but are less effective for neuropathic pain Neuropathic Pain Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. (See also Overview of Pain.) Neuropathic pain may result from Compression of a nerve—for example... read more (due to damage or dysfunction of the nerves, spinal cord, or brain). For many types of pain, especially chronic pain Chronic Pain Chronic pain is pain that lasts or recurs for months or years. Usually, pain is considered chronic if it does one of the following: Lasts for more than 3 months Lasts for more than 1 month after... read more , nondrug treatments Nondrug Pain Treatments Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more are also important.
In some cases, treating the underlying disorder eliminates or minimizes the pain. For example, setting a broken bone in a cast or giving antibiotics for an infected joint helps reduce pain. However, even if the underlying disorder can be treated, pain relievers may still be needed to quickly manage the pain.
(See also Overview of Pain Overview of Pain Pain is an unpleasant sensation signaling actual or possible injury. Pain is the most common reason people seek medical care. Pain may be sharp or dull, intermittent or constant, or throbbing... read more .)
Did You Know...
Drugs used to relieve pain fall into three categories:
Adjuvant (drugs that are usually used to treat other problems such as seizures or depression but that can also relieve 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.
Aspirin and acetaminophen are available without a prescription (over-the-counter, or OTC). Several other nonopioid analgesics (such as ibuprofen, ketoprofen, and naproxen) 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.
Nonsteroidal Anti-Inflammatory Drugs
Many of the most commonly used nonopioid pain relievers are classified as nonsteroidal anti-inflammatory drugs (NSAIDs). Aspirin, ibuprofen, and naproxen are 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 (ketorolac diclofenac, and ibuprofen) can also be given by injection into a vein (intravenously) or muscle (intramuscularly). Indomethacin can be given as a rectal suppository. Diclofenac is also available as a cream.
Although widely used, NSAIDs can have side effects, sometimes serious ones.
Problems in the digestive tract: All NSAIDs tend to irritate the stomach’s lining and cause digestive upset (such as heartburn, indigestion, nausea, bloating, diarrhea, and stomach pain), peptic ulcers Peptic Ulcer Disease A peptic ulcer is a round or oval sore where the lining of the stomach or duodenum has been eaten away by stomach acid and digestive juices. Peptic ulcers can result from Helicobacter pylori... read more , and bleeding in the digestive tract (gastrointestinal bleeding Gastrointestinal Bleeding Bleeding may occur anywhere along the digestive (gastrointestinal [GI]) tract, from the mouth to the anus. Blood may be easily seen by the naked eye (overt), or blood may be present in amounts... read more ). Coxibs (COX-2 inhibitors), a type of NSAID, are less likely to irritate the stomach and cause bleeding than other NSAIDs. Taking NSAIDs with food and using antacids may help prevent stomach irritation. The drug misoprostol can help prevent stomach irritation and ulcers, but it can cause other problems, including diarrhea. Proton pump inhibitors Proton pump inhibitors Stomach acid plays a role in a number of disorders of the stomach, including peptic ulcer, gastritis, and gastroesophageal reflux disease (GERD). Although the amount of acid present in the stomach... read more (such as omeprazole) or histamine-2 (H2) blockers Histamine-2 (H2) blockers Stomach acid plays a role in a number of disorders of the stomach, including peptic ulcer, gastritis, and gastroesophageal reflux disease (GERD). Although the amount of acid present in the stomach... read more (such as famotidine), which are used to treat peptic ulcers, can also help prevent stomach problems due to NSAIDs.
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 except aspirin, 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:
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.
Did You Know...
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. Aspirin is taken by mouth and provides 4 to 6 hours of moderate pain relief.
Because aspirin can 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-coated aspirin can still irritate the stomach because aspirin also reduces the production of substances that help protect the stomach’s lining. These substances are called prostaglandins.
Aspirin increases 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 take aspirin except under a doctor’s supervision. People who take aspirin and anticoagulants (drugs that make blood less likely to clot), such as warfarin, are closely monitored to avoid life-threatening bleeding. Usually, aspirin should not be taken in the week before scheduled surgery.
Aspirin can aggravate asthma. People with nasal polyps are likely to develop wheezing if they take aspirin. A few people, who are sensitive (allergic) to aspirin, may have a severe allergic reaction (anaphylaxis Anaphylactic Reactions Anaphylactic reactions are sudden, widespread, potentially severe and life-threatening allergic reactions. Anaphylactic reactions often begin with a feeling of uneasiness, followed by tingling... read more ), leading to a rash, itching, severe breathing problems, or shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more . Such a reaction requires immediate medical attention.
In very high doses, aspirin 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 (tinnitus Ear Ringing or Buzzing Ringing in the ears (tinnitus) is noise originating in the ear rather than in the environment. It is a symptom and not a specific disease. Tinnitus is very common—10 to 15% of people experience... read more ).
Most children and teenagers should not take aspirin because they could develop Reye syndrome Reye Syndrome Reye syndrome is a very rare but life-threatening disorder that causes inflammation and swelling of the brain and impairment and loss of function of the liver. The cause of Reye syndrome is... read more if they have or have just gotten over influenza or chickenpox. Although rare, Reye syndrome can have serious consequences, including death.
Some NSAIDs are available as creams or gels that are applied directly to the skin over the painful area. For example, diclofenac gel can be applied to a joint to relieve pain due to osteoarthritis Osteoarthritis (OA) Osteoarthritis is a chronic disorder that causes damage to the cartilage and surrounding tissues and is characterized by pain, stiffness, and loss of function. Arthritis due to damage of joint... read more and help improve movement. Diclofenac is also available as a patch, which can be used to relieve acute pain due to minor sprains, strains, and bruises.
Ibuprofen, ketoprofen, and naproxen
NSAIDs such as ibuprofen, ketoprofen, and naproxen are generally believed to be gentler on the stomach than aspirin, although few studies have compared the drugs. Like aspirin, 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 with naproxen than with other NSAIDs. Thus, naproxen may be a better choice when people with a high risk of these disorders require NSAIDs.
Although ibuprofen, ketoprofen, and naproxen generally interfere with blood clotting less than aspirin does, people should not take these drugs with anticoagulants (such as warfarin) except under a doctor’s close supervision.
People who are allergic to aspirin may also be allergic to ibuprofen, ketoprofen, and naproxen. If a rash, itching, breathing problems, or shock develops, medical attention is required immediately.
Coxibs (COX-2 inhibitors)
Coxibs, such as celecoxib, 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:
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)
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).
Acetaminophen is roughly comparable to aspirin in its potential to relieve pain and lower a fever.
But unlike NSAIDs, acetaminophen has 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
How acetaminophen works is not clearly understood.
Acetaminophen is taken by mouth or a suppository inserted into the rectum, and its effects generally last 4 to 6 hours.
Acetaminophen appears to be a very safe drug. However, high doses can lead to liver damage, which may be irreversible (see Acetaminophen Poisoning Acetaminophen Poisoning Acetaminophen, a common ingredient in many prescription and non-prescription drugs, is safe in normal doses, but severe overdose can cause liver failure and death. People sometimes ingest too... read more ). 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 acetaminophen. People who are taking acetaminophen and stop eating because of a bad cold, influenza, or another reason may be more vulnerable to liver damage.
Opioid Pain Relievers
Opioid pain relievers (analgesics)—sometimes called narcotics—are effective for many different types of pain. Usually, they are the strongest pain relievers.
Opioids are chemically related to morphine, a natural substance extracted from poppies. Some opioids are extracted from other plants, and other opioids are produced in a laboratory.
Opioids are often prescribed for a few days to treat severe pain that is likely to lessen quickly (such as pain due to injury or after surgery). Doctors usually switch people to nonopioid pain relievers as soon as possible because opioids may have side effects and there is a risk of misuse or addiction. Opioids are not usually recommended to treat people with chronic pain.
Doctors sometimes prescribe opioids for longer periods of time for people who have severe pain due to cancer or a terminal illness, especially as part of care at the end of life, including hospice care Hospice Care Hospice is a concept and a program of care that is specifically designed to minimize suffering for dying people and their family members. In the United States, hospice is the only widely available... read more . In these situations, side effects can usually be prevented or managed, and misuse or addiction is less of a concern.
Before prescribing opioids for any type of chronic pain, doctors consider
What the usual treatment approach is
Whether other treatments could be used
Whether the person has a high risk of side effects from an opioid
Whether the person is at risk of misuse or abuse of an opioid drug or is likely to use the drugs for other purposes (for example, to sell them)
Doctors may refer people to a pain specialist or a mental health care practitioner who has expertise in substance misuse if the risk of having a problem is high. For example, people who have had an addiction usually need such a referral.
When opioids are prescribed for chronic pain, doctors explain the nature of the person's disorder (if known) and the risks and benefits of other possible treatments, including nonopioid drugs and no treatment. Doctors ask people about their goals and expectations. They usually give the person written information that describes the risks of taking opioids. After people discuss this information with their doctor and understand it, they are asked to sign an informed consent Informed Consent Before performing any invasive test or providing medical treatment, doctors must obtain permission from a competent patient in a manner that is informed and voluntary. The process is known as... read more document.
When doctors prescribe an opioid for chronic pain, they explain the risks and side effects of opioids. People are advised
Not to drink alcohol or take antianxiety drugs or sleep aids when taking the opioid
To take the recommended dose at the recommended times and not to change the dose
To store the opioid in a safe, secure place
Not to share the opioid with anyone
To contact their doctor if the drug makes them drowsy or they have any other side effects (such as confusion, constipation, or nausea)
To dispose of unused pills as directed
To keep naloxone (an opioid antidote) on hand and to learn and teach family members how to administer it if an opioid overdose occurs
If an opioid is prescribed, doctors have usual practices to ensure the person's safety. Doctors typically ask the person to get opioid prescriptions only from one doctor and fill prescriptions at the same pharmacy every time. They see the person frequently for follow-up visits and monitor the use of the drug to make sure it is safe and effective. For example, doctors may periodically test the person's urine to determine whether the drug is being taken correctly. They also ask the person to sign an agreement that specifies conditions required for opioid use, including any monitoring that may be needed. To avoid misuse by others, the person should keep opioids in a safe place and dispose of any unused drugs by returning them to the pharmacy.
Side effects of opioids
Opioids have many side effects. Side effects are more likely to occur in people with certain disorders: kidney failure Overview of Kidney Failure This chapter includes a new section on COVID-19 and acute kidney injury (AKI). Kidney failure is the inability of the kidneys to adequately filter metabolic waste products from the blood. Kidney... read more , a liver disorder Overview of Liver Disease Liver disease can manifest in many different ways. Characteristic manifestations include Jaundice (a yellowish discoloration of the skin and whites of the eyes) Cholestasis (reduction or stoppage... read more , chronic obstructive pulmonary disease Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease is persistent narrowing (blocking, or obstruction) of the airways occurring with emphysema, chronic obstructive bronchitis, or both disorders. Cigarette... read more (COPD), untreated sleep apnea Sleep Apnea Sleep apnea is a serious disorder in which breathing repeatedly stops long enough to disrupt sleep and often temporarily decrease the amount of oxygen and increase the amount of carbon dioxide... read more , dementia Dementia Dementia is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn. Typically, symptoms include memory loss, problems using language and... read more , or another brain disorder.
The following commonly occur when opioids are used:
Mental fuzziness or confusion
Nausea and vomiting
Less common side effects of opioids include
Retention of urine
A dangerous slowing of breathing
Drowsiness is a common side effect of opioids. For some people who take opioids, drowsiness disappears or decreases within a few days. If people continue to feel drowsy, a different opioid can be tried because the degree of drowsiness caused by different opioids varies. Before an important event that requires alertness, people may be given a stimulant drug (such as methylphenidate or modafinil) to offset the drowsiness. For some people, drinking a caffeinated beverage helps offset the drowsiness. When feeling drowsy after taking an opioid, people should avoid driving and take extra care to prevent falls and accidents.
Confusion can also result from taking opioids, especially if people are older. Opioids increase the risk of falls in older people.
Nausea sometimes occurs in people with pain, and opioids can increase the nausea. Antiemetic drugs taken by mouth, suppository, or injection help prevent or relieve nausea. Some commonly used antiemetic drugs are metoclopramide, hydroxyzine, and prochlorperazine.
The itching caused by taking opioids may be relieved by an antihistamine such as diphenhydramine, taken by mouth or given intravenously.
Constipation Constipation in Adults Constipation is difficult or infrequent bowel movements, hard stool, or a feeling that the rectum is not totally empty after a bowel movement (incomplete evacuation). (See also Constipation... read more often develops, especially in older people. Stimulant laxatives Laxatives Constipation is difficult or infrequent bowel movements, hard stool, or a feeling that the rectum is not totally empty after a bowel movement (incomplete evacuation). (See also Constipation... read more , such as senna, help prevent or relieve the constipation. Increasing the intake of fluids and the amount of fiber in the diet can also help. Osmotic agents Laxatives such as polyethylene glycol can also be useful. These agents pull large amounts of water into the large intestine to stimulate bowel movements. Some people need enemas. When these measures are not effective, doctors may prescribe a drug (such as methylnaltrexone) that blocks only the effects of opioids in the stomach and intestine and does not lessen the pain relief.
Retention of urine Urinary Retention Urinary retention is inability to urinate or incomplete emptying of the bladder. People who have incomplete emptying of the bladder may have urinary frequency or urinary incontinence. If the... read more can result from taking opioids, especially in men with an enlarged prostate. Trying to urinate a second time after a brief pause (double voiding) or applying gentle pressure on the lowest part of the abdomen (the area over the bladder) during urination may help. Sometimes a drug that relaxes muscles of the bladder (such as tamsulosin) is used.
For most people, nausea and itching disappear or decrease within a few days. But constipation and retention of urine usually decrease much more slowly, if at all.
Serious side effects can occur when people take too much of an opioid. These side effects include a dangerous slowing of breathing (respiratory depression), coma, and even death. The following adds to the risk of developing respiratory depression and of dying from respiratory arrest:
Having certain conditions (such as liver, kidney, respiratory, or mental health disorders)
Taking other drugs that cause drowsiness (such as benzodiazepines)
Some of these side effects can be reversed with naloxone, an antidote usually given intravenously or sprayed into the nose.
For people who are at increased risk of opioid side effects (including respiratory depression), doctors may prescribe naloxone when they prescribe the opioid. Nurses and family members or caregivers should watch for serious side effects of opioids and, if such side effects occur, be ready to inject naloxone or spray it into the person's nose. Doctors or pharmacists usually teach the person taking the opioid and family members or caregivers how to administer naloxone.
Tolerance Tolerance Tolerance is a person's diminished response to a drug, which occurs when the drug is used repeatedly and the body adapts to the continued presence of the drug. Resistance refers to the ability... read more occurs in some people who take opioids repeatedly over time. They need higher doses because their body adapts to and thus responds less well to the drug. However, for most people, the same opioid dose remains effective for a long time. Often, the need for a higher dose means that the disorder is worsening, not that tolerance is developing.
Physical dependence Long-term effects Opioids are a class of drugs derived from the opium poppy (including synthetic variations) that are pain relievers with a high potential for misuse. Opioids are used to relieve pain, but they... read more usually develops in people who take opioids for a long time. That is, they experience withdrawal symptoms if the drug is stopped. Withdrawal symptoms Withdrawal symptoms Opioids are a class of drugs derived from the opium poppy (including synthetic variations) that are pain relievers with a high potential for misuse. Opioids are used to relieve pain, but they... read more include chills, abdominal cramping, diarrhea, trouble sleeping, and a jittery feeling. When opioids are stopped after long-term use, doctors reduce the dose gradually over a period of time to minimize the development of such symptoms.
Physical dependence is not the same as opioid use disorder Substance Use Disorders Substance use disorders generally involve behavior patterns in which people continue to use a substance despite having problems caused by its use. The substances involved tend to be members... read more (addiction). Dependence is characterized by a craving for the drug and compulsive, uncontrolled use of the drug despite the harm done to the user or other people. Most people who take opioids to control pain and have not previously had problems with drug abuse do not become addicted to opioids. Nonetheless, doctors regularly monitor people who are taking opioid analgesics for signs of addiction.
Administration of opioids
When possible, opioids are taken by mouth (orally Oral route Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space... read more ). When opioids are taken by mouth, the dose and time they are taken can be adjusted more easily. When they need to be taken for a long time, they may be given by mouth or through a patch placed on the skin (transdermally Transdermal route Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space... read more ). Opioids are given by injection Injection routes Drugs are introduced into the body by several routes. They may be Taken by mouth (orally) Given by injection into a vein (intravenously, IV), into a muscle (intramuscularly, IM), into the space... read more (into a muscle or vein) when pain occurs suddenly or when people cannot take them by mouth or through a skin patch.
Problems with use of opioids
Opioids Opioids Opioids are a class of drugs derived from the opium poppy (including synthetic variations) that are pain relievers with a high potential for misuse. Opioids are used to relieve pain, but they... read more are now the leading cause of accidental death and fatal drug overdose in the United States. Problems with using opioids include opioid misuse, diversion, and abuse.
Opioid misuse may be intentional or unintentional. It includes any use that differs from what is prescribed.
Diversion involves selling or giving a prescribed drug to others.
Abuse refers to recreational use of the drug. That is, the drugs are taken for the feelings of pleasure or sensations they produce, rather than to treat pain or another medical condition.
Up to one third of people taking opioids for a long time to treat chronic pain misuse them.
Opioid use disorder Substance Use Disorders Substance use disorders generally involve behavior patterns in which people continue to use a substance despite having problems caused by its use. The substances involved tend to be members... read more is the preferred term for what previously was called opioid addiction. It refers to compulsive use of opioids despite having problems caused by taking them. Also, people who have this disorder may require higher and higher doses to achieve the same effects and may experience withdrawal symptoms when they stop taking the opioid. They may try to stop taking opioids or reduce the amount they are taking but cannot. Taking high doses of opioids for a long time increases the risk of developing opioid use disorder.
Adjuvant analgesics are thought to work by changing the way nerves process pain.
An adjuvant analgesic is the first and only drug used to treat pain due to nerve damage (neuropathic pain Neuropathic Pain Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. (See also Overview of Pain.) Neuropathic pain may result from Compression of a nerve—for example... read more ) and conditions such as fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more .
The adjuvant analgesics most commonly used for pain are
Antidepressants Drug Treatment for Depression Agomelatine, a new type of antidepressant, is a possible treatment for major depressive episodes. Several types of drugs can be used to treat depression: Selective serotonin reuptake inhibitors... read more (such as amitriptyline, bupropion, desipramine, duloxetine, nortriptyline, and venlafaxine)
Oral and topical local anesthetics
Antidepressants can often relieve pain in people even when they do not have depression. Tricyclic antidepressants (such as amitriptyline, nortriptyline, and desipramine) may be more effective for this purpose than other antidepressants, but newer antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and norepinephrine reuptake inhibitors (SNRIs, including duloxetine, venlafaxine, and milnacipran) may have fewer of the side effects that limit how much of the drug can be taken.
Tricyclic antidepressants are effective for neuropathic pain Neuropathic Pain Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. (See also Overview of Pain.) Neuropathic pain may result from Compression of a nerve—for example... read more , headaches Overview of Headache A headache is pain in any part of the head, including the scalp, upper neck, face, and interior of the head. Headaches are one of the most common reasons people visit a doctor. Headaches interfere... read more , fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more , and visceral (organ) hypersensitivity syndromes (such as chronic abdominal pain Chronic Abdominal Pain and Recurring Abdominal Pain Chronic abdominal pain is pain that is present for more than 3 months. It may be present all the time (chronic) or come and go (recurring). Chronic abdominal pain usually occurs in children... read more or pelvic pain Pelvic Pain in Women Pelvic pain is discomfort that occurs in the lowest part of the abdomen. Pain that occurs externally in the genital area (vulva, or labia) is called vulvar pain. Many women have pelvic pain... read more ). The doses of tricyclic antidepressants used to treat pain are usually too low to treat depression or anxiety. Thus, if tricyclic antidepressants are used to treat pain, additional drugs are usually needed to treat depression or anxiety if present.
Duloxetine appears to be effective for neuropathic pain due to diabetes (called diabetic neuropathy Nerve damage in diabetes People with diabetes mellitus have many serious long-term complications that affect many areas of the body, particularly the blood vessels, nerves, eyes, and kidneys. (See also Diabetes Mellitus... read more ), fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more , chronic low back pain Low Back Pain Low back pain and neck pain are among the most common reasons for health care visits. The pain usually results from problems with the musculoskeletal system—most notably the spine, including... read more , chronic musculoskeletal pain, and nerve pain due to chemotherapy. The doses of duloxetine used to treat pain are also adequate to treat depression or anxiety if present. Venlafaxine has similar effects. Milnacipran is effective for fibromyalgia.
People may respond to one antidepressant and not to others, so sometimes doctors try a few drugs until an effective one is found.
Antiseizure drugs may be used to relieve neuropathic pain. Gabapentin and pregabalin are commonly used, but many others, including carbamazepine, clonazepam, lacosamide, lamotrigine, oxcarbazepine, phenytoin, topiramate, and zonisamide, help relieve pain in some people.
Gabapentin can be used to treat the pain that can result from shingles (postherpetic neuralgia Postherpetic Neuralgia Postherpetic neuralgia is chronic pain in areas of skin supplied by nerves infected with herpes zoster ( shingles). Shingles is a painful rash of fluid-filled blisters that is caused by reactivation... read more ) and many other types of neuropathic pain Neuropathic Pain Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. (See also Overview of Pain.) Neuropathic pain may result from Compression of a nerve—for example... read more .
Pregabalin can be used to relieve pain caused by fibromyalgia Fibromyalgia Fibromyalgia is characterized by poor sleep, fatigue, mental cloudiness, and widespread aching and stiffness in soft tissues, including muscles, tendons, and ligaments. Poor sleep, stress, strains... read more or nerve damage due to diabetes (diabetic neuropathy Nerve damage in diabetes People with diabetes mellitus have many serious long-term complications that affect many areas of the body, particularly the blood vessels, nerves, eyes, and kidneys. (See also Diabetes Mellitus... read more ), postherpetic neuralgia, or neuropathic pain due to a problem in the brain or spinal cord.
A local anesthetic, such as lidocaine, may be injected into the skin to control pain due to an injury or even neuropathic pain. Local anesthetics can also be injected around nerves to block pain—a procedure called a nerve block. It is often used to treat pain caused by damage to a specific large nerve. For example, a sympathetic nerve block Nondrug Pain Treatments Pain relievers (analgesics) are the main drugs used to treat pain. Doctors choose a pain reliever based on the type and duration of pain and on the drug's likely benefits and risks. Most pain... read more involves injecting a local anesthetic around a group of nerves near the spine—in the neck for pain in the upper body or in the lower back for pain in the lower body. (A sympathetic nerve block can relieve pain caused by overactivity of the sympathetic nervous system, which prepares the body for stressful or emergency situations.)
Topical anesthetics, such as lidocaine applied as a lotion, an ointment, or a skin patch, can be used to control pain due to some conditions.
Mexiletine, used to treat abnormal heart rhythms, is sometimes used to treat neuropathic pain.
These anesthetics are usually used for a short period of time. For example, rinsing with small amounts of an anesthetic mouthwash a few times a day can relieve pain due to mouth sores. However, some people with chronic pain benefit from using topical anesthetics for a long time. For example, a lidocaine patch or gel can help relieve postherpetic neuralgia Postherpetic Neuralgia Postherpetic neuralgia is chronic pain in areas of skin supplied by nerves infected with herpes zoster ( shingles). Shingles is a painful rash of fluid-filled blisters that is caused by reactivation... read more .
Corticosteroids, such as prednisone and dexamethasone, can be taken by mouth if severe pain is caused by inflammation (as occurs in gout).
Some evidence suggests that baclofen (a muscle relaxant) can help relieve neuropathic pain due to trigeminal neuralgia Trigeminal Neuralgia Trigeminal neuralgia is severe facial pain due to malfunction of the 5th cranial nerve (trigeminal nerve). This nerve carries sensory information from the face to the brain and controls the... read more .
Pamidronate (used to treat certain bone disorders) can help relieve neuropathic pain due to complex regional pain syndrome Complex Regional Pain Syndrome Complex regional pain syndrome is chronic neuropathic pain characterized by persistent burning or aching pain plus certain abnormalities that occur in the same area as the pain. Abnormalities... read more .
Low doses of ketamine (an anesthetic) are sometimes given intravenously in a hospital to people who have complex regional pain syndrome when other treatments are ineffective.
Tizanidine (a muscle relaxant), taken by mouth, and clonidine (used to treat high blood pressure), taken by mouth or applied to the skin as a patch, can help relieve neuropathic pain Neuropathic Pain Neuropathic pain is caused by damage to or dysfunction of the nerves, spinal cord, or brain. (See also Overview of Pain.) Neuropathic pain may result from Compression of a nerve—for example... read more or prevent migraines Migraines A migraine headache is typically a pulsating or throbbing pain that ranges from moderate to severe. It can affect one or both sides of the head. It is often worsened by physical activity, light... read more .
High-strength capsaicin (a substance found in hot peppers), given in a patch, helps relieve neuropathic pain due to postherpetic neuralgia. A low-strength capsaicin cream may also help reduce the pain caused by postherpetic neuralgia and by other disorders such as osteoarthritis Osteoarthritis (OA) Osteoarthritis is a chronic disorder that causes damage to the cartilage and surrounding tissues and is characterized by pain, stiffness, and loss of function. Arthritis due to damage of joint... read more . The cream is most often used by people with localized pain due to arthritis. This cream must be applied several times a day.
Nondrug Pain Treatments
In addition to drugs, many other treatments can help relieve pain.
Applying cold or warm compresses directly to a painful area often helps (see Treatment of Pain and Inflammation Treatment of Pain and Inflammation Professional rehabilitation therapists treat pain and inflammation. Such treatment makes movement easier and enables people to participate more fully in rehabilitation. Techniques used include... read more ).
Neuromodulation methods use electric stimulation include to change how nerves process pain. Techniques include the following:
Transcutaneous electrical nerve stimulation (TENS)
Spinal cord stimulation
Peripheral nerve stimulation
Physical or occupational therapy may be used to relieve chronic pain and help people function better. Sometimes doing exercises or increasing activity level helps. For example, walking regularly can help relieve lower back pain more effectively than resting in bed.
Complementary and integrative medicine Overview of Integrative, Complementary, and Alternative Medicine Integrative medicine and health (IMH) and complementary and alternative medicine (CAM) include a variety of healing approaches and therapies that historically have not been included in conventional... read more may be used to treat chronic pain. For example, doctors may suggest one or more of the following:
Manipulation and body-based therapies (such as chiropractic Chiropractic In chiropractic, a manipulative and body-based practice, the relationship between the structure of the spine and the function of the nervous system is seen as key to maintaining or restoring... read more or osteopathic manipulation and massage therapy Massage Therapy In massage therapy (a manipulative and body-based practice), body tissues are manipulated to reduce pain, relieve muscle tension, and reduce stress. Massage therapy involves a variety of light-touch... read more )
Energy-based therapies (such as therapeutic touch Therapeutic Touch Therapeutic touch, sometimes referred to as a laying on of hands, is a type of energy medicine. The philosophy behind therapeutic touch is to use the therapist’s healing energy (biofield) to... read more and Reiki Reiki Reiki is a type of energy medicine that originated in Japan. In Reiki, practitioners intend to manipulate energy through their hands and cause energy movement in the person’s body to promote... read more )
Acupuncture Acupuncture Acupuncture, a therapy within traditional Chinese medicine, is one of the most widely accepted CAM therapies in the Western world. Licensed practitioners do not necessarily have a medical degree... read more involves inserting tiny needles into specific areas of the body. How acupuncture works is poorly understood, and some experts still doubt the technique’s effectiveness. Some people find substantial relief with acupuncture, at least for a time.
Biofeedback Biofeedback Biofeedback, a type of mind-body medicine, is a method of bringing unconscious biologic processes under conscious control. In biofeedback, electronic devices are used to measure and report information... read more and other cognitive techniques Mind-Body Medicine Complementary or alternative medicine can be classified into five major categories of practice: Whole medical systems Mind-body techniques Biologically based practices Manipulative and body-based... read more (such as relaxation training, hypnosis, and distraction techniques) can help people control, reduce, or cope with pain by changing the way they focus their attention. In one distraction technique, people may learn to visualize themselves in a calm, comforting place (such as in a hammock or on a beach) when they feel pain.
Cognitive behavioral therapy may reduce pain and pain-related disability and help people cope. This type of therapy includes counseling to help people focus on coping with the pain, rather than on its effects and limitations. It may include counseling to help people and their family work together to manage pain.
The importance of psychologic support for people in pain should not be underestimated. Friends and family members should be aware that people in pain suffer, need support, and may develop depression and anxiety, which may require psychologic counseling.