There are a number of causes contributing to most chronic pain. Once your doctor has done what’s possible in terms of treating the causes of pain, remaining chronic pain is not serving any useful purpose. It can be debilitating mentally, emotionally and physically, and the objective is to relieve it. Unfortunately current medical science often can’t do this simply and effectively. Obvious. If they could it wouldn’t be chronic. There is good hope in current research, but at present medical treatment is usually just part of the story. This is not to say that medical treatment can’t make a very big difference, and you should seek and absolutely expect as much pain relief as medicine can offer. The website Stop Pain emphasises that treating pain is important. It should not be minimised or neglected. Unrelieved pain can cause us to:
- Experience depression
- Experience disruptions in activity, appetite and sleep
- Feel helpless and anxious
- Give up hope
- Reject treatment programs
- Stop participating in life to the fullest extent possible
They also remind us that:
- Pain usually can be controlled.
- There are many treatment options.
- To offer the best approaches for pain, doctors must recognize that pain is different in every person.
- All patients who experience pain deserve a detailed evaluation of the pain, the effect of the pain, and the conditions that may be causing the pain.
Therapies overview: The website Daily Strength provide a useful quick overview guide to a range of treatments, both medical and complimentary. The following is an edited summary, laying out the territory we can then look at in more detail.
Anti-inflammatory drugs, both over the counter and by prescription, are essential to treatment of many forms of chronic pain. See our information below on Non-Steroidal Anti-Inflammatories (NSAIDs), steroids etc.
Analgesic refers to the class of drugs that includes most painkillers, such as aspirin, acetaminophen (paracetamol), and ibuprofen. The word analgesic is derived from ancient Greek and means to reduce or stop pain. Non-prescription or over-the-counter pain relievers are generally used for mild to moderate pain. Prescription pain relievers, sold through a pharmacy under the direction of a physician, are used for more moderate to severe pain.
Anticonvulsants are used for the treatment of seizure disorders but are also sometimes prescribed for the treatment of pain. Carbamazepine in particular is used to treat a number of painful conditions, including trigeminal neuralgia. Another antiepileptic drug, gabapentin, is being studied for its pain-relieving properties, especially as a treatment for neuropathic pain.
Antidepressants are sometimes used for the treatment of pain and, along with neuroleptics and lithium, belong to a category of drugs called psychotropic drugs. In addition, anti-anxiety drugs called benzodiazepines also act as muscle relaxants and are sometimes used as pain relievers. Physicians usually try to treat the condition with analgesics before prescribing these drugs.
Antimigraine drugs include the triptans- sumatriptan (Imitrex), naratriptan (Amerge), and zolmitriptan (Zomig)-and are used specifically for migraine headaches. They can have serious side effects in some people and therefore, as with all prescription medicines, should be used only under a doctor’s care.
Chemonucleolysis is a treatment in which an enzyme, chymopapain, is injected directly into a herniated lumbar disc in an effort to dissolve material around the disc, thus reducing pressure and pain. The procedure’s use is extremely limited, in part because some patients may have a life-threatening allergic reaction to chymopapain.
COX-2 inhibitors are one result of the search to develop a drug that works as well as morphine but without its negative side effects. Nonsteroidal anti-inflammatory drugs (NSAIDs) work by blocking two enzymes, cyclooxygenase-1 and cyclooxygenase-2, both of which promote production of hormones called prostaglandins, which in turn cause inflammation, fever, and pain. The newer COX-2 inhibitors primarily block cyclooxygenase-2 (thus the name) and are less likely to have the gastrointestinal side effects sometimes produced by NSAIDs. They do increasingly appear to have other risks, however, as detailed below.
Electrical stimulation can be simple transcutaneous electrical stimulation (TENS), implanted electric nerve stimulation, or deep brain or spinal cord stimulation. See our alternative and complimentary organisations below for more about TENS and other safe, surface techniques. The other forms of electrical stimulation involve major surgical procedures. They only work for some people and are not 100 percent effective. The following techniques each require specialised equipment and medical personnel trained in the specific procedure being used:
- Peripheral nerve stimulation uses electrodes placed surgically on a carefully selected area of the body. The patient is then able to deliver an electrical current as needed to the affected area, using an antenna and transmitter.
- Spinal cord stimulation uses electrodes surgically inserted within the epidural space of the spinal cord. The patient is able to deliver a pulse of electricity to the spinal cord using a small box-like receiver and an antenna taped to the skin.
- Deep brain or intracerebral stimulation is considered an extreme treatment and involves surgical stimulation of the brain, usually the thalamus. It is used for a limited number of conditions, including severe pain, central pain syndrome, cancer pain, phantom limb pain, and other neuropathic pains.
Nerve blocks employ the use of drugs, chemical agents, or surgical techniques to interrupt the relay of pain messages between specific areas of the body and the brain. There are many different names for the procedure, depending on the technique or agent used. Types of surgical nerve blocks include neurectomy; spinal dorsal, cranial, and trigeminal rhizotomy; and sympathectomy, also called sympathetic blockade, in which a drug or an agent such as guanethidine is used to eliminate pain in a specific area (a limb, for example).
Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed and sometimes called non-narcotic or non-opioid analgesics. They work by reducing inflammatory responses in tissues. They include such common drugs as aspirin and ibuprofen. Although paracetamol may have some anti-inflammatory effects, it is generally distinguished from the traditional NSAIDs.
Opioids are derived from the poppy plant and are among the oldest drugs known to humankind. They include codeine and perhaps the most well-known narcotic of all, morphine.
Physical therapy: Physiotherapy and many forms of body work can help many conditions (see our descriptions in Complementary and Alternative Therapies and Self Help).
Steroids: Corticosteroids are powerful medicines to reduce inflammation and the pain it causes. Administration can be oral, injected (as into joints for arthritis or directly into nerves for sciatic pain) or topical. Steroids work on a wide variety of inflammatory conditions and symptoms. Among the best known is probably cortisone. Use of these powerful drugs must be carefully managed. They can have very serious side effects. How you use them and how you stop using them require medical supervision and care on your part. That said, they can be extremely effective and necessary.
Surgery, although not always an option, may be required to relieve pain, especially pain caused by back problems or serious musculoskeletal injuries. Surgery may take the form of a nerve block or it may involve an operation to relieve pain from a ruptured disc, deteriorated joint or some other causative factor.
Surgical procedures for back problems include:
- discectomy or, when microsurgical techniques are used, microdiscectomy, in which the entire disc is removed
- laminectomy, a procedure in which a surgeon removes only a disc fragment, gaining access by entering through the arched portion of a vertebra
- spinal fusion, a procedure where the entire disc is removed and replaced with a bone graft. In a spinal fusion, the two vertebrae are then fused together. Although the operation can cause the spine to stiffen, resulting in lost flexibility, the procedure serves one critical purpose: protection of the spinal cord
Other operations for pain include:
- neurectomy (including peripheral neurectomy) in which a damaged peripheral nerve is destroyed
- rhizotomy, in which a nerve close to the spinal cord is cut. Other rhizotomy procedures include cranial rhizotomy and trigeminal rhizotomy, performed as a treatment for extreme facial pain or for the pain of cancer
- cordotomy, where bundles of nerves within the spinal cord are severed. Cordotomy is generally used only for the pain of terminal cancer that does not respond to other therapies
- dorsal root entry zone operation, or DREZ, in which spinal neurons corresponding to the patient’s pain are destroyed surgically
Occasionally, surgery is carried out with electrodes that selectively damage neurons in a targeted area of the brain. These procedures rarely result in long-term pain relief, but both physician and patient may decide that the surgical procedure will be effective enough that it justifies the expense and risk.
In some cases, the results of an operation are remarkable. As one example, many individuals suffering from trigeminal neuralgia who are not responsive to drug treatment have had great success with a procedure called microvascular decompression, in which tiny blood vessels are surgically separated from surrounding nerves.
Surgical blocks are performed on cranial, peripheral, or sympathetic nerves. They are most often done to relieve the pain of cancer and extreme facial pain, such as that experienced with trigeminal neuralgia, and they are not without problems and complications. They can cause muscle paralysis and, in many cases, result in at least partial numbness. For that reason, the procedure should be reserved for a select group of patients and should only be performed by skilled surgeons.
Stop press news from an article by Dr. Emma Hitt for Medscape, November 22, 2011: A neurostimulation device that harnesses motion sensor technology found in smart phones and computer gaming systems has been approved for the treatment of chronic back and/or leg pain by the US Food and Drug Administration. The device, AdaptiveStim With RestoreSensor (Medtronic), uses an implantable pacemaker-like device to interrupt pain signals, transforming them into a tingling sensation instead of pain. In a news release from Medtronic, the manufacturer points out that the device automatically tailors the level of stimulation to the needs of people with chronic back and/or leg pain by adjusting stimulation to accommodate changes in body position. The device records the level of stimulation required for different positions, so that the intensity of stimulation remains consistent with a person’s movements.
In contrast, current nonadaptive technology requires that patients manually adjust neurostimulation settings with a handheld programmer – more than 90% of participants indicated that they would keep the device turned on all or most of the time, and 80.3% reported functional improvements, including improved comfort during position changes. Use of the device was not associated with an increase in adverse events.
Action on Pain is our source here, followed by Merck Geriatric. When affected by chronic pain many factors induce and add to the stress of the situation and for many people, just gaining access to effective prescription medications can amplify that stress. As well as having understandable apprehensions about the side-affects of some medications, and concerns about becoming dependent or addicted to stronger prescription drugs, countless people face difficulties in receiving specific types of medicines due to postcode prescribing and NHS cutbacks.
In the midst of all this it is easy to become overwhelmed and confused about what is safe and effective for treating pain. These misgiving are shared by numerous individuals and as a result many pharmaceutical companies are beginning to recognize that they need to address patient concerns and ensure that the information they provide is more patient friendly and unambiguous. Try to get your doctor and chemist to give you as much thoughtful advice as possible, and useMedline Plus to get unbiased information.
Drugs alone are not always the answer, as the usefulness of any drug must be balanced against the side effects. Educating yourself about the various treatment options available will enable you to be more confident when talking to your doctor about suitable medications.
Your GP is likely to stick to traditional prescribing methods in finding a safe and effective drug for your pain. This can often seem to be a long drawn out and “by-the-book” exercise which may fuel your feelings of frustration and anxiety. In truth, it can take some time for the effective dose of drugs to build up in your body – and side effects are always a concern – so it may take a while to find the right drug, or combination of drugs, and doses for you.
It is important during this process that you keep communicating your concerns and feelings to your doctor about the progress that is being made in finding a suitable resolution to your pain. Numerous authoritative sources tell us that there may be a tendency to under-prescribe for pain. It is difficult to balance the good and harm drugs may do, but do be clear when your pain is not being sufficiently relieved.
Often your GP will aim to maintain an acceptable amount of pain control for you by prescribing painkillers at one of three levels. This may involve them steadily increasing the dosage of the medicines they prescribe which will become more powerful if the pain worsens and you move up to the next level of drug treatments.
At the start you doctor is likely to prescribe relatively low doses of low-potency analgesic medications like paracetamol. It may be appropriate for them to also prescribe an anti-inflammatory like ibuprofen or another type of non-steroidal anti-inflammatory (NSAID). If the pain persists or becomes more severe, a stronger painkiller like codeine may be needed, and your GP will try different dosage levels with or without NSAIDs to control the pain. If the pain persists or increases to a moderate-to-severe level, then higher strength opioid analgesics (again with or without NSAIDs) can be prescribed. Psychotropic agents like antidepressants and anti-anxiety drugs may also be usefully prescribed. These tackle problems of depression and anxiety which are commonly experienced by people with chronic pain.
Specialist Pain Consultants, Pain Consultants and Specialist Pain Nurse Practitioners have the experience and training to provide more specialist forms of treatment and they are therefore able to prescribe a wider range and combination of drug therapies. If you are not getting acceptable pain relief you can ask to be referred.
Action on Pain’s good advice on medications includes reminders that:
Doctors appointments may be rushed and pressurised so it can be difficult to remember all the questions about your medication when you are there. Make a list of your questions and concerns before the appointment and ensure that you are satisfied with the answers you have received before you leave.
Confident communication is central to ensuring you obtain the best medical care available, so it is to your advantage to generate clear responses to your concerns.
It is important to know why the doctor has prescribed a particular drug; you should know how it should help or relieve your condition or symptoms; you must be clear when, how and how often you need to take the medication; whether it must be taken before or after meals; if it must be taken with water and whether you must avoid alcohol; and whether you must avoid taking any other prescription or over the counter medicines at the same time.
You should ask how long it is likely to be before you start to feel or see the benefits of the medication. If your doctor does not have the time to answer all you questions or you remain unclear on some points, ask to see someone else in the practice who can answer your questions. Many health care providers now have nurse practitioners and Health Care assistants who are trained to help.
Side effects: Although most doctors will tell you about the side affects of your medication if you ask them, nowadays your local chemist may be more helpful. Side-effects can be unpleasant and dangerous. Tell your doctor if you run into any problems which may be caused by your medication.
Dependency on a medication is not the same as addiction (see the information from Merck Medicus below). Dependency arises when your body becomes accustomed to a medication and reacts negatively to its absence or any reduction in dosage. e.g. a diabetic will react negatively if they do not get their insulin but this does not mean that they are addicted to their medication.
Addiction is a neurobiological disease distinguished by activities that include a lack of control over use of the drug, compulsive use, continued use despite harm, and craving. Tolerance is a situation in which the use of a drug brings about adaptive changes within the body that cause a reduction in one or more of the drug’s effects over time. It is because of this that it is advisable to regularly review your medication with your doctor.
Long term medication can cause a number of problems. A drug can help chronic pain for years, and then start to cause difficulties. You need to be aware of this and discuss anything which might be a side effect with your doctor. Do not hesitate. Check whether you need to change medication before unnecessary damage is done.
Action on Pain tells us that patients may often need the help of a pain clinic after taking various medications which are either simply not working on their pain or are giving them inadequate pain relief. There may be many reasons for this, but the simplest and probably most common one is non-compliance; that is they are not taking the drugs regularly as prescribed. Drugs are formulated to work in a particular way and therefore it is important to take the medication as prescribed. If the body has a constant, adequate level of a drug then it can fight the pain much more effectively.
As you already know if you have chronic pain like back pain, it can be very complex and difficult to accurately diagnose and treat. There can be many underlying factors causing chronic pain, and a wide range of potential treatments that may or may not work for the same condition. Different drugs are prescribed according to what sort of pain is being targeted. If the pain is from a chronic inflammation, for instance, an anti-inflammatory treatment is obvious – but it’s often not so easy to find the right one which you can tolerate in terms of side-effects, your general health and your lifestyle and needs.
Nociceptive pain which is felt in the tissues and organs is likely to respond well to classic painkillers such as aspirin, paracetamol, codeine and in moderate to severe cases of pain opiods like morphine may be warranted.
Neuropathic pain, felt from nerves, often responds poorly to the traditional analgesics like aspirin, codeine and morphine. Pain Specialists may often prescribe painkilling drugs which are usually used for treating other conditions like epilepsy and depression. e.g. Gabapentin and Tegretol (antiepileptics); Amitriptyline and Dothiepin.(antidepressants).
If your specialist recommends you try such drugs, it is not because they think you have these other conditions, but rather because they can help to combat certain kinds of pain. These drugs work by preventing the random firing of nerve impulses from nerve cells, which is what causes the pain. The greatest problem with using these medications is that they may often give patients unpleasant side effects.
The advent of aspirin-like analgesics such as Ibuprofen, Voltarol, Mefanamic Acid, Ketoprofen, has opened up several effective options for treating nociceptive pain. Known as non-steroidal anti-inflammatory drugs (NSAIDS), the downside of these newer analgesics drugs is they can cause severe side effects including gastric ulcers and kidney damage, so they need to be used with caution. Newer COX-2 NSAID’s like Celecoxib, and Parecoxib/ Valdecoxib have now also been found to have a significant incidence of causing cardiovascular problems in “at risk” groups. Obviously care needs to be taken by health professionals when prescribing these anti-inflammatory drugs and provided there are no medical reasons to preclude you from being prescribed these analgesics the benefits in pain relief may be most valuable.
The Merck Medicus website does a fairly extensive listing of pain medications which may be prescribed or suggested by your doctor. We edit below for your convenience, but see Merck to learn more. Merck is responsible as always in reminding us that for chronic pain whatever drugs may be used normally need to be supplemented by non-drug treatments (see our discussion of Self Helpoptions).
Analgesics fall into three categories: opioid (narcotic) analgesics, nonopioid analgesics, and adjuvant analgesics (drugs that are usually given for reasons other than pain but that sometimes relieve pain).
Opioid analgesics (narcotics), the most powerful analgesics, are the mainstay for treatment of severe acute pain and chronic pain due to cancer and other serious disorders. Opioids are preferred because they are so effective in controlling pain. The use of opioids to treat chronic pain not due to cancer is becoming more accepted, but opioids are not appropriate for everyone.
Opioids are all chemically related to morphine, a natural substance extracted from poppies. Some opioids are extracted from other plants, and some are synthesised in a laboratory.
Opioids have many side effects. People who take opioids for acute pain often become drowsy. For some people, this drowsiness is welcome, but for others, it is not. Most people who take opioids become tolerant of this effect and do not continue to feel drowsy. Some people who continue to feel drowsy are given stimulant drugs, such as methylphenidate to keep them awake and alert. Opioids may also cause confusion, or anxiety.
Opioids can cause constipation and retention of urine, especially in older people. Stimulant laxatives such as senna help prevent or relieve the constipation. Increasing intake of fluids can also help.
Sometimes people with pain feel nauseated, and opioids can increase the nausea. Antiemetic drugs taken by mouth, suppository, or injection help prevent or relieve nausea.
Taking too much of an opioid [overdose] can have serious side effects, including a dangerous slowing of breathing and even coma. These effects can be reversed with naloxone, an antidote given intravenously. Nurses and family members should watch for side effects of opioids.
Doctors carefully weigh the benefits and side effects when they consider these drugs for the treatment of chronic pain. With repeated use of opioids over time, some people need higher doses because the body adapts to and thus responds less well to the drug; this phenomenon is called tolerance. For other people, the same dose remains effective for a long time.
People who take opioids for a long time usually become dependent on them.. When opioids are stopped after long-term use, the dose must be gradually tapered to minimize the development of withdrawal symptoms.
Dependence is not the same as addiction, which is the disruptive behaviour or activity associated with obtaining and using the drug. Although addiction is possible, it appears to be rare among people who take opioids to control pain. Too often, exaggerated concern about the addiction potential of opioids leads to undertreatment of pain and needless suffering. People with severe pain should not avoid opioids, and adequate doses should be taken as needed. – Note: this is Merck Geriatric’s published view, with which we agree.
When possible, opioids are taken by mouth. Opioids are given by injection when people cannot take them by mouth. For people who are helped by an opioid but cannot tolerate its side effects, an opioid can be administered directly into the space around the spinal cord through a pump, thus providing high concentrations of the drug to the brain. The opioid fentanyl is available as a skin patch. It can provide pain relief for up to 72 hours.
Different opioid analgesics have different advantages and disadvantages.
Morphine, the prototype of these drugs, can be taken by mouth (orally) or by injection. There are two oral forms: sustained-release and immediate-release. Different sustained-release forms provide relief for 8 to 24 hours. These drugs are widely used to treat chronic pain [again, we are quoting from Merck]. The immediate-release form provides short-lived relief, usually for less than 3 hours. In injected forms, 2 to 6 times less morphine is required than in oral forms, because when morphine is taken by mouth, much of the drug is chemically altered (metabolised) by the liver before it reaches the bloodstream. Usually, the difference in the amount needed for the different routes does not change the effects of the drug. Pain relief with injected forms is quicker than that with oral forms, but relief does not last as long.
Morphine may be injected into a vein (intravenously), into a muscle (intramuscularly), or under the skin (subcutaneously). With the intravenous form of morphine pain relief is almost immediate but does not last very long. With the intramuscular form, pain relief is less rapid but lasts somewhat longer. With the subcutaneous form, pain relief is the least rapid but lasts the longest. Morphine starts to work quickly. The oral form can be very effective for chronic pain.
- Codeine is a less potent opioid than morphine. It is often taken in combination with aspirin or paracetamol
- Fentanyl is available as a lozenge that is dissolved in the mouth; it is used to treat breakthrough pain. The patch is often used to treat chronic pain, and lasts for 72 hours
- Meperidine is not preferred for long-term use because it causes side effects, such as psychosis, muscle spasms, tremors, and seizures
- Methadone is a synthetic opioid. Although chemically unlike morphine or heroin, methadone also acts on the opioid receptors and thus produces many of the same effects.
- Levorphanol is a strong alternative to morphine.
- Hydromorphone begins to work quickly. It can be used instead of morphine and is useful for chronic pain.
- Oxycodone can be used instead of morphine to treat chronic pain. Effective, but both this and Pentazocine can cause confusion and anxiety, especially in older people
A variety of nonopioid analgesics are available. Several, such as aspirin, ibuprofen, ketoprofen, naproxen and paracetamol (acetaminophen) are available in prescription and non-prescription (over-the-counter, or OTC) strengths. Prescription-strength formulations contain more active ingredient per dose than OTC formulations. OTC analgesics are reasonably safe to take for short periods of time, but their labels caution against taking them for more than 7 to 10 days to treat pain. If you’re going to use them long-term check with your doctor, and be careful not to overdose.
Nonsteroidal Anti-Inflammatory Drugs
Most nonopioid analgesics are classified as nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs are used to treat mild to moderate pain and may be combined with opioids to treat moderate to severe pain.
How they work: NSAIDs work in two ways: They reduce the sensation of pain, and they reduce the inflammation that often accompanies and worsens pain. NSAIDs produce these effects because they reduce the production of hormone-like substances called prostaglandins. Different prostaglandins have different functions, such as sensitizing pain receptors to mechanical and chemical stimulation and causing blood vessels to dilate.
NSAIDs tend to irritate the stomach’s lining and cause digestive upset (such as heartburn, indigestion, nausea, bloating, diarrhea, and stomach pain), peptic ulcers, and bleeding in the digestive tract.
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 diarrhoea. Proton pump inhibitors (such as omeprazole or histamine-2 (H2) blockers such as famotidine, which are used to treat peptic ulcers, can also help prevent stomach problems due to NSAIDs.
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 also irritate the stomach’s lining.
NSAIDs cause fluid retention and swelling in 1 to 2% of people. Regular use of NSAIDs may also increase the risk of developing a kidney disorder, sometimes resulting in renal failure (a disorder called analgesic nephropathy).
For older people, the risk of side effects due to NSAIDs is increased. For people who drink alcoholic beverages regularly and take NSAIDs, the risk of digestive upset, ulcers, and liver damage may be increased. People with heart failure, high blood pressure, or kidney or liver disorders require a doctor’s supervision when they take NSAIDs. Some prescription heart and blood pressure drugs may not work as well when taken with these analgesics. NSAIDs vary in how quickly they work and how long they relieve pain. Different NSAIDs may be effective for different conditions, and individual people respond to them differently. It also seems that some people can take these medications long-term with no apparent problems, while others cannot.
Common NSAIDs include Aspirin, Ibuprofen, Ketoprofen, Naproxen, and Diclofenac (Voltarol). These and other drugs in this class should not be taken with anticoagulants like warfarin (Coumadin) except under a doctor’s close supervision. People who are allergic to or have difficulty coping with one of the conventional NSAIDs may also have trouble with the others.
Coxibs (COX-2 Inhibitors) are a new alternative to conventional NSAIDs. Other NSAIDs block two enzymes: COX-1, which is involved in the production of the prostaglandins that protect the stomach and play a crucial role in blood clotting; and COX-2, which is involved in the production of the prostaglandins that promote inflammation. Coxibs tend to block only COX-2 enzymes. Thus, coxibs are as effective as other NSAIDs in the treatment of pain and inflammation – but are less likely to damage the stomach; to cause nausea, bloating, heartburn, bleeding, and peptic ulcers; and to interfere with clotting than are other NSAIDs.
However: BBC Health tells us that Rofecoxib and another Cox-2 inhibitor called valdecoxib have been withdrawn from use in the UK. Celecoxib has also been linked to an increased risk of heart attack. This drug hasn’t yet been withdrawn from use because there’s some debate about the research that identified this risk. The manufacturers plan to do more studies to look closely at the problem.
These developments have left both doctors and patients unsure what to do for the best. New research means that safer COX-2 drugs should be forthcoming. Meanwhile people with arthritis who can’t take conventional NSAIDs may well get the help they need from their doctor’s careful choice of a COX-2 inhibitor.
BBC Health reminds is that the aim is to find some sort of balance between relief of pain and improved function on the one hand, and the likelihood of serious adverse effects on the other. Finding this balance isn’t easy, especially for older people who are more likely to suffer from side effects.
Adjuvant analgesics are drugs that are not usually used for pain relief but may relieve pain in certain circumstances and that, when used to relieve pain, are usually used with other analgesics or non-drug pain treatments. The adjuvant analgesics most commonly used for pain are antidepressants, anticonvulsants, and oral and topical local anaesthetics.
Antidepressants can potentially relieve pain in people who do not have depression. There is some evidence that tricyclic antidepressants are more effective for this purpose than other antidepressants, but selective serotonin re-uptake inhibitor (SSRI) antidepressants such as fluoxetine (Prozac) are tolerated better. People may respond to one antidepressant and not others.
Anticonvulsants may be used to relieve neuropathic pain. As BBC Health tells us that this chronic nerve pain affects about 8% of older people in the UK, it is a big subject. Some anticonvulsants may also prevent migraine headaches.
Local anaesthetics: Mexiletine is a local anaesthetic taken by mouth to treat abnormal heart rhythms, and can sometimes be used to treat neuropathic pain. Local anaesthetics are more commonly placed directly on or near a sore area to help reduce pain. Doctors may inject a local anaesthetic, such as lidocaine into the skin to control pain due to an injury or a neuropathic pain syndrome. Local anaesthetics are also used in nerve blocks. For example, a sympathetic nerve block involves injecting a local anaesthetic into 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.
Occasionally, pain related to nerve injury can be treated by injecting a caustic substance, such as phenol, into a nerve to destroy it, by freezing the nerve (in cryotherapy), or by burning the nerve with a radiofrequency probe. These techniques may be used to treat facial pain due to trigeminal neuralgia. Topical anaesthetics like lidocaine, applied as a lotion, ointment, or skin patch, can be used to control pain due to some conditions. These treatments are usually for short-term pain, but some people with chronic pain benefit from using topical anaesthetics for a long time.
A cream containing capsaicin, a substance found in hot peppers, sometimes helps reduce the pain caused by such disorders as herpes zoster and osteoarthritis. It is most often used by people with localized pain due to arthritis. This cream must be applied several times a day.
Where medical and drug research is leading
Edited from Daily Strength: In his research, the late John C. Liebeskind, a renowned pain expert and a professor of psychology at UCLA, found that pain can kill by delaying healing [our emphasis] and causing cancer to spread. He also found evidence that controlling pain and stress allowed the body to fight the disease more effectively.
The link between the nervous and immune systems is an important one. Cytokines, a type of protein found in the nervous system, are also part of the body’s immune system, the body’s shield for fighting off disease. Cytokines can trigger pain by promoting inflammation, even in the absence of injury or damage. Certain types of cytokines have been linked to nervous system injury. After trauma, cytokine levels rise in the brain and spinal cord and at the site in the peripheral nervous system where the injury occurred. Improvements in our understanding of the precise role of cytokines in producing pain, especially pain resulting from injury, may lead to new classes of drugs that can block the action of these substances.
Some pain medications dull the patient’s perception of pain. Morphine is one such drug. It works through the body’s natural pain-killing machinery, preventing pain messages from reaching the brain. Scientists are working toward the development of a morphine-like drug that will have the pain-deadening qualities of morphine but without the drug’s negative side effects, such as sedation and the potential for addiction. Patients receiving morphine also face the problem of morphine tolerance, meaning that over time they require higher doses of the drug to achieve the same pain relief. Studies have identified factors that contribute to the development of tolerance; continued progress in this line of research should eventually allow patients to take lower doses of morphine.
The body’s natural painkillers may yet prove to be the most promising pain relievers, pointing to one of the most important new avenues in drug development. The brain may signal the release of painkillers found in the spinal cord, including serotonin, norepinephrine, and opioid-like chemicals. Many pharmaceutical companies are working to synthesize these substances in laboratories as future medications. Endorphins and enkephalins are other natural painkillers. Endorphins may be responsible for the “feel good” effects experienced by many people after vigorous exercise. This is one of the reasons why exercise is recommended for many forms of chronic pain.
Similarly, peptides, compounds that make up proteins in the body, play a role in pain responses. Mice bred experimentally to lack a gene for two peptides called tachykinins-neurokinin A and substance P-have a reduced response to severe pain. When exposed to mild pain, these mice react in the same way as mice that carry the missing gene. But when exposed to more severe pain, the mice exhibit a reduced pain response. This suggests that the two peptides are involved in the production of pain sensations, especially moderate-to-severe pain. Continued research on tachykinins may pave the way for drugs tailored to treat different severities of pain.
One objective of investigators working to develop the future generation of pain medications is to take full advantage of the body’s pain “switching centre” by formulating compounds that will prevent pain signals from being amplified or stop them altogether. Blocking or interrupting pain signals, especially when there is no injury or trauma to tissue, is an important goal in the development of pain medications. An increased understanding of the basic mechanisms of pain will have profound implications for the development of future medicines. The following areas of research are bringing us closer to an ideal pain drug.
Channels: The frontier in the search for new drug targets is represented by channels. Channels are gate-like passages found along the membranes of cells that allow electrically charged chemical particles called ions to pass into the cells. Ion channels are important for transmitting signals through the nerve’s membrane. The possibility now exists for developing new classes of drugs, including pain cocktails that would act at the site of channel activity to block pain signals.
Trophic Factors: A class of “rescuer” or “restorer” drugs may emerge from our growing knowledge of trophic factors, natural chemical substances found in the human body that affect the survival and function of cells. Trophic factors also promote cell death, but little is known about how something beneficial can become harmful. Investigators have observed that an over-accumulation of certain trophic factors in the nerve cells of animals results in heightened pain sensitivity, and that some receptors found on cells respond to trophic factors and interact with each other. These receptors may provide targets for new pain therapies.
Plasticity: Following injury, the nervous system undergoes a tremendous reorganization. This phenomenon is known as plasticity. For example, the spinal cord is “rewired” following trauma as nerve cell axons make new contacts, a phenomenon known as “sprouting.” This in turn disrupts the cells’ supply of trophic factors. Scientists can now identify and study the changes that occur during the processing of pain. For example, using a technique called polymerase chain reaction, abbreviated PCR, scientists can study the genes that are involved in dealing with by injury and persistent pain. There is evidence that the proteins that are ultimately synthesized by these genes may be targets for new therapies. The dramatic changes that occur with injury and persistent pain underscore that chronic pain should be considered a disease of the nervous system, not just prolonged acute pain or a symptom of an injury. Thus, scientists hope that therapies directed at preventing the long-term changes that occur in the nervous system will prevent the development of chronic pain conditions.
Neurotransmitters: Just as mutations in genes may affect behaviour, they may also affect a number of neurotransmitters involved in the control of pain. Using sophisticated imaging technologies, investigators can now visualize what is happening chemically in the spinal cord. From this work, new therapies may emerge, therapies that can help reduce or obliterate severe or chronic pain.
Systems and Imaging: The idea of mapping cognitive functions to precise areas of the brain dates back to phrenology, the now archaic practice of studying bumps on the head. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and other imaging technologies offer a vivid picture of what is happening in the brain as it processes pain. Using imaging, investigators can now see that pain activates at least three or four key areas of the brain’s cortex – the outer layer of the brain. Interestingly, when patients undergo hypnosis so that the unpleasantness of a painful stimulus is not experienced, activity in some, but not all, brain areas is reduced. This emphasizes that the experience of pain involves a strong emotional component as well as the sensory experience.
We emphasise that last sentence to come back to the present and underline the solid scientific basis for saying that, at this time: the prescribing of pain relieving drugs by Pain Practitioners is rarely the only aspect in the treatment and control of chronic pain. A holistic approach will be needed to help you start to take control over your pain, and this may involve attending Pain Management Programmes, seeing physiotherapists and Occupational Therapists, having hypnotherapy, counselling or sessions with a Pain Psychologist or taking advantage of some of the many other forms of help, skills you can learn and techniques you can use.