Chronic pain is an international health issue, which is estimated to affect eight million people worldwide (Lawrence et al., 2008). Osteoarthritis, the most common form of arthritis, is the leading cause of long-term pain and the fourth most common cause limitation of activity with lower back pain being the most common musculoskeletal pain in older adults (Woolf and Pfleger, 2003). There are many causes for low back pain; for many people no specific cause will be found, even with tests. This is often called non-specific low back pain. The evidence is unclear about which types of mild to moderate back pain gets better quickly without specific treatment. For those for whom pain becomes long-term or severe, no specific cause will be found much of the time, but scanning and testing may give the impression that something can be done to find the cause. Aside from leg pain from nerve root irritation, people with much spinal pathology can have no pain while others can have severe pain from minor degenerative discs and joints (Smidt et al., 2006). Depression is more common in adults with chronic low back pain as also is concurrent pain in areas other than the back (Dunn et al., 2006). These associations may reflect a formidable impact on quality of life. The exploration of gabapentin as a drug to treat chronic low back pain is a response to this assumed substantial quality of life impact. Gabapentin may have an important role to play in pain management, it is not clear what the true value of this drug and identifying the characteristics of patients who are most likely to benefit will be a complex issue (Wiffen et al., 2013).
The prevalence of lower back pain
Low back pain (LBP) is an established contender for the most common and disabling musculoskeletal condition. Global point prevalence of LBP is 12%, with the highest prevalence in Western Europe, followed by North Africa and the Middle East. Low back pain is most prevalent in the 40-80 year age group. It is predicted that the prevalence of LBP will increase in the future due to the aging population and increasing levels of obesity in developing countries. Low and middle income countries have significantly higher prevalence of LBP than high income countries. The lifetime prevalence of low back pain is reported to be as high as 84%, and chronicity is an established problem. Globally, years lived with disability caused by LBP increased by 54% between 1990 and 2015. As a result, LBP now ranks sixth in the list of disorders causing the most years lived with disability. In the United Kingdom, LBP was the most common cause of restricted activity in people under the age of 65 years old. These statistics make overwhelming evidence for LBP being an extremely prevalent condition and the leading cause of disability worldwide.
The impact of lower back pain on daily life
Lower back pain can cause serious disruption to the lives of sufferers. This can be seen quantifiably in terms of work days lost due to illness and through the increased use of health care services. Two studies have highlighted these effects. Deyo et al compared functional outcomes of patients with various severe health problems including lung cancer and myocardial infarction. They found that physical functional impairment was greater in the back pain group than in any of the other groups. Similarly, a study looking specifically at chronic low back pain patients found that this group had significantly worse scores than the general population in eight domains of health, and worse than patients with various other disorders in six domains. Measures of social and psychological function, vitality and bodily pain showed the greatest differences between the back pain group and other groups. A separate study found that reduced work ability in lower back pain patients was comparable to that in the patients with the most serious health problems and was worse than that in the average patient after hip replacement. It is not just the impact can be seen quantitatively through functional impairment. Patients with chronic lower back pain reported that some of the most negatively affected areas of their life were family and social life, recreation, and sex. Factors leading to this included increase in dependency, reduced function, financial strain and unsatisfactory relationships with health care providers. Stankovic et al found that social functioning and mental health in chronic lower back pain patients was comparable to that in patients with depression and patients undergoing rehabilitation from heroin addiction. They concluded that back pain had a multidimensional negative impact on the quality of life, and that global concept of quality of life was the most sensitive way to measure the impact of back pain.
Understanding Gabapentin
Gabapentin is a drug that was first approved by the FDA in 1993 for the treatment of seizures. At the time, it was believed to be a very poor choice for the treatment of acute pain. However, prescribing of this drug for actually many doctors adopt using this medication for various painful conditions and were finding it to be very effective. Gabapentin is considered a GABA analogue. Although it is believed to work on the GABA receptor, it does not actually affect GABA pathways within the body. Its primary mode of action is the inhibition of excitatory neurotransmitters. This is thought to be achieved by the reduction of synaptic release of excitatory neurotransmitters and the reduction of the hypersensitivity of voltage-gated calcium channels. This is a major difference compared to all other analgesic agents, and it is why this medication is much more effective and better tolerated than any other medication in its class. Because this drug has been shown to be effective for reducing the excitability and/or sensitivity of the nervous system, it is now being tried on almost every kind of chronic pain condition and has been found to be very effective for the treatment of fibromyalgia, peripheral neuropathic pain, complex regional pain syndrome, and various other neuropathic pain syndromes.
What is Gabapentin?
Gabapentin (Neurontin) was originally developed as an anti-seizure drug. It is also effective for some patients with painful nerve compression. It is available as a generic medication and is relatively inexpensive. Only you and your doctor can decide if gabapentin is the best medicine for you. Step 1 in finding out will be a short trial of gabapentin—probably 4-6 weeks. If you get no relief from gabapentin, don’t give up too soon. You might benefit from a longer trial, and your doctor will help you make that decision. If you do get relief, you will probably stay on a low dose for a long time. The number 1 concern now is preventing the symptoms from coming back. If you start having symptoms again, you and your doctor might increase the dose. If you are looking for an easy answer, I will disappoint you. Nerve pain is never easy to treat. Any amount of symptom relief with gabapentin is a success, and eventual prevention of symptoms is an even bigger success. Treatment must be tailored to the individual. Unlike taking an aspirin for a headache, you will have to find the amount of medicine that is just right for you. And, as mentioned above, the real long-term goal is prevention of symptoms whenever this is possible.
How does Gabapentin work?
Gabapentin was originally developed to treat epilepsy and is currently often used to relieve neuropathic pain. For postherpetic neuralgia, it is recommended first-line therapy. In the UK, 300mg capsules of gabapentin is currently available as the brand-name anticonvulsant Neurontin. Pain is thought to have both peripheral and central sensitization elements. The process of initiating pain, maintaining it, and intensifying it is controlled by this medication. Gabapentin prevents pain-related responses in animal models of chronic pain and prevents allodynia and hyperalgesia in models of chronic pain at higher doses. It is possible that gabapentin has a higher efficacy in the sciatica patients with the neuropathic pain component. The mechanism of action of this medication is unknown. In contrast to other anticonvulsant medications, there is no established dose-response effect or plasma level monitoring for pain relief with gabapentin. Measures of mood, pain, and activities of daily living may all reflect a response to treatment. Dizziness and drowsiness can be side effects at higher doses. There is also a risk of withdrawal and an increased incidence of adverse events in the elderly population. A 2008 study published by Correll, Johnston, and Regan suggest that gabapentin may be an effective treatment of leg pain and low back pain in post lumbar laminectomy syndrome, however the evidence is level 5.
Common uses of Gabapentin
A big question recently has become: can gabapentin be used to treat back pain? Gabriella et al. did a randomized controlled trial within the Department of Veterans Affairs Health Care System. In this trial, they evaluated the efficacy of gabapentin in patients with chronic radiculopathy. They were given gabapentin at a 3000 mg/day dose versus a placebo. Their conclusion was that gabapentin was effective at providing pain relief to patients with chronic radiculopathy, but it was associated with moderate to severe adverse events. Chronic radiculopathy has been defined as sciatic type leg pain that has lasted longer than 3 months. The study itself defines it as pain that radiates distal to the knee along the course of the involved nerve root accompanied by neurologic signs and positive findings on electrodiagnostic testing. Gabapentin seems to have potential in treating some neurogenic pain conditions like radiculopathy, but the adverse event profile seems to be a limiting factor. This treatment for radiculopathy is similar to what would be given for radicular low back pain. From a pharmacotherapeutic standpoint, use of gabapentin for lower back pain can be quite reasonable given that chronic lower back pain is often a neurologically derived or associated condition. A more recent systematic review and meta-analysis looking at gabapentin or pregabalin for chronic lower back pain and/or radiculopathy did find it effective compared to placebo. This being said, there was no clear recommendation due to the low quality and inconsistency of evidence available. Considering that no specific side effects were noted and the adverse events known in gabapentin are mild, it may be worth trying for appropriate patients who did not respond to treatment with chronic low back pain, but further studies need to be done.
Gabapentin is FDA approved for treating seizures and nerve pain on the skin (post herpetic neuralgia) that follows healing of shingles and may be used to prevent migraines. Most of the remaining NeomedsNow that does not get reabsorbed through the kidneys gets excreted as gabapentin in the urine. Indications for use of gabapentin that are not covered in this policy (e.g. anxiety disorders, bipolar disorder, alcohol withdrawal, delirium, hiccoughs, headache other than migraine, etc.) have insufficient evidence at this time to support its use. Off-label use of gabapentin includes restless leg syndrome, mood stabilization in bipolar disorder, and social phobia. These indications are included in the Canada’s Pharmacy website. This policy will be revised if new information becomes available.
Gabapentin for Lower Back Pain
To date, there has been very little scientific research done on the clinical effectiveness of using gabapentin to treat lower back pain. However, a recent study of postherpetic neuralgia has provided some insight. Study participants who had the symptoms of back pain and leg pain due to nerve damage were given either gabapentin or a placebo. After 8 weeks, they were asked questions about their pain. Those who had been taking gabapentin reported significantly less pain than their counterparts who had been taking the placebo. Since pain symptoms were reduced from nerve pain rather than actual back pain, this could be an indicator that gabapentin has potential to help lower back pain resulting from spinal disorders. At the same time, it should be kept in mind that this is a small amount of evidence and the amount of scientific research done was rated as low, so there is a general lack of good evidence for its effectiveness. At this point, it is mostly up to patient and physician judgement to try it out and see if it helps. Considering that gabapentin has relatively low risks of side effects and drug interactions compared to other add-on medicines, it might be a reasonable option to try. That said, gabapentin is known to be less effective for acute pain than it is for chronic pain, so it might not be worth trying for short-term or self-limiting lower back pain. And it will depend on the cause of the back pain, since there are some cases where gabapentin does not turn out to be very effective for pain.
The effectiveness of Gabapentin for lower back pain
Gabapentin was compared against placebo in a randomized controlled trial including 60 chronic sciatica patients with a 12-week follow-up. The result showed that gabapentin was not superior to the placebo in relieving leg pain and improving sleep quality. However, the limitation of this study was the small number of subjects and the use of a fixed gabapentin dosage. A better randomized control trial performed on 108 Canadian veterans showed better results. It was a double-blind placebo-controlled trial carried out in 18 family practices. The patients were included if they had pain of sciatic nerve distribution for less than 12 months and had an average pain of at least 5 on an 11-point numeric pain intensity scale. Gabapentin titration was initiated at 300 mg three times a day for 5 days, increased to 300 mg twice a day for 5 days, with subsequent uptitration to a maximum tolerated dose of 2400 mg/day, with each dose increase occurring at five-day intervals. The result showed that gabapentin was superior to the placebo in alleviating the radiating leg pain. It should be considered as an effective alternative first-line agent in treating sciatica and other radicular pain. Similarly, a clinical review published in August 2011 had rated gabapentin as an alternative first-line agent for low back pain. Again, it indicated that gabapentin works best in severe, radicular pain. The review had used a complex and well-defined research methodology to provide best-evidence recommendations to clinicians in managing a wide variety of back pain problems. Overall, the review found good evidence that several anticonvulsant agents are effective for various types of chronic nerve-related back pain. Although the greatest body of evidence involves gabapentin and pregabalin. Among them, the largest amount of evidence is available for gabapentin. The prescriber should systematically evaluate the potential benefits and risks of each treatment option. Gabapentin provides promise for those who suffer from chronic nerve-related back pain, with evidence supporting its efficacy with moderate safety concerns.
Recommended dosage of Gabapentin for lower back pain
The recommended dosage when using Gabapentin to treat lower back pain is the same as that for postherpetic neuralgia. This means starting with 300mg on day 1, 300mg twice on day 2, and 300mg three times on day 3. The dose can then be increased to 300mg four times a day, and should not be increased by more than 300mg every five days. This is the dosage that has had the most documented success in the treatment of chronic pain, and is the dosage that I will be using when conducting my trial of this medication. It is important to note the slow titration of the drug, as Gabapentin affects the calcium channels in our nerve cells. The slow titration allows the neurons to adapt, and results in less harmful effects on the nervous system of the patient. This decreased harm, combined with the migration of the drug out of the body could lead to fewer side effects when stopping this drug in comparison to others, a potential benefit for one wishing to treat their chronic pain, but there is increased risk of adverse effects on the nervous system if titration is too fast or the dose is too high. Recommended doses for the elderly and those with renal impairment are lower due to the decreased renal excretion of the drug, and with both there is increased risk of adverse effects on the nervous system. This is due to the action of Gabapentin being only on the nervous system, so any changes to the drug will alter the effects on the nervous system, desired and undesired. So in conclusion, the recommended dosage is a slow increase to 300mg four times daily, with greater and more documented success than any other dosages in the treatment of chronic pain, and decreased risk of side effects to the nervous system if dosed correctly in younger people with normal renal function. This being the recommended target group for those wishing to treat chronic pain associated with the nervous system injury.
Potential side effects of Gabapentin
The potential side effects of gabapentin are always something that must be considered when looking at treatment options. One study by Rusy et al. had to stop its double-blind placebo controlled trials due to the high level of side effects patients were experiencing. This is an indication that gabapentin is not well tolerated by a portion of patients. It was found that side effects increased with dosage. Fatigue (28%) and somnolence (23%) were the most commonly reported with 1800mg of gabapentin per day, whereas, dizziness (28%) and ataxia (28%) were reported by patients taking 2400mg per day. When looking at the treatment of chronic lower back pain, the sedative effect caused by higher doses of gabapentin is something that can seriously hinder a patient’s ability to function in day to day life. This is particularly an issue in patients who require the drug for neuropathic symptoms, in addition to their lower back pain. A Cochrane review by Wiffen et al. in 2013 looked at use of gabapentin in chronic neuropathic pain in adults, summing up evidence from 39 studies in 4140 participants. It concluded that the proportions of patients experiencing at least one adverse event (75.1% with gabapentin and 74.2% with placebo), or leading to withdrawal (17.3% with gabapentin and 11.7% with placebo) were not notably higher in the gabapentin group. This indicates that whilst many patients will have side effects from gabapentin, they are not significant enough to cause them to stop taking the drug. However, there are still a portion of patients who are unable to tolerate gabapentin due to adverse effects. This is again something that must be considered with the severity and impact of a patient’s lower back pain on their life.
Precautions and considerations when using Gabapentin for lower back pain
People with kidney problems are more likely to get side effects or even more problems when taking gabapentin. This is because gabapentin is removed from the body by the kidneys. Therefore, it is important that the general health of the kidney is good in order to avoid toxic build-up of gabapentin. At this stage, there is no recommendation for liver function monitoring. However, if there is existing liver damage, it would be reasonable to monitor liver function tests given gabapentin is metabolized by the liver. Gabapentin has been classified in pregnancy category C by the FDA. This indicates that while no controlled studies have been done to investigate the effects on human pregnancy, there is potential risk for using gabapentin during pregnancy, and possible consequential fetal damage cannot be ruled out. Gabapentin is also excreted in breastmilk and the effects on the breastfed infant are currently unknown according to NPS MedicineWise.
Gabapentin can be safely titrated to effect a therapeutic dose for nerve pain over 1-4 weeks. After a long period of chronic pain, it is possible that the body has adjusted to compensate for the pain, whether this is in posture or minor changes in how we move. This type of pain is often not well treated with anti-inflammatory medications or paracetamol, and may require medications that specifically target nerve pain. When commencing gabapentin, a titration pack is recommended in order to minimize the known side effects. This pack will start at a low dose and increase the dose on a daily or weekly basis to an optimal level. Gabapentin is taken orally and must be absorbed before it can start to work. Gabapentin capsules contain the active ingredient gabapentin, an antiepileptic medicine.
Gabapentin for Hip and Lower Back Pain
We have already identified from the previous paragraphs that there may be a neural pain component to some types of hiv and lower back pain and Gabapentin may provide some pain relief for this. Unfortunately, to date, there is only one study that has been done assessing the effects of an anticonvulsant in pain relief that is specific to hip and/or lower back pain. This was a study assessing the effects of Gabapentin compared to placebo on 150 patients with radicular pain due to lumbar spinal stenosis. This is a chronic painful condition where pain and cramping in the legs are brought on by walking and prolonged standing due to an abnormal narrowness of the spinal canal. Although this is not the specific type of hip and lower back pain we were hoping to look at, radicular pain has similar underlying mechanisms to Gabapentin-responsive peripheral neuropathy, so this study is somewhat translatable to our area of interest. Participants in the study were given Gabapentin or placebo and were followed for four weeks with pain being assessed by the short-form McGill Pain Questionnaire. At the conclusion of the study, those who had used Gabapentin were found to have significantly decreased leg pain compared to those on placebo. Alas, this study has not been able to be expanded into an area of hip and lower back pain more relevant to our study. It is hoped a study will be done in the future that can show more conclusive evidence that Gabapentin is effective for specific types of hip and lower back pain.
Hip and lower back pain is a common and often disabling musculoskeletal condition. When pain becomes chronic, there can be associated psychological effects, which contribute to greater disability and escalating healthcare costs. The Dalhousie Pain Management and Research Centre in Canada has recently promoted the idea that a neuropathic pain component is often present in chronic musculoskeletal pain. A 2007 systematic review of the literature looking at the evidence for this theory found the most compelling evidence in support of the theory was for chronic lower back pain. The same systematic review revealed that the agents possessing the best evidence for efficacy in the management of chronic musculoskeletal pain of a neuropathic nature were the anticonvulsants. Gabapentin is one such anticonvulsant.
The relationship between hip and lower back pain
A common story about the human body is the tale of agonized bones, stubborn knees, and aching hips. Usually in that order. It is somewhat of an all too familiar saga for many. The burden of dealing with this sequence of events becomes evident in the age-old expression “growing old(er) is not for the faint of heart.” One might question, why does the hip give out? When did this lower back pain start? These questions are more closely related than most might realize. The hip joint is intricately linked to the functionality of the entire lower limb. It is responsible for taking the weight of the body during static postures such as standing and walking and especially during dynamic activities such as stair climbing and running. With the hip being a ball and socket joint, it is designed for movement in almost all planes. The only time the hip is not taking the weight of the body on the same side is during the single limb support phase of walking where the opposite side hip is loaded. This is an important fact when considering why people may develop hip and or lower back pain. Changes in the ability or mechanics of the hip can impact the force transferred through the joint during various activities, leading to significant increases in force on other joints such as the lower back. Any injury or disease that affects the way the hips move can also cause problems in the lower back as they are so closely linked in terms of movement and function. It is because of these reasons that hip and lower back pain often coincide.
Using Gabapentin for hip and lower back pain relief
The National Institute of Health (NIH) conducted research that suggests that gabapentin is more effective in treating chronic pain that has a neuropathic origin than it is for acute pain outright. It is estimated that 40% of individuals suffering from lumbar disc herniation can develop a chronic neuropathic pain syndrome, and the percentage of chronic low back pain patients with a neuropathic pain component has been reported to be as high as 37%. However, it is unclear whether gabapentin specifically will be useful in treating neuropathic hip pain due to the absence of clinical trials specific to hip pain. Gabapentin treatment has also been shown to be less effective in the elderly; however, effective doses were well tolerated, suggesting that in the event of side effects, dose reduction may be a more effective approach rather than discontinuation of the drug. While there are no clinical trials specific to the treatment of gabapentin for neuropathic hip pain, the high prevalence of neuropathic pain in lower back pain patients and the consistent efficacy of gabapentin in treating chronic pain suggest that it may be a viable treatment option. In the event of failed treatment, it is a simple matter to discontinue gabapentin without any side effects, aside from the potential return of the pain symptoms. Due to the safety, tolerability, and established efficacy in treating chronic neuropathic pain symptoms, gabapentin remains a treatment option for patients with neuropathic hip pain, despite the absence of specific clinical trial data.
Other treatment options for hip and lower back pain
Some other treatment options which have been shown to be effective for the treatment of hip and lower back pain include spinal manipulative therapy, exercise therapy, weight loss, and physical therapy. These conservative measures have been shown to have an effect on pain intensity and functional improvements. A study by Ronald et al. has shown that spinal manipulative therapy resulted in improvements in both low back and hip pain. These improvements continued for 6 months after treatment. He has suggested that this form of treatment may be of benefit to patients with radiating pain and visible signs of joint dysfunction in the lower back. The therapy may need to be modified in order to accommodate limitations in lower back range of motion. This treatment may have very little adverse effects and could well be a cost-effective way of managing hip and lower back pain. Weight loss may be advised to patients as a way of reducing the pain in their hips and lower back. It is estimated that 1 kg of body weight causes 4 kg of force across the hip joint. Weight loss has a modest effect but is an important part of the long-term management of hip and lower back pain. Physical therapy treatment in the form of strengthening exercises for the hip and lower back was found to improve pain in the short-term, although this effect was less in the long term. There may be no point in telling a patient to do an exercise that only improves pain for a short period of time. Although some benefit can be gained from physical therapy in terms of functional improvements, it may also delay the need for more invasive treatment in people with mild to moderate pain.
