Effect of analgesia plus placebo on low back pain – a systematic review and meta-analysis

Introduction

In acute back pain, the pain will not last more than 6 weeks, and in most cases, the underlying cause of the pain will not cause a serious or long-term problem [1]. On the other hand, chronic back pain can be a serious problem. Chronic pain is serious and dangerous because its symptoms are so severe that they affect health, mobility and quality of life for a long time. While chronic back pain can start suddenly, it usually develops gradually and lasts for more than 6 weeks [2]. Also, chronic back pain can be intermittent, that is, there will be no pain if it does not occur for a while and then it occurs again [3]. Acute pain happens quickly and goes away when there is no cause, but chronic pain lasts longer than six months and can continue when the injury or illness has been treated [4].
A new injury can cause chronic back pain, but usually, underlying problems are the leading cause. Muscular problems (where the back loses strength and stability) are the most common causes [5]. Mild and severe injuries to the lumbar disc can lead to a wide range of symptoms and complications in/of the patient [6]. Spinal cord and nerve root injuries lead to reduced range of motion, temporary or permanent paralysis of a person’s activities [7]. Lower limb paralysis or muscle weakness can cause changes in a person’s standing or walking patterns, which ultimately results in the application of harmful biomechanical forces [8].
In order to relieve back pain, doctors use pain relievers, which include non-steroidal anti-inflammatory drugs [9], muscle relaxants [7], strong pain relievers [10], and antidepressants [11]. According to the World Health Organization, the strong opioids, morphine, methadone, and oxycodone, are recommended as second- or third-line treatments for neuropathic pain and anticonvulsants. The World Health Organization also listed anticonvulsants for which efficacy in the treatment of neuropathic pain is uncertain, including carbamazepine, oxcarbazepine, and sodium valproate [12, 13].
Back pain has many causes, including nervous back pain [1], sciatica pain [14], herniated disc [15], spinal canal stenosis [16], and symptoms of back pain [1].
The present study was conducted with the aim of investigating the effect of analgesia plus placebo on low back pain. The present study attempts to answer this research question: can medication of analgesia plus placebo reduce low back pain?

Material and methods

Researchers in this study searched for key words related to their objectives in the international databases Scopus, Cochrane, Embase and MEDLINE (PubMed) for January 2014 – December 2024; they considered the 27-point PRISMA 2020 checklist at each of the study stages [17].
The medical subject headings (MeSH) search strategy is as follows:
((((((“Low Back Pain”[Mesh]) OR (“Low Back Pain/complications”[Mesh] OR “Low Back Pain/diagnosis”[Mesh] OR “Low Back Pain/diagnostic imaging”[Mesh] OR “Low Back Pain/drug therapy”[Mesh] OR “Low Back Pain/epidemiology”[Mesh] OR “Low Back Pain/etiology”[Mesh] OR “Low Back Pain/prevention and control”[Mesh] OR “Low Back Pain/rehabilitation”[Mesh] OR “Low Back Pain/surgery”[Mesh] OR “Low Back Pain/therapy”[Mesh] )) OR “Back Pain”[Mesh]) OR (“Back Pain/surgery”[Mesh] OR “Back Pain/therapy”[Mesh])) OR “Pain”[Mesh]) AND (“Analgesia”[Mesh] OR “Acupuncture Analgesia”[Mesh] OR “Analgesia, Epidural”[Mesh] OR “Anesthesia and Analgesia”[Mesh] OR “Pain Measurement”[Mesh])) OR (“Pharmaceutical Preparations”[Mesh] OR “Physiological Effects of Drugs”[Mesh] OR “Nonprescription Drugs”[Mesh] OR “Substandard Drugs”[Mesh]).
The selection of articles was limited to the English language, also the articles were selected based on the PICO strategy (Table 1). Two blind, independent researchers examined the data from the chosen studies, and a third researcher provided a summary. There were four levels of heterogeneity assessed for the I2 value: low (≤ 25%), moderate (25–50%), substantial (50–75%), and considerable (≥ 75%).
In the present study, the modified risk of bias in randomized trials tool was used [18]. In this tool, scores of 4–6 indicate low risk of bias, 3–5 indicate moderate bias, and 0–2 indicate high bias.
Heterogeneity among studies was assessed by using the c2 and I2 tests (p < 0.05 and I2 > 75% = high heterogeneity). 95% CI effect size using inverse-variance method and a fixed-effects model (low heterogeneity between studies). Stata was used for the meta-analysis (version 17). A value less than 0.05 was regarded as statistically significant.

Result

When the related key words were used in the original search, 1076 articles were found in the international databases. Two independent, blind researchers went through the files, deleting anything superfluous or irrelevant to the study. The abstracts of 582 studies were reviewed against the inclusion criteria. The full text of 84 articles was then reviewed; only 8 articles were included in the study as they were in line with the objectives of the study (Figure 1).

Study characteristics

The characteristics of the studies are summarized in Table 2.

Efficacy assessments

The meta-analysis showed that use of medication plus placebo can reduce low back pain by 84% [ES 0.84 (–0.25, 1.92); p = 0.04, I2 = 0% (p > 0.05)] (Figure 2).
In studies, Diclofenac, Tramadol, Tizanidine, Aceclofenac, Thiocolchicoside, Naproxen, Metaxalone, Baclofen, and Ibuprofen plus placebo was used to reduce pain, which based on studies had good effectiveness in reducing low back pain (p = 0.04).

Clinical implications

According to the included studies, patients receiving neuropathic pain medications reported drowsiness, dizziness, nausea, vomiting, stomach pain, and indigestion.

Discussion

The human spine is one of the most complex organs in the body, in which bones, muscles, tendons, discs and ligaments all co-ordinate perfectly. Meanwhile, if any part of the spine is injured, it can interfere with the functioning of the whole system, leading to unpleasant consequences. Sitting or standing incorrectly, especially if repeated over a long period of time, can put a lot of strain on your back muscles and spine, eventually leading to back pain [26]. Lifting heavy objects is one of the common activities in daily life that, if not done properly, can cause irreparable damage to muscles and joints, especially in the lower back [27]. Sleeping in an improper position puts a lot of pressure on the spine and can lead to back pain, neck pain, and even more serious injuries over time; choosing wrong shoes and wearing them for a long time can lead to back pain. Flat, low-heeled shoes with an appropriate slope are the best type of shoes to prevent back pain, because they put less pressure on the back of the body [27].
Pain in the left or right lower back may be caused by a variety of causes/factors. Herniated disk is a common cause of disc ruptures in this area. In this case, the intervertebral disc, which is a cushion between the vertebrae, ruptures and the nerves of the spine are pushed forward. This pressure may cause pain, numbness and tingling in the lower back, hips, thighs and feet [28].
Spinal stenosis can also cause pain in the left or right lower back. In this disease, the spinal canal narrows and puts pressure on the spinal nerves [29]. Spinal stenosis usually occurs on both sides, but symptoms may appear on only one side, such as the left side [30].
The treatment of lower back pain depends on its cause. In some cases, pain relievers and anti-inflammatory drugs, physical therapy, or steroid injections can help relieve pain. In more severe cases, surgery may be necessary.
Pain in the upper back usually occurs due to fatigue, overwork, colds, and lack of sleep, and can be treated with enough rest and sleep [31].
Back pain is a common complication which may occur at any age, from children and adolescents to adults, and can occur at least once in a lifetime [32].
Drugs are one of the categories of drugs that deal with the reduction of the production of chemicals such as prostaglandin in the body, which causes fever, inflammation, and pain relief in the body. Of course, prostaglandins cause other effects in the body, for example, they help maintain the mucous lining of the stomach and intestines and cause blood to clot, and they also help the kidneys to work normally. Prostaglandins play a big role in the body and taking painkillers stops their production. So it can be concluded that the use of painkillers has both positive and negative effects [33].
There are many types of over-the-counter pain relievers. Four types of drugs are often used to treat back pain and neck pain: Aspirin (Bayer, Bafarin and Ecotrin). In addition to relieving pain, inflammation and fever, this medicine can reduce the risk of heart attack. Aspirin is available without a doctor’s prescription and sometimes with a prescription. Ibuprofen (Advil). Ibuprofen is used to relieve the pain of many diseases and is used to relieve pain after surgery and inflammatory diseases such as ankylosing spondylitis. This medicine is available without a doctor’s prescription. Naproxen (Alo, Anaprox, Naprosyn). This drug is usually used to treat back pain and muscle strain. It is available to everyone without a doctor’s prescription and with a doctor’s prescription. Celecoxib. This drug is often used to treat pain caused by various types of arthritis, such as osteoarthritis of the spine, rheumatoid arthritis, and is available with a doctor’s prescription [20, 33, 34]. Acetaminophen (Tylenol) relieves pain by blocking pain signals to the brain, and it is available without a doctor’s prescription. Acetaminophen may be combined with other pain relievers. These are combination drugs that are available by prescription. Acetaminophen is not an anti-inflammatory drug and it can be used between doses of nonsteroidal anti-inflammatory drugs to better control your/the pain [35].
Sometimes the patient suffers from discopathy of the back pain and its uncomfortable symptoms to such an extent that even using the best painkillers to relieve the pain of the lumbar disc mentioned in the previous section cannot improve the symptoms and the pain so much/great that even the person cannot do his daily activities or participate in physiotherapy sessions [35]. On the other hand, the specialist recognizes that surgery should not be performed at this time. In this situation, injectable drugs such as steroid injections, cortisone or ozone injections are used to quickly reduce pain. These injections are usually performed in the same area of ​​the injury with local anesthesia. The ozone injection method, which is performed in our center by highly skilled people, does not have the side effects of steroid drugs and can reduce the symptoms of lumbar discopathy for a longer period of time. Even in many patients who have used this method to improve their symptoms, the need for lumbar disc surgery has been eliminated; but you should be careful that not everyone can perform this procedure correctly and this injection must be performed by experienced specialists in a well-equipped center in order to achieve a proper recovery without causing complications [19].
Most back pain will be relieved within a month of conservative measures and use of the best pain relievers for lumbar spinal pain. However, the injury states vary in different patients and lumbar discopathy is a complex disease. For many people, the pain lasts for many months and can become long-lasting and chronic. Then you should avoid total rest as much as possible. Light activities such as walking and daily activities are important to strengthen the spine and prevent further symptoms. In general, you should stop the activity that increases the pain, but do not avoid all activities because of the fear of pain [36].
Acupuncture, as a non-invasive nerve stimulation method, is an effective and safe treatment for neuropathic pain with minimal adverse effects [37]. Physiotherapy is necessary to prevent or reverse changes in trophism, disuse atrophy, subsequent contractures, and deformities [38]. The effects of nerve blocks are rapid, providing relief almost immediately after injection. However, the results are sometimes short-lived and multiple injections may be required for optimal relief. Nerve blocks help with both chronic and acute pain [39, 40].
The current study had/has limitations, there were few randomized controlled trials, which requires further studies to confirm the evidence, and a larger sample size. On the other hand, the studies used different instruments to assess pain, which/thus it would be better to standardize the methodology of future studies. Also, the availability of the drug in different countries should be considered.

Conclusions

In conclusion, when compared to medication plus placebo, adding Diclofenac, Tramadol, Tizanidine, Aceclofenac, Thiocolchicoside, Naproxen, Metaxalone, Baclofen, and Ibuprofen does not improve functioning for acute low back pain. Adding medication did not improve functional recovery. Physiotherapy, lifestyle, proper nutrition, and hydration are factors that can effectively improve the quality of life of a patient with pain.

Disclosures

1. Institutional review board statement: Not applicable.
2. Assistance with the article: None.
3. Financial support and sponsorship: None.
4. Conflicts of interest: None.

References