The efficacy and safety of paracetamol for pain relief: an overview of systematic reviews

Acute back pain: The role of medication, physical medicine and rehabilitation: WFNS spine committee recommendations

Objectives

To formulate the most current, evidence-based recommendations for the role of medication, physical medicine, and rehabilitation in the management of acute low back pain lasting <4 weeks.

Methods

A systematic literature search in PubMed and Google Scholar databases was performed from 2012 to 2022 using the search terms "acute low back pain," "drugs," "bed rest," "physical medicine," rehabilitation." Standardized screening criteria resulted in a total of 39 articles that were analyzed, including 16 RCTs, 8 prospective studies, 6 retrospective studies, and 9 systematic reviews. This up-to-date information was reviewed and presented at two separate meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Two rounds of the Delphi method were utilized to vote on the statements and arrive at a positive or negative consensus.

Results and conclusion

The WFNS Spine Committee finalized twelve recommendation guidelines on the role of medication, physical medicine and rehabilitation in the management of acute LBP. We advocate for a uniform approach to the treatment of these patients, including proper patient education and utilizing drugs with proven efficacy and minimal side effects. First-line pharmacologic agents are acetaminophen and NSAIDs; muscle relaxants can be used for spasms and pain reduction, and opioids should be minimized. Continued activity, rather than bed rest, is recommended, and lumbar spine orthotics may be used to reduce pain and augment functional status. Thermotherapy, cryotherapy, TENs, spinal manipulative therapy, and acupuncture may all be used as adjuncts to improve acute LBP.

Paracetamol Combination Therapy for Back Pain and Osteoarthritis: A Systematic Review and Meta-Analyses

BACKGROUND AND OBJECTIVE

Although paracetamol (acetaminophen) combined with other analgesics can reduce pain intensity in some pain conditions, its effectiveness in managing low back pain and osteoarthritis is unclear. This systematic review investigated whether paracetamol combination therapy is more effective and safer than monotherapy or placebo in low back pain and osteoarthritis.

METHODS

Online database searches were conducted for randomised trials that evaluated paracetamol combined with another analgesic compared to a placebo or the non-paracetamol ingredient in the combination (monotherapy) in low back pain and osteoarthritis. The primary outcome was a change in pain. Secondary outcomes were (serious) adverse events, changes in disability and quality of life. Follow-up was immediate (≤ 2 weeks), short (> 2 weeks but ≤ 3 months), intermediate (> 3 months but < 12 months) or long term (≥ 12 months). A random-effects meta-analysis was conducted. Risk of bias was assessed using the original Cochrane tool, and quality of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twenty-two studies were included. Pain was reduced with oral paracetamol plus a non-steroidal anti-inflammatory drug (NSAID) at immediate term in low back pain (paracetamol plus ibuprofen vs ibuprofen [mean difference (MD) - 6.2, 95% confidence interval (CI) -10.4 to -2.0, moderate evidence]) and in osteoarthritis (paracetamol plus aceclofenac vs aceclofenac [MD - 4.7, 95% CI - 8.3 to - 1.2, moderate certainty evidence] and paracetamol plus etodolac vs etodolac [MD - 15.1, 95% CI - 18.5 to - 11.8; moderate certainty evidence]). Paracetamol plus oral tramadol reduced pain compared with placebo at intermediate term for low back pain (MD - 11.7, 95% CI - 19.2 to - 4.3; very low certainty evidence) and osteoarthritis (MD - 6.8, 95% CI - 12.7 to -0.9; moderate certainty evidence). Disability scores improved in half the comparisons. Quality of life was infrequently measured. All paracetamol plus NSAID combinations did not increase the risk of adverse events compared to NSAID monotherapy.

CONCLUSIONS

Low-to-moderate quality evidence supports the oral use of some paracetamol plus NSAID combinations for short-term pain relief with no increased risk of harm for low back pain and osteoarthritis compared to its non-paracetamol monotherapy comparator.

How is postoperative pain after hip and knee replacement managed? An analysis of two large hospitals in Australia

BACKGROUND

Multimodal analgesia regimens are recommended for the postoperative period after hip and knee replacement surgeries. However, there are no data on practice patterns for analgesic use in the immediate postoperative period after hip and knee replacements in Australia.

OBJECTIVES

To describe analgesic prescribing patterns in the inpatient postoperative phase for patients undergoing hip and knee replacement.

METHODS

Retrospective study of electronic medical record data from two major hospitals in Sydney, Australia. We identified analgesic medication prescriptions for all patients aged 18 years and older who underwent hip or knee replacement surgery in 2019. We extracted data on pain medications prescribed while in the ward up until discharge. These were grouped into distinct categories based on the Anatomical Therapeutic Chemical classification. We described the frequency (%) of pain medications used by category and computed the average oral morphine equivalent daily dose (OMEDD) during hospitalisation.

RESULTS

We identified 1282 surgeries in 1225 patients. Patients had a mean (SD) age of 69 (11.8) years; most (57.1%) were female. Over 99% of patients were prescribed opioid analgesics and paracetamol during their hospital stay. Most patients (61.4%) were managed with paracetamol and opioids only. The most common prescribed opioid was oxycodone (87.3% of patients). Only 19% of patients were prescribed nonsteroidal anti-inflammatories (NSAIDs). The median (IQR) average daily OMEDD was 50.2 mg (30.3-77.9).

CONCLUSION

We identified high use of opioids analgesics as the main strategies for pain control after hip and knee replacement in hospital. Other analgesics were much less frequently used, such as NSAIDs, and always in combination with opioids and paracetamol.

Comparative Efficacy of Breastfeeding or Feeding of Breast Milk on Blood Sampling Pain Relief in Full-Term Neonates: A Systematic Review and Meta-Analysis

Objectives: To evaluate the efficacy of breastfeeding or feeding of breast milk in reducing blood sampling pain in full-term neonates by comparing with other intervention measures. Methods: Related literature was searched from PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials (Central). Only randomized controlled trials (RCTs), which reported the effect of breastfeeding or feeding of breast milk on blood sampling pain in full-term neonates, were eligible. The primary outcome was set as pain score on scales, and the secondary outcomes as physiological and behavioral indicators. The risk of bias in included studies was assessed by the Cochrane Collaboration's tool. Data analysis was performed using RevMan 5.4.1. Main Results: A total of 17 RCTs were included. Breastfeeding showed a stronger effectiveness in reducing blood sampling pain, compared with nonintervention, placebo, mother's holding, breast milk odor, mother's heartbeat, music therapy, skin-to-skin, and Eutectic Mixture of Local Anesthetics ointment. However, the efficacy of glucose or sucrose (12.5%-30% concentration) seems better than breastfeeding. When compared with other interventions, feeding of breast milk yielded different results. Its effect was only stronger than placebo (sterile water or distilled water), massage, or nonintervention. Conclusions: Breastfeeding might be effective for alleviating blood sampling pain in full-term neonates. Its effect is second only to that of glucose/sucrose. The efficacy of feeding of breast milk in reducing blood sampling pain in full-term neonates might not be guaranteed.

Effects of benidipine, paracetamol, and their combination on postoperative and normal tissue pain thresholds

Introduction: In clinical practice, inadequate pain inhibition leads to increased morbidity and mortality. Increased intracellular calcium, oxidants, and proinflammatory cytokines are known to play a role in the pathogenesis of postoperative pain. Therefore, we investigated the analgesic effects of benidipine, paracetamol, and benidipine-paracetamol combination (BPC) on postoperative and normal pain thresholds in rats. Material and methods: Sixty-four male albino Wistar rats weighing 285-295 g were used. The without-incision rats were divided into 4 subgroups: healthy control, benidipine alone, paracetamol alone, and BPC. The scalpel-incision rats were divided into 4 subgroups: scalpel incision, scalpel incision + benidipine, scalpel incision + paracetamol, and scalpel incision + BPC. Paw pain thresholds of rats were measured using a Basile algesimeter. Biochemical analyses were performed on the paw tissues of 6 rats randomly taken from the experimental groups, each containing 8 rats. Rats were sacrificed immediately after the measurements. After the pain threshold tests were finished, the paw tissues were removed and malondialdehyde (MDA), total glutathione (tGSH), cyclooxygenase (COX), and interleukin-6 (IL-6) levels were measured. Results: There was no significant difference between the groups in paw pain threshold and measured biochemical parameters in rats without incision. The decrease in the pain threshold of the incised paw was also best prevented by BPC, followed by benidipine and then paracetamol. Furthermore, increases in scalpel-incised paw tissue MDA, COX-2, and IL-6 levels and the decrease in tGSH were significantly suppressed by benidipine and BPC, while paracetamol could only significantly inhibit the increase in IL-6 production. Conclusion: The combination of the L-type Ca2+ channel blocker benidipine and paracetamol (BPC) may provide potent analgesia. Our experimental results support that BPC may be useful in the treatment of severe pain that cannot be adequately inhibited by paracetamol.

Barriers and facilitators to reducing paracetamol use in low back pain: A qualitative study

BACKGROUND

Paracetamol is widely used for low back pain (LBP), but research questions its efficacy and safety. Patient education booklets have been explored for promoting deprescribing, but barriers and facilitators specific to LBP deprescribing remain unexamined.

OBJECTIVE

To identify contextual factors facilitating and obstructing successful deprescribing of paracetamol for LBP after receiving an educational booklet.

STUDY DESIGN

This study is part of an uncontrolled cohort feasibility study (CEASE NOW) in the community, recruiting from Musculoskeletal Australia and painaustralia.

PATIENT SAMPLE

Twenty-four participants with acute, sub-acute, or chronic LBP, self-reporting paracetamol consumption, were included.

METHODS

Thematic content analysis was used to analyze qualitative data on barriers and facilitators. Data were categorized by deprescribing outcomes: i) successful deprescribing, ii) attempted but failed, or iii) no attempt. Semi-structured telephone interviews were conducted within one week after each participant completed the one-month follow-up.

RESULTS

Successful deprescribing was facilitated by supportive healthcare professionals, willingness, high self-efficacy, fear of future illness, and diverse strategies for deprescribing plans. Barriers included unsupportive healthcare professionals and fear of flare-ups. Participants not attempting deprescribing believed it unnecessary, perceived it as effortful, unquestioningly trusted healthcare professionals, and lacked risk awareness.

CONCLUSIONS

Support from healthcare professionals, patient willingness, perceived necessity, risk awareness, effort, and varied strategies influence deprescribing outcomes for LBP patients using paracetamol. Addressing these factors is crucial when designing interventions to promote safe and effective deprescribing in LBP management.

CaCu3Ti4O12 Perovskite Materials for Advanced Oxidation Processes for Water Treatment

The many pollutants detected in water represent a global environmental issue. Emerging and persistent organic pollutants are particularly difficult to remove using traditional treatment methods. Electro-oxidation and sulfate-radical-based advanced oxidation processes are innovative removal methods for these contaminants. These approaches rely on the generation of hydroxyl and sulfate radicals during electro-oxidation and sulfate activation, respectively. In addition, hybrid activation, in which these methods are combined, is interesting because of the synergistic effect of hydroxyl and sulfate radicals. Hybrid activation effectiveness in pollutant removal can be influenced by various factors, particularly the materials used for the anode. This review focuses on various organic pollutants. However, it focuses more on pharmaceutical pollutants, particularly paracetamol, as this is the most frequently detected emerging pollutant. It then discusses electro-oxidation, photocatalysis and sulfate radicals, highlighting their unique advantages and their performance for water treatment. It focuses on perovskite oxides as an anode material, with a particular interest in calcium copper titanate (CCTO), due to its unique properties. The review describes different CCTO synthesis techniques, modifications, and applications for water remediation.

Pharmacological treatments for low back pain in adults: an overview of Cochrane Reviews

BACKGROUND

Pharmacological interventions are the most used treatment for low back pain (LBP). Use of evidence from systematic reviews of the effects of pharmacological interventions for LBP published in the Cochrane Library, is limited by lack of a comprehensive overview.

OBJECTIVES

To summarise the evidence from Cochrane Reviews of the efficacy, effectiveness, and safety of systemic pharmacological interventions for adults with non-specific LBP.

METHODS

The Cochrane Database of Systematic Reviews was searched from inception to 3 June 2021, to identify reviews of randomised controlled trials (RCTs) that investigated systemic pharmacological interventions for adults with non-specific LBP. Two authors independently assessed eligibility, extracted data, and assessed the quality of the reviews and certainty of the evidence using the AMSTAR 2 and GRADE tools. The review focused on placebo comparisons and the main outcomes were pain intensity, function, and safety.

MAIN RESULTS

Seven Cochrane Reviews that included 103 studies (22,238 participants) were included. There is high confidence in the findings of five reviews, moderate confidence in one, and low confidence in the findings of another. The reviews reported data on six medicines or medicine classes: paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), muscle relaxants, benzodiazepines, opioids, and antidepressants. Three reviews included participants with acute or sub-acute LBP and five reviews included participants with chronic LBP. Acute LBP Paracetamol There was high-certainty evidence for no evidence of difference between paracetamol and placebo for reducing pain intensity (MD 0.49 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -1.99 to 2.97), reducing disability (MD 0.05 on a 0 to 24 scale (higher scores indicate worse disability), 95% CI -0.50 to 0.60), and increasing the risk of adverse events (RR 1.07, 95% CI 0.86 to 1.33). NSAIDs There was moderate-certainty evidence for a small between-group difference favouring NSAIDs compared to placebo at reducing pain intensity (MD -7.29 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -10.98 to -3.61), high-certainty evidence for a small between-group difference for reducing disability (MD -2.02 on a 0-24 scale (higher scores indicate worse disability), 95% CI -2.89 to -1.15), and very low-certainty evidence for no evidence of an increased risk of adverse events (RR 0.86, 95% CI 0. 63 to 1.18). Muscle relaxants and benzodiazepines There was moderate-certainty evidence for a small between-group difference favouring muscle relaxants compared to placebo for a higher chance of pain relief (RR 0.58, 95% CI 0.45 to 0.76), and higher chance of improving physical function (RR 0.55, 95% CI 0.40 to 0.77), and increased risk of adverse events (RR 1.50, 95% CI 1. 14 to 1.98). Opioids None of the included Cochrane Reviews aimed to identify evidence for acute LBP. Antidepressants No evidence was identified by the included reviews for acute LBP. Chronic LBP Paracetamol No evidence was identified by the included reviews for chronic LBP. NSAIDs There was low-certainty evidence for a small between-group difference favouring NSAIDs compared to placebo for reducing pain intensity (MD -6.97 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -10.74 to -3.19), reducing disability (MD -0.85 on a 0-24 scale (higher scores indicate worse disability), 95% CI -1.30 to -0.40), and no evidence of an increased risk of adverse events (RR 1.04, 95% CI -0.92 to 1.17), all at intermediate-term follow-up (> 3 months and ≤ 12 months postintervention). Muscle relaxants and benzodiazepines There was low-certainty evidence for a small between-group difference favouring benzodiazepines compared to placebo for a higher chance of pain relief (RR 0.71, 95% CI 0.54 to 0.93), and low-certainty evidence for no evidence of difference between muscle relaxants and placebo in the risk of adverse events (RR 1.02, 95% CI 0.67 to 1.57). Opioids There was high-certainty evidence for a small between-group difference favouring tapentadol compared to placebo at reducing pain intensity (MD -8.00 on a 0 to 100 scale (higher scores indicate worse pain), 95% CI -1.22 to -0.38), moderate-certainty evidence for a small between-group difference favouring strong opioids for reducing pain intensity (SMD -0.43, 95% CI -0.52 to -0.33), low-certainty evidence for a medium between-group difference favouring tramadol for reducing pain intensity (SMD -0.55, 95% CI -0.66 to -0.44) and very low-certainty evidence for a small between-group difference favouring buprenorphine for reducing pain intensity (SMD -0.41, 95% CI -0.57 to -0.26). There was moderate-certainty evidence for a small between-group difference favouring strong opioids compared to placebo for reducing disability (SMD -0.26, 95% CI -0.37 to -0.15), moderate-certainty evidence for a small between-group difference favouring tramadol for reducing disability (SMD -0.18, 95% CI -0.29 to -0.07), and low-certainty evidence for a small between-group difference favouring buprenorphine for reducing disability (SMD -0.14, 95% CI -0.53 to -0.25). There was low-certainty evidence for a small between-group difference for an increased risk of adverse events for opioids (all types) compared to placebo; nausea (RD 0.10, 95% CI 0.07 to 0.14), headaches (RD 0.03, 95% CI 0.01 to 0.05), constipation (RD 0.07, 95% CI 0.04 to 0.11), and dizziness (RD 0.08, 95% CI 0.05 to 0.11). Antidepressants There was low-certainty evidence for no evidence of difference for antidepressants (all types) compared to placebo for reducing pain intensity (SMD -0.04, 95% CI -0.25 to 0.17) and reducing disability (SMD -0.06, 95% CI -0.40 to 0.29).

AUTHORS' CONCLUSIONS

We found no high- or moderate-certainty evidence that any investigated pharmacological intervention provided a large or medium effect on pain intensity for acute or chronic LBP compared to placebo. For acute LBP, we found moderate-certainty evidence that NSAIDs and muscle relaxants may provide a small effect on pain, and high-certainty evidence for no evidence of difference between paracetamol and placebo. For safety, we found very low- and high-certainty evidence for no evidence of difference with NSAIDs and paracetamol compared to placebo for the risk of adverse events, and moderate-certainty evidence that muscle relaxants may increase the risk of adverse events. For chronic LBP, we found low-certainty evidence that NSAIDs and very low- to high-certainty evidence that opioids may provide a small effect on pain. For safety, we found low-certainty evidence for no evidence of difference between NSAIDs and placebo for the risk of adverse events, and low-certainty evidence that opioids may increase the risk of adverse events.

Ferroptosis in lung cancer: a novel pathway regulating cell death and a promising target for drug therapy

Lung cancer is a common malignant tumor that occurs in the human body and poses a serious threat to human health and quality of life. The existing treatment methods mainly include surgical treatment, chemotherapy, and radiotherapy. However, due to the strong metastatic characteristics of lung cancer and the emergence of related drug resistance and radiation resistance, the overall survival rate of lung cancer patients is not ideal. There is an urgent need to develop new treatment strategies or new effective drugs to treat lung cancer. Ferroptosis, a novel type of programmed cell death, is different from the traditional cell death pathways such as apoptosis, necrosis, pyroptosis and so on. It is caused by the increase of iron-dependent reactive oxygen species due to intracellular iron overload, which leads to the accumulation of lipid peroxides, thus inducing cell membrane oxidative damage, affecting the normal life process of cells, and finally promoting the process of ferroptosis. The regulation of ferroptosis is closely related to the normal physiological process of cells, and it involves iron metabolism, lipid metabolism, and the balance between oxygen-free radical reaction and lipid peroxidation. A large number of studies have confirmed that ferroptosis is a result of the combined action of the cellular oxidation/antioxidant system and cell membrane damage/repair, which has great potential application in tumor therapy. Therefore, this review aims to explore potential therapeutic targets for ferroptosis in lung cancer by clarifying the regulatory pathway of ferroptosis. Based on the study of ferroptosis, the regulation mechanism of ferroptosis in lung cancer was understood and the existing chemical drugs and natural compounds targeting ferroptosis in lung cancer were summarized, with the aim of providing new ideas for the treatment of lung cancer. In addition, it also provides the basis for the discovery and clinical application of chemical drugs and natural compounds targeting ferroptosis to effectively treat lung cancer.

Osteoarthritis year in review 2022: epidemiology & therapy

This 'Year in Review' provides a synopsis of key research themes and individual studies from the clinical osteoarthritis (OA) field, focused on epidemiology and therapy. The electronic database search for the review was adapted from the 2021 year in review search, to increase search specificity for relevant study designs, and was conducted in Medline, Embase and medRxiv (31^st March 2021 to 4^th March 2022). Following screening for eligibility, studies were grouped according to their key research design, including reviews, cohorts and randomised trials. 11 key themes emerged, including the importance of several comorbidities in predicting OA incidence and prevalence, surgical approaches that can reduce the risk of post-traumatic OA, the heterogenous but nevertheless relatively stable nature of OA subgroup trajectories, the paucity of robust studies particularly of surgery for OA and the very modest benefit of many therapies under evaluation in trials. A particular interest of the authors was to consider whether new studies are helping determine how to better ensure the right patient with OA is matched to the right treatment at the right time. There are several new studies developing improved predictive models through big data analytics and machine learning which show promise, need validation, and may support new approaches to stratified care.

Discovery of 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivatives as novel anti-inflammatory agents for the treatment of acute lung injury and sepsis

Acute lung injury (ALI) and sepsis, characterized by systemic inflammatory response syndrome, remain the major causes of death in severe patients. Inhibiting the release of proinflammatory cytokines is considered to be a promising method for the treatment of inflammation-related diseases. In this study, a total of 28 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivatives were designed and synthesized and their anti-inflammatory activities in J774A.1 were evaluated. Among them, derivative 13a was found to significantly inhibit lipopolysaccharide (LPS)-induced expression of the proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) on J774A.1, THP-1 and LX-2 cells, and inhibited the activation of the NF-κB pathway. Furthermore, administration of 13ain vivo significantly improved the symptoms in LPS-induced ALI mice, including alleviation of pathological changes in the lung tissue, reduction of pulmonary edema, and inhibition of macrophage infiltration. Moreover, the administration of 13ain vivo significantly promoted survival in LPS-induced sepsis mice. 13a demonstrated favorable pharmacokinetic properties with T_1/2 value of 11.8 h and F value of 36.3%. Therefore, this study has identified a novel 4-oxo-N-phenyl-1,4-dihydroquinoline-3-carboxamide derivative, 13a, which is an effective anti-inflammatory agent. The findings have laid a foundation for the further development of agents to treat ALI and sepsis.

Efficacy, safety, and tolerability of antidepressants for pain in adults: overview of systematic reviews

OBJECTIVE

To provide a comprehensive overview of the efficacy, safety, and tolerability of antidepressants for pain according to condition.

DESIGN

Overview of systematic reviews.

DATA SOURCES

PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials from inception to 20 June 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews comparing any antidepressant with placebo for any pain condition in adults.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted data. The main outcome measure was pain; for headache disorders it was frequency of headaches. Continuous pain outcomes were converted into a scale of 0 (no pain) to 100 (worst pain) and were presented as mean differences (95% confidence intervals). Dichotomous outcomes were presented as risk ratios (95% confidence intervals). Data were extracted from the time point closest to the end of treatment. When end of treatment was too variable across trials in a review, data were extracted from the outcome or time point with the largest number of trials and participants. Secondary outcomes were safety and tolerability (withdrawals because of adverse events). Findings were classified from each comparison as efficacious, not efficacious, or inconclusive. Certainty of evidence was assessed with the grading of recommendations assessment, development, and evaluation framework.

RESULTS

26 reviews (156 unique trials and >25 000 participants) were included. These reviews reported on the efficacy of eight antidepressant classes covering 22 pain conditions (42 distinct comparisons). No review provided high certainty evidence on the efficacy of antidepressants for pain for any condition. 11 comparisons (nine conditions) were found where antidepressants were efficacious, four with moderate certainty evidence: serotonin-norepinephrine reuptake inhibitors (SNRIs) for back pain (mean difference -5.3, 95% confidence interval -7.3 to -3.3), postoperative pain (-7.3, -12.9 to -1.7), neuropathic pain (-6.8, -8.7 to -4.8), and fibromyalgia (risk ratio 1.4, 95% confidence interval 1.3 to 1.6). For the other 31 comparisons, antidepressants were either not efficacious (five comparisons) or the evidence was inconclusive (26 comparisons).

CONCLUSIONS

Evidence of efficacy of antidepressants was found in 11 of the 42 comparisons included in this overview of systematic reviews-seven of the 11 comparisons investigated the efficacy of SNRIs. For the other 31 comparisons, antidepressants were either inefficacious or evidence on efficacy was inconclusive. The findings suggest that a more nuanced approach is needed when prescribing antidepressants for pain conditions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022311073.

Paracetamol (acetaminophen) overdose and hepatotoxicity: mechanism, treatment, prevention measures, and estimates of burden of disease

INTRODUCTION

Paracetamol is one of the most used medicines worldwide and is the most common important poisoning in high-income countries. In overdose, paracetamol causes dose-dependent hepatotoxicity. Acetylcysteine is an effective antidote, however despite its use hepatotoxicity and many deaths still occur.

AREAS COVERED

This review summarizes paracetamol overdose and toxicity (including mechanisms, risk factors, risk assessment, and treatment). In addition, we summarize the epidemiology of paracetamol overdose worldwide. A literature search on PubMed for poisoning epidemiology and mortality from 1 January 2017 to 26 October 2022 was performed to estimate rates of paracetamol overdose, liver injury, and deaths worldwide.

EXPERT OPINION

Paracetamol is widely available and yet is substantially more toxic than other analgesics available without prescription. Where data were available, we estimate that paracetamol is involved in 6% of poisonings, 56% of severe acute liver injury and acute liver failure, and 7% of drug-induced liver injury. These estimates are limited by lack of available data from many countries, particularly in Asia, South America, and Africa. Harm reduction from paracetamol is possible through better identification of high-risk overdoses, and better treatment regimens. Large overdoses and those involving modified-release paracetamol are high-risk and can be targeted through legislative change.

The Over-the-Counter Medicines Market in Poland

The market of over-the-counter drugs, so-called OTC drugs, is a dynamically developing market driven primarily by self-medication. Their use does not require consultation with a physician, and the patients themselves decide to take them. The distribution of OTC medications in the pharmaceutical market in Poland is diversified. These drugs could be purchased at a pharmacy but also at a supermarket, gas station, or via the internet. The low involvement of public funds in spending on drugs, a relatively small percentage of pharmacy sales of reimbursable prescription drugs, and the difficult access to physicians or general consent to drug advertising all create ideal conditions for creating demand for these drugs. Among the European countries, Poland also has the largest share of OTC drugs in the entire pharmaceutical market, and the percentage of OTCs (without supplements) in the whole drug market in Poland continues to grow. Unfortunately, the non-pharmacy market for the sale of OTC drugs is not adequately controlled in practice, and Polish legal regulations regarding the sale of medicines outside pharmacies are among the most liberal in the European Union. However, this does not change the general attitude of consumers toward purchasing OTC drugs. In fact, further growth of the OTC drug market is forecast. Self-medication will undoubtedly play an important role in the trends which may shape this market in the coming years.

Benefits and harms of treatments for chronic non-specific low back pain without radiculopathy: Systematic review and meta-analysis

BACKGROUND CONTEXT

Currently, there are no published studies that compare non-pharmacological, pharmacological and invasive treatments for chronic low back pain in adults and provide summary statistics for benefits and harms.

PURPOSE

The aim of this review was to compare the benefits and harms of treatments for the management of chronic low back pain without radiculopathy and to report the findings in a format that facilitates direct comparison (Benefit-Harm Scale: level 1 to 7).

DESIGN

Systematic review and meta-analysis of randomized controlled trials, including trial registries, from electronic databases up to 23^rd May 2022.

PATIENT SAMPLE

Adults with non-specific chronic low back pain, excluding radicular pain in any clinical setting.

OUTCOME MEASURES

Comparison of pain at immediate-term (≤2 weeks) and short-term (>2 weeks to ≤12 weeks) and serious adverse events using the Benefit-Harm Scale (level 1 to 7).

METHODS

This was a registered systematic review and meta-analysis of randomized controlled trials. Interventions included non-pharmacological (acupuncture, spinal manipulation), pharmacological and invasive treatments compared to placebo. Best evidence criteria was used. Two independent reviewers conducted eligibility assessment, data extraction and quality appraisal.

RESULTS

The search retrieved 17,362 records. Three studies provided data on the benefits of interventions, and 30 provided data on harms. Studies included interventions of acupuncture (n=8); manipulation (n=2); pharmacological therapies (n=9), including NSAIDs and opioid analgesics; surgery (n=8); and epidural corticosteroid injections (n=3). Acupuncture (standardized mean difference (SMD) -0.51, 95%CI -0.88 to -0.14, n=1 trial, moderate quality of evidence, benefit rating of 3) and manipulation (SMD -0.39, 95%CI -0.56 to -0.21, n=2 trials, moderate quality of evidence, benefit rating of 5) were effective in reducing pain intensity compared to sham. The benefit of the other interventions was scored as uncertain due to not being effective, statistical heterogeneity preventing pooling of effect sizes, or the absence of relevant trials. The harms level warnings were at the lowest (eg, indicating rarer risk of events) for acupuncture, spinal manipulation, NSAIDs, combination ingredient opioids, and steroid injections, while they were higher for single ingredient opioid analgesics (level 4) and surgery (level 6).

CONCLUSIONS

There is uncertainty about the benefits and harms of all the interventions reviewed due to the lack of trials conducted in patients with chronic non-specific low back pain without radiculopathy. From the limited trials conducted, non-pharmacological interventions of acupuncture and spinal manipulation provide safer benefits than pharmacological or invasive interventions. However, more research is needed. There were high harms ratings for opioids and surgery.

Practice guidelines for the treatment of acute migraine and chronic knee osteoarthritis with paracetamol: an expert appraisal on evolution over time between scientific societies

BACKGROUND

Paracetamol is the commonest analgesic worldwide in primary care. Despite evidence-based recommendations for management of acute and chronic pain with paracetamol, practices seem to vary considerably in its modalities of use, with or without restrictions, between renowned scientific societies and over time.

OBJECTIVE

Qualitative assessment of similarities, differences, and changes over time in guidelines for paracetamol use in acute and chronic pain.

METHODS

We focused on two common pain conditions for which paracetamol is widely used: acute migraine and chronic knee osteoarthritis (OA). In 19 guidelines (10 for acute migraine, 9 for chronic knee OA) from 10 scientific societies (AAN/AHS, ACR/AF, CHS, EFNS, EHF/LTB, ESCEO, EULAR, SFEMC, SRF, OARSI) published between 1997 and 2021, methods, results and conclusions were compared, between guidelines and over time.

RESULTS

In acute migraine, there was a shift from no recommendation for paracetamol or recommendation only for mild attacks to recommendation for mild to moderate attacks in updated guidelines, without restriction for use for four of the five scientific societies. In knee OA, although updated guidelines generally used the GRADE system, recommendations remained heterogeneous between scientific societies: recommendation without or with restrictions, or not recommended. Consensus is lacking regarding long-course safety and efficacy in acute pain and pain at mobilization.

CONCLUSIONS

Most migraine guidelines now recommend paracetamol for mild to moderate pain. Knee OA guidelines vary on the use of paracetamol: a more holistic approach is needed for this condition, considering patient profile, disease stage, and pain management during physical activity to clarify its appropriate use.

DANTE Study: The First Randomized, Double-Blind, Placebo and Active-Controlled, Parallel Arm Group Study Evaluating the Analgesic Efficacy and Safety of Dexketoprofen TrometAmol aNd Tramadol Hydrochloride Oral FixEd Dose Combination on Moderate to Severe Acute Pain in Patients with Acute Low Back Pain-Rationale and Design

INTRODUCTION

Despite a wide range of treatment approaches and the availability of treatment recommendations or guidelines, no consensus on the most effective pharmacological therapy of low back pain (LBP) has been reached yet. Therefore, additional clinical evidence, particularly if built upon a rigorous clinical trial design, an evidence-based medication choice, and broader inclusion criteria better acknowledging the heterogeneity and intrinsic variability of LBP is needed. The DANTE study has been designed to comprehensively assess the analgesic efficacy and tolerability of dexketoprofen/tramadol (DKP/TRAM) 75/25 mg in a large cohort of patients with moderate to severe acute LBP.

METHODS

The DANTE study is a phase IV, multicenter, randomized, double-blind, double-dummy parallel group, placebo, and active controlled study. The DANTE study encompasses a single-dose phase (day 1, t0-t8h) and a multiple-dose phase (from t8h to 8 h after intake of last dose at day 5). The DANTE study population includes patients naïve to LBP or patients with previous history of LBP experiencing a new episode of moderate to severe intensity with or without radiculopathy. The clinical phase of the DANTE study started in September 2020 and the anticipated completion date is April 2022.

PLANNED OUTCOMES

The primary endpoint is the time to first achieve a numeric rating scale-pain intensity (NRS-PI) score of < 4 or a pain intensity reduction ≥ 30% from drug intake up to 8 h after the first dose (t8h). Secondary objectives aim are: (1) to evaluate the analgesic efficacy of TRAM/DKP 75/25 mg versus TRAM 100 mg after the first dose; (2) to evaluate the analgesic efficacy of TRAM/DKP 75/25 mg versus TRAM 100 mg after the multiple doses (from t8h until day 5, multiple dose); and (3) to assess the safety and tolerability of the TRAM/DKP 75/25 mg fixed combination after single and multiple doses.

DANTE STUDY REGISTRATION

EudraCT number: 2019-003656-37.

Status quo of pain-related patient reported outcomes and perioperative pain management in 10 415 patients from 10 countries: analysis of registry data

BACKGROUND

Postoperative pain is common at the global level, despite considerable attempts for improvement, reflecting the complexity of offering effective pain relief. In this study, clinicians from Mexico, China, and eight European countries evaluated perioperative pain practices and patient-reported outcomes (PROs) in their hospitals as a basis for carrying out quality improvement (QI) projects in each country.

METHODS

PAIN OUT, an international perioperative pain registry, provided standardized methodology for assessing management and multi-dimensional PROs on the first postoperative day, in patients undergoing orthopedic, general surgery, obstetric & gynecology or urological procedures.

RESULTS

Between 2017-2019, data obtained from 10,415 adult patients in 105 wards, qualified for analysis. At the ward level: 50% (median) of patients reported worst pain intensities ≥7/10 NRS, 25% spent ≥50% of the time in severe pain and 20-34% reported severe ratings for pain-related functional and emotional interference. Demographic variables, country and surgical discipline explained a small proportion of the variation in the PROs, leaving about 88% unexplained. Most treatment processes varied considerably between wards. Ward effects accounted for about 7% and 32% of variation in PROs and treatment processes, respectively.

CONCLUSIONS

This comprehensive evaluation demonstrates that many patients in this international cohort reported poor pain-related PROs on the first postoperative day. PROs and treatments varied greatly. Most of the variance of the PROs could not be explained. The findings served as a basis for devising and implementing QI programs in participating hospitals.

Strategies to manage auxiliary pain medications in chronic pain trials: a topical review

Chronic pain trials commonly allow auxiliary pain medications such as rescue and concomitant analgesics in addition to the randomized treatment. Changes in auxiliary pain medications after randomization represent intercurrent events that may affect either the interpretation or the existence of the measurements associated with the clinical question of interest, complicating the assessment of treatment efficacy. In chronic pain trials, pain intensity typically varies and patients may take the auxiliary medications 1 day but not the next or increase and decrease the dosages temporarily while continuing their randomized study medication. This distinctive feature of auxiliary pain medications as an intercurrent event has received little attention in the literature. Further clarifications on how to manage these issues are therefore pressing. Here we provide perspectives on issues related to auxiliary pain medication-related intercurrent events in randomized controlled chronic pain trials considering the strategies suggested in the E9(R1) addendum to the ICH guideline on statistical principles for clinical trials.

Pain Management in Older Adults with Chronic Wounds

Older people often suffer from different types of ulcers, with the most prevalent being chronic leg ulcers (CLUs) and diabetic foot ulcers. There are major issues in the current medical approach because these ulcers are hard to heal, and, in the case of CLUs, very painful and with a high frequency of relapse. Older people complain of pain more frequently than young people, frequently due to a combination of painful chronic wounds with other comorbidities (e.g. arthritis, peripheral arterial disease, vertebrogenic pain syndrome). However, chronic pain appears to be managed better by older people because the pain sensitivity is downregulated and the pain threshold is higher in older people. Pain management of chronic wounds is often insufficient, especially in older individuals. It is highly important to use non-traumatic wound dressings and pay attention to patients' feelings and fears because pain in chronic ulcers can impair wound healing. Key factors include good preparation for dressing change and adequate analgesia, ideally a combination of topical and oral agents.

Medications for Treating Low Back Pain in Adults. Evidence for the Use of Paracetamol, Opioids, Nonsteroidal Anti-inflammatories, Muscle Relaxants, Antibiotics, and Antidepressants: An Overview for Musculoskeletal Clinicians

BACKGROUND

Because pharmacological therapies may play an important role in managing musculoskeletal pain, the appropriate use of medicines for common conditions like low back pain (LBP) is critical. New evidence on the effects and safety of paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), opioid analgesics, muscle relaxants, antibiotics, and antidepressants for LBP warrants an updated overview for musculoskeletal clinicians on this topic.

CLINICAL QUESTION

How effective and safe are paracetamol, NSAIDs, opioid analgesics, muscle relaxants, antibiotics, and antidepressants compared with placebo for treating LBP?

KEY RESULTS

For acute LBP (<12 weeks), muscle relaxants and NSAIDs may be superior to placebo for reducing pain, but the effects of opioids, antibiotics, and antidepressants are unknown. Paracetamol provides no additional benefit for acute LBP. For chronic LBP (>12 weeks), NSAIDs, antidepressants, and opioids may be superior to placebo for reducing pain, but opioids have an established profile of harms. Antibiotics may also reduce pain for people with chronic LBP with Modic type 1 changes, although the risks may outweigh their benefits. The effects of paracetamol and muscle relaxants for chronic LBP were unclear.

CLINICAL APPLICATION

NSAIDs may have a role in managing acute and chronic LBP, with cautious use in people who may be at greater risk of experiencing adverse events. Paracetamol, opioid analgesics, antibiotics, muscle relaxants, and antidepressants should only be prescribed following a discussion between the treating clinician and the patient, considering the risks and possible benefits, and after or in conjunction with recommended nonpharmacological strategies for improving LBP. J Orthop Sports Phys Ther 2022;52(7):425-431. Epub: 18 May 2022. doi:10.2519/jospt.2022.10788.

The impact of different intensities and domains of physical activity on analgesic use and activity limitation in people with low back pain: a prospective cohort study with a one-year follow-up

BACKGROUND

Analgesics are the most common form of managing low back pain (LBP). No previous study has examined which domains and intensities of physical activity are most beneficial in reducing the frequency of analgesic use for LBP, and its related activity limitation.

METHODS

This cohort study forms part of the AUstralian Twin low BACK pain study, investigating the impact of physical activity on LBP. Information on demographics, LBP and health-related factors, including physical activity were collected at baseline. Data on the total counts of analgesic use and activity limitation for LBP were collected weekly for one-year. Negative binomial regression models were conducted separately for each type of physical activity. Results were presented as Incidence Rate Ratios (IRR) and 95% Confidence Intervals (CI).

RESULTS

From an initial sample of 366 participants, 86 participants reported counts of analgesic use and 140 recorded counts of activity limitation across the follow up period. The negative binomial regression models for analgesic use counts indicated moderate-vigorous physical activity (IRR 0·97, 95% C.I 0·96-0·99) and physical workload (IRR 1·02, 95% C.I 1·01-1·05) to be significant. For activity limitation counts, significant associations were shown for sedentary time (IRR 1·04, 95% C.I 1·01-1·09) and leisure activity (IRR 0·94, 95% C.I 0·81-0·99).

CONCLUSIONS

Our findings highlight the potential importance of supporting engagement in moderate-vigorous and leisure physical activity, as well as minimising sedentary time and physical workload to reduce the risk of activity limitation and the need for analgesic use in people with LBP.

Paracetamol dosing in hospital and on discharge for older people who are frail or have low body weight

Aims

To describe paracetamol dosing and liver function test (LFT) monitoring in older hospital inpatients who are frail or have low body weight.

Methods

Retrospective observational study, at a 790‐bed metropolitan public health service in Australia. Patients aged ≥70 years, with body weight <50 kg or frailty index based on laboratory data (FI‐Lab) score ≥0.3, who were administered paracetamol during an admission with length‐of‐stay >72 hours, were included. Data were extracted from electronic medical records. Paracetamol doses administered in hospital, and doses prescribed on discharge, were compared against consensus guidelines that recommended ≤60 mg/kg/d for older people weighing <50 kg, and ≤3000 mg/d for frail older people.

Results

In total, 240 admissions (n = 229 patients, mean age 84.7 years) were analysed. During 150 (62.5%) admissions, higher than recommended paracetamol doses were prescribed. On 138 (57.5%) occasions, patients were prescribed paracetamol on discharge, and 112/138 (81.2%) doses were higher than recommended. Most discharge prescriptions (97/138, 70.3%) were for regular administration. The median daily dose on discharge for patients <50 kg was 83.7 mg/kg (interquartile range 73.6–90.9 mg/kg). For frail patients ≥50 kg, the median daily discharge dose was 3990 mg (interquartile range 3000–4000 mg). LFTs were measured in hospital for 151/200 (75.5%) and 93/166 (56.0%) patients who received paracetamol for >48 hours and >5 days, respectively.

Conclusion

Majority of paracetamol doses prescribed for frail or low‐weight older patients in hospital and on discharge were higher than recommended in consensus guidelines. LFTs were not measured for 44% patients who received paracetamol regularly for >5 days. Further studies are needed to explore long‐term outcomes of this practice.

Impact of rescue medication in placebo-controlled trials of pharmacotherapy for neuropathic pain and low back pain

ABSTRACT

Rescue medication (RM) consumption is commonly used as a secondary outcome in placebo-controlled trials of chronic pain, but its validity has yet to be established. If participants randomized to placebo take more RM than those randomized to an active drug, the difference in pain between the 2 groups may be reduced, potentially masking effects of the active drug. This study assessed proportional RM consumption in the placebo and active groups according to results of 42 randomized controlled trials of neuropathic pain (NeP), and 29 trials of low back pain, which were included in 2 systematic reviews and meta-analyses. Trial results were assessed based on effect size, statistical significance, and whether the drug was recommended as first-line treatment by the systematic reviews. In trials indicating effect of the investigational drug, RM consumption was generally higher in the placebo groups than in the active groups. In trials reporting a small or a medium effect size of the investigational drug, subjects receiving placebo consumed 17% to 30% more RM than subjects receiving active drug, potentially leading to underestimation of the effects of the investigational drugs. Few trials reported a large effect size. Differences in RM consumption between participants receiving placebo and those receiving active drug were seldom taken in account by the individual trials and not at all by the systemic reviews when making treatment recommendations for NeP or low back pain. Elaboration on analytical methods to assess treatment effects in chronic pain trials using RM is warranted.

Osteoarthritis management: Does the pharmacist play a role in bridging the gap between what patients actually know and what they ought to know? Insights from a national online survey

BACKGROUND

Guidelines encourage engagement in self-care activities for osteoarthritis (OA), but there are gaps in consumers' knowledge about suitable choices for self-care. Community pharmacists are in an ideal position to contribute to OA management through screening and supporting evidence-based pain management choices. Prior research established an association between health literacy and advice-seeking and appropriateness of analgesics choices (both lower in participants with limited health literacy) amongst people living with OA. This article explores the implications of these data for pharmacists in OA management.

METHODS

A national online survey was conducted amongst 628 adults aged 45-74 years, currently residing in Australia, with self-reported symptoms of OA. All data were collected using a customized online questionnaire, which was completed only once. 'Self-reported symptoms of OA' was based on six validated screening questions to identify people with OA without a formal clinical diagnosis.

RESULTS

Respondents matched the typical profile of people diagnosed with OA; more than half were female (56%), knees (59%) and hips (31%) were the primary affected joints and 74% were either overweight or obese. Self-identification of OA was limited (41%). Overall, 38% self-managed their pain, and limited health literacy was associated with less advice-seeking. Efficacy and ease of use were the main reasons cited for prompting use across all classes of nonprescription analgesic, with less than 20% reporting recommendation from a pharmacist. Participants were managing their pain with an average of 1.74 (95% confidence interval: 1.60-1.88) analgesics, but 73% reported inadequate pain relief and 54% had disrupted sleep.

CONCLUSION

Our findings highlight three key themes: lack of self-identification of OA, suboptimal pain relief and limited use of the community pharmacist as a source of management advice. Equipping community pharmacists with tools to identify OA could bridge this gap. More research is needed to determine if it will improve consumers' ability to appropriately manage OA pain.

PATIENT OR PUBLIC CONTRIBUTION

Consumers living with OA contributed to the study outcomes, reviewed the survey questionnaire for face validity and advised on plain language terminology.

Prolonged use of paracetamol and the prescribing patterns on rehabilitation facilities

AIMS AND OBJECTIVES

The study investigated: (a) the usage patterns of paracetamol, and (b) the association between paracetamol use and patient outcomes such as liver and kidney functions among older people.

BACKGROUND

Paracetamol is a well-known analgesic and antipyretic drug, with an excellent safety profile when used within its recommended dose. It is a commonly used drug by people aged over 65 years to treat chronic pain. Prolonged use of paracetamol in the elderly is poorly understood. As such, there is a genuine risk among older people of unintentional overdose.

METHODS

A retrospective analysis of medical records in rehabilitation wards was undertaken from 1 July 2016 to 30 June 2017. Patients' paracetamol use, prescribing patterns and biochemical results were analysed to assess for differences in admission and discharge biochemistry results. The TREND Statement was utilised to guide study reporting (Enhancing the QUAlity and Transparency Of health Research, 2021).

RESULTS

A total of 1119 patients were admitted for seven or more days in a metropolitan tertiary hospital in Melbourne. Almost three-quarters (74%) of patients were administered paracetamol; 76.1% received Immediate-Release Paracetamol (IRP), and 23.9% were given Sustained-release paracetamol (SRP). A proportion (4.5%) of patients in both the IRP and SRP groups received more than the daily recommended dose. There were limited statistically significant differences between patients' admission and discharge biochemistry results; group or time differences were observed, which were indicative of improvements within the paracetamol group.

CONCLUSION

Paracetamol was a commonly used medication among long-stay elderly patients. Precaution to ensure paracetamol use does not exceed recommended daily doses is required. This study suggests that paracetamol used at a therapeutic level in older patients had limited, negative associations with liver and kidney function.

RELEVANCE TO CLINICAL PRACTICE

The clinical practice regarding prolonged use of paracetamol is ambitious. The increased risk of paracetamol toxicity among the frail elderly is a concern. Optimising the dose adjustment in the elderly is important to avoid adverse outcomes.

Paracetamol: A Review of Guideline Recommendations

Musculoskeletal pain conditions are age-related, leading contributors to chronic pain and pain-related disability, which are expected to rise with the rapid global population aging. Current medical treatments provide only partial relief. Furthermore, non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are effective in young and otherwise healthy individuals but are often contraindicated in elderly and frail patients. As a result of its favorable safety and tolerability record, paracetamol has long been the most common drug for treating pain. Strikingly, recent reports questioned its therapeutic value and safety. This review aims to present guideline recommendations. Paracetamol has been assessed in different conditions and demonstrated therapeutic efficacy on both acute and chronic pain. It is active as a single agent and is additive or synergistic with NSAIDs and opioids, improving their efficacy and safety. However, a lack of significant efficacy and hepatic toxicity have also been reported. Fast dissolving formulations of paracetamol provide superior and more extended pain relief that is similar to intravenous paracetamol. A dose reduction is recommended in patients with liver disease or malnourished. Genotyping may improve efficacy and safety. Within the current trend toward the minimization of opioid analgesia, it is consistently included in multimodal, non-opioid, or opioid-sparing therapies. Paracetamol is being recommended by guidelines as a first or second-line drug for acute pain and chronic pain, especially for patients with limited therapeutic options and for the elderly.