Efficacy and safety of nonsteroidal antiinflammatory drugs for cancer pain: a meta-analysis

Clinical Presentation and Management of Malignant Psoas Syndrome: A Scoping Review of Case Reports and Case Series

Malignant psoas syndrome (MPS) is a rare and underreported clinical syndrome that significantly impacts the quality of life of cancer patients through metastatic infiltration of the iliopsoas muscle. Patients suffering from MPS often present with painful hip flexion, loss of mobility, and immense pain in their legs and back. The current literature describing the clinical presentation, management, and prognosis of MPS is limited primarily to case reports and outdated literature reviews. There remains a gap in the current knowledge of MPS and in the management of this complex cancer-related pain syndrome. Thus, this scoping review aimed to map current case reports and case series on MPS for clinical presentation, treatment modalities, and resulting prognoses of MPS in late-stage cancer patients. A systemized search using the databases Embase and PubMed (Medline) was conducted to access case reports and case series published between January 1990 and October 2022 that met the study's inclusion criteria: (1) adult patients with metastatic cancer; (2) MPS symptoms secondary to infiltration of iliopsoas; (3) clinical presentation, treatment modality, and prognosis; and (4) English-language text. Our search strategy yielded 1926 citations. After removing 629 duplicates, 1,283 reports were excluded due to failure to meet eligibility criteria (n=1,271) or inaccessibility (n=12). Using the JBI appraisal tools for case reports and case series, a total of 14 articles remained for the final review. With histories of either genitourinary, hepatic, gastric, or skin cancer, each case reported new onset intense pain in the legs, back, abdomen, or pelvis with associated symptoms such as flexion of the hip or gait disorder. A computerized tomography (CT) scan, magnetic resonance imaging (MRI), or positron emission tomography (PET) scan typically confirmed metastasis into the iliopsoas causing these symptoms, which suggested MPS. Each case utilized two to seven different pain management strategies to alleviate MPS symptoms. Many cases first used opioids for pain relief. Following a necessitated increase in morphine equivalent daily dose, a subsequent increase in the strength of analgesic, change in route of administration, and integration of combination drug therapy were generally added to the treatment regime. Many cases reported successful management of symptoms through utilizing methadone, radiation therapy, botulinum toxin injection, increased opioid dosage, or epidural catheter administration of opioids. A unified clinical definition of MPS may be required to inform physicians of this syndrome to help support clinical decisions regarding treatments for patients. The studies indicated that a clearer guideline for treatment protocol may be warranted as most cases reported utilizing various treatment medication dosages and procedures with vastly differing results.

The Extract of Corydalis yanhusuo Prevents Morphine Tolerance and Dependence

The opioid epidemic was triggered by an overprescription of opioid analgesics. In the treatment of chronic pain, repeated opioid administrations are required which ultimately lead to tolerance, physical dependence, and addiction. A possible way to overcome this conundrum consists of a co-medication that maintains the analgesic benefits of opioids while preventing their adverse liabilities. YHS, the extract of the plant Corydalis yanhusuo, has been used as analgesic in traditional Chinese medicine for centuries. More recently, it has been shown to promote analgesia in animal models of acute, inflammatory, and neuropathic pain. It acts, at least in part, by inhibiting the dopamine D2 receptor, suggesting that it may be advantageous to manage addiction. We first show that, in animals, YHS can increase the efficacy of morphine antinociceptive and, as such, decrease the need of the opioid. We then show that YHS, when coadministered with morphine, inhibits morphine tolerance, dependence, and addiction. Finally, we show that, in animals treated for several days with morphine, YHS can reverse morphine dependence and addiction. Together, these data indicate that YHS may be useful as a co-medication in morphine therapies to limit adverse morphine effects. Because YHS is readily available and safe, it may have an immediate positive impact to curb the opioid epidemic.

Percutaneous Cervical Cordotomy for the Treatment of Cancer Pain: A Prospective Case Series of 52 Patients with a Long-Term Follow-Up

AIM

The aim of this study is to describe the effects of percutaneous cervical cordotomy (PCC) on pain, opioid consumption, adverse events, and satisfaction in palliative care patients with cancer pain after PCC until end of life.

METHODS

This is a prospective observational case series of 58 PCCs in 52 consecutive patients. Indication for PCC was unilateral cancer pain with a maximum numeric rating scale (NRS) of pain above 5 despite maximal conservative treatment. The PCC was fluoroscopy guided. A radiofrequency lesion was made at 95°C for 20 seconds. The pain location and pain scores, analgesic medication, the cranial and caudal borders of dermatomes hypoesthetic for pin pricks, dysesthesia, urinary retention, Horner's syndrome, muscle strength, Karnofsky performance scale (KPS) score, patient satisfaction, hospital anxiety and distress score (HADS), and RAND 36 score were evaluated at 1 day; 1 and 6 weeks; and 3, 6, 9, 12 18, and 24 months after PCC, or until death if death occurred during the follow-up period.

RESULTS

Pain relief after PCC was intense (change in median maximum NRS from 9 to 0) and persistent. Median opioid use per day was 240 mg (145 to 565 mg) before PCC and 55 mg (0 to 120 mg) after PCC. The upper and lower borders of dermatomes hypoesthetic for pin pricks were stable over time. The most common side effects were short-term (< 1 week) neck pain (28%), dysesthesia (40%), and mild loss of muscle strength (11%). Approximately 83% of the patients were satisfied or very satisfied with the results of PCC 1 week after the procedure, and this percentage remained high in the long term. There was no significant change in the KPS score, HADS, and RAND 36 score.

CONCLUSION

Percutaneous cervical cordotomy is an effective treatment for unilateral cancer pain. The reduction in pain, reduction in opioid consumption, and hypoesthetic area remain stable until death.

Investigating the Multitarget Mechanism of Traditional Chinese Medicine Prescription for Cancer-Related Pain by Using Network Pharmacology and Molecular Docking Approach

Gu-tong formula (GTF) has achieved good curative effects in the treatment of cancer-related pain. However, its potential mechanisms have not been explored. We used network pharmacology and molecular docking to investigate the molecular mechanism and the effective compounds of the prescription. Through the analysis and research in this paper, we obtained 74 effective compounds and 125 drug-disease intersection targets to construct a network, indicating that quercetin, kaempferol, and β-sitosterol were possibly the most important compounds in GTF. The key targets of GTF for cancer-related pain were Jun proto-oncogene (JUN), mitogen-activated protein kinase 1 (MAPK1), and RELA proto-oncogene (RELA). 2204 GO entries and 148 pathways were obtained by GO and KEGG enrichment, respectively, which proved that chemokine, MAPK, and transient receptor potential (TRP) channels can be regulated by GTF. The results of molecular docking showed that stigmasterol had strong binding activity with arginine vasopressin receptor 2 (AVPR2) and C-X3-C motif chemokine ligand 1 (CX3CL1) and cholesterol was more stable with p38 MAPK, prostaglandin-endoperoxide synthase 2 (PTGS2), and transient receptor potential vanilloid-1 (TRPV1). In conclusion, the therapeutic effect of GTF on cancer-related pain is based on the comprehensive pharmacological effect of multicomponent, multitarget, and multichannel pathways. This study provides a theoretical basis for further experimental research in the future.

Indian Society for Study of Pain, Cancer Pain Special Interest Group Guidelines on Pharmacological Management of Cancer Pain (Part I)

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group guidelines on pharmacological management of cancer pain in adults provides a structured, step-wise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub drafts addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website, and circulated by E-mail to all the ISSP and Indian Association of Palliative Care (IAPC) members. We recommend that analgesics for cancer pain management should follow the World Health Organization three-step analgesic ladder appropriate for the severity of pain. The use of paracetamol and nonsteroidal anti-inflammatory drugs alone or in combination with opioids for mild-to-moderate pain should be used. For mild-to-moderate pain, weak opioids such as tramadol, tapentadol, and codeine can be given in combination with nonopioid analgesics. We recommend morphine as the opioid of first choice for moderate-to-severe cancer pain.

Zebrafish, a model to develop nanotherapeutics that control neutrophils response during inflammation

Neutrophils are crucial modulators of the inflammation process, and their uncontrolled response worsens several chronic pathologies. The p38 mitogen-activated protein kinases (MAPKs) activity is critical for normal immune and inflammatory response through the regulation of pro-inflammatory cytokines synthesis. In this work, we study the effect of hybrid lipid-polymer nanoparticles loaded with the p38 MAPK inhibitor SB203580 in an acute and chronic inflammatory model in zebrafish containing a transgenic neutrophil cell line that constitutively expresses a green fluorescent protein. We identify the existence of at least two neutrophils subpopulation involved in the response during the acute inflammation triggered; a first-responder p38α-independent subset and a second-responder p38α-dependent subset. In the case of chronic inflammation, neutrophils recruited in the intestine only during the inflammation process, migrate in a p38α-dependent manner. Likewise, we establish that SB203580-loaded in NPs exerts their action during at least a double period than the inhibitor administers directly in both types of inflammation. Our results demonstrate the exceptional potential of the zebrafish as an inflammatory model for studying novel nanotherapeutics that selectively inhibit the neutrophils response, and to identify functional neutrophils subpopulations involved in the inflammation process.

Pearls for opioid use in seriously ill patients

Opioids are often the foundation of pain management in seriously ill patients. Unfortunately, even experienced providers carry with them information that they consider "fact", when this information is not based on scientific evidence, but on "myth". Several topics were elicited based on common beliefs and misconceptions in clinical practice. These were identified via a survey of pharmacist pain and palliative care providers. Pearls from these topics were chosen that were based on evidence and would have the greatest bearing on clinical practice. The pearls address topics such as not using opioids as first-line analgesics for all types of pain, opioid-induced hyperalgesia, opioid risk management in cancer patients, use of buprenorphine in hospice and palliative care settings and use of naloxone in seriously ill patients. The pearls are supported by clinical evidence extracted from several references. They are intended to make readers give thought to opioid therapy which is strictly evidence-based, and not historical or anecdote-based. Practical recommendations are provided to give readers a starting point to base clinical decisions going forward. Readers may discover that "facts" they once learned about opioid use in seriously ill patients are actually "myths" that are a figment of the past.

Molecular Basis of Cancer Pain Management: An Updated Review

Pain can have a significantly negative impact on the quality of life of patients. Therefore, patients may resort to analgesics to relieve the pain. The struggle to manage pain in cancer patients effectively and safely has long been an issue in medicine. Analgesics are the mainstay treatment for pain management as they act through various methods on the peripheral and central pain pathways. However, the variability in the patient genotypes may influence a drug response and adverse drug effects that follow through. This review summarizes the observed effects of analgesics on UDP-glucuronosyl (UGT) 2B7 isoenzyme, cytochrome P450 (CYP) 2D6, μ-opioid receptor μ 1 (OPRM1), efflux transporter P-glycoprotein (P-gp) and ATP-binding cassette B1 ABCB1/multiple drug resistance 1 (MDR1) polymorphisms on the mechanism of action of these drugs in managing pain in cancer. Furthermore, this review article also discusses the responses and adverse effects caused by analgesic drugs in cancer pain management, due to the inter-individual variability in their genomes.

Comparative Efficacy of Therapeutics for Chronic Cancer Pain: A Bayesian Network Meta-Analysis

PURPOSE

Opioids are the primary choice for managing chronic cancer pain. However, many nonopioid therapies are currently prescribed for chronic cancer pain with little published evidence comparing their efficacy.

METHODS

Electronic databases were searched for randomized controlled trials (RCTs) comparing any systemic pharmaceutical intervention and/or combination thereof in treating chronic cancer pain. The primary outcome was global efficacy reported as an odds ratio (OR). The secondary outcome was change in pain intensity reported as a standardized mean difference (SMD).

RESULTS

We included 81 RCTs consisting of 10,003 patients investigating 11 medication classes. Most RCTs (80%) displayed low risk of bias. The top-ranking classes for global efficacy were nonopioid analgesics (network OR, 0.30; 95% credibility interval [CrI], 0.13 to 0.67), nonsteroidal anti-inflammatory drugs (network OR, 0.44; 95% CrI, 0.22 to 0.90), and opioids (network OR, 0.49; 95% CrI, 0.27 to 0.86), whereas the top-ranked interventions were lidocaine (network OR, 0.04; 95% CrI, 0.01 to 0.18; surface under the cumulative ranking curve analysis [SUCRA] score, 98.1), codeine plus aspirin (network OR, 0.22; 95% CrI, 0.08 to 0.63; SUCRA score, 81.1), and pregabalin (network OR, 0.29; 95% CrI, 0.08 to 0.92; SUCRA score, 73.8). In terms of reducing pain intensity, we found that no class was superior to placebo, whereas the following top-ranked interventions were superior to placebo: ziconotide (network SMD, −24.98; 95% CrI, −32.62 to −17.35; SUCRA score, 99.8), dezocine (network SMD, −13.56; 95% CrI, −23.37 to −3.69; SUCRA score, 93.5), and diclofenac (network SMD, −11.22; 95% CrI, −15.91 to −5.80; SUCRA score, 92.9).

CONCLUSION

There are significant differences in efficacy among current regimens for chronic cancer pain. Our evidence suggests that certain nonopioid analgesics and nonsteroidal anti-inflammatory drugs can serve as effectively as opioids in managing chronic cancer pain.

Systematic review and meta-analysis on non-opioid analgesics in palliative medicine

Non-opioid analgesics are widely used for pain relief in palliative medicine. However, there is a lack of evidence-based recommendations addressing the efficacy, tolerability, and safety of non-opioids in this field. A comprehensive systematic review and meta-analysis on current evidence can provide a basis for sound recommendations in clinical practice. A database search for controlled trials on the use of non-opioids in adult palliative patients was performed in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PsycINFO, and EMBASE from inception to 18 February 2018. Endpoints were pain intensity, opioid-sparing effects, safety, and quality of life. Studies with similar patients, interventions, and outcomes were included in the meta-analyses. Our systematic search was able to only identify studies dealing with cancer pain. Of 5991 retrieved studies, 43 could be included (n = 2925 patients). There was no convincing evidence for satisfactory pain relief by acetaminophen alone or in combination with strong opioids. We found substantial evidence of moderate quality for a satisfactory pain relief in cancer by non-steroidal anti-inflammatory drugs (NSAIDs), flupirtine, and dipyrone compared with placebo or other analgesics. There was no evidence for a superiority of one specific non-opioid. There was moderate quality of evidence for a similar pain reduction by NSAIDs in the usual dosage range compared with up to 15 mg of morphine or opioids of equianalgesic potency. The combination of NSAID and step III opioids showed a beneficial effect, without a decreased tolerability. There is scarce evidence concerning the combination of NSAIDs with weak opioids. There are no randomized-controlled studies on the use of non-opioids in a wide range of end-stage diseases except for cancer. Non-steroidal anti-inflammatory drugs, flupirtine, and dipyrone can be recommended for the treatment of cancer pain either alone or in combination with strong opioids. The use of acetaminophen in the palliative setting cannot be recommended. Studies are not available for long-term use. There is a lack of evidence regarding pain treatment by non-opioids in specific cancer entities.

Pain Management in Metastatic Bone Disease: A Literature Review

Cancer means an uncontrolled division of abnormal cells in the body. It is a leading cause of death today. Not only the disease itself but its complications are also adding to the increase in mortality rate. One of the major complications is the pain due to metastasis of cancer. Pain is a complex symptom which has physical, psychological, and emotional impacts that influence the daily activities as well as social life. Pain acts as an alarm sign, telling the body that something is wrong. Pain can manifest in a multitude fashion. Management of bone pain due to metastasis involves different modes with some specific treatments according to the type of primary cancer. Over the years various treatment modalities have been tried and tested to improve the pain management including the use of non-steroidal anti-inflammatory drugs (NSAIDs), opioids, bisphosphonates, tricyclic antidepressants, corticosteroids, growth factors and signaling molecules, ET-1 receptor antagonists, radiotherapy as well as surgical management. The topic of discussion will cover each one of these in detail.

Long-term low-dose morphine for patients with moderate cancer pain is predominant factor effecting clinically meaningful pain reduction

PURPOSE

Patients with cancer often experience pain that affects their daily activities and quality of life. The analgesic ladder recommended by the World Health Organization has proved insufficient for many, and its scientific basis has been questioned. This retrospective study investigated factors related to adherence to long-term opioid therapy for patients with moderate cancer pain, including an evaluation of low-dose morphine relative to tramadol.

METHODS

Clinical data were collected of patients with moderate cancer pain (n = 353) who received either low-dose morphine or tramadol and were followed for ≥ 27 weeks. Factors related to regime adherence were investigated, including the analgesia type, cancer therapy (antitumor therapy or palliative care), pain type (nociceptive, neuropathic, or mixed), and living distance to the hospital. Factors related to clinically meaningful pain reduction (≥ 30% reduction in pain from baseline) were also investigated.

RESULTS

Patients taking tramadol, receiving antitumor therapy, experiencing neuropathic pain, and living far from the hospital were more likely to change analgesic strategy compared with, respectively, patients receiving low-dose morphine, palliative care, experiencing nociceptive pain, and living nearby. Factors that increased the likelihood of adherence to the analgesic regime were also associated with the likelihood of clinically meaningful pain reduction. Among adverse effects, a significantly higher percentage of patients experienced constipation in the tramadol group compared with those given morphine.

CONCLUSIONS

Among patients with moderate cancer pain, long-term low-dose morphine was safe and more effective than tramadol for clinically meaningful pain reduction, and patients were less likely to change the analgesic strategy.

Acute Pain Management

Acute pain management is improving steadily over the past few years, but training and professional education are still lacking in many professions. Untreated or undertreated acute pain could have detrimental effects on the patient in terms of comfort and recovery from trauma or surgery. Acute undertreated pain can decrease a patient's vascular perfusion, increase oxygen demand, suppress the immune system, and possibly risk increased incidence of venous thrombosis. Although acute postoperative pain needs to be managed aggressively, patients are most vulnerable during this period for developing adverse effects, and therefore, patient assessment and careful drug therapy evaluation are necessary processes in therapeutic planning. Acute pain management requires careful and thorough initial assessment and follow-up reassessment in addition to frequent dosage adjustments, and managing analgesic induced side effects. Analgesic selection and dosing must be based on the patient's past and recent analgesic exposure. There is no single acute pain management regimen that is suitable for all patients. Analgesics must be tailored to the individual patient.

Use of EMLA as an adjunct for burning pain associated with a liposarcoma

Objective. To report the successful use of EMLA cream (a topical anesthetic) for the relief of neuro pathic pain in a patient with a liposarcoma.

Case Summary. A 63-year-old male with a lipo sarcoma was admitted to the hospital to establish an effective pain control regimen. Despite the use of high-dose hydromorphone, dexamethasone, and in domethacin, he still complained of a burning sensa tion in the skin over the tumor site. EMLA—applied regularly every 8 hours, was started, and within 24 hours the patient reported relief from this pain.

Discussion. While there is some experience with the use of systemically administered anesthetics for the control of neuropathic pain in cancer patients, there is little reported experience of the use of topical anesthetics. EMLA has, however, been successfully used for postherpetic neuralgia. Adverse reactions from its use for reducing the pain of venipuncture are usually mild and transient, and repeated use does not appear to increase the risk of toxicity. In this case, the patient's pain was well-controlled without any observ able adverse reactions.

Summary. This patient experienced relief of burning pain when EMLA was added to his treatment regimen. EMLA cream could be considered as a treatment option for cancer patients experiencing neuropathic pain, but the patients most likely to benefit and the optimal treatment regimen have yet to be determined by a prospective study.

WITHDRAWN: NSAIDS or paracetamol, alone or combined with opioids, for cancer pain

This review is out of date, although it is correct at the date of publication. The review may be misleading as new studies could alter the original conclusions. All previous versions of the review can be found in the ‘Other versions’ tab. A new author team intends to develop four new reviews on this topic, which will serve to update and supersede this review. The new reviews will cover paracetamol, paracetamol plus opioids, NSAIDs, and NSAIDs plus opioids, for cancer pain. For more information, contact the PaPaS Review Group.

The editorial group responsible for this previously published document have withdrawn it from publication.

[Update on oncological pain in the elderly]

Pain is a prevalent symptom in cancer geriatric patients, appearing in up to 90% of patients with terminal cancer. This requires a multidimensional approach, as there is a high percentage of inappropriate assessments and treatments. Unrecognized or poorly treated pain in the geriatric population, especially in cancer patients, leads to the development of disabling symptoms such as depression, anxiety, isolation, sleep disturbances, and appetite, and very especially, loss of functional capacity and quality of life. In this review an analysis is made on the most relevant studies on the diagnosis and management of cancer pain in the geriatric population.

Open questions in the treatment of cancer pain: time for a strong evidence-based approach?

Pain affects patients with cancer at any stage of their disease. Yet, it is not adequately treated in a significant percentage of cases. In 1986, the WHO proposed a three-step approach for the treatment of pain in cancer patients (from nonopioids to weak opioids to strong opioids, according to pain intensity) following the recommendations of an international group of experts. The application of the WHO strategy demonstrated that a clear and simple approach is of educational value and ensured worldwide dissemination. However, there is little evidence that the WHO approach is the best, and there are still several points to debate on the treatment of cancer pain.

Confronting the challenges of effective pain management in children following tonsillectomy

Tonsillectomy is an extremely common surgical procedure associated with significant morbidity and mortality. The post-operative challenges include: respiratory complications, post-tonsillectomy hemorrhage, nausea, vomiting and significant pain. The present model of care demands that most of these children are managed in an ambulatory setting. The recent Federal Drug Agency (FDA) warning contraindicating the use of codeine after tonsillectomy in children represents a significant change of practice for many pediatric otolaryngological surgeons. This introduces a number of other safety concerns when deciding on a safe alternative to codeine, especially since most tonsillectomy patients are managed by lay primary caregiver's at home. This review outlines the safety issues and proposes, based on currently available evidence, a preventative multi-modal strategy to manage pain, nausea and vomiting without increasing the risk of post-tonsillectomy bleeding.

State of art of managing pain in patients with cancer

Pain in cancer patients involves complex interactions between physiological, psychological, sociocultural, sensory, cognitive, and behavioral dimensions. Pain management interventions will be most effective when pharmacological and nonpharmacological treatments are individualized after exploring the various contributors to pain and suffering, and the patient and family are educated and involved in decision making. This entails a systematic multidimensional approach with frequent reassessments of pain and related outcomes.

Nonopioid Drugs in the Treatment of Cancer Pain

The WHO analgesic ladder for the treatment of cancer pain provides a three-step sequential approach for analgesic administration based on pain severity that has global applicability. Nonopioids were recommended for mild pain, with the addition of mild opioids for moderate pain and strong opioids for severe pain. Here, we review the evidence for the use of nonopioid analgesic agents in patients with cancer and describe the mode of action of the main drug classes. Evidence supports the use of anti-inflammatory drugs such as acetaminophen/paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs) for mild cancer pain. Adding an NSAID to an opioid for stronger cancer pain is efficacious, but the risk of long-term adverse effects has not been quantified. There is limited evidence to support using acetaminophen with stronger opioids. Corticosteroids have a specific role in spinal cord compression and brain metastases, where improved analgesia is a secondary benefit. There is limited evidence for adding corticosteroids to stronger opioids when pain control is the primary objective. Systematic reviews suggest a role for antidepressant and anticonvulsant medications for neuropathic pain, but there are methodologic issues with the available studies. Bisphosphonates improve pain in patients with bony metastases in some tumor types. Denosumab may delay worsening of pain compared with bisphosphonates. Larger studies of longer duration are required to address outstanding questions concerning the use of nonopioid analgesia for stronger cancer pain.

Managing pain after thoracic surgery

SUMMARY It is generally accepted that thoracic surgery for lung cancer produces some of the most intense and difficult perioperative and chronic pain challenges. In the acute period of recovery, practitioners must optimize patient comfort and pulmonary function. This can be achieved through a combination of systemic treatment and regional analgesic options. Thoracic surgery also causes relatively high levels of persistent postsurgical pain. Many of the cases of persistent pain have a clear neuropathic pain mechanism, but a significant number of cases do not. While persistent pain correlates directly with the extent of operative trauma, even video-assisted thoracoscopic surgery approaches can cause chronic pain. Persistent pain is treated with medical and interventional therapies customized to an individual patient’s complaints and medication tolerance.

Pathobiology and management of prostate cancer-induced bone pain: recent insights and future treatments

Prostate cancer (PCa) has a high propensity for metastasis to bone. Despite the availability of multiple treatment options for relief of PCa-induced bone pain (PCIBP), satisfactory relief of intractable pain in patients with advanced bony metastases is challenging for the clinicians because currently available analgesic drugs are often limited by poor efficacy and/or dose-limiting side effects. Rodent models developed in the past decade show that the pathobiology of PCIBP comprises elements of inflammatory, neuropathic and ischemic pain arising from ectopic sprouting and sensitization of sensory nerve fibres within PCa-invaded bones. In addition, at the cellular level, PCIBP is underpinned by dynamic cross talk between metastatic PCa cells, cellular components of the bone matrix, factors associated with the bone microenvironment as well as peripheral components of the somatosensory system. These insights are aligned with the clinical management of PCIBP involving use of a multimodal treatment approach comprising analgesic agents (opioids, NSAIDs), radiotherapy, radioisotopes, cancer chemotherapy agents and bisphosphonates. However, a major drawback of most rodent models of PCIBP is their short-term applicability due to ethical concerns. Thus, it has been difficult to gain insight into the mal(adaptive) neuroplastic changes occurring at multiple levels of the somatosensory system that likely contribute to intractable pain at the advanced stages of metastatic disease. Specifically, the functional responsiveness of noxious circuitry as well as the neurochemical signature of a broad array of pro-hyperalgesic mediators in the dorsal root ganglia and spinal cord of rodent models of PCIBP is relatively poorly characterized. Hence, recent work from our laboratory to develop a protocol for an optimized rat model of PCIBP will enable these knowledge gaps to be addressed as well as identification of novel targets for drug discovery programs aimed at producing new analgesics for the improved relief of intractable PCIBP.

Painful boney metastases

Boney metastasis may lead to terrible suffering from debilitating pain. The most likely malignancies that spread to bone are prostate, breast, and lung. Painful osseous metastases are typically associated with multiple episodes of breakthrough pain which may occur with activities of daily living, weight bearing, lifting, coughing, and sneezing. Almost half of these breakthrough pain episodes are rapid in onset and short in duration and 44% of episodes are unpredictable. Treatment strategies include: analgesic approaches with "triple opioid therapy", bisphosphonates, chemotherapeutic agents, hormonal therapy, interventional and surgical approaches, steroids, radiation (external beam radiation, radiopharmaceuticals), ablative techniques (radiofrequency ablation, cryoablation), and intrathecal analgesics.

Pain management

Despite published guidelines and educational programs on the assessment and treatment of cancer-related pain, in any stage of oncological disease, unrelieved pain continues to be a substantial worldwide public health concern either in patients with solid and haematological malignancies. The proper and regular self-reporting assessment of pain is the first step for an effective and individualized treatment. Opioids are the mainstay of analgesic therapy and can be associated with non-opioids drugs such as paracetamol or non-steroidal anti-inflammatory drugs and to adjuvant drugs (for neuropathic pain and symptom control). The role and the utility of weak opioids (i.e. codeine, dihydrocodeine, tramadol) are a controversy point. Morphine has been placed by World Health Organization on its Essential Drug List. In the comparative study with other strong opioids (hydromorphone, oxycodone), there is no evidence to show superiority or inferiority with morphine as the first choice opioid. Oral methadone is a useful and safe alternative to morphine. Methadone presents the potential to control pain difficult to manage with other opioids. although the oral route of opioid administration is considered the one of choice, intravenous, subcutaneous, rectal, transdermal, sublingual, intranasal, and spinal routes must be used in particular situation. Transdermal opioids such as fentanyl and buprenorphine are best reserved for patients whose opioid requirements are stable. Switching from one opioid to another can improve analgesia and tolerability.

Potential protective effect of sunitinib after administration of diclofenac: biochemical and histopathological drug-drug interaction assessment in a mouse model

Sunitinib is a tyrosine kinase inhibitor for GIST and advanced renal cell carcinoma. Diclofenac is used in cancer pain management. Coadministration may mediate P450 toxicity. We evaluate their interaction, assessing biomarkers ALT, AST, BUN, creatinine, and histopathological changes in the liver, kidney, heart, brain, and spleen. ICR mice (male, n = 6 per group/dose) were administered saline (group A) or 30 mg/kg diclofenac ip (group B), or sunitinib po at 25, 50, 80, 100, 140 mg/kg (group C) or combination of diclofenac (30 mg/kg, ip) and sunitinib (25, 50, 80, 100, 140 mg/kg po). Diclofenac was administered 15 min before sunitinib, mice were euthanized 4 h post-sunitinib dose, and biomarkers and tissue histopathology were assessed. AST was 92.2 ± 8.0 U/L in group A and 159.7 ± 14.6 U/L in group B (p < 0.05); in group C, it the range was 105.1-152.6 U/L, and in group D, it was 156.0-209.5 U/L (p < 0.05). ALT was 48.9 ± 1.6 U/L (group A), 95.1 ± 4.5 U/L (p < 0.05) in group B, and 50.5-77.5 U/L in group C and 82.3-115.6 U/L after coadministration (p < 0.05). Renal function biomarker BUN was 16.3 ± 0.6 mg/dl (group A) and increased to 29.9 ± 2.6 mg/dl in group B (p < 0.05) and it the range was 19.1-33.3 mg/dl (p < 0.05) and 26.9-40.8 mg/dl in groups C and D, respectively. Creatinine was 5.9 pmol/ml in group A; 6.2 pmol/ml in group B (p < 0.01), and the range was 6.0-6.2 and 6.2-6.4 pmol/ml in groups C and D, respectively (p < 0.05 for D). Histopathological assessment (vascular and inflammation damages) showed toxicity in group B (p < 0.05) and mild toxicity in group C. Damage was significantly lesser in group D than group B (p < 0.05). Spleen only showed toxicity after coadministration. These results suggest vascular and inflammation protective effects of sunitinib, not shown after biomarker analysis.

Heterogeneity of chronic pain

Chronic pain is a widespread public health issue that has many effects on physical, emotional and cognitive functions. An estimated 10-55% of all adults are thought to have chronic pain. Chronic pain is a multifactorial condition, caused by the complex interplay of nociceptive, neuropathic or mixed pathogenic mechanisms. Chronic pain is associated with specific and non-specific medical conditions such as cancer, HIV/AIDS, rheumatoid arthritis, fibromyalgia, osteoarthritis, low back pain or spinal stenosis and is broadly categorized as cancer pain and non-cancer pain. Evaluation of chronic pain requires a clear understanding of the nature of the pain and its underlying pathophysiology. Adequate assessment of pain, using validated tools, is an essential prerequisite of successful pain management. Unidimensional scales are useful for the measurement of pain intensity, while multidimensional scales measure both pain intensity and the extent to which pain interferes with life activity and emotional functioning. Patients should be reassessed and followed up in order to monitor progress and measure improvements in pain.

Role of pain medications, consultants, and other services in improved pain control of elderly adults with cancer in geriatric evaluation and management units

OBJECTIVES

To determine whether pain medication use and inpatient consultations and services were associated with significantly better pain control.

DESIGN

Secondary data analysis from a randomized two-by-two factorial trial. Hospitalized, frail individuals aged 65 and older were randomized to receive care in a geriatric inpatient unit, a geriatric outpatient clinic, both, or neither.

SETTING

Eleven Veterans Affairs Medical Centers.

PARTICIPANTS

Ninety-nine individuals with a diagnosis of cancer, excluding nonmelanoma skin cancer; 44 received geriatric evaluation and management unit (GEMU) care and 55 usual care.

MEASUREMENTS

Pain medications were measured at baseline and discharge; consultations and other services were quantified for the entire admission.

RESULTS

Participants receiving GEMU care had a significantly higher number of consultations than those in usual care. Participants in GEMU care received psychiatry, endocrinology, and psychology consultations 12.7% (P = .004), 9.1% (P = .04), and 21.8% (P = .05) times more, respectively, and occupational and physical therapy 27.3% (P = .004) and 18.2% (P = .04) more, respectively. There were no significant differences in pain medication use between intervention and usual care.

CONCLUSION

Significantly greater use of psychology, psychiatry, physical and occupational therapy in the GEMU participants may have improved the effectiveness of pain management in individuals in inpatient GEMUs. Although analgesic use was not significantly different between the GEMU and usual care groups, small sample size may have limited the ability to detect these differences.

The role of paracetamol and nonsteroidal anti-inflammatory drugs in addition to WHO Step III opioids in the control of pain in advanced cancer. A systematic review of the literature

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and paracetamol are used widely in the management of mild to moderate cancer pain and are frequently combined with opioids in the treatment of moderate to severe pain.

AIM

To perform a systematic literature review of the evidence of the efficacy and toxicity of NSAIDs or paracetamol added to WHO Step III opioid treatment for cancer pain.

DESIGN AND DATA SOURCES

A systematic literature review of MedLine, EMBASE and Cochrane Central register of controlled trials database was carried out using both text words and MeSH/EMTREE terms.

RESULTS

Seven eligible papers were retrieved from the new search and five from the Cochrane review. Five of seven studies showed an additive effect of NSAIDs when combined with opioids either by improving analgesia (three studies) or by reducing the opioid dose (two studies). Paracetamol was only marginally effective in one of five trials. The study designs were not adequate to assess differences in side effects between the opioids alone and opioids in combination with NSAIDs or paracetamol.

CONCLUSIONS

The evidence from the available clinical trials is of limited amount and quality, but it weakly supports the proposal that the addition of an NSAIDs to WHO Step III opioids can improve analgesia or reduce opioid dose requirement. There is insufficient evidence to support the use of paracetamol in combination with Step III opioids. Data on the toxicity of NSAIDs in this indication are insufficient owing to the small number of patients and the short duration of treatment reported in the studies.

An assessment of the efficacy and safety of diclofenac potassium liquid-filled capsules in patients with various levels of baseline pain intensity

CONTEXT

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC; Zipsor*) is a novel formulation of diclofenac potassium used to treat mild to moderate acute pain.

OBJECTIVE

To investigate whether DPSGC 25 mg provided significant reduction in pain intensity compared with placebo, regardless of baseline pain intensity, a post hoc analysis was performed of pooled data from two replicate randomized controlled trials (NCT00366444 and NCT00375934) that evaluated the safety and efficacy of DPSGC in postbunionectomy treatment.

METHODS

Patients from the two randomized trials were assigned to one of two subgroups: patients with baseline numerical pain rating scale (NPRS) scores of 4 or greater to less than 7 and those with baseline NPRS scores of 7 or greater. Within each subgroup, efficacy and safety of DPSGC was compared with placebo.

RESULTS

Across the two studies, 73 DPSGC- and 59 placebo-treated patients had baseline pain intensity scores ranging from 4 or greater to less than 7, while 128 DPSGC- and 141 placebo-treated patients had baseline pain intensity scores of 7 or greater. Significantly lower mean 48-hour NPRS scores were observed in the DPSGC group, regardless of baseline pain intensity (P < 0.0001). In both subgroups, at least twice as many patients treated with DPSGC rated the study drug as very good or excellent compared with patients taking placebo. Potential limitations for this post hoc analysis include study design and patient population. As with all studies investigating treatment for pain, the use of rescue medication may also be a potential limitation.

CONCLUSIONS

DPSGC provided significantly greater improvements in pain compared with placebo following bunionectomy, regardless of patients' baseline pain level.

Cancer pain and its relationship to systemic inflammation: an exploratory study

Pain is the commonest symptom in cancer patients, whereas inflammation is implicated in cancer development and progression. The relationship between pain and inflammation in cancer is therefore of interest; however, it is challenging to examine because multiple factors may affect these variables. This study assessed the relationship between cancer pain and systemic inflammation using a retrospective analysis of 2 clinical trial datasets of patients with cancer cachexia. Included patients had gastrointestinal, lung, or pancreatic cancer. Pain was assessed using the pain subscale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C-30. Inflammation was assessed using C-reactive protein (CRP). A regression analysis between pain and logarithmically transformed CRP was run, and Pearson correlation coefficients were calculated. A total of 718 patients entered the trials, of whom 449 had CRP measured. Both trial populations were well matched. Pain positively correlated with CRP. The Pearson correlation coefficients were 0.126 and 0.163 for trials 1 and 2, respectively. This correlation was statistically significant at the P<.05 level. These findings support that pain is related to systemic inflammation in a cohort of cancer patients. Many factors can affect pain and inflammation in cancer, demonstrating that any relationship that exists between pain and inflammation is of interest. This is in keeping with work showing this relationship in nonmalignant pain. Studies targeting inflammation and assessing its effect on pain in cancer would be an important step in the research agenda.

Management of cancer pain

In the last decades, studies validating the WHO analgesic ladder have been shown to have methodological limitations and different problems are unresolved due to a lack of controlled studies on this subject. These problems include a better definition of the role of NSAIDs, the prolonged use of NSAIDs in cancer pain, and the utility of step 2. Moreover, the indications for using different strong opioids and alternate routes of administration to improve pain relief in difficult pain situations are not well established. The proportion of patients who do not benefit from these treatments remain unclear, and how the opioid response may be improved with the use of adjuvants is also uncertain. This review will offer an update on these problems and the existing therapeutic opportunities.

Diclofenac potassium liquid-filled soft gelatin capsules for the treatment of postbunionectomy pain

OBJECTIVE

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC) is a rapidly absorbed formulation of diclofenac approved for the treatment of mild to moderate acute pain in adults (≥18 years of age). The objective of this study was to investigate the efficacy and safety of DPSGC 25 mg in a multicenter, randomized, double-blind, placebo-controlled study in patients experiencing pain following first metatarsal bunionectomy.

RESEARCH DESIGN AND METHODS

Patients experiencing a requisite level of pain (≥4 based on an 11-point numeric pain rating scale [NPRS]; 0 = no pain, 10 = worst pain possible) on the day following surgery were randomized to receive DPSGC 25 mg or placebo. Patients received a second dose (remedication) on request or at 8 hours postdose followed by additional doses every 6 hours through the end of postsurgery Day 4. Rescue medication (hydrocodone/acetaminophen) was available as needed after the second dose.

CLINICAL TRIAL REGISTRATION

NCT00375934.

MAIN OUTCOME MEASURE

The primary efficacy endpoint was the average NPRS score over the 48 hour inpatient multiple-dose period.

RESULTS

DPSGC provided a significant improvement in mean 48 hour NPRS scores over placebo (3.29 vs 5.74, respectively; p < 0.0001), as well as for summed pain intensity difference (203.1 vs 86.6; p < 0.0001). Patients treated with DPSGC experienced a faster onset of meaningful pain relief compared with placebo (p = 0.0034). Rescue medication use on Day 1 and Day 2 was reduced in the DPSGC group compared with placebo (53.5% vs 92.1% on Day 1; 30.3% vs 67.3% on Day 2; p < 0.0001). DPSGC was well tolerated and no patients treated with DPSGC reported serious adverse events. As with any study, there are potential limitations including study design and patient population.

CONCLUSION

These results indicate that DPSGC reduced pain in patients who underwent bunionectomy and this novel formulation of diclofenac potassium may be a practical option for treating mild to moderate acute pain.

Characterization of cancer-induced bone pain: an exploratory study

PURPOSE

Cancer-induced bone pain (CIBP) is the commonest cause of pain in patients with cancer. Its association with increased morbidity combined with limitations of currently available therapies makes it a clinical challenge. Clinical characterization of this complex pain syndrome is essential in underpinning clinical management and informing future research. The aim of this exploratory study was to characterise CIBP using self-rating scales.

PATIENTS AND METHODS

A cross-sectional survey of patients with CIBP was carried out in a regional oncology centre. Patients described their pain over the preceding 24 h using the McGill Pain Questionnaire, Brief Pain Inventory (BPI), and a breakthrough pain questionnaire. Multiple linear regression analyses were conducted.

RESULTS

Fifty-five patients were recruited. Annoying, gnawing, aching, and nagging were the most commonly used words to describe CIBP. From the BPI, median average pain was 4/10 and worst pain was 7/10 on a 0-10 Numerical Rating Scale. The worst pain score correlated more strongly with BPI interference score (p=0.001). Forty-one patients had breakthrough pain. Patients with breakthrough pain had higher total BPI interference scores than those with no breakthrough pain; median (IQR); 35.0 (2.5-44.7) vs. 18.5 (5.5-26.7), p<0.01. Of the patients, 20/41 (48%) had breakthrough pain of rapid onset (less than 5 min) and short duration (less than 15 min).

CONCLUSION

In CIBP, worst pain most accurately reflects the characteristics of pain flares and functional impairment. Breakthrough pain is often unpredictable, sudden onset and short duration. Further characterization studies of CIBP in the broader cancer population are needed.

Long-term continuous subcutaneous infusion of ketoprofen combined with morphine: a safe and effective approach to cancer pain

OBJECTIVES

According to international guidelines, nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are the cornerstone drugs for cancer pain. In clinical practice, severe cancer pain often requires 3 step analgesics and alternative routes of administration, thus NSAIDs are usually abandoned. Our aim was to evaluate feasibility, safety, and efficacy of ketoprofen combined with opioids in long-term continuous subcutaneous infusion (CSI) for cancer pain in a prospective observational open-label pilot study.

METHODS

Ketoprofen was added to morphine CSI in 172 consecutive patients (study group, SG). Concomitantly, 48 received opioids CSI without ketoprofen for contraindication to NSAIDs (control group, CG). CSI was delivered through a single-use elastomeric pump refilled weekly. Safety was evaluated according to the number of adverse events and their severity. The measures of efficacy were pain relief (NRS, Numerical Rating Scale), percentage of patients that needed to increase morphine dosage, and median relative increase between weeks 2 and 4.

RESULTS

Toxicity typically attributable to NSAIDs were recorded in 4.1% of patients after 3 months of treatment and the combination of NSAIDs and corticosteroids seems not to influence the risk of gastrointestinal adverse effects. The local side effects related to the CSI regimen were negligible in both the groups. By the fourth week, pain was well controlled (NRS 0 to 2) in 80% of patients receiving ketoprofen compared with 46% of patients without ketoprofen (P<0.01.) Moreover, the percentage of patients needing to increase the morphine dosage (40.5% vs. 68.7% P<0.01) and the relative dose increase (12% vs. 25% P<0.005) were significantly lower in the SG.

CONCLUSIONS

Ketoprofen CSI in combination with opioids is a feasible, safe, and effective approach to cancer pain.

Higher pain scores, similar opioid doses and side effects associated with antipyretic analgesics in specialised tertiary pain care

PURPOSE

To evaluate whether non-opioid antipyretic analgesics are associated with lower pain scores, opioid doses and side effects in pain patients in tertiary care.

METHODS

In a cross-sectional observational study, data from 519 Caucasians (197 men, 322 women; mean age 55.6 ± 15 years) who had undertaken pain therapy for various causes for 77.5 ± 90.8 months, obtained in three separate study centres, was analysed for actual 24-h pain scores, daily opioid doses and the occurrence of side effects.

RESULTS

Of the 519 patients, 352 received opioids and 260 antipyretic analgesics, from whom 154 received both classes and 304 only either class. The administration of non-opioid antipyretic analgesics was associated with higher average pain scores (4.6 ± 2.5 vs 3.9 ± 2.6; P = 0.01), tendentially higher average oral morphine equivalent doses (121.8 ± 162.2 vs 146.7 ± 242.4 mg/d; P = 0.25) and a similar incidence of side effects (P = 0.21). These results were correspondingly seen when analysing the three study centres separately as independent cohorts.

CONCLUSIONS

With the caution advised for cross-sectional data, the results dispute a clinical benefit of non-opioid antipyretic analgesics for most chronic pain patients in tertiary care and draw attention towards prospectively re-evaluating the utility of non-opioid antipyretic analgesics in tertiary pain care in a randomised placebo controlled trial.