Pharmacological treatment of neuropathic cancer pain: a comprehensive review of the current literature

Pregabalin for Neuropathic Pain in Post-radiotherapy Head and Neck Cancer Patients: A Retrospective Study and Review of the Literature

INTRODUCTION

Head and neck cancer (HNC) patients may experience neuropathic pain (NP) due to radiotherapy (RT), which may become chronic. Pregabalin, an anticonvulsant, alters the transmission of painful stimuli at the synaptic level, modifying their perception. Pregabalin is used in NP treatment, but limited data exist on RT-treated HNC patients. This retrospective study aimed to present a case series of HNC patients with chronic NP after RT managed with pregabalin.

METHODS

HNC patients' records from the Department of Oral Medicine and Pathology and Hospital Dentistry, School of Dentistry, National and Kapodistrian University of Athens (NKUA), were searched. Outcome measures were obtained using the Douleur Neuropathique 4 (DN4) scale for NP and the numeric rating scale (NRS) for pain. The use of additional analgesic medication was also recorded.

RESULTS

Five HNC (four oral and one nasopharyngeal cancer) patients (mean age 58.5 years) who had received RT (mean total dose 64.7 gray (Gy)) and developed chronic (i.e., present for at least three months after RT) NP, characterized by a positive DN4 score ≥4, were identified. The initial assessment was five months to six years after RT (mean DN4=4.6±0.89 and mean NRS=6±3.08). "Burning," "pins and needles," and "numbness" were the NP descriptors mostly used. Pregabalin was titrated up to 150-300 mg per day; paracetamol and/or tramadol were also administered (daily doses 3000 mg and 100-150 mg, respectively). A substantial pain relief (≥50%) according to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) (mean DN4=1.6±1.67 and NRS=1.6±1.67) was reported after two to three months of treatment, when tapering was initiated. Two patients (2/5) had complete remission of symptoms (DN4=0, NRS=0). No serious adverse effects were reported; one patient reported excess salivation.

CONCLUSIONS

Pregabalin may be a promising option for managing RT-related chronic NP in HNC patients. Further studies, including randomized controlled trials on RT-treated HNC patients, should be conducted.

Comprehensive assessment of pain characteristics, quality of life, and pain management in cancer patients: a multi-center cross-sectional study

INTRODUCTION

Pain is the most common complaint among cancer patients, significantly impairing their health-related quality of life (HRQOL). There is limited evidence on the characteristics of pain among cancer patients in Nepal with low-resource settings.

OBJECTIVES

The primary objective of this study was to evaluate the clinical characteristics of pain, factors influencing pain intensity, and the association of pain severity with quality of life (QoL) among cancer patients. Secondary objectives included investigating perceived barriers to pain management and medication adherence among these patients.

METHODS

This multi-center, cross-sectional study enrolled adult patients (over 18 years old) with reported cancer diagnoses experiencing pain. Socio-demographic characteristics (e.g., age, gender, educational status), clinical characteristics (e.g. cancer diagnosis, staging), and pain characteristics (e.g., duration, type, location, medicines used for pain management, etc.) were recorded. Outcomes were assessed using the Numeric rating scale (NRS), Pain management Index, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire, Barriers Questionnaire II, Medication Adherence Rating Scale, and Hospital Anxiety and Depression Scale.

RESULTS

Four hundred and eight patients participated in the study. The mean ± SD age was 54.87 ± 15.65, with 226 patients (55.4%) being female. The most common cancer diagnoses were cervical (17.6%), lung (11.8%), and colon/rectum (12.0%) cancers. The most common pain locations were the head and neck (27.0%); a majority (55.6%) reported pain duration of more than 3 months. Nociceptive pain was reported by 42.4% of patients; the mean ± SD of NRS was 4.31 ± 2.69, with 32.4% of patients experiencing moderate pain. Patients with mixed pain type (B = 1.458, p < 0.001) or pain in multiple sites (B = 1.175, p < 0.001), lower Karnofsky Performance Status (KPS) (B = -1.308, p < 0.001), and specific cancer diagnoses such as prostate (B = -2.045, p = 0.002), pancreatic (B = 1.852, p = 0.004), oesophageal (B = 1.674, p = 0.012), and ovarian cancer (B = 1.967, p = 0.047), experienced varying degrees of increased NRS score. The combined chemotherapy and radiotherapy treatment modality was associated with a lower NRS score (B = -0.583, p = 0.017). A significant inverse relationship was observed between pain severity and global health status/QoL (B = -37.36, p < 0.001. Key barriers to pain management included moderate perceptions of physiological effects, communication issues between doctors and patients, and concerns about the harmful effects of pain medicine. The prevalence of non-adherence to pain medications was 13.97%.

CONCLUSION

In conclusion, this study highlights the multi-faceted nature of pain management and QoL for cancer patients in Nepal with low-resource settings. These findings underscore the multifactorial nature of pain perception in cancer patients, with mixed pain types, pain in multiple sites, lower KPS, and specific cancer diagnoses, all contributing significantly to pain severity. Additionally, pain severity was associated with declining QoL. These findings contribute valuable insights into the complex aspects of cancer pain and its broader implications for the well-being of patients, offering a foundation for targeted interventions and improved pain management strategies in the context of cancer care in low-resource settings.

A systematic review of steroid use in peripheral nerve pathologies and treatment

Background

The use of corticosteroids has become a part of the standard of care in various pathologies but their use in peripheral nerve injury treatment is limited. Given corticosteroids' anti-inflammatory properties and their regulatory role in neuronal protein production and myelination, corticosteroids could serve as an adjunct therapy for peripheral nerve injuries. This review aims to systematically investigate the current use of corticosteroid treatment in peripheral nerve pathologies.

Methods

The systematic search was performed on PubMed, MEDLINE, EMBASE, Scopus, Cochrane, and Web of Science using keywords such as "corticosteroid treatment," "peripheral nerve damage," "peripheral neuropathy," and "complications." The PRISMA guidelines were used to conduct the systematic review and all articles were reviewed by the corresponding author. After the initial search, individual study titles and abstracts were further screened and categorized using an inclusion and exclusion criteria followed by a final full-text review.

Results

Out of the total 27,922 identified records, 203 studies were included based on the selection criteria. These studies focused on the use and efficacy of steroids across a spectrum of compression and non-compression peripheral neuropathies such as cubital tunnel syndrome and chronic inflammatory demyelinating polyradiculoneuropathy. Various studies noted the promising role of steroids in offering pain relief, nerve block, and nerve regeneration effects. Additionally, safety considerations and potential complications regarding steroid use in peripheral nerve injuries were analyzed.

Conclusion

While there is currently limited clinical utilization of corticosteroids in peripheral nerve pathologies, the anti-inflammatory and regenerative effects that steroids provide may be a beneficial tool in managing various peripheral neuropathies and their associated pain. Additional clinical trials and investigation into the mechanism of action could improve the reputation of steroid use as peripheral nerve injury treatment.

Neuropathic Pain in Cancer: What Are the Current Guidelines?

OPINION STATEMENT

Neuropathic cancer pain is experienced by 30-40% of patients with cancer. It significantly reduces quality of life and overall wellbeing for patients living with and beyond cancer. The underlying mechanisms of neuropathic pain in patients with cancer are complex and involve direct tumour involvement, nerve compression or infiltration, chemotherapy and/or radiotherapy-induced nerve damage, or post-surgical complications. It is crucial for healthcare professionals to assess and manage neuropathic cancer pain effectively. There is increasing recognition that standardisation of neuropathic pain assessment leads to tailored management and improved patient outcomes. Pain management strategies, including medication, interventional analgesia, physical and complementary therapy, can help alleviate neuropathic pain and improve the patient's comfort and quality of life.

Successful use of Rectal Pregabalin for the Treatment of Chemotherapy-Induced Neuropathic Pain-a Case Report

INTRODUCTION

A 65-year-old female patient could no longer take oral food or medications due to a duodenal occlusion associated with metastatic urothelial carcinoma. Her pre-existing chemotherapy-induced polyneuropathy had been well treated with pregabalin orally.

METHODS

Since only preparations for oral use of pregabalin are available, pregabalin suppositories were compounded by the hospital pharmacy for rectal use in this patient.

RESULTS

With the rectal administration, the treatment was successfully continued; we measured a good increase in serum levels and the symptoms improved significantly.

DISCUSSION

Cancer patients often need to be treated with co-analgesics. At the end of life, treatment often cannot be continued due to lack of other than oral administration. Our case adds to the low evidence of pregabalin administered rectally.

Efficacy of Duloxetine on electrodiagnostic findings of Paclitaxel-induced peripheral neuropathy, does it have a prophylactic effect? A randomized clinical trial

This study aimed to evaluate the efficacy of Duloxetine on electrodiagnostic findings of Paclitaxel-induced peripheral neuropathy in patients with breast cancer. This randomized, double-blind clinical trial was conducted on 40 patients with breast cancer who received Paclitaxel as their first chemotherapy session. All the patients were randomly allocated into two groups, intervention (20 subjects) and placebo (20 subjects). The intervention group received 30 mg duloxetine/day in the first week, followed by 60 mg (twice daily) until 8 weeks. The patient neurotoxicity questionnaire (PNQ) was used to evaluate the severity of neuropathy. Nerve conduction study was also performed. The evaluations were performed at the baseline and 8 weeks after the treatment. Out of 20 subjects in the placebo group, 10 (50%) patients had neurotoxicity (two milds, three moderate, four severe, and one incapacitated), according to PNQ. However, in the duloxetine group, two patients had mild neurotoxicity ( P = 0.03). Significant differences between groups related to the mean of Median Sensory Latency ( P <0.001), Median Motor Latency ( P < 0.001), and Median Motor velocity ( P = 0.001) were reported. However, the relative risk of polyneuropathy between the two groups (relative risk: 1) was not significant. Regarding the results, duloxetine could be an effective treatment for preventing paclitaxel-induced peripheral neuropathy in patients with breast cancer, and an electrodiagnostic study confirmed this effect.

Efficacy and Security of Tetrodotoxin in the Treatment of Cancer-Related Pain: Systematic Review and Meta-Analysis

The pharmacological treatment of cancer-related pain is unsatisfactory. Tetrodotoxin (TTX) has shown analgesia in preclinical models and clinical trials, but its clinical efficacy and safety have not been quantified. For this reason, our aim was to perform a systematic review and meta-analysis of the clinical evidence that was available. A systematic literature search was conducted in four electronic databases (Medline, Web of Science, Scopus, and ClinicalTrials.gov) up to 1 March 2023 in order to identify published clinical studies evaluating the efficacy and security of TTX in patients with cancer-related pain, including chemotherapy-induced neuropathic pain. Five articles were selected, three of which were randomized controlled trials (RCTs). The number of responders to the primary outcome (≥30% improvement in the mean pain intensity) and those suffering adverse events in the intervention and placebo groups were used to calculate effect sizes using the log odds ratio. The meta-analysis showed that TTX significantly increased the number of responders (mean = 0.68; 95% CI: 0.19-1.16, p = 0.0065) and the number of patients suffering non-severe adverse events (mean = 1.13; 95% CI: 0.31-1.95, p = 0.0068). However, TTX did not increase the risk of suffering serious adverse events (mean = 0.75; 95% CI: -0.43-1.93, p = 0.2154). In conclusion, TTX showed robust analgesic efficacy but also increased the risk of suffering non-severe adverse events. These results should be confirmed in further clinical trials with higher numbers of patients.

Pharmacological Management of Neuropathic Pain after Radiotherapy in Head and Neck Cancer Patients: A Systematic Review

Background: Neuropathic pain (NP) in head and neck cancer (HNC) patients represents a treatment challenge. Most studies investigating drugs against NP are conducted in patients suffering with diabetic neuropathy or postherpetic neuralgia, while data are limited in cancer pain management. Additionally, regarding cancer therapy-related NP, most of the studies do not focus on HNC patients. The aim of this review is to identify the studies on systematically administered medication for NP management that included HNC patients under radiotherapy. Methods: A systematic literature search was performed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in PubMed, Cochrane Library, Web of Science and ClinicalTrials.gov on 30 October 2021. The medical subject heading (MeSH) terms were (“head and neck cancer” OR “tumor”) AND “neuropathic pain” AND “medication” AND “radiotherapy.” The Cochrane Collaboration tool was used for quality assessment. Results: The search identified 432 articles. Three more articles were identified after searching the reference lists of the retrieved articles. A total of 10 articles met the eligibility inclusion criteria and were included in this review; 6 on gabapentin, 1 on pregabalin, 1 on nortriptyline, 1 on methadone, and 1 on ketamine. Statistically significant results in pain reduction compared to placebo or standard pain medication were found in the studies on pregabalin (p = 0.003), methadone (p = 0.03), ketamine (p = 0.012), and in two out of six gabapentin studies (p < 0.004). Two of the studies (both concerning gabapentin) had no comparison arm. Conclusions: Treatments including pregabalin, methadone, ketamine, and gabapentin were found to provide pain relief against HNC NP. While there is a plethora of pharmacological treatments available for the management of NP, only a few studies have been conducted regarding the pharmacological management of therapy-related NP in HNC patients. More studies should be conducted regarding the pharmacological approaches in HNC therapy-related NP so that specific treatment algorithms can be developed.

Neuropathic Pain in Neurologic Disorders: A Narrative Review

Neuropathic pain is defined as a painful condition caused by neurological lesions or diseases. Sometimes, neurological disorders may also be associated with neuropathic pain, which can be challenging to manage. For example, multiple sclerosis (MS) may cause chronic centralized painful symptoms due to nerve damage. Other chronic neuropathic pain syndromes may occur in the form of post-stroke pain, spinal cord injury pain, and other central pain syndromes. Chronic neuropathic pain is associated with dysfunction, disability, depression, disturbed sleep, and reduced quality of life. Early diagnosis may help improve outcomes, and pain control can be an important factor in restoring function. There are more than 100 different types of peripheral neuropathy and those involving sensory neurons can provoke painful symptoms. Accurate diagnosis of peripheral neuropathy is essential for pain control. Further examples are represented by gluten neuropathy, which is an extraintestinal manifestation of gluten sensitivity and presents as a form of peripheral neuropathy; in these unusual cases, neuropathy may be managed with diet. Neuropathic pain has been linked to CoronaVirus Disease (COVID) infection both during acute infection and as a post-viral syndrome known as long COVID. In this last case, neuropathic pain relates to the host’s response to the virus. However, neuropathic pain may occur after any critical illness and has been observed as part of a syndrome following intensive care unit hospitalization.

Diclofenac versus tramadol for mucositis related pain in head and neck cancer patients undergoing concurrent chemoradiation-a phase 3 study

Background

Oral mucositis related pain during CTRT in head and neck cancers is a common problem. Unfortunately, in spite of it being common, there is limited evidence for selection of systemic analgesic in this situation. Hence, this study was designed to compare the analgesic effect of a non-steroidal anti-inflammatory drug (diclofenac) versus a weak opioid (tramadol).

Patients and methods

This was an open-label, parallel design, superiority randomised controlled study. In this study, head and neck cancer patients undergoing radical or adjuvant chemoradiation, who had grade 1 or above mucositis (in accordance with Common Terminology Criteria for Adverse Events version 4.03) and had pain related to it were randomly assigned to either diclofenac or tramadol for mucositis related pain control. The primary endpoint was analgesia after the first dose. The secondary endpoints were the rate of change in analgesic within 1 week, adverse events and quality of life.

Results

One hundred and twenty-eight patients were randomised, 66 in diclofenac and 62 in tramadol arm. The median area under the curve for graph of pain across time after first dose of pain medication for the diclofenac arm and the tramadol arm was 348.936 units (range: 113.64–1,969.23) and 420.87 (101.97–1,465.96), respectively, (p = 0.05619). Five patients (8.1%) in the tramadol arm and 11 patients (16.7%) in the diclofenac arm required a change in analgesic within 1 week of starting the analgesic (p = 0.184). There was no statistically significant difference in any adverse events between the two arms. However, the rate of any grade of renal dysfunction was numerically higher in the diclofenac arm (10.6% versus 4.8%, p = 0.326).

Conclusion

In this phase 3 study, evaluating diclofenac and tramadol for chemoradiation induced mucositis pain, there was no statistical difference in analgesic activity of these two drugs.

Influence of Lidocaine including Buprenorphine for Postoperative Analgesia after the Extraction of Mandibular Third Molars: A Randomized Controlled, Double-Blind, Split-Mouth Study

Background

The presence of opioid receptors around the peripheral nerves offers the possibility of providing postoperative analgesia, thereby encouraging the study of the effect of opioids in combination with local anesthesia (LA). Studies have also reported the efficacy of peripherally administered opioids in achieving adequate analgesia in regions with inflammation. Applying the concept of peripheral opioid receptors, our study aimed to evaluate the effectiveness of opioid analgesia in managing postoperative pain. The split-mouth study was carried out to evaluate the efficacy of buprenorphine added to lidocaine 2% in providing postoperative analgesia after the surgical extraction of the impacted mandibular third molar.

Materials and Methods

We conducted a randomized, double-blinded, split-mouth trial among 21 patients with impacted mandibular third molars bilaterally. In all patients, bilateral impacted mandibular third molars were extracted at different periods. The primary outcomes assessed were postoperative analgesia by the VAS score and the number of rescue analgesics consumed by patients at 24, 48, and 72 hours of interval via a questionnaire.

Results

There was a statistical significant difference in postoperative analgesia duration at 24 (P = 0.012) and 48 hours (P = 0.024), respectively, between the test and control group. Even though the mean number of rescue analgesics consumed by the test group was less than that of the control group, no significant difference was seen.

Conclusion

Buprenorphine added to lidocaine 2% showed a minimal decrease in the pain score and duration of postoperative analgesia with no difference in the frequency of rescue analgesics consumed between the test and control.

Materials Chemistry of Neural Interface Technologies and Recent Advances in Three-Dimensional Systems

Advances in materials chemistry and engineering serve as the basis for multifunctional neural interfaces that span length scales from individual neurons to neural networks, neural tissues, and complete neural systems. Such technologies exploit electrical, electrochemical, optical, and/or pharmacological modalities in sensing and neuromodulation for fundamental studies in neuroscience research, with additional potential to serve as routes for monitoring and treating neurodegenerative diseases and for rehabilitating patients. This review summarizes the essential role of chemistry in this field of research, with an emphasis on recently published results and developing trends. The focus is on enabling materials in diverse device constructs, including their latest utilization in 3D bioelectronic frameworks formed by 3D printing, self-folding, and mechanically guided assembly. A concluding section highlights key challenges and future directions.

Innovative Approach for the Prevention of Chemotherapy-Induced Peripheral Neuropathy in Cancer Patients: A Pilot Study With the Hilotherm Device, the Poliambulanza Hospital Experience

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is an adverse event of taxanes, with no effective prevention or treatment available and a highly negative impact on patient quality of life. The aim of this study is to asses that the constant application of cooled cuffs on the hands and feet prevent and mitigate CIPN.

METHODS

Patients with breast, gynecologic, and pancreatic cancer who received weekly paclitaxel (PTX), PTX/carboplatin, and nab-paclitaxel (nab-PTX)/gemcitabine for any indication at the therapeutic scheduled dosage were included in this prospective study. Hilotherm Chemo care device forms a closed-loop system with cuffs and tubes through which a coolant flows at a temperature of 10 °C. CIPN was monitored using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (edition 3.0), and the tolerability and side effects were scored by using the Common Terminology Criteria for Adverse Events (T4.03 2017).

RESULTS

To date, we have enrolled 64 patients. Of these, 54 (84%) completed all cooling cycles. Continuous cooling was well tolerated by all patients. No patients had grade >2 CIPN or had serious or lasting adverse events as a result of Hilotherapy. The median time to CIPN onset was 77 days for the entire population.

CONCLUSION

Hilotherapy has good effectiveness and tolerability and seems to be able to prevent or reduce the symptoms of CIPN. We are still recruiting patients to obtain more data and to collect data at 3 months after the end of chemotherapy. Prospective studies seem to be warranted.

Oral Complications of Head and Neck Cancer Therapy

Current therapies for Head and Neck cancer treatment are extremely advanced. Though, they cause oral complications which have deleterious effects on basic life functions, affect oral and overall health, may lead to significant morbidity and treatment discontinuation and have an impact on survivorship and quality of life. As new therapies are introduced, a new spectrum of oral complications is rising, compromising the mucosal integrity and the salivary function, that may not be recognized, reported and treated properly. Oral complications, often permanent and extremely painful, may include mucositis, xerostomia, dysgeusia, infections, trismus and fibrosis, risk of dental disease and necrosis of the jaw, neurosensory disorders and when targeted therapies and immunotherapy are involved, aphthoid and lichenoid lesions can also be reported. Increased awareness is required for the prevention and management of these complications, which can be best provided by a multidisciplinary team.

Non-opioid Analgesics and Emerging Therapies

Pain is a common and debilitating symptom of cancer. Cancer-related pain can occur at any point along the continuum from diagnosis to treatment to survivorship¹. A systematic review published in 2016 estimated the prevalence of cancer pain to be 55% in those undergoing antineoplastic treatment, 66.4% in advanced cancer, and 39.3% in the post-treatment population. Thirty-eight percent of cancer patients in this pooled analysis experienced moderate to severe pain².

Serum Concentrations of Lidocaine During Bariatric Surgery

Lidocaine has been shown to be clinically beneficial during bariatric surgery. However, information about lidocaine serum concentrations in this setting is scarce. This prospective clinical trial included 42 obese patients undergoing laparoscopic bariatric surgery. They received lidocaine based on adjusted body weight. Administration began with a 1.5 mg·kg bolus of intravenous lidocaine followed by a continuous infusion of 2 mg·kg·hour. After skin closure, administration was decreased to 1 mg·kg·hour until discharge from the recovery room. No serum concentrations of lidocaine were outside the usual accepted range (1.5-5 µg·mL).

The Incidence of Oxaliplatin-Induced Peripheral Neurotoxicity at Khartoum Oncology Hospital: A Cross-Sectional Survey

Objective:

Using oxaliplatin-based chemotherapy in the treatment of cancer patients can cause a unique form of acute and chronic peripheral neurotoxicities. This study mainly aims to assess the incidence of oxaliplatin-induced peripheral neuropathy (OXAIPN).

Methods:

A cross-sectional study among 121 patients treated with oxaliplatin-based chemotherapy was conducted during the period of January to April 2019 at Khartoum Oncology Hospital. The incidence of acute neurotoxicity was assessed using a descriptive questionnaire for most common hyperexcitability and transient symptoms, while the incidence of chronic neurotoxicity was measured by the 20-item European Organization for Research and Treatment of Cancer Quality of Life Questionnaire for patients with chemotherapy-induced peripheral neuropathy and graded by the National Cancer Institute's Common Terminology Criteria for Adverse Events, Version 4.03.

Results:

Acute and chronic OXAIPN were found in 49.6% and 41.3% of patients, respectively. Most of the patients who developed acute OXAIPN symptoms manifested cold-induced pharyngolaryngeal dysesthesias (73.3%) or perioral paresthesias (71.7%). No significant association exists between the severity of chronic neurotoxicity and basic demographics. Most (79.1%) of the patients did not inform the doctors about their complaints, and 43.5% of those who informed doctors did not take any medication to manage OXAIPN.

Conclusions:

This study exhibits that oxaliplatin-based chemotherapy can cause symptoms of peripheral neurotoxicity in most of the patients with colorectal or gastric cancer in the form of acute neurotoxicity or chronic neurotoxicity.

Cancer Pain Management: An Italian Delphi Survey from the Rational Use of Analgesics (RUA) Group

Background

In patients with cancer, the prevalence of pain is high, and pain management is often challenging despite the wide availability of drugs and guidelines.

Methods

This Delphi survey was organized within the Rational Use of Analgesics (RUA) Group projects to reach a consensus among Italian palliative care specialists on pain assessment and management. Items were identified from recent publications on cancer pain and guidelines.

Results

This survey included input from 190 palliative care specialists representing all Italian territory. A consensus was reached on 17 statements. Items concerning pain assessment achieved over 70% agreement amongst the participants. Items on principles of pain management and management according to type of pain, including breakthrough cancer-related pain and neuropathic pain also achieved high levels of agreement.

Conclusion

Results from the RUA project showed that Italian palliative care specialists had a particular interest in items related to pain challenges, in addition to the evaluation and control of pain associated with cancer. However, some discrepancies between current guidelines and clinical practice were observed.

The effects of teaching methods of palliative care on life pattern of old women with chronic pain

Chronic pain is among problems of old people and causes changes in their life pattern and processes. Teaching palliative care can help old people suffering from chronic pain to live an active life. The aim of this research was to determine effects of educating of palliative care on life pattern of elderly women with chronic pain. The present study was a Quasi-experimental design with pre-test and post test was conducted on 30 elderly women suffering from chronic pain in 2018 in Iran. The Questionnaire for evaluating the Pattern of Life with Pain in the elderly was filled before the intervention, group educating of palliative care was carried out using an educational package, and the questionnaire was completed again immediately and one and three months after. The data was analyzed using mean, standard deviations, Fisher's F test, and Greenhouse-Geisser and Bonferroni post-hoc test by employing SPSS- 16. Mean changes before teaching palliative care significantly differed from those of immediately and one and three months after the educational program (p = 0.0), (p = 0.004). There were significant differences between the stages of immediately and one month after the educational program and that of three months after it (p = 0.001), (p = 0.002). Concerning the personal life patterns, there were statistically significant differences between the stage immediately after the educational program and those before the intervention and three months after it (p = 0.005), (p = 0.000). Regarding the social life pattern, only the stage of one month after the educational program significantly differed from that of three months (p = 0.005). Mean growth in life pattern of the old women suffering from chronic pain in the stages after the intervention indicated the importance of and the necessity for palliative care during old age. Moreover, the success of this education three months after the educational program as compared to immediately and one month after it indicates that allocation of sufficient time plays a very important role in transferring information and in teaching methods of palliative care to old people.

Personalized Radiation Therapy in Cancer Pain Management

The majority of advanced cancer patients suffer from pain, which severely deteriorates their quality of life. Apart from analgesics, bisphosphonates, and invasive methods of analgesic treatment (e.g., intraspinal and epidural analgesics or neurolytic blockades), radiation therapy plays an important role in pain alleviation. It is delivered to a growing primary tumour, lymph nodes, or distant metastatic sites, producing pain of various intensity. Currently, different regiments of radiation therapy methods and techniques and various radiation dose fractionations are incorporated into the clinical practice. These include palliative radiation therapy, conventional external beam radiation therapy, as well as modern techniques of intensity modulated radiation therapy, volumetrically modulated arch therapy, stereotactic radiosurgery or stereotactic body radiation therapy, and brachytherapy or radionuclide treatment (e.g., radium-223, strontium-89 for multiple painful osseous metastases). The review describes the possibilities and effectiveness of individual patient-tailored conventional and innovative radiation therapy approaches aiming at pain relief in cancer patients.

Risk of incident claims for chemotherapy-induced peripheral neuropathy among women with breast cancer in a Medicare population

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and disabling consequence of neurotoxic therapies, yet factors that modulate the development and clinical impact of CIPN are poorly understood. This epidemiological analysis identifies risk factors for the incidence of CIPN.

METHODS

This retrospective analysis of Surveillance, Epidemiology, and End Results-Medicare data examined predictors of incident CIPN claims among 11,149 women aged 66 years or older with American Joint Commission on Cancer (AJCC) stage II to IV breast cancer (and no secondary cancer diagnosis or preexisting neuropathy) who received chemotherapy.

RESULTS

Overall, new CIPN claims occurred for 8.3% of patients within 1 year of starting chemotherapy. Risk emerged approximately 3 months after the start of chemotherapy and increased throughout 1 year. Paclitaxel as part of first-line therapy increased CIPN risk 2.7-fold in comparison with nonneurotoxic agents (15.9% vs 5.0%), with lower incidence rates for carboplatin and paclitaxel (11.9%), carboplatin and docetaxel (9.3%), carboplatin alone (7.7%), and docetaxel alone (6.6%). The CIPN incidence rate was higher for women who at the time of their breast cancer diagnosis were relatively young (within this Medicare sample), were at AJCC stage II or III, were married or had an equivalent status, and had fewer comorbidities, but it did not differ by race/ethnicity or poverty level.

CONCLUSIONS

These Medicare claims database findings indicate that women aged 66 years or older with breast cancer are susceptible to CIPN from taxane and/or platinum compounds, with risk emerging approximately 3 months into treatment. Prospective studies of symptom emergence and clinical response (eg, stopping chemotherapy and adjunctive treatments) are indicated to determine how best to inform patients of this risk and to manage CIPN in this population.

Chronic idiopathic axonal polyneuropathy: Prevalence of pain and impact on quality of life

BACKGROUND AND AIM

Chronic idiopathic axonal polyneuropathy (CIAP) is a term describing axonal neuropathies of insidious onset, with slow or no progression of the disease over at least 6 months and with no etiology being identified despite appropriate investigations. We aimed to establish the prevalence of pain in patients with CIAP and investigate the impact of pain on quality of life (QoL).

METHODS

All consecutive patients with CIAP attending a specialist neuropathy clinic were invited to participate. Pain was assessed via the DN4 questionnaire and the visual analogue scale (VAS). Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of neuropathy. The SF-36 questionnaire was used to measure participants' quality of life.

RESULTS

Fifty-five patients with CIAP were recruited (63.6% male, mean age 73.4 ± 8.7 years). Based on the DN4 questionnaire, peripheral neuropathic pain was present in 33 patients (60.0%). After having adjusted for age, gender and disease severity pain showed significant negative correlations with the energy/fatigue domain of QoL (β = -0.259, p = 0.049), with the emotional well-being domain (β = -0.368, p = 0.007) and the general health perception domain (β = -0.356, p = 0.007).

CONCLUSION

Pain is very prevalent in CIAP and is associated with poorer emotional well-being, worse general health perception, and increased fatigue.

Pharmacokinetic and pharmacodynamic studies of pregabalin suppositories based on pharmacological research

OBJECTIVES

As commercially available pregabalin preparations are limited to oral administration, it is impossible to use it as an adjuvant analgesic for neuropathic cancer-related pain in terminally ill cancer patients with oral feeding difficulties. The objective of this study was to develop a pregabalin suppository to be available at hospitals.

METHODS

Pregabalin suppositories were prepared using bases comprising six different compositions of Witepsol H-15, Witepsol S-55, and Witepsol E-75. The suppository release test and stability test were performed in vitro. The pharmacokinetics and pharmacodynamics of the suppositories were assessed in rats.

KEY FINDINGS

In the in vitro releasing test, the pregabalin suppositories with H-15, H-15 : S-55 = 1 : 1, H-15 : S-55 = 2 : 1, H-15 : S-55 = 1 : 2 released approximately 100% of the pregabalin within 180 min. Among these pregabalin suppositories, only the suppository with H-15 : S-55 = 2 : 1 demonstrated an equivalent AUC_0-∞ with the oral administration group. Consistent with the results of the pharmacokinetic study, the pregabalin suppository with H-15 : S-55 = 2 : 1 exhibited antinociceptive effects. In addition, the pregabalin suppository with H-15 : S-55 = 2 : 1 was stable for 12 weeks when refrigerated with light shielding.

CONCLUSIONS

The pregabalin suppositories prepared in this study may be applicable for pain control for terminally cancer ill patients with oral feeding difficulties.

Tramadol: a valuable treatment for pain in Southeast Asian countries

Background

The supply of controlled drugs is limited in the Far East, despite the prevalence of health disorders that warrant their prescription. Reasons for this include strict regulatory frameworks, limited financial resources, lack of appropriate training amongst the medical profession and fear of addiction in both general practitioners and the wider population. Consequently, the weak opioid tramadol has become the analgesic most frequently used in the region to treat moderate to severe pain.

Methods

To obtain a clearer picture of the current role and clinical use of tramadol in Southeast Asia, pain specialists from 7 countries in the region were invited to participate in a survey, using a questionnaire to gather information about their individual use and experience of this analgesic.

Results

Fifteen completed questionnaires were returned and the responses analyzed. Tramadol is used to manage acute and chronic pain caused by a wide range of conditions. Almost all the specialists treat moderate cancer pain with tramadol, and every one considers it to be significant or highly significant in the treatment of moderate to severe non-cancer pain. The reasons for choosing tramadol include efficacy, safety and tolerability, ready availability, reasonable cost, multiple formulations and patient compliance. Its safety profile makes tramadol particularly appropriate for use in elderly patients, outpatients, and for long-term treatment. The respondents strongly agreed that tighter regulation of tramadol would reduce its medical availability and adversely affect the quality of pain management. In some countries, there would no longer be any appropriate medication for cancer pain or the long-term treatment of chronic pain.

Conclusions

In Southeast Asia, tramadol plays an important part in the pharmacological management of moderate to severe pain, and may be the only available treatment option. If it were to become a controlled substance, the standard of pain management in the region would decline.

A neuropathic pain component as a predictor of improvement in pain interference after radiotherapy for painful tumors: A secondary analysis of a prospective observational study

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A neuropathic component was related to worse pain interference scores at baseline.

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A neuropathic component predicted a greater reduction in pain interference.

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Older patients and male patients tended to have a neuropathic component.

Background and purpose

We previously demonstrated that patients with a tumor-related neuropathic pain component were more likely to experience a pain response after radiotherapy (RT) than those without. It is unknown whether the presence of a neuropathic component also favorably influences pain interference. In a secondary analysis of our previous prospective observational study, we investigated if the presence of a neuropathic component of the index pain caused by the irradiated tumors predicts greater reduction in pain interference.

Material and methods

For patients scheduled for RT for painful tumors, Brief Pain Inventory data were collected at initiation of RT and 1, 2, and 3 months thereafter. Multivariable linear regression analyses were performed to investigate the effects of the presence of a neuropathic component on the changes in pain interference scores (i.e., follow-up minus baseline). We used 10 covariates as potential confounders.

Results

Of the 302 analyzable patients, 93 (31%) were diagnosed as having a neuropathic component of the index pain. Multivariable linear regression analyses revealed that all the point estimates of regression coefficients at 1-, 2-, and 3-month follow-up were negative values; some were statistically significant. At 2-month follow-up, patients with a neuropathic component experienced greater reductions in their pain interference scores for walking ability (p = 0.048), normal work (p = 0.021), sleep (p = 0.001), and enjoyment of life (p = 0.010) than those without it.

Conclusions

The presence of a neuropathic pain component predicted a greater reduction in pain interference after RT. Patients with neuropathic tumor-related pain should be offered the option of receiving palliative RT.

Gluten neuropathy: prevalence of neuropathic pain and the role of gluten-free diet

BACKGROUND AND AIM

Peripheral neuropathy is a common extraintestinal manifestation of gluten sensitivity (gluten neuropathy). We aimed to establish the prevalence of neuropathic pain in patients with otherwise idiopathic PN and gluten sensitivity (positive antigliadin, endomysial, and/or transglutaminase antibodies, with or without enteropathy) and to describe any contributory factors.

METHODS

All consecutive patients with gluten neuropathy (GN) attending a specialist gluten/neurology clinic were invited to participate. Pain was assessed via the DN4 questionnaire and the visual analog scale. Overall Neuropathy Limitations Scale was used to assess the severity of neuropathy. The Mental Health Index (MHI-5) was used to measure participants' general mental health status.

RESULTS

In total, 60 patients (76.7% males, mean age 69.9 ± 10.1 years) with GN were recruited. Neuropathic pain was present in 33 patients (55.0%). Comparison between groups of painful and not painful GN did not show significant differences regarding age, gender, neuropathy severity and neuropathy type. Patients with painless GN were more likely to be on a strict gluten-free diet (55.6 versus 21.2%, p = 0.006). Patients with painful GN presented with significantly worse MHI-5 score (75.9 ± 13.8 versus 87.4 ± 8.1, p < 0.001). Multivariate analysis showed that, after adjusting for age, gender and MHI-5, strict gluten-free diet was associated with lowering the odds of peripheral neuropathic pain by 88.7% (95% CI 47.2-97.6%, p = 0.006).

CONCLUSION

Neuropathic pain is very prevalent in GN and is associated with poorer mental health status. Strict gluten-free diet might be protective as it is associated with a significant reduction of the odds of peripheral neuropathic pain associated to GN.

Quality of Life in Patients with Gluten Neuropathy: A Case-Controlled Study

Background: Gluten neuropathy (GN) is defined as an otherwise idiopathic peripheral neuropathy in the presence of serological evidence of gluten sensitivity (positive native gliadin antibodies and/or transglutaminase or endomysium antibodies). We aimed to compare the quality of life (QoL) of GN patients with that of control subjects and to investigate the effects of a gluten-free diet (GFD) on the QoL. Methods: All consecutive patients with GN attending a specialist neuropathy clinic were invited to participate. The Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of the neuropathy. The 36-Item Short Form Survey (SF-36) questionnaire was used to measure participants’ QoL. A strict GFD was defined as effectively being able to eliminate all circulating gluten sensitivity-related antibodies. Results: Fifty-three patients with GN and 53 age- and gender-matched controls were recruited. Compared to controls, GN patients showed significantly worse scores in the physical functioning, role limitations due to physical health, energy/fatigue, and general health subdomains of the SF-36. After adjusting for age, gender, and disease severity, being on a strict GFD correlated with better SF-36 scores in the pain domain of the SF-36 (beta 0.317, p = 0.019) and in the overall health change domain of the SF-36 (beta 0.306, p = 0.017). Conclusion: In GN patients, physical dysfunctioning is the major determinant of poor QoL compared to controls. Routine checking of the elimination of gluten sensitivity-related antibodies that results from a strict GFD should be encouraged, as such elimination ameliorates the overall pain and health scores, indicating a better QoL.

Effect profile of paracetamol, Δ9-THC and promethazine using an evoked pain test battery in healthy subjects

BACKGROUND

A battery of evoked pain tasks (PainCart) was developed to investigate the pharmacodynamic properties of novel analgesics in early-phase clinical research. As part of its clinical validation, compounds with different pharmacological mechanisms of actions are investigated. The aim was to investigate the analgesic effects of classic and nonclassic analgesics compared to a sedating negative control in a randomized placebo-controlled crossover study in 24 healthy volunteers using the PainCart.

METHODS

The PainCart consisted of pain tasks eliciting electrical, pressure, heat, cold and inflammatory pain. Subjective scales for cognitive functioning and psychotomimetic effects were included. Subjects were administered each of the following oral treatments: paracetamol (1000 mg), Δ9-THC (10 mg), promethazine (50 mg) or matching placebo. Pharmacodynamic measurements were performed at baseline and repeated up to 10 h postdose.

RESULTS

Paracetamol did not show a significant reduction in pain sensation or subjective cognitive functioning compared to placebo. Promethazine induced a statistically significant reduction in PTT for cold pressor and pressure stimulation. Furthermore, reduced subjective alertness was observed. Δ9-THC showed a statistically significant decrease in PTT for electrical and pressure stimulation. Δ9-THC also demonstrated subjective effects, including changes in alertness and calmness, as well as feeling high and psychotomimetic effects.

CONCLUSIONS

This study found a decreased pain tolerance due to Δ9-THC and promethazine, or lack thereof, using an evoked pain task battery. Pain thresholds following paracetamol administration remained unchanged, which may be due to insufficient statistical power. We showed that pain thresholds determined using this pain test battery are not driven by sedation.

SIGNIFICANCE

The multimodal battery of evoked pain tasks utilized in this study may play an important role in early-phase clinical drug development. This battery of pain tasks is not sensitive to the effects of sedation alone, and thus suitable to investigate the analgesic potential of novel analgesic compounds.

Cancer-Related Neuropathic Pain: Review and Selective Topics

Neuropathic pain is the result of neuroplastic and neuroinflammatory changes from trauma or diseases that damage the somatosensory system. Cancer-related neuropathic pain is caused by treatment, cancer, or paraneoplastic reactions to cancer. Approximately 30% of patients with cancer have neuropathic pain, mostly mixed nociceptive and neuropathic pain. History, physical examination, quantitative sensory testing, skin punch biopsies, and functional MRIs help to divide pain into phenotypes that may facilitate analgesic choices. Guidelines for treating cancer-related neuropathic pain are not consistent and are highly dependent on trials in patients without cancer. Combinations of analgesics are promising, whereas evidence for cannabinoids is meager.

Pain in Platin-Induced Neuropathies: A Systematic Review and Meta-Analysis

Introduction

Platin-induced peripheral neuropathy (PIPN) is a common cause of PN in cancer patients. The aim of this paper is to systematically review the current literature regarding PIPN, with a particular focus on epidemiological and clinical characteristics of painful PIPN, and to discuss relevant management strategies.

Methods

A systematic computer-based literature search was conducted on the PubMed database.

Results

This search strategy resulted in the identification of 353 articles. After the eligibility assessment, 282 articles were excluded. An additional 24 papers were identified by scanning the reference lists. In total, 95 papers met the inclusion criteria and were used for this review. The prevalence of neuropathic symptoms due to acute toxicity of oxaliplatin was estimated at 84.6%, whereas PN established after chemotherapy with platins was estimated at 74.9%. Specifically regarding pain, the reported prevalence of pain due to acute toxicity of oxaliplatin was estimated at 55.6%, whereas the reported prevalence of chronic peripheral neuropathic pain in PIPN was estimated at 49.2%.

Conclusion

Peripheral neuropathy is a common complication in patients receiving platins and can be particularly painful. There is significant heterogeneity among studies regarding the method for diagnosing peripheral neuropathy. Nerve conduction studies are the gold standard and should be performed in patients receiving platins and complaining of neuropathic symptoms post-treatment.

Multicenter, cross-sectional observational study of the impact of neuropathic pain on quality of life in cancer patients

PURPOSE

Neuropathic cancer pain (NCP) is a common and potentially debilitating symptom in cancer patients. We investigated the prevalence of NCP, as well as its management and association with QOL.

METHODS

Cancer patients with pain ≥1 on the visual analogue scale (VAS) were surveyed with the Douleur Neuropathique (DN4) questionnaire, the Brief Pain Inventory-Short Form (BPI-SF), and the EuroQOL five dimensions (EQ-5D) questionnaire. The associations between NCP and pain severity or NCP and QOL, while controlling for variables relevant to QOL, were then analyzed.

RESULTS

A total of 2003 patients were enrolled in this survey; the prevalence of NCP was 36.0% (n = 722, 95% CI, 32.5-39.5). We found that NCP in cancer patients was closely correlated to a higher pain severity (BPI-SF; 4.96 ± 1.94 versus 4.24 ± 2.02, p < 0.001), and in patients with NCP, pain more severely interfered with daily living, as compared to those without NCP (BPI-SF; 4.86 ± 2.71 versus 4.41 ± 2.87, p < 0.001). Patients with NCP also had worse QOL than those without NCP, as measured by EQ-5D index score (0.47 ± 0.30 vs. 0.51 ± 0.30, p = 0.005), and this was confirmed using multivariate analysis (p < 0.001), even after controlling for other variables such as age, sex, disease stage, cancer duration, radiotherapy, chemotherapy, and comorbidities. Importantly, adjuvant analgesics were used in less than half of patients with NCP (n = 358, 46.4%).

CONCLUSIONS

We found that NCP in cancer patients was significantly associated with a worsened QOL, and current management is inadequate. Therefore, future research aimed at developing improved strategies for management of NCP is required.

Common oral complications of head and neck cancer radiation therapy: mucositis, infections, saliva change, fibrosis, sensory dysfunctions, dental caries, periodontal disease, and osteoradionecrosis

Patients undergoing radiation therapy for the head and neck are susceptible to a significant and often abrupt deterioration in their oral health. The oral morbidities of radiation therapy include but are not limited to an increased susceptibility to dental caries and periodontal disease. They also include profound and often permanent functional and sensory changes involving the oral soft tissue. These changes range from oral mucositis experienced during and soon after treatment, mucosal opportunistic infections, neurosensory disorders, and tissue fibrosis. Many of the oral soft tissue changes following radiation therapy are difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. We discuss the presentation, prognosis, and management strategies of the dental structure and oral soft tissue morbidities resulting from the administration of therapeutic radiation in head and neck patient. A case for a collaborative and integrated multidisciplinary approach to the management of these patients is made, with specific recommendation to include knowledgeable and experienced oral health care professionals in the treatment team.

SEOM clinical guideline for treatment of cancer pain (2017)

Pain is a highly prevalent symptom in patients with cancer. Despite therapeutic advances and well-accepted treatment guidelines, a percentage of patients with pain are under-treated. Currently, it has been recognized that several barriers in pain management still exist and, in addition, there are new challenges surrounding complex subtypes of pain, such as breakthrough and neuropathic pain, requiring further reviews and recommendations. This is an update of the guide our society previously published and represents the continued commitment of SEOM to move forward and improve supportive care of cancer patients.

Pain as a First Manifestation of Paraneoplastic Neuropathies: A Systematic Review and Meta-Analysis

INTRODUCTION

Paraneoplastic neurological syndromes (PNS) consist of a heterogeneous group of neurological disorders triggered by cancer. The aim of this systematic review is to estimate the reported prevalence of pain in patients with paraneoplastic peripheral neuropathy (PPN).

METHODS

A systematic computer-based literature search was conducted on PubMed database.

RESULTS

Our search strategy resulted in the identification of 126 articles. After the eligibility assessment, 45 papers met the inclusion criteria. Full clinical and neurophysiological data were further extracted and involved 92 patients with PPN (54.5% males, mean age 60.0 ± 12.2 years). The commonest first manifestation of PPN is sensory loss (67.4%), followed by pain (41.3%), weakness (22.8%), and sensory ataxia (20.7%). In 13.0% of the cases, pain was the sole first manifestation of the PPN. During the course of the PPN, 57.6% of the patients may experience pain secondary to the neuropathy.

CONCLUSIONS

Pain is very prevalent within PPN. Pain specialists should be aware of this. Detailed history-taking, full clinical examination, and requesting nerve conduction studies might lead to an earlier diagnosis of an underlying malignancy.

Painful Peripheral Neuropathy and Cancer

Peripheral neuropathy (PN) is very prevalent in cancer patients and a leading cause of pain related to cancer. However, the underlying pathophysiological mechanisms vary significantly. Peripheral neuropathy can be a direct or an indirect complication of cancer or cancer-related treatment, or a pre-existing comorbidity not related to cancer. PN might also occur as a paraneoplastic neurological syndrome. Such syndromes are immune-mediated manifestations that usually precede the diagnosis of cancer or cancer’s relapse. Pain is very prevalent in paraneoplastic peripheral neuropathies and, therefore, merits attention.

Depression and chronic pain in the elderly: links and management challenges

Aging is an inevitable process and represents the accumulation of bodily alterations over time. Depression and chronic pain are highly prevalent in elderly populations. It is estimated that 13% of the elderly population will suffer simultaneously from the two conditions. Accumulating evidence suggests than neuroinflammation plays a critical role in the pathogenesis of both depression and chronic pain. Apart from the common pathophysiological mechanisms, however, the two entities have several clinical links. Their management is challenging for the pain physician; however, both pharmacologic and nonpharmacologic approaches are available and can be used when the two conditions are comorbid in the elderly patients.

Latin-American guidelines for cancer pain management

Cancer is a major public health issue. Poor pain management has devastating consequences that seriously affect quality of life, diminish functionality and place a huge emotional burden on patients and their relatives. A group of Latin American opinion leaders were invited to participate in a meeting to discuss areas associated with cancer pain. The expert panel reviewed the latest literature to draft region-specific guidelines for effective pain management. The guidelines make recommendations on tailoring treatment to the specific type of pain and provide local physicians with the state-of-the art findings in the field. Management should be with pharmacological approaches (nonopioid, adjuvant and opioid analgesics, as well as oncologic therapies and interventional procedures) and nonpharmacological approaches.

Pregabalin prescription for terminally ill cancer patients receiving specialist palliative care in an acute hospital

Background

Pregabalin is recommended as an adjuvant analgesic for neuropathic cancer-related pain, and may be taken at all steps of the World Health Organization analgesic ladder. However, unlike opioids, pregabalin treatments are limited to an oral administration route. If patients have oral feeding difficulties, it is not possible to administer any drug as an adjuvant analgesic for neuropathic cancer-related pain. Therefore, the aim of the present study was to clarify the problems of pain control after pregabalin discontinuation in terminally ill cancer patients.

Methods

Our subjects comprised cancer patients who died during their hospital stay and were referred between April 2013 and October 2015 to the palliative care team of the 899-bed Cancer Hospital at the Nippon Medical School Hospital in Japan. The medical records of each patient were retrospectively reviewed, and patient characteristics were recorded.

Results

We obtained data on 183 patients during the study period. Thirty-eight (20.8 %) patients were treated with pregabalin. Thirty-three (86.8 %) out of 38 patients were prescribed pregabalin for neuropathic cancer-related pain. The incidence of bony metastases was significantly higher in patients administered pregabalin than in those not taking the drug (non-pregabalin group 32.4 % vs pregabalin group 57.9 %). Pregabalin was ultimately discontinued in all patients, with the main reason being oral feeding difficulties (81.6 %). After the discontinuation of pregabalin, the amount of opioid drugs administered was increased in 56.5 % of patients with oral feeding difficulties.

Conclusion

Our results demonstrated that the amount of opioid drugs administered was increased in more than 50 % of patients following the discontinuation of pregabalin, and was repeatedly increased for some patients. A new administration route is required for cancer patients unable to take oral medication.

Trial registration

UMIN000022507. May 28, 2016 retrospectively registered.

Pharmacogenomics for personalized pain medicine

Pharmacogenomics aims to unravel the way that human genetic variation affects drug efficacy and toxicity. Genome-wide association studies and candidate gene findings suggest that genetic approaches may help choose the most appropriate drug and dosage while preventing adverse drug reactions (ADRs). Pain is an unpleasant feeling that usually results from tissue damage. The management of different types of pain (acute, chronic, inflammatory, neuropathic, or cancer) is challenging. Currently, drug intervention is the first-line therapy for resolving pain. However, differences in drug efficacy between individuals are common with pain medications. Moreover, some patients experience ADRs after being treated with specific pain drugs. This review discusses the use of drugs for pain management in the context of the recent pharmacogenomic studies on ADRs and drug efficacy.

The Prevalence and Characteristics of Pain in Critically Ill Cancer Patients: A Prospective Nonrandomized Observational Study

Context:

Pain is a distressing symptom common to all stages and ubiquitous at all levels of care in cancer patients. However, there is a lack of scientific literature on prevalence, severity, predictors, and the quality of pain in cancer patients admitted to an Intensive Care Unit (ICU).

Objectives:

To elucidate the prevalence of pain, moderate to severe pain, neuropathic pain, chronic pain, and pain as the most distressing symptom in critically ill-cancer patients at the time of ICU admission.

Methods:

We prospectively interviewed 126 patients within first 24 h of admission to a medical ICU. The patients were assessed for the presence of pain, its severity, sites, duration, nature, and its impact as a distressing symptom. Numerical Rating Scale and self-report version of Leeds Assessment of Neuropathic Signs and Symptoms were used to elucidate intensity of pain and neuropathic pain, respectively. Demographic characteristics such as age and sex, primary site, and stage of cancer were considered for a possible correlation with the prevalence of pain.

Results:

Of 126 patients included in the study 95 (75.40%), 79 (62.70%), 34 (26.98%), and 17 (13.49%) patients had pain, moderate-severe, chronic, and neuropathic pain, respectively. The average duration of pain was 171.16 ± 716.50 days. Totally, 58 (46.03%) and 42 (42.01%) patients had at least one and more than equal to 2 neuropathic pain symptoms, respectively. The primary malignancies associated with the highest prevalence of pain were genitourinary, hematological, and head and neck whereas breast and lung cancers were associated with the highest prevalence of neuropathic and chronic pain, respectively.

Conclusion:

The prevalence of pain among critically ill-cancer patients is high. Assessment for pain at the time of ICU admission would ensure appropriate assessment for the presence, type, severity, and the significance imparted to it.