Use of non-opioid analgesics as adjuvants to opioid analgesia for cancer pain management in an inpatient palliative unit: does this improve pain control and reduce opioid requirements?

Crizotinib inhibits the metabolism of tramadol by non-competitive suppressing the activities of CYP2D1 and CYP3A2

Objectives

To investigate the interaction between tramadol and representative tyrosine kinase inhibitors, and to study the inhibition mode of drug-interaction.

Methods

Liver microsomal catalyzing assay was developed. Sprague-Dawley rats were administrated tramadol with or without selected tyrosine kinase inhibitors. Samples were prepared and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for analysis. Besides, liver, kidney, and small intestine were collected and morphology was examined by hematoxyline-eosin (H&E) staining. Meanwhile, liver microsomes were prepared and carbon monoxide differential ultraviolet radiation (UV) spectrophotometric quantification was performed.

Results

Among the screened inhibitors, crizotinib takes the highest potency in suppressing the metabolism of tramadol in rat/human liver microsome, following non-competitive inhibitory mechanism. In vivo, when crizotinib was co-administered, the AUC value of tramadol increased compared with the control group. Besides, no obvious pathological changes were observed, including cell morphology, size, arrangement, nuclear morphology with the levels of alanine transaminase (ALT) and aspartate transaminase (AST) increased after multiple administration of crizotinib. Meanwhile, the activities of CYP2D1 and CYP3A2 as well as the total cytochrome P450 abundance were found to be decreased in rat liver of combinational group.

Conclusions

Crizotinib can inhibit the metabolism of tramadol. Therefore, this recipe should be vigilant to prevent adverse reactions.

Characterizing Opioid Prescribing Trends of Medical Oncologists From 2013 to 2019: Analysis From the Centers for Medicare & Medicaid Services Medicare Part D Prescribers Database

PURPOSE

Opioid prescribing trends in medical oncology are poorly defined past 2017, the year after the CDC updated opioid prescription guidelines in noncancer settings. We aim to characterize pain management by medical oncologists by analyzing opioid and gabapentin prescribing trends from 2013 to 2019, identify physician-related factors associated with prescribing patterns, and assess whether CDC guidelines for nononcologic settings changed prescribing patterns.

METHODS

The Centers for Medicare & Medicaid Services (CMS) Medicare Part D Prescribers-by Provider, CMS Medicare Part D Prescribers-by Provider and Drug, and CMS Medicare Physician National Downloadable files from 2013 to 2019 were merged by National Provider Identification. The database included physicians' sex, years of practice, regions, and practice settings. Multivariable binary logistic regression identified significant predictors of total opioid, long-acting opioid, and gabapentin prescriptions.

RESULTS

Binary logistic regression modeling revealed no significant difference in mean daily total opioid prescriptions from 2013 to 2017. Daily opioid prescriptions by medical oncologists decreased significantly after 2017 (P < .001). Increased opioid prescribing was associated with physician male sex (P < .001), practicing over 10 years (P < .001), and practice in nonurban areas (P < .001). Opioid prescribing was greatest in the South and Midwest United States (P < .001). The same patterns were observed with total long-acting opioid prescriptions, whereas gabapentin prescribing increased from 2013 to 2019 (P < .001).

CONCLUSION

Opioid prescriptions by medical oncologists decreased significantly from 2013 to 2019, but this decrease was most substantial from 2017 to 2019. These results may imply that the 2016 CDC guidelines influenced medical oncologists, particularly more junior physicians in urban settings, to manage chronic cancer pain with alternative therapies.

Toward a Psychological Model of Chemical Coping with Opioids in Cancer Care

LEARNING OBJECTIVES AFTER PARTICIPATING IN THIS CME ACTIVITY, THE PSYCHIATRIST SHOULD BE BETTER ABLE TO

• Outline the risk factors involved with opioid accessibility in patients receiving treatment for cancer.• Identify factors to address in order to mitigate risk for opioid misuse during cancer care.

ABSTRACT

Most patients with advanced cancer receive treatment for related pain. Opioid accessibility, however, is a risk factor for misuse, which can present care challenges and quality-of-life concerns. There is a lack of consistent universal screening prior to initiation of opioid prescribing. One crucial issue in treating this population is adequately identifying and mitigating risk factors driving opioid misuse. Drawing on theory and research from addiction science, psychology, palliative care, and oncology, the presented conceptual framework suggests that risk factors for opioid misuse during cancer care can be stratified into historical, current, malleable, and unmalleable factors. The framework identifies necessary factors to address in order to mitigate risk for opioid misuse during cancer care, and offers key directions for future research.

Dexamethasone Coanalgesic Administration in Steroid Naïve and Steroid Non-Naïve Patients for the Prevention of Pain Flares after Palliative Radiotherapy for Bone Metastases

Objective

Dexamethasone could be an effective prophylactic agent for the prevention of pain flares after palliative radiotherapy (RT) for uncomplicated bone metastases. To date, there are no data on its prophylactic coanalgesic (opioid-sparing) effect after RT in patients with complicated bone metastases compared to uncomplicated ones, which is the aim of our study.

Methods

Twenty-nine American Society of Anaesthesiologists (ASA) III-IV patients, aged ≥18, treated with single-fraction 8 Gy/1 or multi-fraction 20 Gy/5 RT for painful uncomplicated bone metastases (steroid naïve patients, n = 14) or complicated ones (steroid non-naïve patients, n = 15), were examined retrospectively. All patients received parenteral dexamethasone (4 mg or 8 mg daily, 1 hour before RT, followed by the same dose for the next 4 days) along with their background and breakthrough pain opioid intake (morphine equivalents) during their 5-day in-hospital stay. Pain severity (numeric rating scale) and analgesic consumption were recorded at admission, daily during the hospital stay, and for 10 days following treatment. Binary logistic regression was used to determine predictive factors for pain flare occurrence.

Results

A higher ASA score is the only determinant positively influencing opioid consumption (P = 0.018) and pain flare as well (OR = 15.00; 95% CI: 2, 24-100, 48; P = 0.005). Lower dose 4 mg dexamethasone was revealed as a moderate analgesic agent in steroid naïve patients with no side effects, whereas in steroid non-naïve patients the predominantly higher dose 8 mg dexamethasone had minimal impact on pain flares prevention at the expense of more pronounced immunosuppression (P = 0.039).

Conclusions

Irrespective of the supporting evidence of dexamethasone potential for prevention of RT-induced pain flare, our data failed to reveal its efficacy in the real practice world (a case mix of uncomplicated and complicated bone metastases). Further dose-effect bigger studies are needed, identifying optimal doses of dexamethasone intake and its optimal duration in high-risk patients.

A Survey of Knowledge and Barriers of Healthcare Professionals toward Opioid Analgesics in Cancer Pain Management

PURPOSE

Pain is among the most frequent and troubling symptoms in cancer patients. Despite the availability of updated treatment guidelines and effective pharmacological therapies, undertreatment of cancer pain remains a global problem. Opioids are the mainstay analgesics to treat moderate-to-severe cancer pain. The goal of this study was to assess the knowledge and barriers towards opioid analgesics for cancer pain management among healthcare professionals in Oncology Units in Jordan.

METHODS

A structured questionnaire was administered to healthcare professionals (consultant doctors, resident doctors, pharmacists, and nurses) at three Oncology Units in a cross-sectional study design.

RESULTS

A total of 201 healthcare professionals completed the questionnaire. The average age was 34.8 ± 8.1 years (range 23-58) and 49.3% of respondents were nurses. The mean score for the knowledge of opioids was 12.5 ± 3.2 out of 24 points (range 2-20). An acceptable level of knowledge was observed in 50.7% of participants, while 49.3% had poor knowledge. Knowledge items mostly answered incorrectly were related to opioid administration, pharmacology, dosing, adverse events, rotation, and toxicity. Knowledge scores were significantly higher for consultant doctors compared to pharmacists and nurses (p=0.016 and p < 0.001, respectively). Healthcare professionals who handled opioid analgesics had significantly higher mean knowledge scores than those who did not (p=0.012). Linear regression analysis revealed that being a consultant physician has an independent, statistically significant association with higher knowledge scores. Among perceived barriers to using opioids, fear of addiction by patients was the most frequently reported barrier by respondents (79.6%). Other highly recognized barriers were fear of adverse effects by patients (67.2%) and lack of training programs on opioid dosing and monitoring (63.7%).

CONCLUSIONS

This study revealed major gaps in the knowledge of opioids and pain management among healthcare professionals. There is an urgent need for developing innovative interventions to improve the knowledge of opioid analgesics and the understanding of pain management guidelines among healthcare professionals in Jordan.

Opioid Analgesia and Opioid-Induced Adverse Effects: A Review

Opioids are widely used as therapeutic agents against moderate to severe acute and chronic pain. Still, these classes of analgesic drugs have many potential limitations as they induce analgesic tolerance, addiction and numerous behavioural adverse effects that often result in patient non-compliance. As opium and opioids have been traditionally used as painkillers, the exact mechanisms of their adverse reactions over repeated use are multifactorial and not fully understood. Older adults suffer from cancer and non-cancer chronic pain more than younger adults, due to the physiological changes related to ageing and their reduced metabolic capabilities and thus show an increased number of adverse reactions to opioid drugs. All clinically used opioids are μ-opioid receptor agonists, and the major adverse effects are directly or potentially connected to this receptor. Multifunctional opioid ligands or peripherally restricted opioids may elicit fewer adverse effects, as shown in preclinical studies, but these results need reproducibility from further extensive clinical trials. The current review aims to overview various mechanisms involved in the adverse effects induced by opioids, to provide a better understanding of the underlying pathophysiology and, ultimately, to help develop an effective therapeutic strategy to better manage pain.

Opioid therapy vs. multimodal analgesia in head and neck Cancer (OPTIMAL-HN): study protocol for a randomized clinical trial

Background

Radiation-induced mucositis (RIM) pain confers substantial morbidity for head and neck cancer (HNC) patients undergoing radiotherapy alone (RT) or chemoradiotherapy (CRT), often reducing treatment compliance. However, no standard currently exists for the treatment of RIM, and high dose opioid therapy, with its associated side effects and increased risk for chronic opioid use, remains the cornerstone of HNC pain management. The goal of this randomized clinical trial is to compare multimodal analgesia using analgesic medications with different mechanisms of action, to the institutional standard of opioid analgesia alone, in order to ascertain the optimal analgesic regimen for the management of RIM pain in HNC patients.

Methods

In this open-label, single-institution, non-inferiority, randomized clinical trial, sixty-two patients with mucosal head and neck malignancies treated with curative-intent radiation will be randomized in a 1:1 ratio, stratified by RT or CRT, between Arm 1: opioid analgesia alone as per the institutional standard, or Arm 2: multimodal analgesia using Pregabalin, Acetaminophen, and Naproxen, in addition to opioids, if required. The primary endpoint is the average 11-Numeric Rating Scale (11-NRS) score for pain during the last week of radiation treatment. Secondary endpoints include: average weekly opioid use, duration of opioid requirement, average daily 11-NRS score for pain, average weekly opioids dispensed, quality of life, hospitalizations for analgesic medication-induced complications, time to feeding tube insertion, weight loss, toxicity, treatment interruptions, and death within 3 months of completing RT treatment. Patients are eligible once analgesia is required for moderate 4/10 pain.

Discussion

This study will assess the efficacy and safety of multimodal analgesia and its impact on opioid requirements, clinical outcomes, and quality of life, as a potential new standard treatment for RIM pain in HNC patients undergoing definitive RT or CRT.

Trial registration

ClinicalTrials.gov Identifier: NCT04221165. Date of registration: January 9, 2020. Appendix 2 reports the World Health Organization trial registration dataset.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12904-021-00735-0.

The pattern of change in opioid and adjuvant prescriptions for cancer pain before and after referral to a comprehensive program in the Palliative Care Center in Kuwait

Background

Cancer-related pain is a complicated symptom that often coincides with fatigue, depression, and anxiety. Although many safe treatments are available, inadequate control of Cancer-related pain continues to lead to suffering in cancer patients. This study’s aim is to describe pain control, and the pattern of change in opioid and adjuvant medication prescriptions, before and after referral to the Palliative Care Center.

Methods

We conducted a prospective cohort study in adult cancer patients the Palliative Care Center between January 1, 2016 and December 30, 2017. We measured pain intensity and other associated symptoms via the Revised Edmonton Symptom Assessment System (ESAS-r) and documented detailed analgesics and adjuvant medication history before starting any palliative care and on days 0, 3, 6, and 14.

Results

The analysis included 240 patients whose cancer-related pain, anxiety, and depression scores meaningfully improved by day 6. The changes in the median (interquartile ranges) of Cancer-related pain, anxiety, and depression scores from day 0 to day 6 were: 6 (4–8) to 3 (1–4); 6 (4–9) to 2 (1–4); and 3 (2–6) to 2 (1–4), respectively, with p < 0.001 for all. Morphine was the most common opioid administered; the percentage using it increased from 20.4% (n = 49) before referral to 49.6% (n = 119) on day 6 (p < 0.001). The median morphine equivalent daily dose decreased from a median (interquartile ranges) of 60(31–93) mg/day before referral to 34(22–66) mg/day on day 6 (p < 0.001). There was also a statistically significant increase in the percentage of patients taking adjuvant medications, from 38.8% before referral to 84.2% on day 6 (p < 0.001). Comparing D0 to D6, the number of patients using Gabapentinoids significantly increased from 57(23.75%) to 79(32.9%) (p < 0.001), amitriptyline dramatically increased from 14 (5.8%) to 44 (18.3%) (p < 0.001), and other antidepressant drugs increased from 15 (6.2%) to 34 (14.1%) (p < 0.001).

Conclusion

After referral to the Palliative Care Center, patients’ pain and other symptoms scores decreased significantly, even with lower median morphine equivalent daily doses, arguably through more appropriately directed opioid use. This is evidence for the effectiveness of the comprehensive program at the Palliative Care Center in Kuwait.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12904-021-00717-2.

Association Between Dual Trajectories of Opioid and Gabapentinoid Use and Healthcare Expenditures Among US Medicare Beneficiaries

OBJECTIVES

Little is known about relationships between opioid- and gabapentinoid-use patterns and healthcare expenditures that may be affected by pain management and risk of adverse outcomes. This study examined the association between patients' opioid and gabapentinoid prescription filling/refilling trajectories and direct medical expenditures in US Medicare.

METHODS

This cross-sectional study included a 5% national sample (2011-2016) of fee-for-service beneficiaries with fibromyalgia, low back pain, neuropathy, or osteoarthritis newly initiating opioids or gabapentinoids. Using group-based multitrajectory modeling, this study identified patients' distinct opioid and gabapentinoid (OPI-GABA) dose and duration patterns, based on standardized daily doses, within a year of initiating opioids and/or gabapentinoids. Concurrent direct medical expenditures within the same year were estimated using inverse probability of treatment weighted multivariable generalized linear regression, adjusting for sociodemographic and health status factors.

RESULTS

Among 67 827 eligible beneficiaries (mean age ± SD = 63.6 ± 14.8 years, female = 65.8%, white = 77.1%), 11 distinct trajectories were identified (3 opioid-only, 4 gabapentinoid-only, and 4 concurrent OPI-GABA trajectories). Compared with opioid-only early discontinuers ($13 830, 95% confidence interval = $13 643-14 019), gabapentinoid-only early discontinuers and consistent low-dose and moderate-dose gabapentinoid-only users were associated with 11% to 23% lower health expenditures (adjusted mean expenditure = $10 607-$11 713). Consistent low-dose opioid-only users, consistent high-dose opioid-only users, consistent low-dose OPI-GABA users, consistent low-dose opioid and high-dose gabapentinoid users, and consistent high-dose opioid and moderate-dose gabapentinoid users were associated with 14% to 106% higher healthcare expenditures (adjusted mean expenditure = $15 721-$28 464).

CONCLUSIONS

Dose and duration patterns of concurrent OPI-GABA varied substantially among fee-for-service Medicare beneficiaries. Consistent opioid-only users and all concurrent OPI-GABA users were associated with higher healthcare expenditures compared to opioid-only discontinuers.

Clinical Efficacy of Controlled-Release Morphine Tablets Combined with Celecoxib in Pain Management and the Effects on WNK1 Expression

OBJECTIVES

This study was designed to evaluate the clinical efficacy of controlled-release morphine tablets combined with celecoxib in relieving osteocarcinoma-related pain and the effects of the combination on WNK1 expression.

METHODS

A total of 110 patients with osteocarcinoma-related pain were selected and divided into two groups based on the treatment administered, including the control group (treated with controlled-release morphine tablets alone) and the study group (treated with a combination of controlled-release morphine tablets and celecoxib). We compared the treatment efficacy, pain level (visual analog scale (VAS)), time of onset of breakthrough pain (BTP), dose of morphine, incidence of adverse events, quality of life (QOL) score, and With-no-lysine 1 (WNK1) expression in the peripheral blood (PB) as determined with qRT-PCR before and after treatment, of the two groups.

RESULTS

The total effective rate of the study group was higher than that of the control group, while the VAS score, time of onset of BTP, dose of morphine, incidence of adverse events, QOL score, and relative WNK1 expression in the PB were lower than those of the control group (p<0.05).

CONCLUSION

Combination treatment with controlled-release morphine tablets and celecoxib can be extensively used in the clinical setting because it effectively improves the symptoms, QOL score, and adverse effects in patients with osteocarcinoma-related pain.

Use of gabapentinoid medications among US adults with cancer, 2005-2015

BACKGROUND

Gabapentinoid use for long-term cancer pain control may be problematic, given unclear mechanisms of action and increased concerns for physical dependence. The purpose of this report is to examine trends of gabapentinoid use among US adults with cancer from 2005 to 2015.

METHODS

We conducted a serial, cross-sectional study using data from the Medical Expenditure Panel Survey (MEPS). We performed multiple logistic regression to examine the annual percentages of gabapentinoid users, which were adjusted for age, sex, and US region of residence. The amount of gabapentinoid prescriptions filled in 2015 was also estimated.

RESULTS

The adjusted percentage of gabapentinoid users in 2015 was 5.60% (3.79%, 7.41%), 2.39 times greater than the percentage in 2005 (p < .001). By 2015, the number of gabapentinoid prescriptions had grown to approximately 3.52 million (2.40 million, 4.65 million).

CONCLUSION

We observed greater than a twofold increase in the trend of gabapentinoid medication use among US adults with cancer. Investigations on the long-term efficacy of gabapentinoids for complex pain syndromes, and mitigation of risks, is essential to guide informed clinical management and keep patients safe.

Patterns and predictors of outpatient opioid use after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy

Background: Long-term opioid use is a well-known complication after surgery. In this retrospective study of adults who had undergone cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), we sought to determine the rates and factors associated with outpatient opioid use within the sixth and twelfth postoperative months. Methods: Records of 288 opioid-naïve patients were included. Logistic regression models were used to determine factors prognostic of outpatient opioid use. Results: The median patient age was 54 years, and 63% were female. Rates of outpatient opioid use within the sixth and twelfth postoperative months were 21 and 13%, respectively. In the multivariate analysis, every doubling in the amount of in-hospital postoperative opioid consumption was associated with a 44% increase in odds of opioid use within the sixth postoperative month (OR 1.44, 95% CI 1.11-1.87, p = .006) and a 70% increase within the twelfth postoperative month (OR 1.70, 95% CI 1.70-2.37, p = .001). Other factors associated with opioid use within the sixth postoperative month included physical status (OR 5.26, 95% CI 1.08-25.55, p = .039) and recent additional surgery (OR 23.02, 95% CI 2.03-261.30, p = .011). Age (OR 4.39, 95% CI 1.77-10.89, p = .001) and tumor grade (OR 3.31, 95% CI 1.31-8.41, p = .012) were associated with opioid use within the twelfth postoperative month. Conclusion: In this study, the amount of in-hospital postoperative opioid consumption was an important contributory factor to outpatient opioid use in the sixth and twelfth postoperative months. Synopsis In this study of adults who had undergone CRS-HIPEC, higher postoperative opioid consumption during hospitalization was associated with higher odds of opioid use within the sixth and twelfth postoperative months.

Adjuvant Use and the Intensification of Pharmacologic Management for Pain in Nursing Home Residents with Cancer: Data from a US National Database

OBJECTIVES

Our objective was to describe the prevalence of adjuvants to opioid therapy and changes in these agents for pharmacologic management in nursing home residents with cancer.

METHODS

We included Medicare beneficiaries with cancer and documented opioid use at nursing home admission in 2011-2013 (N = 3268). The Minimum Data Set 3.0 provided information on sociodemographic and clinical characteristics. Part D claims provided information on opioid and adjuvant use during the 7 days after admission and 90 days later. Proportions of changes in these agents were estimated. Separate logistic models estimated associations between resident characteristics and (1) use of adjuvants at admission and (2) intensification of pharmacologic management at 90 days.

RESULTS

Nearly 20% of patients received adjuvants to opioids at admission, with gabapentin the most common adjuvant (34.4%). After 90 days, approximately 25% had maintained or intensified pharmacologic management. While advanced age (≥ 85 vs. 65-74 years, adjusted odds ratio [aOR] 0.80; 95% confidence interval [CI] 0.63-1.02) and comorbidities, including dementia (aOR 0.65; 95% CI 0.53-0.82) and depression (aOR 1.55; 95% CI 1.29-1.87), were associated with adjuvant use at admission, worse cognitive impairment (severe vs. no/mild, aOR 0.80; 95% CI 0.64-0.99) and presence of more severe pain (moderate/severe vs. no pain, aOR 1.60; 95% CI 1.26-2.03) were associated with intensification of drug regimen.

CONCLUSION

Given aging-related changes and the presence of comorbid conditions in older adults, safety studies of these practices are warranted.

A Retrospective Analysis of Pain Burden in Hospitalized Young Adult Cancer Patients Compared with Their Older Adult Counterpart

CONTEXT

Research shows an increased symptom burden in young adult (YA) cancer patients compared with their older adult counterpart.

OBJECTIVES

The purpose of this study was to identify differences in clinical characteristics and related outcomes between YA and older adult cancer patients admitted for cancer-related pain.

MATERIALS AND METHODS

We retrospectively identified 190 hospitalized patients in a single academic center with admissions for cancer-related pain. Patients were grouped into either "young adult" (18-39) or "older adult" (>40) cohorts. We compared differences in patient characteristics and pain regimens.

RESULTS

Median oral morphine equivalent per 24 hours was higher in the YA group (194 mg vs. 70 mg, p = 0.010). Younger patients received patient-controlled analgesia (PCA) more frequently (p = 0.023). The number of palliative care consults and adjuvants prescribed did not differ between groups (p > 0.05), although YAs more frequently had an inpatient pain anesthesia consult (p = 0.047).

CONCLUSION

Findings show increased opioid requirements and PCA use in YAs being treated for malignancy compared with their older adult counterpart.

Ten Tips Palliative Care Pharmacists Want the Palliative Care Team to Know When Caring for Patients

As palliative care (PC) moves upstream in the course of serious illness and the development of drugs and their indications rapidly expand, PC providers must understand common drug indications and adverse effects to ensure safe and effective prescribing. Pharmacists, experts in the nuances of medication management, are valuable resources and colleagues for PC providers. This article will offer PC providers 10 useful clinical pharmacy tips that PC pharmacists think all PC providers should know for safe and effective symptom management. Close collaboration with or addition of a trained pharmacist to your PC team can improve clinical care for all PC patients.

Sex differences in innate immunity and its impact on opioid pharmacology

Morphine has been and continues to be one of the most potent and widely used drugs for the treatment of pain. Clinical and animal models investigating sex differences in pain and analgesia demonstrate that morphine is a more potent analgesic in males than in females. In addition to binding to the neuronal μ-opioid receptor, morphine binds to the innate immune receptor toll-like receptor 4 (TLR4), located on glial cells. Activation of glial TLR4 initiates a neuroinflammatory response that directly opposes morphine analgesia. Females of many species have a more active immune system than males; however, few studies have investigated glial cells as a potential mechanism driving sexually dimorphic responses to morphine. This Mini-Review illustrates the involvement of glial cells in key processes underlying observed sex differences in morphine analgesia and suggests that targeting glia may improve current treatment strategies for pain. © 2016 Wiley Periodicals, Inc.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

The research on long-term clinical effects and patients' satisfaction of gabapentin combined with oxycontin in treatment of severe cancer pain

Gabapentin has been used as an adjuvant for treatment of cancer pain. Previous studies showed that opioids combined with gabapentin for management of cancer pain reduced the dosage of opioids.The objective of this study was to explore the clinical effect and patients' satisfaction of oxycontin combined with gabapentin in treatment of severe cancer pain. After titration of morphine, 60 severe cancer patients with visual analog score (VAS) more than 7 were randomly divided into trial group (n = 30) and control group (n = 30). The control group was administered oxycontin and placebo, and the trial group was given oxycontin and gabapentin. VAS score was recorded pre- and post-treatment; while daily dose of oxycontin, daily cost of pain relief and life quality score were observed 1 week, 1 month, 2 months, 3 months, and 6 months post-treatment. We found that daily dose of oxycontin 1 month post was comparable between the 2 groups (P > 0.05). Three months post, compared with control group (58.0 ± 15.2 mg), average daily dose of oxycontin was significant lower in trial group (33.4 ± 11 mg) (P < 0.001). Average daily cost of pain relief in trail group (34.5 ± 10.2 RMB) was less than the control group (52.4 ± 13.7 RMB) (P < 0.001). Life quality score increased in all of the patients in both group post-treatment (P < 0.05); while life quality score in trail group was greater than in control group 3 months (46.8 ± 4.5 vs 43.5 ± 4.6, P = 0.007) and 6 months (46.5 ± 4.8 vs 41.4 ± 4.3, P < 0.001) post-treatment. The incidence of drowsiness and dizziness was comparable between the 2 groups (P > 0.05), while the incidence of nausea and vomiting (P = 0.038), and constipation (P < 0.001) was higher in the control group.We concluded that oxycontin combined with gabapentin used in severe cancer pain management can control pain effectively, decreased the dose of oxycontin and the cost of cancer pain relief, and reduced the incidence of nausea and vomiting, and constipation, increased the life quality.

Role of fosaprepitant, a neurokinin Type 1 receptor antagonist, in morphine-induced antinociception in rats

OBJECTIVES

Opioids such as morphine form the cornerstone in the treatment of moderate to severe pain. However, opioids also produce serious side effects such as tolerance. Fosaprepitant is a substance P (SP) receptor antagonist, which is used for treating chemotherapy-induced nausea and vomiting. SP is an important neuropeptide mediating transmission of pain at the spinal level. Thus, it was hypothesized that combining morphine with fosaprepitant would increase the antinociceptive effect of morphine. The objectives were to evaluate the effect of fosaprepitant on morphine-induced antinociception in rats and to investigate its mechanism of action.

METHODS

Sprague-Dawley rats were injected with morphine (10 mg/kg twice daily) and/or fosaprepitant (30 mg/kg once daily) for 7 days. Pain threshold was assessed by the hot plate test. Expression of SP and calcitonin gene-related peptide (CGRP) in the spinal cords of these rats was evaluated by immunohistochemistry.

RESULTS

Morphine administration resulted in an antinociceptive effect compared to the control group (day 1 and to a lesser extent on day 4). The decreased antinociception despite continued morphine treatment indicated development of tolerance. Co-administration of fosaprepitant attenuated tolerance to morphine (days 1 and 3) and increased the antinociceptive effect compared to control group (days 1-4). Expression of SP was increased in the morphine + fosaprepitant group.

CONCLUSIONS

The results show that fosaprepitant attenuates the development of tolerance to morphine and thereby, increases the antinociceptive effect. This is likely linked to decreased release of SP from presynaptic terminals.

The McGill University Health Centre Cancer Pain Clinic: A Retrospective Analysis of an Interdisciplinary Approach to Cancer Pain Management

Context. The McGill University Health Center (MUHC) Cancer Pain Clinic offers an interdisciplinary approach to cancer pain management for patients. The core team includes a nurse clinician specialist in oncology and palliative care, a palliativist, an anaesthetist, and a radiation oncologist. This tailored approach includes pharmacological and nonpharmacological therapies offered concurrently in an interdisciplinary fashion. Objectives. Description of the interdisciplinary MUHC cancer pain approach and analysis of treatments and outcomes. Methods. A retrospective analysis of new outpatients completing two subsequent visits (baseline and follow-ups: FU₁, FU₂) was conducted. Variables included (a) symptom severity measured by the Edmonton Symptom Assessment Scale, (b) pain and disability measured with the Brief Pain Inventory, and (c) analgesic plan implementation including pharmacological and nonpharmacological therapies. Results. 71 charts were reviewed. Significant pain relief was achieved consistently at FU₁ and FU₂. The average pain severity decreased by 2 points between initial assessment and FU₂. More than half (53%) of patients responded with a pain reduction greater than 30%. Severity of other symptoms (i.e., fatigue, nausea, depression, and anxiety) and disability also decreased significantly at FU₂. The total consumption of opioids remained stable; however, the consumption of short acting preparations decreased by 52% whereas the prescription of nonopioid agents increased. Beyond drug management, 60% of patients received other analgesic therapies, being the most common interventional pain procedures and psychosocial approaches. Conclusion. The MUHC interdisciplinary approach to cancer pain management provides meaningful relief of pain and other cancer-related symptoms and decreases patients' disability.