No pain, no strain: Targin® mitigates pain and constipation following spinal cord injury.

BACKGROUND: Opioids effectively reduce chronic pain, but present significant side effects including opioid-induced constipation. Oxycodone/naloxone decreases pain and constipation in cancer patients, however its effect on spinal cord injury population remains understudied. METHODS: We assessed whether oxycodone/naloxone reduces pain, constipation, and severity of autonomic dysreflexia in an individual with spinal cord injury. A 55-year-old male with C5 lesion presented with chief complaint of chronic pain received 5/2.5 mg and 20/10 mg oxycodone/naloxone for 6 and 2 weeks, respectively. RESULTS: Oxycodone/naloxone improved pain, bowel function, and autonomic dysreflexia severity. INTERPRETATION: Oxycodone/naloxone was effective in managing chronic pain and constipation in the studied case.

Oxycodone/naloxone versus tapentadol in real-world chronic non-cancer pain management: an observational and pharmacogenetic study.

Tapentadol (TAP) and oxycodone/naloxone (OXN) potentially offer an improved opioid tolerability. However, real-world studies in chronic non-cancer pain (CNCP) remain scarce. Our aim was to compare effectiveness and security in daily pain practice, together with the influence of pharmacogenetic markers. An observational study was developed with ambulatory test cases under TAP (n = 194) or OXN (n = 175) prescription with controls (prescribed with other opioids (control), n = 216) CNCP patients. Pain intensity and relief, quality of life, morphine equivalent daily doses (MEDD), concomitant analgesic drugs, adverse events (AEs), hospital frequentation and genetic variants of OPRM1 (rs1799971, A118G) and COMT (rs4680, G472A) genes, were analysed. Test CNCP cases evidenced a significantly higher pain relief predictable due to pain intensity and quality of life (R2 = 0.3), in front of controls. Here, OXN achieved the greatest pain relief under a 28% higher MEDD, 8-13% higher use of pregabalin and duloxetine, and 23% more prescription change due to pain, compared to TAP. Whilst, TAP yielded a better tolerability due the lower number of 4 [0-6] AEs/patient, in front of OXN. Furthermore, OXN COMT-AA homozygotes evidenced higher rates of erythema and vomiting, especially in females. CNCP real-world patients achieved higher pain relief than other traditional opioids with a better tolerability for TAP. Further research is necessary to clarify the potential influence of COMT and sex on OXN side-effects.

The role of spinal inhibitory neuroreceptors in the antihyperalgesic effect of warm water immersion therapy.

OBJECTIVE: Warm water immersion therapy (WWIT) has been widely used in the treatment of various clinical conditions, with analgesic and anti-inflammatory effects. However, its mechanism of action has not been fully investigated. The present study analyzed the role of spinal inhibitory neuroreceptors in the antihyperalgesic effect of WWIT in an experimental model of inflammatory pain. METHODS: Mice were injected with complete Freund's adjuvant (CFA; intraplantar [i.pl.]). Paw withdrawal frequency to mechanical stimuli (von Frey test) was used to determine: (1) the effect of intrathecal (i.t.) preadministration of naloxone (a non-selective opioid receptor antagonist; 5 µg/5 µl), (2); AM281 (a selective cannabinoid receptor type 1 [CB1] antagonist; 2 µg/5 µl), (3); and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX; a selective adenosine A1 receptor antagonist; 10 nmol/5 µl), on the antihyperalgesic (pain-relieving) effect of WWIT against CFA-induced hyperalgesia. RESULTS: Intrathecal naloxone, AM281, and DPCPX significantly prevented the antihyperalgesic effect of WWIT. This study suggests the involvement of spinal (central) receptors in the antihyperalgesic effect of WWIT in a model of inflammatory pain. CONCLUSIONS: Taken together, these results suggest that opioid, CB1, and A1 spinal receptors might contribute to the pain-relieving effect of WWIT.

Implication of Opioid Receptors in the Antihypertensive Effect of a Novel Chicken Foot-Derived Peptide.

The peptide AVFQHNCQE demonstrated to produce nitric oxide-mediated antihypertensive effect. This study investigates the bioavailability and the opioid-like activity of this peptide after its oral administration. For this purpose, in silico and in vitro approaches were used to study the peptide susceptibility to GI digestion. In addition, AVFQHNCQE absorption was studied both in vitro by using Caco-2 cell monolayers and in vivo evaluating peptide presence in plasma from Wistar rats by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Both in vivo and in vitro experiments demonstrated that peptide AVFQHNCQE was not absorbed. Thus, the potential involvement of opioid receptors in the BP-lowering effect of AVFQHNCQE was studied in the presence of opioid receptors-antagonist Naloxone. No changes in blood pressure were recorded in rats administered Naloxone, demonstrating that AVFQHNCQE antihypertensive effect is mediated through its interaction with opioid receptors. AVFQHNCQE opioid-like activity would clarify the antihypertensive properties of AVFQHNCQE despite its lack of absorption.

Screening for Unhealthy Drug Use: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Illicit drug use is among the most common causes of preventable morbidity and mortality in the US. Objective: To systematically review the literature on screening and interventions for drug use to inform the US Preventive Services Task Force. Data Sources: MEDLINE, PubMed, PsycINFO, Embase, and Cochrane Central Register of Controlled Trials through September 18, 2018; literature surveillance through September 21, 2019. Study Selection: Test accuracy studies to detect drug misuse and randomized clinical trials of screening and interventions to reduce drug use. Data Extraction and Synthesis: Critical appraisal and data abstraction by 2 reviewers and random-effects meta-analyses. Main Outcomes and Measures: Sensitivity, specificity, drug use and other health, social, and legal outcomes. Results: Ninety-nine studies (N = 84 206) were included. Twenty-eight studies (n = 65 720) addressed drug screening accuracy. Among adults, sensitivity and specificity of screening tools for detecting unhealthy drug use ranged from 0.71 to 0.94 and 0.87 to 0.97, respectively. Interventions to reduce drug use were evaluated in 52 trials (n = 15 659) of psychosocial interventions, 7 trials (n = 1109) of opioid agonist therapy, and 13 trials (n = 1718) of naltrexone. Psychosocial interventions were associated with increased likelihood of drug use abstinence (15 trials, n = 3636; relative risk [RR], 1.60 [95% CI, 1.24 to 2.13]; absolute risk difference [ARD], 9% [95% CI, 5% to 15%]) and reduced number of drug use days (19 trials, n = 5085; mean difference, -0.49 day in the last 7 days [95% CI, -0.85 to -0.13]) vs no psychosocial intervention at 3- to 4-month follow-up. In treatment-seeking populations, opioid agonist therapy and naltrexone were associated with decreased risk of drug use relapse (4 trials, n = 567; RR, 0.75 [95% CI, 0.59 to 0.82]; ARD, -35% [95% CI, -67% to -3%] and 12 trials, n = 1599; RR, 0.73 [95% CI, 0.62 to 0.85]; ARD, -18% [95% CI, -26% to -10%], respectively) vs placebo or no medication. While evidence on harms was limited, it indicated no increased risk of serious adverse events. Conclusions and Relevance: Several screening instruments with acceptable sensitivity and specificity are available to screen for drug use, although there is no direct evidence on the benefits or harms of screening. Pharmacotherapy and psychosocial interventions are effective at improving drug use outcomes, but evidence of effectiveness remains primarily derived from trials conducted in treatment-seeking populations.

Oleoyl alanine (HU595): a stable monomethylated oleoyl glycine interferes with acute naloxone precipitated morphine withdrawal in male rats.

RATIONALE: Oleoyl glycine, a little studied fatty acid amide similar in structure to anandamide, interferes with nicotine addiction in mice and acute naloxone-precipitated morphine withdrawal (MWD) in rats. Because endogenous oleoyl glycine is subject to rapid enzymatic deactivation, we evaluated the potential of more stable analogs to interfere with opiate withdrawal. OBJECTIVES: The potential of monomethylated oleoyl glycine (oleoyl alanine, HU595) to interfere with somatic and aversive effects of acute naloxone-precipitated MWD, its duration, and mechanism of action was assessed in male Sprague Dawley rats. The potential of dimethylated oleoyl glycine (HU596) to interfere with the aversive effects of naloxone-precipitated MWD was also investigated. RESULTS: Oleoyl alanine (HU595) interfered with somatic and aversive effects produced by naloxone-precipitated MWD at equivalent doses (1 and 5 mg/kg, i.p.) as we have reported for oleoyl glycine; however, oleoyl alanine produced a longer lasting (60 min) interference, yet did not produce rewarding or aversive effects on its own and did not modify locomotor activity. HU596 was not effective. The interference with aversive effects of naloxone-precipitated MWD by oleoyl alanine was prevented by both a PPARα antagonist and a CB1 receptor antagonist. Accordingly, the compound was found to inhibit FAAH and activate PPARα in vitro. Finally, oleoyl alanine also reduced acute naloxone-precipitated MWD anhedonia, as measured by decreased saccharin preference. CONCLUSIONS: Oleoyl alanine (also an endogenous fatty acid) may be a more stable and effective treatment for opiate withdrawal than oleoyl glycine.

Myasthenic crisis and late deep vein thrombosis following thymectomy in a patient with myasthenia gravis: A case report.

INTRODUCTION: Surgical stress and pain are potential provoking factors for postoperative myasthenic crisis (POMC). We report the occurrence of early POMC and late deep vein thrombosis (DVT) in a man with myasthenia gravis (MG) undergoing thymectomy, addressing possible link between reversal of opioid overdose with naloxone and the triggering of POMC. PATIENT CONCERNS: A 71-year-old man with impaired renal function (ie, estimated glomerular filtration rate [egfr]: 49.1 mL/min/1.73 m) with diagnosis of MG made 2 months ago was scheduled for thymectomy. After uncomplicated surgery, he experienced opioid overdose that was treated with naloxone. Hyperlactatemia then developed with a concomitant episode of hypertension. Three hours after reversal, he suffered from myasthenic crisis presenting with respiratory failure and difficult weaning from mechanical ventilation. DIAGNOSIS: Stress-induced hyperlactatemia and subsequent myasthenic crisis INTERVENTIONS:: Pyridostigmine and immunosuppressive therapy with prednisolone were initiated. Hyperlactatemia subsided on postoperative day (POD) 5. Tracheal extubation was performed successfully on POD 6. OUTCOMES: During the course of hospitalization, his eGFR (ie, 88.9 mL/min/1.73 m) was found to improve postoperatively. After discharge from hospital, he developed DVT in the left femoral and popliteal veins on POD 24 when he was readmitted for immediate treatment with low-molecular-weight heparin. He was discharged without sequelae on POD 31. There was no recurrence of myasthenic crisis or DVT at 3-month follow-up. CONCLUSIONS: Following naloxone administration, hyperlactatemia may be an indicator of pain-related stress response, which is a potential provoking factor for myasthenic crisis. Additionally, patients with MG may have an increased risk of DVT possibly attributable to immune-mediated inflammation. These findings highlight the importance of perioperative avoidance of provoking factors including monitoring of stress-induced elevations in serum lactate concentration, close postoperative surveying for myasthenic crisis, and early recognition of possible thromboembolic complications in this patient population.

Prolonged-Release (PR) Oxycodone/Naloxone Improves Bowel Function Compared with Oxycodone PR and Provides Effective Analgesia in Chinese Patients with Non-malignant Pain: A Randomized, Double-Blind Trial.

INTRODUCTION: Prolonged-release oxycodone/naloxone (OXN PR), combining an opioid analgesic with selective blockade of enteric µ-opioid receptors, provided effective analgesia and improved bowel function in patients with moderate-to-severe pain and opioid-induced constipation in clinical trials predominantly conducted in Western countries. This double-blind randomized controlled trial investigated OXN PR (N = 116) versus prolonged-release oxycodone (OXY PR, N = 115) for 8 weeks at doses up to 50 mg/day in patients with moderate-to-severe, chronic, non-malignant musculoskeletal pain and opioid-induced constipation recruited in China. METHODS: A total of 234 patients at least 18 years of age with non-malignant musculoskeletal pain for more than 4 weeks that was moderate-to-severe in intensity and required round-the-clock opioid therapy were randomized (1:1) to OXN PR or OXY PR. The primary endpoint was bowel function using the Bowel Function Index (BFI). Secondary endpoints included safety, Brief Pain Inventory-Short Form (BPI-SF), use of analgesic and laxative rescue medication, and health-related quality of life (EQ-5D). RESULTS: While BFI scores were comparable at baseline, at week 8 improvements were greater with OXN PR vs OXY PR (least squares mean [LSM] difference (95% CI) - 9.1 (- 14.0, - 4.2); P < 0.001. From weeks 2 to 8, mean BFI scores were in the range of normal bowel function (≤ 28.8) with OXN PR but were in the range of constipation (> 28.8) at all timepoints with OXY PR. Analgesia with OXN PR was similar and non-inferior to OXY PR on the basis of modified BPI-SF average 24-h pain scores at week 8: LSM difference (95% CI) - 0.3 (- 0.5, - 0.1); P < 0.001. The most frequent treatment-related AEs were nausea (OXN PR 5% vs OXY PR 6%) and dizziness (4% vs 4%). CONCLUSION: OXN PR provided clinically meaningful improvements in bowel function and effective analgesia in Chinese patients with moderate-to-severe musculoskeletal pain and pre-existing opioid-induced constipation. TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT01918098.

Comparison of the Pharmacokinetic Properties of Naloxone Following the Use of FDA-Approved Intranasal and Intramuscular Devices Versus a Common Improvised Nasal Naloxone Device.

For more than a decade, first responders and the general public have been able to treat suspected opioid overdoses using an improvised nasal naloxone device (INND) constructed from a prefilled syringe containing 2 mg of naloxone (1 mg/mL) attached to a mucosal atomization device. In recent years, the U.S. Food and Drug Administration (FDA)-approved Ezvio, an autoinjector that delivers 2 mg by intramuscular injection and Narcan nasal spray (2- and 4-mg strengths; 0.1 mL/dose) for the emergency treatment of a known or suspected opioid overdose. The present study was conducted to compare the pharmacokinetics of naloxone using the FDA-approved devices (each administered once) and either 1 or 2 administrations using the INND. When naloxone was administered twice using the improvised device, the doses were separated by 2 minutes. The highest maximum plasma concentration was achieved using the 4-mg FDA-approved spray. The highest exposures at 5 minutes postdose, based on AUC values, were after administration with the autoinjector and the 4-mg FDA-approved spray; at 10, 15, and 20 minutes postdose, the latter yielded the greatest exposure. Even after 2 administrations, the INND failed to achieve naloxone plasma levels comparable to the FDA-approved devices at any time. The ease of use and higher plasma concentrations achieved using the 4-mg FDA-approved spray, compared with the INND, should be considered when deciding which naloxone device to use.

Elective Naloxone-Induced Opioid Withdrawal for Rapid Initiation of Medication-Assisted Treatment of Opioid Use Disorder.

We present a case of elective naloxone-induced opioid withdrawal followed by buprenorphine rescue to initiate opioid use disorder treatment in the emergency department. This strategy may represent a safe alternative to prescribing buprenorphine for outpatient initiation, a method that puts the patient at risk for complications of unmonitored opioid withdrawal, including relapse. After confirmation that the naloxone-induced withdrawal was adequately treated with buprenorphine, the patient was discharged with prescribed buprenorphine to follow up in an addiction medicine clinic, where he was treated 2 days later.

Challenges with take-home naloxone in reducing heroin mortality: a review of fatal heroin overdose cases in Victoria, Australia.

AIM: Take-home naloxone (THN) programs have been implemented in order to reduce the number of heroin-overdose deaths. Because of recent legislative changes in Australia, there is a provision for a greater distribution of naloxone in the community, however, the potential impact of these changes for reduced heroin mortality remains unclear. The aim of this study was to examine the characteristics of the entire cohort of fatal heroin overdose cases and assess whether there was an opportunity for bystander intervention had naloxone been available at the location and time of each of the fatal overdose events to potentially avert the fatal outcome in these cases. METHODS: The circumstances related to the fatal overdose event for the cohort of heroin-overdose deaths in the state of Victoria, Australia between 1 January 2012 and 31 December 2013 were investigated. Coronial data were investigated for all cases and data linkage was performed to additionally investigate the Emergency Medical Services information about the circumstances of the fatal heroin overdose event for each of the decedents. RESULTS AND DISCUSSION: There were 235 fatal heroin overdose cases identified over the study period. Data revealed that the majority of fatal heroin overdose cases occurred at a private residence (n = 186, 79%) and where the decedent was also alone at the time of the fatal overdose event (n = 192, 83%). There were only 38 cases (17%) where the decedent was with someone else or there was a witness to the overdose event, and in half of these cases the witness was significantly impaired, incapacitated or asleep at the time of the fatal heroin overdose. There were 19 fatal heroin overdose cases (8%) identified where there was the potential for appropriate and timely intervention by a bystander or witness. CONCLUSION: This study demonstrated that THN introduction alone could have led to a very modest reduction in the number of fatal heroin overdose cases over the study period. A lack of supervision or a witness to provide meaningful and timely intervention was evident in most of the fatal heroin overdose cases.

Low-Dose Versus High-Dose Postoperative Naloxone Infusion Combined With Patient-Controlled Analgesia for Adolescent Idiopathic Scoliosis Surgery: A Randomized Controlled Trial.

STUDY DESIGN: Randomized controlled trial. OBJECTIVES: The aim of this prospective randomized clinical trial was to compare low (0.5 µg/kg/h) and high (2.5 µg/kg/h) dose naloxone infusion on the time to tolerate liquids and meals after surgery, patient-controlled analgesia (PCA) opioid requirements, nausea and pruritus ratings, and hospital length of stay. SUMMARY OF BACKGROUND DATA: Adolescents undergoing posterior spinal fusion often receive PCA after surgery and may experience common opioid-associated side effects, including nausea and pruritus. Low-dose naloxone infusion has been shown to reduce the incidence of pruritus and nausea while preserving analgesia, although an ideal dose has not been determined. Less is known about the potential for naloxone to improve bowel function after surgery. METHODS: Eighty-four patients (age 10-21 years) were randomly allocated to receive low- or high-dose naloxone infusion postoperatively. Surgical anesthetic consisted of propofol and opioid infusion with intrathecal morphine (10-15 µg/kg) at the conclusion of surgery. A visual analog scale (VAS) was used to rate nausea and pruritus. RESULTS: The groups had similar time to oral liquid intake after surgery and transition from PCA to oral pain medication. The VAS scores for pruritus and nausea were also similar, as was the need to treat these side effects. Morphine equivalents were similar between groups on postoperative day (POD) 0 and 1. On POD 2, the high-dose infusion group had significantly greater PCA bolus use (1.41±0.9 vs. 1.04±0.6; p<.05), although pain scores did not differ significantly. Hospital length of stay was similar for the two groups. CONCLUSION: High-dose naloxone infusion was associated with similar rates of opioid side effects as low-dose. Increased PCA use noted on POD 2 may represent partial reversal of opioid analgesia in the high-dose naloxone group. LEVEL OF EVIDENCE: Level 1.

Mu-opioid antagonists for opioid-induced bowel dysfunction in people with cancer and people receiving palliative care.

BACKGROUND: Opioid-induced bowel dysfunction (OIBD) is characterised by constipation, incomplete evacuation, bloating, and gastric reflux. It is one of the major adverse events of treatment for pain in cancer and in palliative care, resulting in increased morbidity and reduced quality of life.This is an update of two Cochrane reviews. One was published in 2011, Issue 1 on laxatives and methylnaltrexone for the management of constipation in people receiving palliative care; this was updated in 2015 and excluded methylnaltrexone. The other was published in 2008, Issue 4 on mu-opioid antagonists (MOA) for OIBD. In this updated review, we only included trials on MOA (including methylnaltrexone) for OIBD in people with cancer and people receiving palliative care. OBJECTIVES: To assess the effectiveness and safety of MOA for OIBD in people with cancer and people receiving palliative care. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, and Web of Science to August 2017. We also searched clinical trial registries and regulatory websites. We contacted manufacturers of MOA to identify further data. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that assessed the effectiveness and safety of MOA for OIBD in people with cancer and people at a palliative stage irrespective of the type of terminal disease they experienced. DATA COLLECTION AND ANALYSIS: Two review authors assessed risk of bias and extracted data. The appropriateness of combining data from the trials depended upon sufficient homogeneity across the trials. Our primary outcomes were laxation, impact on pain relief, and adverse events. Impact on pain relief was a primary outcome because a possible adverse effect of MOAs is a reduction in pain relief from opioids. We assessed the evidence on these outcomes using GRADE. MAIN RESULTS: We identified four new trials for this update, bringing the total number included in this review to eight. In total, 1022 men and women with cancer irrespective of stage or at a palliative care stage of any disease were randomised across the trials. The MOAs evaluated were oral naldemedine and naloxone (alone or in combination with oxycodone), and subcutaneous methylnaltrexone. The trials compared with MOA with a placebo or with the active intervention administered at different doses or in combination with other drugs. The trial of naldemedine and the two of naloxone in combination with oxycodone were in people with cancer irrespective of disease stage. The trial on naloxone alone was in people with advanced cancer. The four trials on methylnaltrexone were undertaken in palliative care where most participants had cancer. All trials were vulnerable to biases; four were at a high risk as they involved a sample of fewer than 50 participants per arm.In the trial of naldemedine compared to placebo in 225 participants, there were more spontaneous laxations over the two-week treatment for the intervention group (risk ratio (RR) 1.93, 95% confidence intervals (CI) 1.36 to 2.74; moderate-quality evidence). In comparison with higher doses, lower doses resulted in fewer spontaneous laxations (0.1 mg versus 0.2 mg: RR 0.73, 95% CI 0.55 to 0.95; 0.1 mg versus 0.4 mg: RR 0.69, 95% CI 0.53 to 0.89; moderate-quality evidence). There was moderate-quality evidence that naldemedine had no effect on opiate withdrawal. There were five serious adverse events. All were in people taking naldemedine (low-quality evidence). There was an increase in the occurrence of other (non-serious) adverse events in the naldemedine groups (RR 1.36, 95% CI 1.04 to 1.79, moderate-quality evidence). The most common adverse event was diarrhoea.The trials on naloxone taken either on its own, or in combination with oxycodone (an opioid) compared to oxycodone only did not evaluate laxation response over the first two weeks of administration. There was very low-quality evidence that naloxone alone, and moderate-quality evidence that oxycodone/naloxone, had no effect on analgesia. There was low-quality evidence that oxycodone/naloxone did not increase the risk of serious adverse events and moderate-quality evidence that it did not increase risk of adverse events.In combined analysis of two trials of 287 participants, we found methylnaltrexone compared to placebo induced more laxations within 24 hours (RR 2.77, 95% CI 1.91 to 4.04. I² = 0%; moderate-quality evidence). In combined analysis, we found methylnaltrexone induced more laxation responses over two weeks (RR 9.98, 95% CI 4.96 to 20.09. I² = 0%; moderate-quality evidence). The proportion of participants who had a rescue-free laxation response within 24 hours of the first dose was 59.1% in the methylnaltrexone arms and 19.1% in the placebo arm. There was moderate-quality evidence that the rate of opioid withdrawal was not affected. Methylnaltrexone did not increase the likelihood of a serious adverse event; there were fewer in the intervention arm (RR 0.59, 95% CI 0.38 to 0.93; I² = 0%; moderate-quality evidence). There was no difference in the proportion of participants experiencing an adverse event (RR 1.17, 95% CI 0.94 to 1.45; I² = 74%; low-quality evidence). Methylnaltrexone increased the likelihood of abdominal pain and flatulence.Two trials compared differing methylnaltrexone schedules of higher doses with lower doses. For early laxation, there was low-quality evidence of no clear difference between doses on analgesia and adverse events. Both trials measured laxation response within 24 hours of first dose (trial one: RR 0.82, 95% CI 0.41 to 1.66; trial two: RR 1.07, 95% CI 0.81 to 1.42). AUTHORS' CONCLUSIONS: In this update, the conclusions for naldemedine are new. There is moderate-quality evidence to suggest that, taken orally, naldemedine improves bowel function over two weeks in people with cancer and OIBD but increases the risk of adverse events. The conclusions on naloxone and methylnaltrexone have not changed. The trials on naloxone did not assess laxation at 24 hours or over two weeks. There is moderate-quality evidence that methylnaltrexone improves bowel function in people receiving palliative care in the short term and over two weeks, and low-quality evidence that it does not increase adverse events. There is a need for more trials including more evaluation of adverse events. None of the current trials evaluated effects in children.

Oxycodone/naloxone in postoperative pain management of surgical patients.

BACKGROUND: The role of analgesia is crucial in the management of postoperative pain. Different combinations of oral analgesics have been proposed in the past. The oxycodone/naloxone (OXN) combination is a recent addition and is being used by different surgical specialties. The aim of our study was to clarify the possible role, advantages, and disadvantages of OXN in the pain management of surgical patients. METHOD: The authors retrieved the included studies after performing a systematic search in PubMed and Scopus. RESULTS: Ten studies (six randomized controlled trials, three retrospective studies, and a prospective study) were eligible for inclusion in this review. In total, 1,996 patients were included. Six studies reported on orthopedic procedures while four studies referred to colorectal, gynecologic, cardiac, and thoracic surgery procedures, respectively. The analgesic effect of OXN was evaluated in nine out of 10 studies, where OXN showed superiority only in two out of nine studies. Postoperative bowel function was evaluated in seven out of 10 studies. Patients treated with OXN did not show any significant differences in bowel function when compared to control groups. No superiority was found regarding the possible adverse events. CONCLUSION: Analgesia is crucial to postoperative recovery. Pain control can be achieved a combination of different analgesics, including OXN. This oral analgesic combination can have the potential to minimize side effects, such as opioid-induced constipation and optimize the recovery period.

Analgesic Efficacy and Safety of Prolonged-Release Oxycodone/Naloxone in Korean Patients with Chronic Pain from Spinal Disorders.

BACKGROUND: A prolonged-release formulation of oxycodone/naloxone has been shown to be effective in European populations for the management of chronic moderate to severe pain. However, no clinical data exist for its use in Korean patients. The objective of this study was to assess efficacy and safety of prolonged-release oxycodone/naloxone in Korean patients for management of chronic moderate-to-severe pain. METHODS: In this multicenter, single-arm, open-label, phase IV study, Korean adults with moderate-to-severe spinal disorder-related pain that was not satisfactorily controlled with weak opioids and nonsteroidal anti-inflammatory drugs received prolonged-release oral oxycodone/naloxone at a starting dose of 10/5 mg/day (maximum 80/40 mg/day) for 8 weeks. Changes in pain intensity and quality of life (QoL) were measured using a numeric rating scale (NRS, 0-10) and the Korean-language EuroQol-five dimensions questionnaire, respectively. RESULTS: Among 209 patients assessed for efficacy, the mean NRS pain score was reduced by 25.9% between baseline and week 8 of treatment (p < 0.0001). There was also a significant improvement in QoL from baseline to week 8 (p < 0.0001). The incidence of adverse drug reactions was 27.7%, the most common being nausea, constipation, and dizziness; 77.9% of these adverse drug reactions had resolved or were resolving at the end of the study. CONCLUSIONS: Prolonged-release oxycodone/naloxone provided significant and clinically relevant reductions in pain intensity and improved QoL in Korean patients with chronic spinal disorders. (ClinicalTrials.gov identifier: NCT01811238).

Laxative Use in Inpatients on Oxycodone/Naloxone Prolonged Release and Oxycodone Prolonged Release for Cancer and Non-cancer Pain.

OBJECTIVE: To examine the laxative prescriptions in hospital inpatients with cancer and non-cancer pain on oxycodone compared to oxycodone plus naloxone combination. DESIGN: Retrospective case note review. SETTING: A palliative care inpatient unit and a general medical ward in a large tertiary referral hospital. PARTICIPANTS: Eighty-four patients receiving oxycodone or combination oxycodone/naloxone on general medical (45 patients) and palliative care wards (39 patients). MAIN OUTCOME MEASURES: The primary recorded outcomes were regular opioid dose (milligrams per day) and number of prescribed laxatives (type, doses, and frequency per day). RESULTS: Sixty-three (75%) patients in the study were on at least one laxative. In the general medicine inpatients, those on combined oxycodone/naloxone received on average 3.7 laxative doses per day compared to the oxycodone patients receiving 1.6 doses a day. In the palliative medicine population, both groups received a similar number of laxatives, despite the oxycodone/naloxone patients being on lower opioid doses. CONCLUSION: This retrospective study of hospital inpatients with cancer and non-cancer pain found that laxative use was not reduced in those on combined oxycodone/naloxone compared to oxycodone alone, suggesting that despite the interpretations of the clinical trials in the phase IV setting, the addition of naloxone had no effect on reducing laxative use.

Oral oxycodone/naloxone for pain control in cirrhosis: Observational study in patients with symptomatic metastatic hepatocellular carcinoma.

BACKGROUND & AIMS: Pain management in cirrhosis is a clinical challenge. Most analgesics are metabolized in the liver and cirrhosis may deeply alter their concentration, favouring the appearance of side effects. We aimed to assess the efficacy and safety of oral prolonged-release association of oxycodone/naloxone tablets (OXN) in the treatment of moderate/severe cancer pain in cirrhotic patients with metastatic hepatocellular carcinoma (HCC). METHODS: We enrolled n = 32 HCC patients with moderate/severe cancer pain unresponsive to paracetamol alone or associated with codeine or tramadol. All patients received an initial OXN dose of 5 mg bid to be gradually increased in case of insufficient analgesia. At baseline and follow-up visits, we evaluated: pain intensity (using the Numerical Rating Scale, NRS), patients' autonomy in daily activities (Barthel Functioning Index); bowel dysfunction (Bowel Function Index, BFI), signs of hepatic encephalopathy (HE) and other opioid-induced side effects. RESULTS: No clinically significant adverse effects were reported (median follow-up 122 days). No significant worsening of the BFI score was noted and no cases of HE were detected. Two patients (6.3%) discontinued treatment before T14 because of mild nausea and dizziness. The remaining n = 30 patients were assessed for efficacy. Treatment led to a significant reduction in the mean of pain scores both at T14 (-37.1 ± 16.3%, P < .001) and at T28 (-55.6 ± 21.5%, P < .001); Barthel scores showed gradual and significant increase from T0 (81.6 ± 13.0) to T14 (86.5 ± 11.4, P = .001) and to T28 (88.3 ± 13.6, P = .009). CONCLUSIONS: OXN may be considered a safe and effective option in the fragile population of cirrhotic patients.

Opioid-Induced Constipation Relief From Fixed-Ratio Combination Prolonged-Release Oxycodone/Naloxone Compared With Oxycodone and Morphine for Chronic Nonmalignant Pain: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

CONTEXT: Opioid-induced constipation (OIC) is one of the most frequent and severe adverse events (AEs) after treatment with opioids. Recent studies have indicated that fixed-ratio combination prolonged-release oxycodone/naloxone (OXN PR) could decrease OIC with similar pain relief compared with other opioids. OBJECTIVES: We systematically reviewed (PROSPERO registration numbers: CRD42016036244) the constipation relief of OXN PR compared with other opioids regardless of formulation, prolonged release, or extended release used for the relief of chronic pain. METHODS: Relevant studies were identified by searching PubMed, EMBASE, Web of Science, and the Cochrane library from inception to May 2016, with an update to December 2016. We quantitatively analyzed OIC (assessed by bowel function index [BFI]), pain intensity, and AEs. RESULTS: A total of 167 articles were identified from the databases. Finally seven studies with 3217 patients were included in our meta-analysis, including 1322 patients in OXN PR treatment groups and 1885 patients in prolonged-release oxycodone (OXY PR) or prolonged-release morphine (MOR PR) control group. The relative risk (RR) of OIC was decreased in OXN PR (RR 0.52, 95% CI 0.44; 0.62). Whether BFI was better or worse at baseline, the mean difference (MD) of BFI -17.48 95% CI -21.60; -13.36) was better after treatment with OXN PR with clinical importance at the end of intervention; moreover, the BFI of the OXN PR-treated group was closer to normal BFI scores. However, clinical BFI change from baseline to the end measurement only existed in patients when the baseline BFI was high (mean [SDs] 61.0 [23.39]-67.40 [19.51]), and the MD of the BFI was -15.96 (95% CI -25.56; -15.48). The RR of AEs was also smaller (RR 0.80; 95% CI 0.69-0.93), but the severity or duration of AEs was not reported. Pain intensity was also significantly decreased in the OXN PR treatment groups (MD -3.84, 95% CI -7.14; -0.55), although there was no clinically meaningful difference. CONCLUSION: For people with chronic pain, treatment with OXN PR decreases the incidence of OIC and provides intermediate-term bowel function improvement with clinical importance; in addition, pain relief is not weakened. The OIC after treatment with OXN PR for cancer-related pain and over the long term remains unknown.

Combatting pain after orthopedic/trauma surgery- perioperative oral extended-release tapentadol vs. extended-release oxycodone/naloxone.

BACKGROUND: High post-operative pain scores after "minor" orthopedic/trauma surgery are in part attributed to inadequate prescription of opioid analgesics. Novel concepts aiming to achieve sufficient analgesia while minimizing opioid-related side effects by avoiding fluctuating plasma levels are based on perioperative oral administration of extended-release opioids beginning with the first dose pre-operatively. This is the first study to evaluate analgesic efficacy and side effect rates of extended-release tapentadol compared to oxycodone/naloxone following orthopedic/trauma surgery. METHODS: This randomized, observer-blinded, active-controlled prospective clinical trial had 2 co-primary endpoints: (1) Analgesic efficacy: Mean pain level on a numeric rating scale (NRS) from 0 to 10 during exercise over 5 days. (2) Safety: Side effect sum score of the following events: Nausea, vomiting, constipation, sedation, vertigo, somnolence. The study was powered to detect superiority of tapentadol for at least one endpoint pending statistical proof of non-inferiority for both endpoints in a first step. RESULTS: Two hundred sixty-six trauma patients were randomized to receive either tapentadol (n = 133) or oxycodone/naloxone (n = 133). Analgesic efficacy: Mean (±SD) daily pain levels in the first five post-operative days were 2.8 ± 1.3 in both groups. Mean maximum pain intensity during exercise in the first 24 h after surgery was 3.8 ± 1.9 (tapentadol) and 3.8 ± 2.1 (oxycodone/naloxone). Statistically tapentadol was non-inferior but not superior to oxycodone/naloxone. SAFETY: Vomiting on day 1 occurred in 11%, constipation in 35% of the tapentadol patients and in 16% and 30% of the oxycodone/naloxone patients (p = 0.60 and 0.33), respectively. The incidence of sedation/ vertigo was <10%, that of somnolence <2% in both groups (p > 0.3, respectively). The sum score of side effect events was 51% in the tapentadol vs. 49% in the oxycodone/naloxone group; risk difference 3% [95% CI, -8 to 14%]; p = 0.6). Non-inferiority of tapentadol could not be concluded as the pre-defined non-inferiority margin was exceeded. CONCLUSIONS: With both concepts, mean maximum pain intensity during exercise within the first 24 h after orthopedic/trauma surgery was reduced to a score of <4. This analgesic efficacy came at the cost of mainly gastro-intestinal side effects. Thus, we now use a prophylaxis against nausea and vomiting and pre-emptive laxatives as part of these concepts. TRIAL REGISTRATION: https://eudract.ema.europa.eu (EudraCT- Nr. 2011-003238-15 ); October 24th, 2012.