The role of oxycodone/naloxone in the management of patients with pain and opioid-induced constipation

The Pharmacological Treatment of Chronic Pain: From Guidelines to Daily Clinical Practice

In agreement with the International Association for the Study of Pain, chronic pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. To date, there are several types of pain: nociceptive, neuropathic, and nociplastic. In the present narrative review, we evaluated the characteristics of the drugs used for each type of pain, according to guidelines, and their effects in people with comorbidity to reduce the development of severe adverse events.

Preventing nausea and vomiting after gynecological laparoscopic surgery by patient-controlled intravenous analgesia with a naloxone admixture: A randomized controlled trial

BACKGROUND

Opioid-induced nausea and vomiting are common side effects of patient-controlled intravenous analgesia (PCIA). This study aimed to explore the inhibitory effect of a naloxone admixture on the incidence of sufentanil-induced postoperative nausea and vomiting (PONV).

METHODS

A total of 132 Uyghur American Society of Anesthesiologists I and II patients scheduled to undergo elective gynecological laparoscopic surgery were recruited; among these, 120 patients were enrolled and randomly allocated into 4 groups: patients receiving PCIA but no naloxone were included in the control group (group A); patients receiving PCIA with a low-dose naloxone admixture at 0.2 μg·kg-1·h-1 were included in group B; patients receiving PCIA with naloxone admixture at 0.4 μg·kg-1·h-1 were included in group C; patients receiving PCIA with naloxone admixture at 0.6 μg·kg-1·h-1 were included in group D. All patients were administered sufentanil at 0.04 kg-1·h-1, butorphanol at 2 kg-1·h-1, and dexmedetomidine at 0.08 kg-1·h-1 using a PCIA device within 2 days of surgery. The occurrence of nausea and vomiting, visual analogue scores for pain intensity, mean arterial pressure, heart rate, oxygen saturation, pruritus, lethargy, respiratory depression, etc, was recorded at 2, 8, 12, 24, and 48 hours postoperatively.

RESULTS

There was a significant difference in the PONV scores between the groups at 8, 12, and 24 hours after surgery (P < 0.01). At 8 and 12 hours, the score of group C/D was significantly lower than that of group A/B (P < 0.01). At 24 hours after surgery, the PONV score of group B/C/D was significantly lower than that of group A (P < 0.01). No significant difference was observed in the general data and visual analogue scores for postoperative pain between the 4 groups.

CONCLUSION

Naloxone admixture administered at 0.4 to 0.6 μg·kg-1·h-1 can exert an effective inhibitory effect on the incidence and intensity of PONV in gynecological laparoscopic surgery.

Cost-Effectiveness Analysis of Tapentadol Versus Oxycodone/Naloxone in both Branded and Generic Formulations in Patients with Musculoskeletal Pain

BACKGROUND AND OBJECTIVES

Current evidence shows that tapentadol hydrochloride prolonged-release is more cost effective than other opioids. However, the introduction into the market of generic formulations of traditional comparators, leading to potential savings due to their lower price, creates space for further research. The objective of this study is to evaluate and compare the efficacy of tapentadol versus oxycodone/naloxone and the economic impact of the two alternatives in both branded and generic formulations.

METHODS

A cost-effectiveness analysis was performed using the third-payer perspective (TPP), with specific reference to the Italian National Health Service. A Markov model was implemented to simulate transitions between states, comparing two arms: The first arm simulated the administration of tapentadol, while the second simulated the administration of oxycodone/naloxone, both branded and generic. The results were reported in terms of net monetary benefit (NMB). The willingness to pay (WPT) was estimated at €35,000/quality-adjusted life year.

RESULTS

Tapentadol was dominant in all scenarios, assuming a population of 1000 individuals over a 1-year time horizon. In all cases, although the prices of oxycodone/naloxone generic formulations were lower, the costs associated with treatment discontinuation were always higher than those associated with tapentadol. The comparison with the branded formulation of oxycodone/naloxone was associated with the highest savings of €431.77 per patient, and with the highest NMB of €1943.77 per patient.

CONCLUSION

The results of this pharmacoeconomic evaluation promote the use of tapentadol in comparison with oxycodone/naloxone, confirming the results obtained in previous studies with reference to the generic formulations.

LP1 and LP2: Dual-Target MOPr/DOPr Ligands as Drug Candidates for Persistent Pain Relief

Although persistent pain is estimated to affect about 20% of the adult population, current treatments have poor results. Polypharmacology, which is the administration of more than one drug targeting on two or more different sites of action, represents a prominent therapeutic approach for the clinical management of persistent pain. Thus, in the drug discovery process the "one-molecule-multiple targets" strategy nowadays is highly recognized. Indeed, multitarget ligands displaying a better antinociceptive activity with fewer side effects, combined with favorable pharmacokinetic and pharmacodynamic characteristics, have already been shown. Multitarget ligands possessing non-opioid/opioid and opioid/opioid mechanisms of action are considered as potential drug candidates for the management of various pain conditions. In particular, dual-target MOPr (mu opioid peptide receptor)/DOPr (delta opioid peptide receptor) ligands exhibit an improved antinociceptive profile associated with a reduced tolerance-inducing capability. The benzomorphan-based compounds LP1 and LP2 belong to this class of dual-target MOPr/DOPr ligands. In the present manuscript, the structure-activity relationships and the pharmacological fingerprint of LP1 and LP2 compounds as suitable drug candidates for persistent pain relief is described.

Management of Opioid-Induced Constipation and Bowel Dysfunction: Expert Opinion of an Italian Multidisciplinary Panel

The prescribing and use of opioid analgesics is increasing in Italy owing to a profusion in the number and types of opioid analgesic products available, and the increasing prevalence of conditions associated with severe pain, the latter being related to population aging. Herein we provide the expert opinion of an Italian multidisciplinary panel on the management of opioid-induced constipation (OIC) and bowel dysfunction. OIC and opioid-induced bowel dysfunction are well-recognised unwanted effects of treatment with opioid analgesics that can profoundly affect quality of life. OIC can be due to additional factors such as reduced mobility, a low-fibre diet, comorbidities, and concomitant medications. Fixed-dose combinations of opioids with mu (μ) opioid receptor antagonists, such as oxycodone/naloxone, have become available, but have limited utility in clinical practice because the individual components cannot be independently titrated, creating a risk of breakthrough pain as the dose is increased. A comprehensive prevention and management strategy for OIC should include interventions that aim to improve fibre and fluid intake, increase mobility or exercise, and restore bowel function without compromising pain control. Recommended first-line pharmacological treatment of OIC is with an osmotic laxative (preferably polyethylene glycol [macrogol]), or a stimulant laxative such as an anthraquinone. A second laxative with a complementary mechanism of action should be added in the event of an inadequate response. Second-line treatment with a peripherally acting μ opioid receptor antagonist (PAMORA), such as methylnaltrexone, naloxegol or naldemedine, should be considered in patients with OIC that has not responded to combination laxative treatment. Prokinetics or intestinal secretagogues, such as lubiprostone, may be appropriate in the third-line setting, but their use in OIC is off-label in Italy, and should therefore be restricted to settings such as specialist centres and clinical trials.

Identification of high-impact gene-drug pairs for pharmacogenetic testing in Alberta, Canada

OBJECTIVES

To facilitate decision-making and priority-setting related to Alberta's Pharmacogenomics (PGx) testing implementation strategy by identifying gene-drug pairs with the highest potential impact on prescribing practices in Alberta.

PATIENTS AND METHODS

Annual drug dispensing data for Alberta from 2012 to 2016 for 57 medications with PGx-based prescribing guidelines were obtained, along with population estimates and demographics (age and ethnicity). Frequencies of actionable PGx genotypes by ethnicity were obtained from the Pharmacogenomics Knowledgebase (PharmGKB). Annual dispensing activity for each of the 57 medications was calculated for the full population (all ages) and children/youth (0-19 years). Alberta ethnicity data were cross-referenced with genetic frequency data for each of the main ethnic groups from PharmGKB to estimate the proportion of individuals with actionable genotypes. Actionable genotype proportions and drug dispensing frequencies were collectively used to identify high impact gene-drug pairs.

RESULTS

We found (a) half of the drugs with PGx-based prescribing guidelines, namely, analgesics, proton pump inhibitors, psychotropics, and cardiovascular drugs, were dispensed at high frequencies (>1% of the entire population), (b) the dispensing rate for about one-third of these drugs increased over the 5-year study period, (c) between 1.1 and 45% of recipients of these drugs carried actionable genotypes, and (d) the gene-drug pairs with greatest impact in Alberta predominatly included CYP2C19 or CYP2D6.

CONCLUSIONS

We uncovered specific patterns in drug dispensing and identified important gene-drug pairs that will inform the planning and development of an evidenced-based PGx testing service in Alberta, Canada. Adaptation of our approach may facilitate the process of evidence-based PGx testing implementation in other jurisdictions.

Factors related to pain management adequacy in patients receiving palliative care: data from a tertiary hospital in Indonesia

BACKGROUND Adequate pain management must be applied to improve the quality of life, particularly in patients receiving palliative care. Thus, this study aimed to determine the factors related to pain management adequacy in patients receiving palliative care. METHODS This cross-sectional study included all patients sent for consultation to the palliative care team complaining of pain in Cipto Mangunkusumo Hospital, Jakarta, Indonesia from 2016 to 2018. All data such as gender, age, employment status, disease type, primary cancer location, pain intensity, analgesic drug treatment duration, and the presence of anxiety and depression were retrieved from medical records. Pain management adequacy was evaluated using the pain management index. Logistic regression included all variables with p<0.25 related to pain management adequacyin bivariate analysis. RESULTS Out of 175 patients with pain, 85.7% reported having adequate pain management. Pain was more adequately treated in patients with employment (p = 0.001), milder pain intensity (p<0.001), those using opioids (p<0.001), and those who did not experience anxiety (p = 0.05). Factors related to pain management adequacy were opioid use (OR = 3.23, 95% CI = 1.71–6.13) and milder pain (OR = 11.15, 95% CI = 3.89–31.99). CONCLUSIONS Most of the patients received adequate pain management which related to opioid use and milder pain.

Efficacy and Safety of Peripherally Acting Mu-Opioid Receptor Antagonists for the Treatment of Opioid-Induced Constipation: A Bayesian Network Meta-analysis

OBJECTIVE

To assess the efficacy and safety of peripherally acting mu-opioid receptor antagonists (PAMORAs) for the treatment of opioid-induced constipation (OIC).

METHODS

Randomized controlled trials (RCTs) were searched for OIC therapy comparing PAMORAs with placebo. Both a pairwise and network meta-analysis were performed. The surface under the cumulative ranking area (SUCRA) was used to determine the efficacy and safety of OIC treatment using different PAMORAs.

RESULTS

The primary target outcome was a response that achieves an average of three or more bowel movements (BMs) per week. In the network meta-analysis, four PAMORAs (naldemedine, naloxone, methylnaltrexone, and alvimopan) showed a better BM response than the placebo. Naldemedine was ranked first (odds ratio [OR] = 2.8, 95% credible interval [CrI] = 2-4.5, SUCRA = 89.42%), followed by naloxone (OR = 2.9, 95% CrI = 1.6-5.3, SUCRA = 87.44%), alvimopan (OR = 2.2, 95% CrI = 1.3-3.5, SUCRA = 68.02%), and methylnaltrexone (OR = 1.7, 95% CrI = 1.0-2.8, SUCRA = 46.09%). There were no significant differences in safety found between the PAMORAs and the placebo.

CONCLUSIONS

We found that PAMORAs are effective and can be safely used for the treatment of OIC. In network meta-analysis, naldemedine and naloxone appear to be the most effective PAMORAs for the treatment of OIC.

Naldemedine: A New Option for OIBD

Opioid-induced bowel dysfunction (OIBD) is a common complication in long-term opioid users and abusers. It is a burdensome condition, which significantly limits quality of life and is associated with increasing health costs. OIBD affects up to 60% of patients with chronic non-cancer pain and over 80% of patients suffering from cancer pain and is one of the conditions of the most common symptoms associated with opioid maintenance. Given the continued use of opioids for chronic pain management in appropriate patients, OIBD is likely to persist in clinical practice in the coming years. We will herein review its underlying pathophysiological mechanisms and the available treatments. In the last years, pharmaceutical research has focused on the opportunity of targeting peripheral mu-opioid receptors without affecting their analgesic activity in the central nervous system, and several peripherally acting mu-opioid receptors antagonists (PAMORAs) drugs have been approved. We will mainly focus on naldemedine, discussing its pharmacological properties, its clinical efficacy and side effects. Head-to-head comparisons between naldemedine and the other PAMORAs are not available yet, but some considerations will be discussed based on the pharmacological and clinical data. As a whole, the available data suggest that naldemedine is a valid treatment option for OIBD, as it is a well-tolerated drug that alleviates constipation without affecting analgesia or causing symptoms of opioid withdrawal.