Digital Therapeutics for Improving Effectiveness of Pharmaceutical Drugs and Biological Products: Preclinical and Clinical Studies Supporting Development of Drug + Digital Combination Therapies for Chronic Diseases

Limitations of pharmaceutical drugs and biologics for chronic diseases (e.g., medication non-adherence, adverse effects, toxicity, or inadequate efficacy) can be mitigated by mobile medical apps, known as digital therapeutics (DTx). Authorization of adjunct DTx by the US Food and Drug Administration and draft guidelines on "prescription drug use-related software" illustrate opportunities to create drug + digital combination therapies, ultimately leading towards drug-device combination products (DTx has a status of medical devices). Digital interventions (mobile, web-based, virtual reality, and video game applications) demonstrate clinically meaningful benefits for people living with Alzheimer's disease, dementia, rheumatoid arthritis, cancer, chronic pain, epilepsy, depression, and anxiety. In the respective animal disease models, preclinical studies on environmental enrichment and other non-pharmacological modalities (physical activity, social interactions, learning, and music) as surrogates for DTx "active ingredients" also show improved outcomes. In this narrative review, we discuss how drug + digital combination therapies can impact translational research, drug discovery and development, generic drug repurposing, and gene therapies. Market-driven incentives to create drug-device combination products are illustrated by Humira® (adalimumab) facing a "patent-cliff" competition with cheaper and more effective biosimilars seamlessly integrated with DTx. In conclusion, pharma and biotech companies, patients, and healthcare professionals will benefit from accelerating integration of digital interventions with pharmacotherapies.

Pharmacological Treatments and Therapeutic Drug Monitoring in Patients with Chronic Pain

Pain is an unpleasant sensory and emotional experience that affects every aspect of a patient's life and which may be treated through different pharmacological and non-pharmacological approaches. Analgesics are the drugs most commonly used to treat pain, and in specific situations, the use of opioids may be considered with caution. These drugs, in fact, do not always induce optimal analgesia in patients, and several problems are associated with their use. The purpose of this narrative review is to describe the pharmacological approaches currently used for the management of chronic pain. We review several aspects, from the pain-scale-based methods currently available to assess the type and intensity of pain, to the most frequently administered drugs (non-narcotic analgesics and narcotic analgesics), whose pharmacological characteristics are briefly reported. Overall, we attempt to provide an overview of different pharmacological treatments while also illustrating the relevant guidelines and indications. We then report the strategies that may be used to reduce problems related to opioid use. Specifically, we focus our attention on therapeutic drug monitoring (TDM), a tool that could help clinicians select the most suitable drug and dose to be used for each patient. The actual potential of using TDM to optimize and personalize opioid-based pain treatments is finally discussed based on recent scientific reports.

Pain management in pediatric age. An update

Differently from the adult patients, in paediatric age it is more difficult to assess and treat efficaciously the pain and often this symptom is undertreated or not treated. In children, a selection of appropriate pain assessment tools should consider the age, the cognitive level, the presence of eventual disability, the type of pain and the situation in which it is occurring. Improved understanding of developmental neurobiology and paediatric analgesic drug pharmacokinetics should facilitate a better management of childhood pain. The objective of this update is to discuss the current practice and the recent advances in pediatric pain management.  Using PubMed and the Cochrane Library we conducted an extensive literature analysis on pediatric pain assessment and commonly used analgesic agents in this kind of patients. According to our results, a multimodal analgesic regimen provides a better pain control and a functional outcome in children. Cooperation and communication among the anaesthesiologist, the surgeon and the paediatrician remains essential for successful anaesthesia and pain management in childhood.

Pain Management at the End of Life in the Emergency Department: A Narrative Review of the Literature and a Practical Clinical Approach

Access to pain management is a fundamental human right for all people, including those who are at the end of life (EOL). In end-stage patients, severe and uncontrolled pain is a common cause of admission to the emergency department (ED), and its treatment is challenging due to its complex, often multifactorial genesis. The aim of this narrative review was to identify the available literature on the management of severe EOL pain in the ED. The MEDLINE, SCOPUS, EMBASE, and CENTRAL databases were searched from inception to 1 April 2023 including randomised controlled trials, observational studies, systemic or narrative reviews, case reports, and guidelines on the management of EOL pain in the ED. A total of 532 articles were identified, and 9 articles were included (5 narrative reviews, 2 retrospective studies, and 2 prospective studies). Included studies were heterogeneous on the scales used and recommended for pain assessment and the recommended treatments. No study provided evidence for a better approach for EOL patients with pain in the ED. We provide a narrative summary of the findings and a review of the management of EOL pain in clinical practice, including (i) the identification of the EOL patients and unmet palliative care needs, (ii) a multidimensional, patient-centred assessment of the type and severity of pain, (iii) a multidisciplinary approach to the management of end-of-life pain, including an overview of non-pharmacological and pharmacological techniques; and (iv) the management of special situations, including rapid acute deterioration of chronic pain, breakthrough pain, and sedative palliation.

Sustaining Life versus Altering Life-Saving Drugs: Insights to Explain the Paradoxical Effect of Extracorporeal Membrane Oxygenation on Drugs

There has been a substantial increase in the use of extracorporeal membrane oxygenation (ECMO) support in critically ill adults. Understanding the complex changes that could affect drugs' pharmacokinetics (PK) and pharmacodynamics (PD) is of suitable need. Therefore, critically ill patients on ECMO represent a challenging clinical situation to manage pharmacotherapy. Thus, clinicians' ability to predict PK and PD alterations within this complex clinical context is fundamental to ensure further optimal and, sometimes, individualized therapeutic plans that balance clinical outcomes with the minimum drug adverse events. Although ECMO remains an irreplaceable extracorporeal technology, and despite the resurgence in its use for respiratory and cardiac failures, especially in the era of the COVID-19 pandemic, scarce data exist on both its effect on the most commonly used drugs and their relative management to achieve the best therapeutic outcomes. The goal of this review is to provide key information about some evidence-based PK alterations of the drugs used in an ECMO setting and their monitoring.

Small Synthetic Hyaluronan Disaccharide BIS014 Mitigates Neuropathic Pain in Mice

Neuropathic pain (NP) is a challenging condition to treat, as the need for new drugs to treat NP is an unmet goal. We investigated the analgesic potential of a new sulfated disaccharide compound, named BIS014. Oral administration (p.o.) of this compound induced ameliorative effects in formalin-induced nociception and capsaicin-induced secondary mechanical hypersensitivity in mice, but also after partial sciatic nerve transection (spared nerve injury), chemotherapy (paclitaxel)-induced NP, and diabetic neuropathy induced by streptozotocin. Importantly, BIS014, at doses active on neuropathic hypersensitivity (60 mg/kg/p.o.), did not alter exploratory activity or motor coordination (in the rotarod test), unlike a standard dose of gabapentin (40 mg/kg/p.o.) which although inducing antiallodynic effects on the NP models, it also markedly decreased exploration and motor coordination. In docking and molecular dynamic simulation studies, BIS014 interacted with TRPV₁, a receptor involved in pain transmission where it behaved as a partial agonist. Additionally, similar to capsaicin, BIS014 increased cytosolic Ca²⁺ concentration ([Ca²⁺]_c) in neuroblastoma cells expressing TRPV₁ receptors; these elevations were blocked by ruthenium red. BIS014 did not block capsaicin-elicited [Ca²⁺]_c transients, but inhibited the increase in the firing rate of action potentials in bradykinin-sensitized dorsal root ganglion neurons stimulated with capsaicin. Perspective: We report that the oral administration of a new sulfated disaccharide compound, named BIS014, decreases neuropathic pain from diverse etiology in mice. Unlike the comparator gabapentin, BIS014 does not induce sedation. Thus, BIS014 has the potential to become a new efficacious non-sedative oral medication for the treatment of neuropathic pain.

Impact of analgesic regimen on patient outcome following subarachnoid hemorrhage: positive adjuvant effects of metamizole

INTRODUCTION

Various analgesics are used to control intense headaches in patients following subarachnoid hemorrhage. In addition to pain control, it has been shown that some analgesics can affect various pathophysiological cascades. Therefore, we devised a study to assess whether the use of metamizole has a significant impact on the development of ischemic complications, hydrocephalus, and the overall outcome in patients following aneurysmal subarachnoid hemorrhage in the context of the other non-opioids and opioids effects.

METHODS

In our retrospective, single-center cohort study, we enrolled 192 patients diagnosed with subarachnoid hemorrhage. We recorded their initial clinical status, comorbidities, and the daily dosage of analgesics over 14 days of hospitalization after the onset of subarachnoid hemorrhage. Using univariate and subsequent multivariate logistic regression analysis, we assessed the influence of various factors, including analgesics, on the development of delayed cerebral ischemia and hydrocephalus, as well as on 2-week and 6-month outcomes.

RESULTS

Although the administration of non-opioids, in general, had no effect on the development of delayed cerebral ischemia or hydrocephalus, the use of metamizole as the main analgesic was associated with a significantly lower chance of poor outcome at both 2-weeks and 6-months, as well as the development of delayed cerebral ischemia. As opioids were indicated primarily for analgosedation in mechanically ventilated patients with poor clinical status, their usage was associated with a significantly higher chance of poor outcome, delayed cerebral ischemia, and hydrocephalus.

CONCLUSION

Our results suggest that the prescription of metamizole may be associated with better outcomes and a lower chance of delayed cerebral ischemia development in patients after subarachnoid hemorrhage. Considering the retrospective nature of our study and the limited worldwide availability of metamizole due to its prohibition in some countries, our results do not demonstrate a clear benefit but rather justify the need for subsequent prospective studies.

Antinociceptive Effects of VV-Hemorphin-5 Peptide Analogues Containing Amino phosphonate Moiety in Mouse Formalin Model of Pain

BACKGROUND

Hemorphins are endogenous hemoglobin-derived peptides that belong to the family of "atypical" opioid peptides with both affinities to opioid receptors and ability to release other endogenous opioid peptides.

OBJECTIVE

In the present study, peptide analogues of Valorphin (VV-hemorphin-5) containing amino phosphonate moiety synthesized by solid-phase peptide synthesis (Fmoc-strategy) were investigated for their potential antinociceptive activities and compared to the reference VV-H in formalin- induced model of acute and inflammatory pain in mice.

METHODS

The hemorphin analogues were prepared by replacement of the one and/or two N-terminal Val in VV-hemorphin5 (VV-H) with ((dimethoxy phosphoryl) methyl)-L-valine and ((dimethoxy phosphoryl) methyl)-L-leucine to obtain the compounds pVV-H, pL-H, and pLV-H. Aiming to additionally prove the importance of amino acid valine, we introduced the ((dimethoxy phosphoryl) methyl)-L-leucine to the N-side of VV-hemorphin-5 (pLVV-H). The experiments were carried out on adult male ICR mice. All peptides were administered intracerebroventricularly at three doses (50, 25 and 12,5 μg/mouse). We have studied the effects of the peptides on acute (1st phase) and inflammatory (2nd phase) pain reaction using un experimental model with intraplantar formalin injection.

RESULTS

VV-H showed a significant antinociceptive effect both in the acute and inflammatory phases of the test. Although Valorphin hexa-, hepta-, and octapeptide analogs demonstrated a significant antinociceptive effect, they showed substantial differences considering their effective dose and the phase of the test as compared to the Valorphin.

DISCUSSION

Data showed that modified heptapeptides pVV-H and pLV-H exerted the same or better antinociception in acute and inflammatory pain, in comparison to the reference peptide, while pL-H and pLVV-H analogues were less effective.

CONCLUSION

Our study contributes to the elucidation of the role of Valine and the number of amino acid residues in the structure of hemorphin peptide analogs in their effectiveness in suppressing both acute and inflammatory experimental pain.

Drug-related challenges following primary total hip and knee arthroplasty

We aimed to characterize the in-hospital analgesic use among total hip or knee arthroplasty (THA or TKA) patients, and to identify possible drug-related challenges. We identified 15 263 patients operated with a THA or TKA between 1 January 2012 and 30 April 2016. The prevalence of analgesic users and patients with potential clinically relevant drug-drug interactions (DDIs), along with the prevalence of readmission among patients with vs. without a DDI, were calculated. A DDI was defined as the combination of (A) a diuretic, an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, and an non-steroidal anti-inflammatory Drug (NSAID); (B) warfarin and an NSAID; and (C) a benzodiazepine or a benzodiazepine-related drug and an opioid. The prevalence of analgesics administered in THA and TKA patients was 99.3% and 99.1% for paracetamol and 93.8% and 98.8% for opioids, respectively. The prevalence of patients who received interaction A, B or C was 8.4%, 2.5% and 40.7%, respectively. Patients with vs. without a DDI had a higher prevalence of 30-day readmission. In conclusion, most THA and TKA patients were administered paracetamol or opioids. The prevalence of 30-day readmission was higher in patients with than in patients without a potential clinically relevant DDI.

The Prevalence of Selected Potential Drug-Drug Interactions of Analgesic Drugs and Possible Methods of Preventing Them: Lessons Learned From the Analysis of the Real-World National Database of 38 Million Citizens of Poland

Introduction: Drug-drug interactions may lead to poor health outcomes, as well as increased costs and utilization of healthcare services. Unfortunately, real-world data continuously prove high prevalence of potential drug-drug interactions (pDDIs) worldwide. Among identified drivers, ageing, multimorbidity and polypharmacy play a very important role. With these factors being widespread, the need for implementation of strategies minimizing the burden of pDDIs becomes an urgency. This, however, requires a better understanding of the prevalence of pDDIs and the underlying causative factors.

Aim of study: To assess the real-world prevalence of pDDIs and its characteristics in the general population of Poland, using analgesic drugs as a model, and to find out whether pDDIs are caused by prescribing coming from the very same prescribers (co-prescribing).

Methods: A retrospective analysis of the 2018 dispensation data of the National Health Fund (NHF) - the only Polish public healthcare payer organization with nationwide coverage. We searched for selected pDDIs of non-steroidal anti-inflammatory drugs (NSAIDs) with antihypertensives, other NSAIDs (double use), oral glucocorticoids, oral anticoagulants, selective serotonin reuptake inhibitors (SSRIs), serotonin–norepinephrine reuptake inhibitors (SNRIs), and antiplatelet drugs; as well as opioides with SSRIs, SNRIs, gabapentinoids, and benzodiazepines. A pDDI was deemed present if two drugs standing in a possible conflict were dispensed within the same calendar month.

Results: Out of 38.4 million citizens of Poland, 23.3 million were dispensed prescribed drugs reimbursed by NHF in 2018. In this cohort, we have identified 2,485,787 cases of analgesic drug pDDIs, corresponding with 6.47% of the Polish population. Out of these, the most prevalent pDDI was caused by “NSAIDs + antihypertensives” (1,583,575 cases, i.e., 4.12% of the Polish population), followed by “NSAIDs + NSAIDs” (538,640, 1.40%) and “NSAIDs + glucocorticoids” (213,504, 0.56%). The most persistent pDDIs among those studied were caused by “Opioids + Gabapentinoids” (2.19, 95%CI: 2.16–2.22 months). On average, 76.63% of all cases of pDDIs were caused by drugs prescribed by the very same prescribers.

Conclusion: Based on high-quality, nationwide data, we have found a high prevalence of analgesic drugs-related pDDIs in Poland. Over ¾ of the identified pDDIs were caused by co-prescribing, i.e., prescriptions issued by the same prescribers. The significance of the problem, illustrated with our findings on analgesic drugs-related pDDIs in Poland, deserves much more scientific and policymaker attention.

Evaluation of Phenotypic and Genotypic Variations of Drug Metabolising Enzymes and Transporters in Chronic Pain Patients Facing Adverse Drug Reactions or Non-Response to Analgesics: A Retrospective Study

This retrospective study evaluates the link between an adverse drug reaction (ADR) or a non-response to treatment and cytochromes P450 (CYP), P-glycoprotein (P-gp) or catechol-O-methyltransferase (COMT) activity in patients taking analgesic drugs for chronic pain. Patients referred to a pain center for an ADR or a non-response to an analgesic drug between January 2005 and November 2014 were included. The genotype and/or phenotype was obtained for assessment of the CYPs, P-gp or COMT activities. The relation between the event and the result of the genotype and/or phenotype was evaluated using a semi-quantitative scale. Our analysis included 243 individual genotypic and/or phenotypic explorations. Genotypes/phenotypes were mainly assessed because of an ADR (n = 145, 59.7%), and the majority of clinical situations were observed with prodrug opioids (n = 148, 60.9%). The probability of a link between an ADR or a non-response and the genotypic/phenotypic status of the patient was evaluated as intermediate to high in 40% and 28.2% of all cases, respectively. The drugs in which the probability of an association was the strongest were the prodrug opioids, with an intermediate to high link in 45.6% of the cases for occurrence of ADRs and 36.0% of the cases for non-response. This study shows that the genotypic and phenotypic approach is useful to understand ADRs or therapeutic resistance to a usual therapeutic dosage, and can be part of the evaluation of chronic pain patients.

Regulators of G protein signalling as pharmacological targets for the treatment of neuropathic pain

Neuropathic pain, a specific type of chronic pain resulting from persistent nervous tissue lesions, is a debilitating condition that affects about 7% of the population. This condition remains particularly difficult to treat because of the poor understanding of its underlying mechanisms. Drugs currently used to alleviate this chronic pain syndrome are of limited benefit due to their lack of efficacy and the elevated risk of side effects, especially after a prolonged period of treatment. Although drugs targeting G protein-coupled receptors (GPCR) also have several limitations, such as progressive loss of efficacy due to receptor desensitization or unavoidable side effects due to wide receptor distribution, the identification of several molecular partners that contribute to the fine-tuning of receptor activity has raised new opportunities for the development of alternative therapeutic approaches. Regulators of G protein signalling (RGS) act intracellularly by influencing the coupling process and activity of G proteins, and are amongst the best-characterized physiological modulators of GPCR. Changes in RGS expression have been documented in a range of models of neuropathic pain, or after prolonged treatment with diverse analgesics, and could participate in altered pain processing as well as impaired physiological or pharmacological control of nociceptive signals. The present review summarizes the experimental data that implicates RGS in the development of pain with focus on the pathological mechanisms of neuropathic pain, including the impact of neuropathic lesions on RGS expression and, reciprocally, the influence of modifying RGS on GPCRs involved in the modulation of nociception as well as on the outcome of pain. In this context, we address the question of the relevance of RGS as promising targets in the treatment of neuropathic pain.

Efficacy of ketoprofen lysine salt and paracetamol/acetaminophen to reduce pain during rapid maxillary expansion: A randomized controlled clinical trial

BACKGROUND

Rapid maxillary expansion (RME) is an orthopaedic procedure indicated for a wide variety of clinical conditions.

AIM

The aim of the study was to compare the effects of ketoprofen lysine salt (KLS) vs paracetamol/acetaminophen (P) on pain perception during RME.

DESIGN

One hundred and fifty-one subjects (mean age 8.6 year) were enrolled in this prospective controlled clinical trial according to inclusion criteria: prepuberal stage of development, negative posterior transverse interarch discrepancy, non-concurrent use of other drugs. First phase: n.40 allocated to Group 1 used 40 mg of KLS, n.40 to Group 2 used 250 mg of P, n.36 to Group 3 as control group. Second phase: n.35 allocated to Group 4 used 40 mg ketoprofen lysine salt once a day for the first 3 days of activation. Pain experience was reported on a numeric rating scale (0-4) and a 100-mm visual analogue scale. Pain perception was tested with the Mann-Whitney test (P < 0.05).

RESULTS

Pain perception was higher during the first 3 days of activation and it was described as mild to moderate. Group 1 experienced significantly less pain during the fourth, fifth, and sixth day (P < 0.05) compared with Group 2. Patients of the Group 4 reported significantly lower pain during the whole period of RME activation (P < 0.05).

CONCLUSIONS

The perceived higher pain was reported during the second and third day of expansion. The analgesic effect of KLS is more effective than P during the fourth, fifth, and sixth day. The use of KLS during the first 3 days of activation seems to be able reducing pain during the whole active phase.

CYP2D6 genotype can help to predict effectiveness and safety during opioid treatment for chronic low back pain: results from a retrospective study in an Italian cohort

Background

Opioids are widely used for chronic low back pain (CLBP); however, it is still unclear how to predict their effectiveness and safety. Codeine, tramadol and oxycodone are metabolized by CYP/CYP450 2D6 (CYP2D6), a highly polymorphic enzyme linked to allele-specific related differences in metabolic activity.

Purpose

CYP2D6 genetic polymorphisms could potentially help to predict the effectiveness and safety of opioid-based drugs in clinical practice, especially in the treatment of CLBP.

Patients and methods

A cohort of 224 Italian patients with CLBP treated with codeine or oxycodone was retrospectively evaluated to determine whether adverse reactions and effectiveness were related to CYP2D6 single-nucleotide polymorphisms. CYP2D6 genotyping was performed using the xTAG^® CYP2D6 Kit v3 (Luminex) to determine CYP2D6 metabolizer phenotype (poor, intermediate, rapid and ultrarapid). Subjects from the cohort were categorized into two groups according to the occurrence of side effects (Case) or benefit (Control) after chronic analgesic treatment. The impact of CYP2D6 polymorphism on treatment outcome was tested at the metabolizer phenotype, diplotype and haplotype levels.

Results

CYP2D6 polymorphism was significantly associated with opioid treatment outcome (Omnibus P=0.018, for both global haplotype and diplotype distribution test). CYP2D6*6 and *9 carriers, alleles characterized by a reduced (*9) or absent (*6) enzymatic activity, were significantly (P<0.05) associated with therapeutic failure. CYP2D6 ultrarapid metabolizers (CYP2D6*2N patients) showed an increased risk of side effects, as would be predicted. Despite their low frequency, CYP2D6 *1/*11, *4/*6 and *41/* 2N diplotypes showed significant (P<0.05) associations of efficacy and side effects with chronic opioid treatment.

Conclusion

Our results showed that reduced CYP2D6 activity is correlated with lack of therapeutic effect. We found that the pharmacogenetic analysis of CYP2D6 could be helpful in foreseeing the safety and effectiveness of codeine or oxycodone treatment in CLBP.

Overview of microRNA Modulation in Analgesic Research

MicroRNA(miRNA)-mediated gene regulation underlies cellular processes, playing an important role in homeostasis and diseases. The expression and function of miRNAs are altered by various pharmacological agents, with differences in the endogenous levels of miRNAs influencing drug efficacy and toxicity. Thus, miRNA levels could be a biomarker for predicting treatment response, efficacy, and safety. In addition, elucidating the mechanistic significance of miRNA alterations can aid in the identification of therapeutic targets and patient selection, and guide personalized therapy. Discussed in this overview are the properties of miRNA, their modulation, and the ways to measure them. The effects of different classes of analgesics, including opioid and non-opioid, are described as examples of drug-induced modifications of miRNA, with a discussion on how measurement of miRNA levels in patients receiving analgesic therapy can assist in maximizing effectiveness while minimizing the untoward responses to this drug class. © 2017 by John Wiley & Sons, Inc.

A service improvement project to review prescribing information provided by general practitioners for new referrals to a UK National Health Service hospital pain clinic: potential implications of CYP2D6 enzyme inhibition

INTRODUCTION

Chronic pain is often managed using co-prescription of analgesics and adjuvants, with concomitant medication prescribed for comorbidities. Patients may have suboptimal response to some analgesics or be at risk of drug interactions or adverse drug reactions (ADRs) due to polypharmacy affecting CYP2D6 enzyme activity. The aim of the service improvement project was to determine the proportion of patients referred to a specialist pain service in the UK National Health Service (NHS) by general practitioners (GPs) who may be at risk of suboptimal analgesic response or ADRs due to CYP2D6 inhibition through polypharmacy. This was achieved by reviewing clinical prescribing information provided by GPs at time of referral. It was hoped that the findings could be used to aid clinical and prescribing decisions without conducting CYP2D6 genotyping or phenotyping.

METHODS

A review of letters from 250 patients referred to an NHS hospital pain service from GPs over a 3-month period was undertaken. Information about current and concomitant medications was analysed to identify the potential for CYP2D6 inhibition and adverse events.

RESULTS

Letters failed to provide information about current pain medication for 20 (8%) patients or non-pain concomitant medication for 54 (21.6%) patients. Of 176 patients, 52 (29.5%) patients with information about non-pain concomitant medication had been prescribed at least one known CYP2D6 inhibitor. A total of 35 (19.9%) patients were identified as being at risk of an adverse drug reaction and 33 (18.75%) patients at risk of suboptimal analgesic response due to co-administration of CYP2D6 inhibitors.

CONCLUSION

The review revealed the need for improved detail in GP referral letters used to transfer care to UK NHS hospital pain clinics. There is a need to consider an individual's CYP2D6 phenotype when prescribing analgesic prodrugs to manage persistent pain. Caution is needed when patients are co-prescribed codeine or tramadol with selective serotonin reuptake inhibitors (SSRIs).

PHEDRE trial protocol - observational study of the prevalence of problematic use of Equimolar Mixture of Oxygen and Nitrous Oxide (EMONO) and analgesics in the French sickle-cell disease population

BACKGROUND

The use of analgesics can lead to cases of drug abuse and dependence. It can also cause pseudo-addiction in patients suffering from pain. What is the actual situation in patients suffering from severe sickle-cell disease, exposed to acute pain during vaso-occlusive crises? Evaluation of the use of analgesics, on the basis of Diagnostic and Statistical Manual of Mental Disorders criteria for substance abuse and dependence, makes it possible to differentiate the symptoms occurring only in a context of pain, in the aim of managing the pain, and thus describing pseudo-addiction, from symptoms also occurring when there is no pain, and more in favour of true addiction. Currently there is no data available in France on this problem, and no studies have been carried out in children or adolescents with sickle-cell disease. The purpose of the study is to evaluate the prevalence of problematic use of equimolar mixture of oxygen and nitrous oxide and other analgesic drugs in a population of subjects with severe sickle-cell disease in France.

METHODS/DESIGN

PHEDRE (Pharmacodépendance Et DREpanocytose-drug dependence and sickle-cell disease) is an observational, descriptive and transversal study. Patients under the age of 26 with sickle-cell disease are included in the study by the doctors looking after them in sickle-cell disease centres. The patients are then contacted by a trained researcher for a telephone interview, including an evaluation of the Diagnostic and Statistical Manual of Mental Disorders criteria for abuse and dependence to equimolar mixture of oxygen and nitrous oxide and for each of the analgesic drugs taken by the patient. The data are also completed using the subject's medical record.

DISCUSSION

This study will make it possible to provide an initial quantitative and qualitative evaluation of problematic use of equimolar mixture of oxygen and nitrous oxide and analgesic drugs in the sickle-cell disease population. The results will be used firstly to provide additional data essential for monitoring the risk of overdose, abuse, dependence and misuse of these products, and to begin awareness-raising and to provide information for health care professionals, in order to significantly improve the management of sickle-cell disease-related pain.

TRIAL REGISTRATION

Clinical Trials.gov ID: NCT02580565 registered 16 October 2015 Unique Protocol ID: RC14_0344.

Psychiatric agents and implications for perioperative analgesia

The use of antidepressants, anxiolytics, mood stabilizers, anticonvulsants, and major tranquilizers introduces neurochemical, behavioral, cognitive, and emotional factors that increase the complexity of medical and surgical tasks. Increasingly, various classes of psychotropic medications are being prescribed in the perioperative setting for their analgesic properties in patients with or without a psychiatric diagnosis. In many cases, the precise mechanisms of action and dose-response relationships by which these agents mediate analgesia are largely unclear. An appreciation of the side effects and adverse-effect profiles of such medications and familiarity with the clinically relevant drug interactions that may occur in the perioperative setting are imperative to ensure the best possible outcome in dealing with patients on these medications. This review focuses on various classes of psychotropic agents, which are addressed individually, with particular focus on their analgesic properties. The latest published research is summarized, deficiencies in our current collective knowledge are discussed, and evidence-based recommendations are made for clinical practice.

Spectrofluorimetric and spectrophotometric analysis of two analgesic drugs in pharmaceutical formulations and biological fluids

Simple, reliable, sensitive, and accurate spectrofluorimetric and spectrophotometric methods were proposed for the determination of two selected analgesic drugs, namely tramadol and morphine, in pharmaceuticals and biological fluids. The proposed methods were based on the oxidation of the studied drugs by Cerium (Ce)IV in an acidic medium. The spectrofluorimetric method is based on measuring the relative fluorescence intensity of Ce(III) arising from Ce(IV) at 350 nm with an excitation wavelength at 250 nm. The spectrophotometric method involves on addition of a known excess of Ce(IV) to the studied drugs in an acid medium, followed by the determination of residual Ce(IV) by reacting with a fixed amount of methyl orange and measuring the absorbance at 510 nm. Different variables affecting the reaction conditions, such as the concentrations of Ce(IV), type and concentration of the acid medium, reaction time, temperature, and the diluting solvents, were carefully studied and optimized.