Recent prescription status of oral analgesics in Japan in real-world clinical settings: retrospective study using a large-scale prescription database

Hospital Discharge Prescription of Drugs That May Raise Blood Pressure in Patients With Hypertension

PURPOSE

This study aimed to determine the frequency of discharge prescriptions of drugs that may raise blood pressure (BP) in hospitalized patients with hypertension and identify factors associated with these prescriptions.

METHODS

A retrospective cross-sectional analysis was conducted using a nationwide inpatient database in Japan, focusing on adults with hypertension discharged from acute care hospitals between April 2021 and March 2022. The primary outcome was the prescription of drugs that may raise BP at discharge. A multivariable linear probability model was employed to assess the relationship between patient and hospital characteristics and the likelihood of receiving these prescriptions.

RESULTS

Among 979 234 patients with hypertension (mean age: 75.3 years, standard deviation: 13.2), 230 792 (23.6%) received at least one drug that may elevate BP at discharge. Non-steroidal anti-inflammatory drugs (NSAIDs) were the most frequently prescribed (46.6%), followed by glucocorticoids (35.3%), atypical antipsychotics (15.1%), antidepressants (7.9%), and Japanese herbal medicines (6.1%). Prescription prevalence was higher among female patients, younger adults, those admitted for medical conditions, non-emergency hospitalizations, patients with disabilities, and those with a Charlson Comorbidity Index of 1. Patients hospitalized for musculoskeletal or skin conditions, transferred to another hospital, or discharged from high-volume hospitals were also more likely to receive these prescriptions.

CONCLUSIONS

Drugs that may raise BP are commonly prescribed at discharge for patients with hypertension. This highlights the need for targeted interventions to optimize medication management at discharge, aiming to improve BP control and patient outcomes.

Granulation Methods and the Mechanisms for Improving Hardness of Loxoprofen Sodium Hydrate-Containing Tablets

Objectives: We investigated the compression mechanisms for loxoprofen sodium (LXP), which is known to occur as a dihydrate, and identified parameters that influence the tablet hardness of LXP tablets prepared by the wet granulation method. Method: LXP granules were prepared with water or ethanol as the solvent, dried under various conditions and sieved for particle size control, with 1% Mg-st added before tablet compression. Results: The findings indicated that both the granulation solvent and drying temperature significantly impacted the tablet hardness. Granules prepared with ethanol exhibited higher hardness as compared with those prepared with water. The tablet hardness varied with varying drying temperatures. Discussion: Principal component analysis (PCA) identified positive correlations between the tablet hardness and the surface free energy (SFE), polar component (γ(p)), and cohesion, and a negative correlation with the dispersive component (γ(d)). Granules prepared with ethanol exhibited a higher γ(p), likely due to the differing solubility in ethanol and water, leading to enhanced interparticle binding. This study confirmed that use of the eutectic mixture of LXP and Mg-st exerted no significant influence. Crystal structure analysis indicated that the hydration states varied according to the drying temperature, suggesting the higher γ(p) in anhydrous forms, due to the lower hydrophobicity, contributed to increased tablet hardness. Conclusion: This research offers insights for optimizing the formulation conditions to improve the LXP tablet hardness. Appropriate selection of the solvent and drying temperature mitigates tablet hardness issues, while assessment of SFE can help in the selection of suitable additives.

Preliminary Analysis of Drug-Induced Ototoxicity in South Korea: Trends From a National Sample Dataset

BACKGROUND AND OBJECTIVES

Certain medications are associated with ototoxicity. This study assesses drug-induced ototoxicity in South Korea by analyzing the Korean national health data.

SUBJECTS AND METHODS

Hospital records of National Health Insurance members from 2009 to 2016 were reviewed. Data were compared between patients with and without hearing loss (HL). Individuals with HL were identified as having a primary diagnosis code for sensorineural HL or another type of HL in at least one outpatient or inpatient record according to the International Classification of Diseases-10.

RESULTS

The members in the HL group increased slightly from 0.8% to 1.0% relative to the total sample, compared with 99.2% to 99.0% among the controls. The proportion of males in the HL group ranged from 45.6% to 47.6%, compared with 48.4% to 48.8% among the controls. The proportion of those aged ≥65 years in the HL group increased from 34.1% to 41.4%, compared with 10.6% to 13.3% among the controls. Hypertension prevalence (24.7%-25.7%) in the HL group was higher than that in the control group (12%-12.6%). Diabetes prevalence in the HL group was 10.6%-12.3%, compared with 4.4%-5.9% among the controls. The use of proton pump inhibitor components increased, particularly esomeprazole magnesium trihydrate and rabeprazole sodium, whereas the usage of pantoprazole sodium sesquihydrate and revaprazan was high initially but declined subsequently. The usage of painkillers such as acetaminophen, loxoprofen sodium, and ibuprofen remained high, and antibiotics such as cephalosporins indicated the highest usage. However, the use of penicillin antibiotics such as amoxicillin decreased significantly. Anticancer agents showed relatively low usage compared with other drug categories, whereas antihistamines showed extremely high usage across all years, with a continual increase.

CONCLUSIONS

These correlations and the underlying mechanisms necessitate further investigation, as several medicines have been linked to an increased risk of HL.

A photocrosslinkable and anti-inflammatory hydrogel of loxoprofen-conjugated chitosan methacrylate

Polymer-drug conjugates are widely used for drug delivery. Herein, we report an injectable hydrogel for local delivery of nonsteroidal anti-inflammatory drugs (NSAIDs) using chitosan (CS) as a carrier polymer. Loxoprofen (LOX) was conjugated to the backbone of CS via carbodiimide chemistry to obtain the LOX-CS conjugate. This conjugation transformed the water-insoluble unmodified CS into the water-soluble LOX-CS conjugate. In particular, the LOX-CS conjugate did not precipitate at pH 7, allowing smooth subsequent chemical modification with methacrylic anhydride (MA) to synthesize LOX-CS methacrylate (LOX-CS-MA) with significantly higher methacrylation substitution. The LOX-CS-MA was capable of in situ gel formation under visible light irradiation in the presence of a benzoin-2,4,6-trimethylbenzoylphosphinate lithium (LAP) photoinitiator. Our results show that the LOX-CS-MA hydrogel exhibited good cytocompatibility and blood compatibility. It promoted M2 polarization, inhibited pro-inflammatory gene expression, and upregulated anti-inflammatory gene expression of macrophages. Furthermore, the LOX-CS-MA hydrogel significantly reduced reactive oxygen species (ROS) and nitric oxide (NO) produced by lipopolysaccharide (LPS)-stimulated macrophages. A subcutaneous implanted LOX-CS-MA hydrogel in a rat model revealed significantly reduced inflammatory cell density, decreased cell infiltration, and a much thinner fibrous capsule compared to the CS methacrylate (CS-MA) hydrogel, thus markedly alleviating the inflammatory response. This study highlights the feasibility of CS-drug conjugates in preparing CS-based methacrylate hydrogels for sustained drug release.

Biodegradation of non-steroidal anti-inflammatory drug loxoprofen by a hyper lignin-degrading fungus Phanerochaete sordida YK-624 under non-ligninolytic conditions

Loxoprofen has been widely used as a non-steroidal anti-inflammatory drug globally and it can also persist in the environment. Although it is known to be a non-toxic drug, its presence may still pose a potential risk to organisms in the environment. Here, the hyper lignin-degrading fungus Phanerochaete sordida YK-624 was used to study the degradation of loxoprofen. This fungus showed excellent loxoprofen biodegradation ability with 90.4% and 93.4% after one day of incubation at lower concentrations of 0.01 and 0.005 mM, respectively. And at a higher concentration of 0.1 mM, a significant removal of 94.2% was also observed after 10 days of incubation. In this study, four metabolites were isolated and determined by HR-ESI-MS and NMR. Furthermore, LC/MS analysis suggested the presence of intermediate hydroxy loxoprofen. In addition, loxoprofen-OH was also identified as a metabolite of loxoprofen through comparison with the synthesized compounds. In this metabolism of loxoprofen, cytochrome P450 may play a significant role. Interestingly, P. sordida YK-624 showed enantioselectivity in the degradation process of loxoprofen. By these results, three degradation pathways of loxoprofen by P. sordida YK-624 were hypothesized. To the best of our knowledge, this is the first report describing the potential degradation mechanisms of loxoprofen by a white-rot fungus.

Glucocorticoid treatment and clinical outcomes in patients with polymyalgia rheumatica: A cohort study using routinely collected health data

OBJECTIVE

We aimed to describe the following in patients with polymyalgia rheumatica (PMR): (1) real-world glucocorticoid (GC) therapy, (2) improvement in inflammatory parameters associated with disease activity (C-reactive protein [CRP] level and erythrocyte sedimentation rate [ESR]), and (3) incidence of GC-related adverse events (AEs).

METHODS

A cohort study was conducted using a Japanese electronic medical records database. We included newly diagnosed PMR patients aged≥50years with baseline CRP levels≥10mg/L and/or ESR>30mm/h and an initial GC dose of≥5mg/day. The outcomes were GC dose, inflammatory parameters, and GC-related AEs.

RESULTS

A total of 373 PMR patients (mean age, 77.3 years) were analyzed. The median initial GC dose was 15.0mg/day, which gradually decreased to 3.5mg/day by week 52. The median cumulative GC dose at week 52 was 2455.0mg. The median CRP level on day 0 was 64.3mg/L, which decreased during weeks 4-52 (1.4-3.2mg/L). At week 52, 39.0% of patients had a CRP level>3.0mg/L. The cumulative incidence of GC-related AEs at week 52 was 49.0% for osteoporosis, 30.2% for diabetes, 14.9% for hypertension, 12.2% for peptic ulcer, 11.3% for dyslipidemia, 2.9% for glaucoma, and 4.3% for serious infection. The incidence of osteoporosis and diabetes increased with the GC dose.

CONCLUSION

The incidence of GC-related AEs was associated with the GC dose in PMR patients. Further research is required to identify treatment strategies that can effectively control PMR disease activity while minimizing GC use.

Mechanism of action of Shaoyao-Gancao decoction in relieving chronic inflammatory pain via Sema3G protein regulation in the dorsal root ganglion

Objective

The purpose of this study was to analyze the impact of Shaoyao-Gancao decoction (SGD) on proteins with significant changes in the dorsal root ganglion (DRG) in rats and to explore the role of the Semaphorin 3G (Sema3G) protein in the DRG and its downstream factors, interleukin-6 (IL-6) and CC-motif chemokine ligand 2(CCL2), in the treatment of chronic inflammatory pain (CIP).

Methods

We created a CIP rat model using 100 μL of complete Freund's adjuvant (CFA) that was injected into the left posterior plantar of rats. Then, we administered SGD intragastrically. We tested the animals for behavioral changes and protein expression levels in DRG pre- and post-drug intervention.

Results

Rats in the SGD group showed significantly increased paw withdrawal threshold (PWT), paw withdrawal latency (PWL), and relative expression levels of the Sema3G protein in the DRG (all P < 0.05), while the relative mRNA expression levels of IL-6 and CCL2 in the DRG of the rats were significantly decreased (P < 0.05) when compared with the model group.

Conclusion

In this study, we found that Shaoyao-Gancao decoction was effective in improving the PWT and PWL of rats with CIP. It reduced CIP by upregulating the expression of Sema3G in the DRG and inhibiting the relative mRNA expression levels of IL-6 and CCL2.

Safety of mirogabalin and pregabalin in Japanese patients with neuropathic pain: a retrospective cohort study

BACKGROUND

Few studies have compared the safety risks between the gabapentinoids, pregabalin, and mirogabalin in post-marketing clinical settings. We assessed reported events associated with gabapentinoid use in patients with neuropathic pain.

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study between September 2020 and December 2020 using the community pharmacies records in Japan. The pharmacists identified new vs. prevalent users of mirogabalin and pregabalin in September 2020 and reported data regarding baseline and adverse events to the Japan Pharmaceutical Association using web-based questionnaires. The incidence of events and hazard ratio (HR) were consequently compared.

RESULTS

New users of mirogabalin and pregabalin were identified (n = 1,650 and 2,244; mean age (SD): 69 (15) and 68 (16) years; women: 59% and 56%, respectively). Although serious events were not reported, a marked difference in HRs of common adverse events, including somnolence (1.6), dizziness (1.3), nausea (2.8), edema (3.1), and acetaminophen (2.0)/antidepressant (2.4) addition, was observed.

CONCLUSION

No new serious safety concerns were found for mirogabalin and pregabalin use in patients with neuropathic pain, although the HR of some events indicated increased risk among mirogabalin users. However, further studies are needed as estimates for events occurring in small numbers with wide confidence intervals.

Chronic pain and continuity of analgesic treatment during the COVID-19 pandemic

INTRODUCTION

Chronic pain can trigger both physical and mental health complications. During the COVID-19 pandemic, patients with chronic diseases have had reduced access to some medications.

OBJECTIVE

To determine the pharmacological management of patients with chronic pain and its continuity during the COVID-19 pandemic.

METHODS

This was a retrospective longitudinal study of the continuity of analgesic use in patients with chronic pain between September 1, 2019 and February 28, 2021 based on a drug dispensing database. Survival analysis was performed until the discontinuation of chronic analgesics.

RESULTS

A total of 12,701 patients who were being treated for chronic pain were identified. Their median age was 70.3 years, and 74.4% were women. The pain of rheumatological origin was the most frequent etiology (46.1%); the most used medications were nonopioid analgesics (78.9%), pain modulators (24.8%) and opioid analgesics (23.3%). A total of 76.1% of the patients experienced interruptions in their management during the study period. The median time to the first interruption of treatment was 5.0 months (95% CI: 4.8-5.2). Those who were treated for oncological pain experienced a greater number of interruptions in their management.

CONCLUSIONS

The pharmacological management of patients with chronic pain is heterogeneous, and this real-world study showed that a high proportion of patients experienced an interruption of pain management during the 12 months following the onset of the COVID-19 pandemic.

Protocol for the RETHINK study: a randomised, double-blind, parallel-group, non-inferiority clinical trial comparing acetaminophen and NSAIDs for treatment of chronic pain in elderly patients with osteoarthritis of the hip and knee

INTRODUCTION

In patients with chronic pain, oral analgesics are essential treatment options to manage pain appropriately, improve activities of daily living abilities and achieve a higher quality of life (QOL). It is desirable to select analgesics for elderly patients based on comparative data on analgesic effect and risk of adverse events; however, there are few comparative studies so far. The purpose of this study is to determine whether the efficacy and safety of acetaminophen are non-inferior to non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of chronic pain associated with osteoarthritis of the hip and knee in elderly patients.

METHODS AND ANALYSIS

This study is a multicentre, randomised controlled, double-blind, parallel-group study to compare the analgesic effect and adverse events between acetaminophen or NSAIDs (loxoprofen or celecoxib). A total of 400 elderly patients with osteoarthritis of the hip and knee will be recruited from five institutions in Japan. Patients of 65 years or older with osteoarthritis-related pain will be registered and randomly assigned to acetaminophen, loxoprofen or celecoxib with 2:1:1 allocation. The primary endpoint is change in the Brief Pain Inventory (BPI) item 3 (worst pain) score from baseline to week 8. The secondary endpoints are BPI item 3 score change from baseline to week 4, health-related QOL measured by Short Form-8 Health Survey, and occurrence of adverse events including gastrointestinal disorders and abnormal liver function. Data will be analysed in accordance with a predefined statistical analysis plan.

ETHICS AND DISSEMINATION

This study protocol was approved by the Kyushu University Hospital Certified Institutional Review Board for Clinical Trials on 28 January 2021 (KD2020004) and the chief executive of each participating hospital. The results of the study will be submitted to international peer-reviewed journals, and the main findings will be presented at international scientific conferences.

TRIAL REGISTRATION NUMBER

jRCTs071200112.

Risk of parkinsonism and related movement disorders with gabapentinoids or tramadol: A case-crossover study

INTRODUCTION

A safety signal concerning parkinsonism and related movement disorders with gabapentinoids (gabapentin and pregabalin) or tramadol was detected by reviewing individual case reports and data mining in spontaneous report databases. Well-designed pharmacoepidemiological studies are needed to assess the signal.

OBJECTIVE

This study aimed to investigate the association of exposure to gabapentinoids or tramadol with the risk of parkinsonism and related movement disorders.

METHODS

We conducted a case-crossover study using a Japanese electronic medical records database. Patients with newly diagnosed parkinsonism or related movement disorders between January 1, 2007, and April 14, 2019, were identified. The diagnosis date of outcomes was defined as the index date. We assessed the exposure of each patient to gabapentinoids or tramadol during a 90-day hazard period ending 1 day before the index date and in three 90-day reference periods. Multivariable conditional logistic regression models were employed to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs). To confirm the robustness of the primary findings, we also performed sensitivity analyses using a case-case-time-control design, a different time window for hazard and reference periods, a different definition of outcome, and different number of reference periods.

RESULTS

A total of 28,972 eligible cases were included in the primary analysis. Exposure to gabapentinoids (aOR, 2.12; 95% CI, 1.73-2.61) and tramadol (aOR, 2.04; 95% CI, 1.57-2.64) was associated with increased risk. Results were consistent across sensitivity analyses.

CONCLUSION

Our findings serve as a caution to physicians who prescribe gabapentinoids or tramadol in routine clinical practice.

Relationship between the dose titration and adherence of mirogabalin in patients with peripheral neuropathic pain depending on renal function: a nationwide electronic medical record database study

BACKGROUND

Mirogabalin has been attracting attention for treating peripheral neuropathic pain. The package insert recommends that mirogabalin should be titrated depending on renal function. Here, we investigated the relationship between dose titration patterns and adherence, and persistence of mirogabalin treatment.

RESEARCH DESIGN AND METHODS

Peripheral neuropathic pain patients who initiated mirogabalin between March 2020 and May 2021 were identified using an electronic medical record database. The dose titration pattern was described according to degrees of renal function. Regression analyses were performed to compare adherence and persistence between the patients with and without titration.

RESULTS

Of the 4,138 identified patients, 1,696 (41.0%) titrated the dose within 45 days and were more adherent than those without titration (Adjusted odds ratio: 1.75, 95% CI 1.21, 2.54). Of the total 952 patients with renal function parameters, 229 (24.1%) titrated to the effective dose within 45 days and were less likely to discontinue than those without titration (Adjusted hazard ratio: 0.57, 95% CI 0.40, 0.81).

CONCLUSION

Mirogabalin dose titration was associated with better adherence and persistence. It is important for mirogabalin treatment to determine the initial prescription dose based on renal function and subsequent dose titration according to the package insert.

TRIAL REGISTRATION

UMIN000047313.

Efficacy of Combination Therapy with Pregabalin in Neuropathic Pain: A Preclinical Study in the Rat L5 Spinal Nerve Ligation Model

PURPOSE

Neuropathic pain is sometimes difficult to manage because of limited efficacy of analgesic monotherapy even at high doses. Combination therapy may help address this issue, but there is little evidence for its effectiveness. Therefore, we evaluated the efficacy of combination therapy with pregabalin, an anchor drug for treating neuropathic pain, using the rat L5 spinal nerve ligation model.

METHODS

Experiments were performed on four-week-old L5 spinal nerve ligated male Sprague-Dawley rats. Mechanical allodynia was assessed using the von Frey test, where the 50% withdrawal threshold was evaluated for five drugs: pregabalin, duloxetine, venlafaxine, tramadol, and celecoxib. The single-drug experiment included 112 rats, where each drug was tested independently. Median effective doses (ED₅₀s) were determined. Combinations of pregabalin with each of the other four drugs were tested (n=84). The 50% withdrawal threshold in the von Frey test was evaluated. The ED₅₀ of each combination was determined experimentally. Isobolographic analyses were conducted to assess the synergistic potential of the drug combinations, excluding pregabalin-celecoxib, since the ED₅₀ of celecoxib could not be determined.

RESULTS

In the single-drug experiment, all drugs except celecoxib resulted in a dose-dependent increase in the 50% withdrawal threshold 2 h after administration, with a maximum possible effect ranging from 4.4% to 79.6%. Similarly, all pregabalin combinations demonstrated a dose-dependent increase in the 50% withdrawal threshold, with pregabalin-tramadol showing the greatest increment. Isobolographic analysis of this combination revealed synergistic effects. Specifically, the combination index was γ=0.4 (<1). Combinations of pregabalin with duloxetine and venlafaxine demonstrated additive (γ=0.9) and antagonistic effects (γ=2.0), respectively.

CONCLUSION

This study demonstrated that combination of pregabalin with tramadol has synergistic antiallodynic effects, while that with duloxetine has additive effects. Moreover, pregabalin combined with venlafaxine was potentially antagonistic. Pregabalin combined with tramadol may serve as a promising drug combination for the effective management of neuropathic pain.

Prescribing Pattern of Analgesics in Colombia. Are there Differences between Capital Cities and Municipalities? A Cross-Sectional Study

BACKGROUND

Analgesics provide multiple clinical benefits but they are not without risks.

OBJECTIVE

The aim of this study was to compare the outpatient prescribing pattern of analgesics between cities and municipalities in Colombia and to identify the variables associated with prescribing opioid analgesics.

METHODS

This was a cross-sectional study that identified the prescription of analgesics for outpatient use from a population database of 8.5 million Colombians. A descriptive, bivariate, and multivariate analysis was performed.

RESULTS

A total of 573,248 patients were identified who had received prescriptions for an analgesic. Mean age was 46.5 ± 23.6 years and 65.7% were females. The most commonly prescribed analgesics were non-opioid analgesics, antispasmodics, and opioid analgesics. The average milligram equivalent of morphine was higher in capital cities than in municipalities. Age ≥ 65 years (odds ratio [OR] 2.60, 95% confidence interval [CI] 2.54-2.67), male sex (OR 1.09, 95% CI 1.07-1.11), dispensing in cities (OR 2.25, 95% CI 2.20-2.30) and experiencing chronic pain (OR 13.25, 95% CI 10.89-16.14) were associated with an increased risk of receiving an opioid analgesic.

CONCLUSIONS

Differences were found in the prescription of analgesics between capital cities and municipalities. The use of opioids does not appear to be in line with the recommendations for clinical practice, and they were mainly prescribed for elderly males with chronic non-oncological pain and for residents of capital cities.

Symptom-based pharmacotherapy for neuropathic pain related to spinal disorders: results from a patient-based assessment

Existing guidelines advocate an updated therapeutic algorithm for chronic neuropathic pain (NeP), but pharmacotherapeutic management should be individualized to pain phenotypes to achieve higher efficacy. This study was aimed to evaluate the efficacy of medications, based on NeP phenotypes, and to propose symptom-based pharmacotherapy. This retrospective study was enrolled 265 outpatients with chronic NeP related to spinal disorders. The patients were classified into three groups: spinal cord-related pain, radicular pain, and cauda equina syndrome. Data were obtained from patient-based questionnaires using Neuropathic Pain Symptom Inventory (NPSI) and the Brief Scale for Psychiatric Problems in Orthopaedic Patients, and from clinical information. The proportions of patients with ≥ 30% and ≥ 50% reduction in NPSI score for each pain subtype (spontaneous pain, paroxysmal pain, evoked pain, and paresthesia/dysesthesia) and drugs were evaluated. The pain reduction rate was significantly lower in patients with spinal cord-related pain, especially for paresthesia/dysesthesia. For spinal cord-related pain, duloxetine and neurotropin had insufficient analgesic effects, whereas mirogabalin was the most effective. Pregabalin or mirogabalin for radicular pain and duloxetine for cauda equina syndrome are recommended in cases of insufficient analgesic effects with neurotropin. The findings could contribute to better strategies for symptom-based pharmacotherapeutic management.

Cost-Effectiveness Analysis of the Treatment Strategies with or without Opioid Medications in Surgery-Eligible Patients with Osteoarthritis in Japan

AIM

The aim of this study was to evaluate the cost effectiveness of treatment strategies without opioid medications (non-opioid treatment strategy) versus strategies with opioid medications (opioid treatment strategy) among surgery-eligible patients with osteoarthritis (OA) of the knee or hip in Japan.

MATERIALS AND METHODS

We built a Markov cohort model to evaluate outcomes for the treatment strategies in surgery-eligible patients aged ≥ 65 years with OA of the knee or hip in Japan. The opioid treatment strategy as an intervention includes a health state with opioid medication in the treatment pathway. On the other hand, for the non-opioid treatment strategy, there is no health state with opioid medication. A targeted literature review and database analysis were conducted to identify and define the values of the variables included in the model. The time horizon was set to 30 years, and a 2% discount was applied for cost and quality-adjusted life-years (QALYs). Sensitivity analysis and scenario analysis were performed in the model. The outcomes were QALYs and the incremental cost-effectiveness ratio (ICER).

RESULTS

In the base-case analysis, the non-opioid treatment strategy was dominant over the opioid treatment strategy and associated with an incremental cost and QALYs of - 53,878 JPY (- 499 USD) and 0.03 QALYs, respectively, in patients with knee OA, and - 54,129 JPY (- 502 USD) and 0.02 QALYs, respectively, in patients with hip OA. One-way sensitivity analysis showed the ICER was most sensitive to the QALY for opioid monotherapy. Probabilistic sensitivity analyses showed a high degree of uncertainty associated with the results.

LIMITATIONS

Study limitations included assumptions related to transition probabilities of the health states, and a lack of Japanese-specific data for transition probabilities, incidence of adverse events and utility values.

CONCLUSIONS

This study suggests that the non-opioid treatment strategy is cost effective compared with the opioid treatment strategy in the management of surgery-eligible patients with OA of the knee or hip. However, this final conclusion may not be accurate as the methodology is heavily reliant on assumptions.

A large-scale database study for the prescription status of a new voltage-gated Ca2+ channel α2δ ligand, mirogabalin, in Japan

BACKGROUND

A new voltage-gated Ca²⁺ channel α₂δ ligand, mirogabalin, was first approved for treating peripheral neuropathic pain in Japan in 2019. This is the first report on the prescription status of mirogabalin using a large-scale prescription database.

RESEARCH DESIGN AND METHODS

The authors analyzed the prescription data of 12,924 patients prescribed mirogabalin between 1 June and 31 August 2020. The endpoints were the number of patients prescribed, prescription days, prescription doses, dose changes, co-prescription patterns, medication possession ratio (MPR), and treatment discontinuation rates (TDRs).

RESULTS

Mirogabalin was newly prescribed to 7,914 patients in the 3-month study period. Most patients were prescribed mirogabalin at about 10 mg/day during the study period, and 30.9% of patients were prescribed ≥ 20 mg/day on Day 90 after the first prescription. The most frequently prescribed concomitant drug was celecoxib. The MPR (80 to 110%) was 86.2%, indicating good treatment adherence. The cumulative TDRs during ≤ 7 Days, Days 31-60, and 61-90 were 14.0%, 70.0%, and 77.9%, respectively.

CONCLUSIONS

Mirogabalin was prescribed to a considerable number of patients. These results may be useful for optimizing mirogabalin use for patients with peripheral neuropathic pain in daily clinical practice.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000042592.

Pharmacokinetics of loxoprofen in a self-administered overdose in a Japanese patient admitted to hospital

Background

Loxoprofen is a propionic acid derivative and is the most widely prescribed non-steroidal anti-inflammatory drug in Japan. Loxoprofen is generally considered to be relatively nontoxic.

Case presentation

A 33-year-old man (body weight, 55 kg) who intentionally took an overdose of 100 tablets of loxoprofen (6000 mg) as a suicide attempt was emergently admitted to Kyoto Medical Center. On arrival, the patient was suffering disorders of consciousness. His plasma concentrations of loxoprofen and its reduced trans-alcohol metabolite were 52 and 24 μg/mL, 3.7 and 2.3 μg/mL, 0.81 and 0.54 μg/mL, and 0.015 and 0.011 μg/mL, respectively, at 4, 26, 50, and 121 h after the oral overdose. The observed apparent terminal elimination half-life of loxoprofen during days 1 and 2 of hospitalization was in the range 6–12 h, which is several times longer than the reported normal value. This finding implied nonlinearity of loxoprofen pharmacokinetics over the current 100-fold dose range, which could affect the accuracy of values simulated by a simplified physiologically based pharmacokinetic (PBPK) model founded on data from a normal dose of 60 mg. The reasons for the delayed eliminations from plasma of loxoprofen and its trans-alcohol metabolite in this case are uncertain, but slight renal impairment (low eGFR values) developed on the second and third hospital days and could be a causal factor.

Conclusions

Because the patient’s level of consciousness had gradually improved, he was discharged on the fourth day of hospitalization. The virtual plasma exposures of loxoprofen and its reduced trans-alcohol metabolite estimated using the current simplified PBPK model were lower than the measured values in the overdose case. The present results based on drug monitoring data and pharmacokinetic predictions could serve as a useful guide in cases of loxoprofen overdose.

A review of a new voltage-gated Ca2+ channel α2δ ligand, mirogabalin, for the treatment of peripheral neuropathic pain

INTRODUCTION

Neuropathic pain (NeP) is a chronic and refractory condition in many patients, and its treatment is a challenge for physicians. A new voltage-gated Ca²⁺ channel α₂δ ligand, mirogabalin, has a high specific binding affinity for the α₂δ subunit, with a slower dissociation rate for α₂δ-1 than α₂δ-2 compared to that of pregabalin. Mirogabalin was shown to be effective in NeP animal models, with a margin of safety between central nervous system side effects and the analgesic effect of the dose. It exerted a favorable analgesic effect, was well tolerated in patients with peripheral NeP (P-NeP), and was first approved in Japan in 2019 and subsequently in Korea and Taiwan in 2020.

AREAS COVERED

The purpose of this article is to review the pharmacological characteristics, pharmacokinetics, and efficacy and safety of mirogabalin for NeP based on the results of non-clinical and clinical studies.

EXPERT OPINION

Although there are several first-line therapies for NeP, insufficient efficacy and adverse drug reactions of NeP drugs often cause patient dissatisfaction. Mirogabalin was effective and well tolerated with a step-wise dose increase in clinical studies on P-NeP patients. Thus, mirogabalin is expected to be a useful treatment option for patients with P-NeP.

An Investigation of the Molecular Mechanisms Underlying the Analgesic Effect of Jakyak-Gamcho Decoction: A Network Pharmacology Study

Herbal drugs have drawn substantial interest as effective analgesic agents; however, their therapeutic mechanisms remain to be fully understood. To address this question, we performed a network pharmacology study to explore the system-level mechanisms that underlie the analgesic activity of Jakyak-Gamcho decoction (JGd; Shaoyao-Gancao-Tang in Chinese and Shakuyaku-Kanzo-To in Japanese), an herbal prescription consisting of Paeonia lactiflora Pallas and Glycyrrhiza uralensis Fischer. Based on comprehensive information regarding the pharmacological and chemical properties of the herbal constituents of JGd, we identified 57 active chemical compounds and their 70 pain-associated targets. The JGd targets were determined to be involved in the regulation of diverse biological activities as follows: calcium- and cytokine-mediated signalings, calcium ion concentration and homeostasis, cellular behaviors of muscle and neuronal cells, inflammatory response, and response to chemical, cytokine, drug, and oxidative stress. The targets were further enriched in various pain-associated signalings, including the PI3K-Akt, estrogen, ErbB, neurotrophin, neuroactive ligand-receptor interaction, HIF-1, serotonergic synapse, JAK-STAT, and cAMP pathways. Thus, these data provide a systematic basis to understand the molecular mechanisms underlying the analgesic activity of herbal drugs.

Comparison of the Effectiveness of Pharmacological Treatments for Patients with Chronic Low Back Pain: A Nationwide, Multicenter Study in Japan

INTRODUCTION

Chronic low back pain (CLBP) is a leading cause of disability, yet there is limited high-quality evidence to identify the most suitable pharmacological therapy. The purpose of this Japanese nationwide, multicenter, prospective study was to compare the effectiveness of four representative drug therapies-acetaminophen, celecoxib, loxoprofen, and a tramadol and acetaminophen (T+A) combination drug-to establish evidence for a drug of choice for CLBP.

METHODS

Patients with CLBP (N=471) received one of the four treatments and were evaluated, prospectively and comprehensively, once every month for six months using a visual analog scale (VAS) for LBP, the Japanese Orthopedic Association (JOA) score, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), the Roland-Morris Disability Questionnaire (RDQ), the EuroQol five-dimensions three-levels (EQ-5D-3L), and the Short Form-8 item health survey (SF-8). We conducted multivariable linear regression analyses of the four drugs at 1 and 6 months after drug allocation. Differences with P<0.05 were considered statistically significant.

RESULTS

Patients who received acetaminophen showed a significant improvement from baseline in the mental health subscale of the JOABPEQ at one month (P=0.02) and the JOA score at six months (P<0.01). None of the other outcome measures among the four drugs differed significantly. Across groups, all outcome measures, except the mental component summary (MCS) score of the SF-8, improved equivalently, although most measurements showed no obvious cumulative effect over six months. The MCS score of the SF-8 decreased gradually over six months in all groups.

CONCLUSIONS

Most of the outcome measures among the treated groups were not significantly different, indicating similar treatment effects of the four drugs for CLBP. Our study indicated the limit of each outcome measure for evaluating the patient status, suggesting that a single outcome measure is insufficient to reflect treatment effectiveness.

[Is Concomitant Therapy with Acetaminophen and Low-dose Aspirin a Risk Factor for CKD Progression? A 6-Year Cohort Study]

Concomitant therapy with acetaminophen (APAP) and low-dose aspirin is often used in clinical settings; however, it is unclear whether this combination is involved in the progression of chronic kidney disease (CKD). We hypothesized that concomitant therapy with APAP and low-dose aspirin may cause CKD progression. We carried out a retrospective 6-year cohort study that included all patients who received low-dose aspirin from January 2011 to December 2016 at Kaetsu Hospital. Primary outcome was defined as CKD progression at the end of the study compared with baseline. Among the 441 patients treated during the study period, we identified 89 cases of CKD progression. Multivariate regression analysis showed that exposure to APAP>50 g [odds ratio (OR), 2.68, 95% confidence interval (CI), 1.08-6.70], age increase by 1 year (OR, 1.05, 95% CI, 1.02-1.08), and diabetes mellitus (OR, 2.40, 95% CI, 1.41-4.08) had positive associations with CKD progression. Our findings suggested that concomitant therapy with APAP and low-dose aspirin increased the risk of CKD progression. Therefore, we recommend more thorough monitoring of serum creatinine when patients are on such concomitant therapy. Moreover, it is important to advise users of low-dose aspirin to avoid unnecessary use of APAP, in order to reduce the risk of CKD progression.

Persistence of pregabalin treatment in Taiwan: a nation-wide population-based study

Background

Pregabalin is approved for the treatment of neuropathic pain, fibromyalgia, and seizure disorders, although the pivotal trials were mostly carried out in Europe or North America. The prescribing patterns among different indications in Asia have rarely been explored.

Methods

This was a population-based retrospective cohort study based on the National Health Insurance Research Database in Taiwan. Prescriptions of pregabalin were identified, and data regarding demographics, indications, co-existing diagnoses, and concomitant medications were extracted. Pregabalin users were followed for at least one year, and factors associated with persistence at one year were determined by using multivariate logistic regression analysis.

Results

Between June 2012 and December 2016, 114,437 pregabalin users (mean age 60.7 ± 15.4 years, 57.8% female) were identified. The indications included post-herpetic neuralgia (PHN) (30.5%), musculoskeletal diseases other than fibromyalgia (21.2%), fibromyalgia (18.4%), diabetic peripheral neuropathic pain (DPNP) (11.7%) and epilepsy (2.9%). Overall, 62.5% and 6.4% of patients achieved a maximum dose of ≥150 and ≥ 300 mg/day, respectively. The median duration of persistent pregabalin use was 28 days (interquartile range 14–118 days). The one-year persistence rate was 12.1%, and the indications associated with the highest and lowest persistence rates were epilepsy (42.4%) and PHN (6.1%), respectively. Male gender (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.09–1.18), older age (OR 1.01 per year, 95% CI 1.01–1.01), indications other than PHN, especially epilepsy (OR 8.04, 95% CI 7.33–8.81, PHN as reference), and a higher initial dose (OR 1.12 per 75 mg, 95% CI = 1.10–1.15) were associated with persistence at one year, whereas the initial concomitant use of antiviral agents decreased the likelihood (OR 0.41, 95% CI 0.35–0.47).

Conclusions

Pregabalin prescriptions for pain disorders were limited to short-term use, which is consistent around the world. However, the average prescribed dose in Taiwan was lower than those in Western countries, and was frequently below the recommended ranges. Potential causes included the duration of natural history of PHN, and off-label prescriptions for pain in acute herpes zoster, rather than PHN, as well as intolerance to the side effects.

Nonsteroidal anti-inflammatory drugs use in patients with chronic kidney disease are often prescribed from different clinicians than those who diagnosed them

PURPOSE

When prescribing nonsteroidal anti-inflammatory drugs (NSAIDs) for chronic kidney disease (CKD), patients' pathology and concomitant medications should be considered. In our pharmaceutical experience, NSAIDs are often prescribed by departments that are different from those that diagnosed CKD. That is, NSAIDs may be prescribed for patients without the advice of the clinicians who diagnosed them. In this study, we aimed to elucidate how frequently such cases occur.

METHODS

We used the large health insurance claims database constructed by JMDC Inc., Tokyo. We evaluated the proportions of CKD diagnosis and NSAID prescription by different clinical departments and institutions.

RESULTS

A total of 224 014 out-patients were included in the analysis; they were divided into CKD (n = 1501) and non-CKD groups (n = 222 513). The internal medicine departments diagnosed CKD most frequently (74.8% of the patients) and surgical departments rarely diagnosed CKD. However, the proportion of prescribed NSAIDs was high in other departments, especially surgical departments. In the CKD group, 50.4% of the patients received CKD diagnosis and NSAID prescription from different clinical departments; 72.8% of the patients received a diagnosis and prescription from different medical institutions.

CONCLUSION

Our study revealed that NSAIDs are often prescribed to patients with CKD from different clinicians than those who diagnosed them.

A descriptive study of pain treatment and its follow-up in primary care of elderly patients after orthopaedic care

Background

Pain treatment post orthopaedic care in the elderly is complicated and requires careful follow-up. Current guidelines state all patients prescribed opioids should have a plan for gradual reduction, with the treatment progressively reduced and ended if any pain remains after more than three months. How this works in primary care remains to be explored.

The aim was to describe pain treatment and its follow-up in primary care of elderly patients after orthopaedic care.

Methods

In this descriptive study, medical case histories were collected for patients ≥ 75 years, which were enrolled at two rural primary care units in southern Sweden, and were discharged from orthopaedic care. Pain medication follow-up plans were noted, as well as current pain medication at discharge as well as two, six and twelve weeks later.

Results

We included a total of 49 community-dwelling patients with medication aid from nurses in municipality care and nursing home residents, ≥ 75 years, discharged from orthopaedic care. The proportion of patients prescribed paracetamol increased from 28/49 (57%) prior to admission, to 38/44 (82%) after 12 weeks. The proportion of patients prescribed opioids increased from 5/49 (10%) to 18/44 (41%). Primary care pain medication follow-up plans were noted for 16/49 patients (33%).

Conclusions

Many patients still used pain medication 12 weeks after discharge, and follow-up plans were quite uncommon, which may reflect upon lacking follow-up of these patients in primary care.

Cross-sectional study of patient satisfaction with oral analgesics in patients with chronic pain in Japan

BACKGROUND

Chronic pain is often difficult to treat, and many patients are not satisfied with analgesic treatment. The authors assessed patient satisfaction with oral analgesics in patients with chronic pain in Japan.

RESEARCH DESIGN AND METHODS

This was an observational cross-sectional study conducted in dispensing pharmacies. A patient satisfaction questionnaire survey was conducted in 781 patients prescribed one nonsteroidal anti-inflammatory drug (NSAID) or neuropathic pain (NeP) drug for at least 90 consecutive days. The primary endpoint was patient satisfaction with analgesics. The secondary endpoints were pain relief, activity of daily living (ADL) improvement and doctor-patient communication.

RESULTS

The proportions of patients who answered 'satisfied if anything' or better for patient satisfaction in the NSAID and NeP drug groups were 70.0% and 65.2%, respectively, whereas those of patients who answered 'satisfied' were 43.3% and 29.4%, respectively. The proportions of patients with improved pain relief, ADL improvement, and good doctor-patient communication were numerically higher than those of patients who answered 'satisfied if anything' or better.

CONCLUSIONS

Approximately two-thirds of the patients were satisfied with current analgesics. Patient satisfaction with oral analgesics could be influenced by multiple factors.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000036456.