Potential drug-induced constipation: A retrospective study using a Japanese claims database.

Background and Aim: Detailed clinical information regarding drug-induced constipation (DIC) is limited. This study aimed to investigate the real-world situation of DIC. Methods: This retrospective study used data from a Japanese claims database registered from 2014 to 2021. The constipation cohort included subjects with at least one record of treated constipation, while the non-constipation cohort was selected through random stratified sampling method, to match the constipation cohort by gender. The study population and control with at least one history of a known causative drug (CD) were matched 1:1 using propensity scores. The proportion of potential DIC (pDIC), the timing of diagnosis for pDIC, and the proportion of prescriptions by drug class for both the CDs and the laxatives were calculated, while logistic regression analysis was performed to explore additional associated factors. Results: Of the 4 533 905 subjects, 178 852 were eligible in both the study population and the control. The pDIC group comprised of 19 485 patients, which accounted for 10.9% of all treated constipation subjects, while the non-constipation with CD group had 10 430 subjects. The median duration between the recorded CD prescription and treated constipation was 38.0 days. The most frequently prescribed CD was cardiovascular drugs (47.9%). All CD classes, being male, and some comorbidities were associated with the occurrence of pDIC. Conclusion: The pDIC subjects accounted for about 11% of all treated constipation cases. Since DIC requires different treatment regimens compared to other constipation types, physicians should be cognizant to provide patients with optimized treatments.

Comparative profiles of lubiprostone, linaclotide, and elobixibat for chronic constipation: a systematic literature review with meta-analysis and number needed to treat/harm.

OBJECTIVE: To comprehensively evaluate the efficacy, safety, patient symptoms, and quality-of-life (QoL) of lubiprostone, linaclotide, and elobixibat as treatment for chronic constipation (CC). DESIGN: Systematic literature review (SLR) and meta-analysis (MA). Literature searches were conducted on PubMed and Embase using the Ovid platform. METHODS: SLR including randomized controlled trials (RCTs) and observational studies was conducted to identify the overall efficacy and safety of lubiprostone, linaclotide, and elobixibat. Thereafter, MA was performed using only RCTs. The number needed to treat (NNT) and number needed to harm (NNH) analyses were additionally conducted. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was efficacy regarding change in spontaneous bowel movements. Secondary outcomes included safety, constipation-related symptoms, and QoL. RESULTS: Twenty-four studies met the inclusion criteria for the SLR: 17 RCTs, 4 observational studies, and 3 single-arm trials. Feasibility assessment for the MA resulted in 14 studies available for safety data analysis, and 8 available for efficacy analysis, respectively. Three drugs showed similar efficacy in the MA and NNT analysis. However, the NNH analysis revealed distinct safety profiles: lubiprostone, linaclotide, and elobixibat were linked to the highest risk of nausea, diarrhea, and abdominal pain, respectively. CONCLUSION: The current study provides an updated overview of the efficacy, safety, patient symptoms, and QoL of the three drugs with different mechanisms of action for CC treatment.The findings could help physicians adopt an individualized approach for treating patients with CC in clinical practice.

Barriers to healthcare access in patients with chronic pain or potential migraine in Japan: a cross-sectional internet survey.

Purpose: Chronic pain and migraines often go untreated despite patient- and economic-related burdens (e.g., impaired quality of life and productivity). Understanding the reasons for non-treatment is important to enable interventions aimed at improving care-seeking behaviors. However, reports on disease-specific justifications for nontreatment in Japan are limited. We aimed to determine the barriers to healthcare access in untreated patients with chronic pain or migraines. Patients and methods: This was a non-interventional, cross-sectional, internet questionnaire survey of patients with chronic pain or migraines. The primary endpoint was to identify the reasons for untreated chronic pain or migraines. Secondary endpoints included factors associated with healthcare access, including patient background, patient-reported outcomes, and awareness of generic or authorized generic drugs (AG). Results: We surveyed 1,089 patients with chronic pain [605 (55.6%) untreated] and 932 patients with migraines [695 (74.6%) untreated] in 2021. The main reasons for not seeking treatment for chronic pain was "my pain is tolerable" and for migraine, "I can manage my pain with over-the-counter drugs." Background factors significantly associated with untreated chronic pain were younger age, less time required to access the nearest medical institution, less pain, higher activities of daily living (ADL) scores, and lower awareness of generic drugs and AG. Among patients with migraine, notable characteristics included being female, having shorter travel times to the nearest medical facility, residing in municipalities with populations under 50,000, experiencing moderate to severe pain, having higher ADL scores, and displaying lower awareness of AG. The AG awareness rate was 2-fold higher in treated patients than in untreated patients. Conclusion: Educating patients regarding the risks associated with pain and its underlying causes, availability of inexpensive treatment options, and location of appropriate treatment facilities may increase treatment rates.

Effectiveness and safety of lubiprostone after switching from stimulant laxatives in elderly patients with chronic constipation.

Background and Aim: Stimulant laxatives may cause electrolyte abnormalities, dehydration, and abdominal pain; their long-term use can lead to tolerance and subsequent refractory constipation. We investigated the effectiveness, safety, and quality of life after switching from stimulant laxatives to lubiprostone in elderly patients with chronic constipation (CC). Methods: This multicenter, interventional, open-label, single-arm, before-and-after comparison study enrolled 99 Japanese patients aged 65-90 years with CC who took stimulant laxatives for ≥2 weeks prior to switching to lubiprostone monotherapy. Results: The mean ± SD spontaneous defecations at Week 1 of 7.8 ± 6.2 times/week was not significantly different from that at baseline (8.3 ± 4.7). Spontaneous defecations were significantly reduced at Weeks 2 (-1.5 ± 4.0, P < 0.001) and 4 (-1.5 ± 3.7, P < 0.001). The Bristol Stool Form Scale score did not change from baseline (4.7 ± 0.9) at Weeks 1 (4.5 ± 1.3) or 4 (4.3 ± 1.3), but it did at Week 2 (4.3 ± 1.5, P < 0.05). The Patient Assessment of Constipation Quality of Life questionnaire score increased (0.36 ± 0.07, P < 0.001) after 28 days. Nausea was the only symptom that worsened from baseline and was the most frequently reported adverse drug reaction (15.2%). Conclusion: Switching to lubiprostone monotherapy for CC was not associated with significant concerns in short-term spontaneous defecation frequency and safety, but it might affect the efficacy and patient quality of life over 2 weeks. Careful treatment strategies facilitating gradual switching to lubiprostone monotherapy may be needed in patients using stimulant laxatives.

Dietary therapy for patients with chronic pancreatitis in Japan: a cross-sectional online survey of physicians and registered dietitians.

Background: This study was aimed towards understanding the current status of dietary therapy for patients with pancreatic exocrine insufficiency (PEI) in Japan and its alignment with Japanese recommendations for high-fat intake and concomitant high-potency pancreatic enzyme replacement therapy (PERT) by surveying treating physicians and registered dietitians. Methods: The 19-item physicians' online questionnaire collected data about the number of patients with PEI treated, methods used to assess PEI and nutritional status in patients with PEI, as well as provision of dietary guidance and details of treatment with PERT. The 10-item registered dietitians' online questionnaire captured data about the provision of dietary guidance, including setting (inpatient or outpatient) and details of nutritional guidance provided to patients. Results: Overall, 35 physicians and 23 dietitians completed the respective questionnaires. The primary cause of PEI in patients treated by physicians during the previous month was chronic pancreatitis (80.5%). Of 30 (86%) physicians who reported implementing dietary guidance for patients with PEI, less than half (43%) followed national guidelines and most (83%) implemented a low-fat diet. The use of PERT in recently treated patients with PEI was low. Amongst 11 (48%) dietitians who reported providing dietary guidance to patients with chronic pancreatitis and PEI, 7 (64%) recommended restricting fat intake in patients with uncompensated chronic pancreatitis. Dietitians overall were more likely to provide guidance about alcohol avoidance (91%) than smoking cessation (48%) to appropriate patients. Conclusion: This survey suggests that additional educational efforts are required to align the management practices of physicians and registered dietitians with evidence-based clinical practice guidelines for Japanese patients with chronic pancreatitis and PEI.

Therapeutic Potential of Orally Administered Rubiscolin-6.

Rubiscolins are naturally occurring opioid peptides derived from the enzymatic digestion of the ribulose bisphosphate carboxylase/oxygenase protein in spinach leaves. They are classified into two subtypes based on amino acid sequence, namely rubiscolin-5 and rubiscolin-6. In vitro studies have determined rubiscolins as G protein-biased delta-opioid receptor agonists, and in vivo studies have demonstrated that they exert several beneficial effects via the central nervous system. The most unique and attractive advantage of rubiscolin-6 over other oligopeptides is its oral availability. Therefore, it can be considered a promising candidate for the development of a novel and safe drug. In this review, we show the therapeutic potential of rubiscolin-6, mainly focusing on its effects when orally administered based on available evidence. Additionally, we present a hypothesis for the pharmacokinetics of rubiscolin-6, focusing on its absorption in the intestinal tract and ability to cross the blood-brain barrier.

Comparative effectiveness of early initiation of oral nonsteroidal anti-inflammatory drug and oral acetaminophen therapies on the time to knee replacement in patients with knee osteoarthritis in Japan.

BACKGROUND: Although disease-modifying properties of nonsteroidal anti-inflammatory drugs (NSAIDs) for osteoarthritis (OA) have been reported, the effects of NSAIDs on OA progression remain controversial. The purpose of this study was to investigate the effect of early initiation of oral NSAID therapy on the progression of knee OA. METHODS: In this retrospective cohort study, we extracted data of patients newly diagnosed with knee OA between November 2007 and October 2018 from a Japanese claims database. The primary outcome was the time to knee replacement (KR), and the secondary outcome was the time to composite event including joint lavage and debridement, osteotomy, or arthrodesis in addition to KR. Weighted Cox regression analysis with standardized mortality/morbidity ratio (SMR) weight was performed to compare the outcomes between patients prescribed oral NSAID (NSAID group) and those prescribed oral acetaminophen (APAP) (APAP group) early after a diagnosis of knee OA. Propensity scores were calculated using logistic regression conditioned on potential confounding factors, and SMR weights were calculated using the propensity scores. RESULTS: The study population comprised 14,261 patients, who were divided into two groups as follows: 13,994 in the NSAID group and 267 in the APAP group. The mean ages of patients in the NSAID and APAP groups were 56.9 and 56.1 years, respectively. Furthermore, 62.01% and 68.16% patients in the NSAID and APAP groups, respectively, were female. The NSAID group had a reduced risk of KR compared with the APAP group in the analysis using SMR weighting (SMR-weighted hazard ratio, 0.19; 95% confidence interval, 0.05-0.78). While no statistically significant difference was found for the risk of composite event between the two groups (SMR-weighted hazard ratio, 0.56; 95% confidence interval, 0.16-1.91). CONCLUSIONS: The risk of KR in the NSAID group was significantly lower than that in the APAP group after accounting for residual confounding using SMR weighting. This finding suggests that oral NSAID therapy early after the initial diagnosis is associated with a reduced risk of KR in patients with symptomatic knee OA.

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.

Evaluation of the Intracellular Signaling Activities of κ-Opioid Receptor Agonists, Nalfurafine Analogs; Focusing on the Selectivity of G-Protein- and ß-Arrestin-Mediated Pathways.

Opioid receptors (ORs) are classified into three types (µ, δ, and κ), and opioid analgesics are mainly mediated by µOR activation; however, their use is sometimes restricted by unfavorable effects. The selective κOR agonist nalfurafine was initially developed as an analgesic, but its indication was changed because of the narrow safety margin. The activation of ORs mainly induces two intracellular signaling pathways: a G-protein-mediated pathway and a ß-arrestin-mediated pathway. Recently, the expectations for κOR analgesics that selectively activate these pathways have increased; however, the structural properties required for the selectivity of nalfurafine are still unknown. Therefore, we evaluated the partial structures of nalfurafine that are necessary for the selectivity of these two pathways. We assayed the properties of nalfurafine and six nalfurafine analogs (SYKs) using cells stably expressing κORs. The SYKs activated κORs in a concentration-dependent manner with higher EC50 values than nalfurafine. Upon bias factor assessment, only SYK-309 (possessing the 3S-hydroxy group) showed higher selectivity of G-protein-mediated signaling activities than nalfurafine, suggesting the direction of the 3S-hydroxy group may affect the ß-arrestin-mediated pathway. In conclusion, nalfurafine analogs having a 3S-hydroxy group, such as SYK-309, could be considered G-protein-biased κOR agonists.

The Use of a Network Analysis to Identify Associations and Temporal Patterns Among Non-communicable Diseases in Japan Based on a Large Medical Claims Database.

BACKGROUND: Reducing the considerable non-communicable disease (NCD) burden in the aging Japanese population depends on better understanding of the comorbid and temporal relationships between different NCDs. OBJECTIVE: We aimed to identify associations between NCDs and temporal patterns of NCDs in Japan using data from a large medical claims database. METHODS: The study used three-digit International Classification of Diseases, Tenth Revision codes for NCDs for employees and their dependents included in the MinaCare database, which covers the period since 2010. Associations between pairs of NCDs were assessed by calculating risk ratios. The calculated risk ratios were used to create a network of closely associated NCDs (risk ratio > 15, statistically significant) and to assess temporal patterns of NCD diagnoses (risk ratio ≥ 5). The Infomap algorithm was used to identify clusters of diseases for different sex and age strata. RESULTS: The analysis included 4,200,254 individuals (age < 65 years: 98%). Many of the temporal associations and patterns of the diseases of interest identified in this study were previously known. Regarding the diseases of interest, these associations can be classified as comorbidities, early manifestations initially diagnosed as something else, diseases attributable to or that cause the disease of interest, or caused by pharmacological treatment. International Classification of Diseases, Tenth Revision chapters that were most associated with other chapters included L Diseases of the skin and subcutaneous tissue. In the age-stratified and gender-stratified networks, clusters with the highest numbers of International Classification of Diseases, Tenth Revision codes included I Diseases of the circulatory system and F Mental and behavioral disorders. CONCLUSIONS: Our findings reinforce established associations between NCDs and underline the importance of comprehensive NCD care.

Novel Opioid Analgesics for the Development of Transdermal Opioid Patches That Possess Morphine-Like Pharmacological Profiles Rather Than Fentanyl: Possible Opioid Switching Alternatives Among Patch Formula.

BACKGROUND: Transdermal fentanyl is widely used in the treatment of severe pain because of convenience, safety, and stable blood concentrations. Nevertheless, patients often develop tolerance to fentanyl, necessitating the use of other opioids; transdermal buprenorphine patch is widely used as an analgesic agent, though available formulation does not provide comparable analgesic effect as transdermal fentanyl patch. Opioids bind to the opioid receptor (OR) to activate both G protein-mediated and ß-arrestin-mediated pathways. We synthesized morphine-related compounds with high transdermal absorbability (N1 and N2) and evaluated their OR activities pharmacologically in comparison with fentanyl and morphine. METHODS: In cells stably expressing µ-opioid receptor (MOR), δ-opioid receptor (DOR), and κ-opioid receptor (KOR), G protein-mediated pathways were assessed using the CellKey and an intracellular cyclic adenosine monophosphate (cAMP) assay, while ß-arrestin-mediated pathways were analyzed with ß-arrestin recruitment and receptor internalization assays. Furthermore, analgesic effects were evaluated using a tail-flick test in mice, and the analgesic effect on fentanyl-tolerant mice was evaluated. RESULTS: In the CellKey and cAMP assays, both N1 and N2 showed the highest affinity for MOR and acted as full agonists as well as partial agonists for DOR and KOR. In the ß-arrestin and internalization assays, only fentanyl acted as a full agonist; N1 and N2 acted as partial agonists of MOR. In the mouse tail-flick test, N1 and N2 showed analgesic effects equivalent to those of fentanyl and morphine. In fentanyl-tolerant mice, fentanyl showed a diminished analgesic effect, whereas N1 and N2 as well as morphine retained their analgesic effects. CONCLUSIONS: While N1 and N2 have higher transdermal absorbability than fentanyl, they also have analgesic effects comparable to those of morphine, suggesting that they may be attractive compounds for the development of novel opioid patches for transitioning from fentanyl patches.

In Vitro Analyses of Spinach-Derived Opioid Peptides, Rubiscolins: Receptor Selectivity and Intracellular Activities through G Protein- and ß-Arrestin-Mediated Pathways.

Activated opioid receptors transmit internal signals through two major pathways: the G-protein-mediated pathway, which exerts analgesia, and the ß-arrestin-mediated pathway, which leads to unfavorable side effects. Hence, G-protein-biased opioid agonists are preferable as opioid analgesics. Rubiscolins, the spinach-derived naturally occurring opioid peptides, are selective δ opioid receptor agonists, and their p.o. administration exhibits antinociceptive effects. Although the potency and effect of rubiscolins as G-protein-biased molecules are partially confirmed, their in vitro profiles remain unclear. We, therefore, evaluated the properties of rubiscolins, in detail, through several analyses, including the CellKeyTM assay, cADDis® cAMP assay, and PathHunter® ß-arrestin recruitment assay, using cells stably expressing µ, δ, κ, or µ/δ heteromer opioid receptors. In the CellKeyTM assay, rubiscolins showed selective agonistic effects for δ opioid receptor and little agonistic or antagonistic effects for µ and κ opioid receptors. Furthermore, rubiscolins were found to be G-protein-biased δ opioid receptor agonists based on the results obtained in cADDis® cAMP and PathHunter® ß-arrestin recruitment assays. Finally, we found, for the first time, that they are also partially agonistic for the µ/δ dimers. In conclusion, rubiscolins could serve as attractive seeds, as δ opioid receptor-specific agonists, for the development of novel opioid analgesics with reduced side effects.

Cost-effectiveness analysis of branded and authorized generic celecoxib for patients with chronic pain in Japan.

OBJECTIVES: The aim of this study was to examine the cost-effectiveness of branded and authorized generic (AG) celecoxib for chronic pain patients with osteoarthritis (OA), rheumatoid arthritis (RA), and low back pain (LBP), using real-world cost information for loxoprofen and pharmacotherapy for gastrointestinal bleeding. METHODS: This cost-effectiveness analysis was performed as a long-term simulation using the Markov model from the Japanese public healthcare payer's perspective. The analysis was conducted using loxoprofen with real-world weighted price by branded/generic distribution (hereinafter, loxoprofen with weighted price) as a comparator. In the model, we simulated the prognosis of patients with chronic pain by OA, RA, and LBP treated with loxoprofen or celecoxib, over a lifetime period. RESULTS: A cost-increase of 129,688 JPY (1,245.00 USD) for branded celecoxib and a cost-reduction of 6,268 JPY (60.17 USD) for AG celecoxib were recognized per patient in lifetime horizon, compared to loxoprofen with weighted price. No case was recognized to reverse the results of cost-saving by AG celecoxib in one-way sensitivity analysis. The incremental cost-effectiveness ratio of branded celecoxib attained 5,403,667 JPY/QALY (51,875.20 USD/QALY), compared to loxoprofen with the weighted price. CONCLUSION: The current cost-effectiveness analysis for AG celecoxib revealed its good value for costs, considering the patients' future risk of gastrointestinal injury; also, the impact on costs due to AG celecoxib against loxoprofen will be small. It implies that the disadvantage of AG celecoxib being slightly more expensive than generic loxoprofen could be offset by the good cost-effectiveness during the prognosis.

Insomnia and caregiver burden in chronic pain patients: A cross-sectional clinical study.

Insomnia is a major comorbid symptom of chronic pain and is likely to affect caregiver burden. This cross-sectional study investigated the association between insomnia in chronic pain patients and family caregiver burden. Participants were 60 patients with chronic pain of ≥3 months duration. Demographic and clinical information were collected using the Athens Insomnia Scale (AIS), the Pain Disability Assessment Scale (PDAS), the Hospital Anxiety and Depression Scale (HADS), and a pain intensity numerical rating scale (NRS). Family members who accompanied chronic pain patients to hospital completed the Zarit Burden Interview (ZBI). Univariate regression analysis and multiple regression analysis were conducted to clarify the associations between ZBI scores and total/subscale AIS scores. Covariates were age; sex; pain duration; and scores on the PDAS, HADS anxiety subscale, HADS depression subscale, and NRS. Insomnia was independently associated with ZBI scores [ß: 0.27, 95% confidence interval (CI): 0.07-0.52, p = 0.001]. Scores on the AIS subscale of physical and mental functioning during the day were significantly associated with ZBI scores (ß: 0.32, 95% CI: 0.05-0.59, p = 0.007). In conclusion, the findings suggest that in chronic pain patients, comorbid insomnia and physical and mental daytime functioning is associated with family caregiver burden independently of pain duration, pain-related disability, and pain intensity.

Association between change in self-efficacy and reduction in disability among patients with chronic pain.

PURPOSE: This study aimed to investigate whether changes in psychosocial factors and pain severity were associated with reduction in disability due to pain among patients with chronic pain. We hypothesized that increased self-efficacy would reduce disability. PATIENTS AND METHODS: This longitudinal observational study included 72 patients. Patients' psychological and physical variables were assessed before and after 3 months of treatment. Demographic and clinical information were collected, including the Pain Disability Assessment Scale (PDAS), the Pain Self-Efficacy Questionnaire (PSEQ), the Hospital Depression and Anxiety Scale, and the Numeric Rating Scale (NRS) to assess pain intensity. First, univariate regression analyses were conducted to clarify associations between change in PDAS and sex, age, pain duration, changes in psychosocial factors (self-efficacy, anxiety, and depression) and change in pain intensity. Second, multivariate regression was conducted using the variables identified in the univariate analyses (PSEQ and NRS) to detect the most relevant factor for reducing disability. RESULTS: Univariate regression analyses clarified that changes in PSEQ (ß = -0.31; 95% CI: -0.54--0.08, p = 0.008) and NRS (ß = 0.24; 95% confidence interval [CI]: 0.01-0.47, p = 0.04) were associated with reduction in PDAS. Multivariate regression analysis demonstrated that change in PSEQ (ß = 0.26; 95% CI: -0.50--0.02; p = 0.01) was associated with a reduction in disability, independent of change in NRS. CONCLUSION: These findings suggest improved self-efficacy is associated with reduced disability in patients with chronic pain, independent of reduction in pain intensity. Focusing on improvement in self-efficacy may be an effective strategy in chronic pain treatment in addition to pain relief.