Cysteine Leukotriene Receptor Antagonist-Montelukast Effects on Diabetic Retinal Microvascular Endothelial Cells Curtail Autophagy.

Purpose: Diabetic macular edema (DME) is the primary cause of vision impairment in diabetic retinopathy (DR) patients. A previous study has shown the efficacy of montelukast, a cysteinyl leukotriene receptor (CysLTR)1 antagonist, in a diabetic mouse model. This study aims to understand the CysLTR1 signaling in retinal endothelial cells and the impact of montelukast. Methods: Primary human retinal microvascular endothelial cells (HRECs) challenged with 20 ng/mL TNF-α and 30 mM D-glucose (D-glu) for six to 24 hours served as a model of endothelial activation. HRECs were incubated with L-glucose (L-glu) as an osmotic control. CysLTR1 knockdown and montelukast pretreatment assessed CysLTR1 antagonism. Gene expression, protein expression, and cell-permeable dyes were utilized to measure autophagy and inflammation. Transendothelial electrical resistance (TER) and transendothelial migration of mononuclear leukocytes across HRECs monolayer were measured as a functional assessment of vascular permeability. Results: Endothelial activation induced by hyperglycemia and inflammation increased CysLTR1 expression, triggering autophagy within two to six hours, IL-1ß production, loss of junction integrity, decreased TER, and increased leukocyte migration within six to 24 hours. Pretreatment with montelukast effectively alleviated these effects, demonstrating its dependence on CysLTR1. Conclusions: Dysfunctional retinal endothelium initiates a self-reinforcing loop of inflammation, autophagy, and compromised integrity associated with heightened CysLTR1 levels. The antagonistic effect of montelukast against CysLTR1 effectively mitigates these detrimental changes. This study reveals CysLTR1 as a potential therapeutic target in treating DME and offers a novel strategy to mitigate detrimental changes in DR.

Time to Sustained Recovery Among Outpatients With COVID-19 Receiving Montelukast vs Placebo: The ACTIV-6 Randomized Clinical Trial.

Importance: The effect of montelukast in reducing symptom duration among outpatients with mild to moderate COVID-19 is uncertain. Objective: To assess the effectiveness of montelukast compared with placebo in treating outpatients with mild to moderate COVID-19. Design, Setting, and Participants: This randomized clinical trial (Accelerating COVID-19 Therapeutic Interventions and Vaccines [ACTIV]-6) was conducted from January 27 through June 23, 2023, during the circulation of Omicron subvariants. Participants aged 30 years or older with confirmed SARS-CoV-2 infection and 2 or more acute COVID-19 symptoms for less than 7 days were included across 104 US sites. Interventions: Participants were randomized 1:1 to receive montelukast, 10 mg once daily, or matched placebo for 14 days. Main Outcomes and Measures: The primary outcome was time to sustained recovery (defined as ≥3 consecutive days without symptoms). Secondary outcomes included time to death; time to hospitalization or death; a composite of health care utilization events (hospitalization, urgent care clinic visit, emergency department visit, or death); COVID-19 clinical progression scale score; and difference in mean time unwell. A modified intention-to-treat approach was used for the analysis. Results: Among 1250 participants who were randomized and received the study drug or placebo, the median age was 53 years (IQR, 42-62 years), 753 (60.2%) were female, and 704 (56.3%) reported receiving 2 or more doses of a SARS-CoV-2 vaccine. Among 628 participants who received montelukast and 622 who received placebo, differences in time to sustained recovery were not observed (adjusted hazard ratio [AHR], 1.02; 95% credible interval [CrI], 0.92-1.12; P = .63 for efficacy). Unadjusted median time to sustained recovery was 10 days (95% CI, 10-11 days) in both groups. No deaths occurred, and hospitalizations were reported for 2 participants (0.3%) in each group; the composite of health care utilization events was reported for 18 participants (2.9%) in the montelukast group and 18 (2.9%) in the placebo group (AHR, 1.01; 95% CrI, 0.45-1.84; P = .48 for efficacy). Five participants (0.4%) experienced serious adverse events (3 [0.5%] in the montelukast group and 2 [0.3%] in the placebo group). Conclusions and Relevance: In this randomized clinical trial of outpatients with mild to moderate COVID-19, treatment with montelukast did not reduce duration of COVID-19 symptoms. These findings do not support the use of montelukast for the treatment of mild to moderate COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04885530.

Zafirlukast ameliorates lipopolysaccharide and bleomycin-induced lung inflammation in mice.

Acute lung injury (ALI) is the result of damage to the capillary endothelia and the alveolar epithelial cell caused by various direct and indirect factors, leading to significant pulmonary interstitial and alveolar edema and acute hypoxic respiratory insufficiency. A subset of ALI cases progresses to irreversible pulmonary fibrosis, a condition with fatal implications. Zafirlukast is a leukotriene receptor antagonist licensed for asthma prevention and long-term treatment. This study demonstrated a significant improvement in lung tissue pathology and a reduction in inflammatory cell infiltration in models of lipopolysaccharide (LPS)-induced ALI and bleomycin (BLM)-induced lung inflammation following zafirlukast administration, both in vivo and in vitro. Moreover, zafirlukast was found to suppress the inflammatory response of alveolar epithelial cells in vitro and lung inflammation in vivo by reducing the activation of the TLR4/NF-κB/NLRP3 inflammasome pathway. In conclusion, zafirlukast relieved lung injury and the infiltration of inflammatory cells in the lung by regulating the TLR4/NF-κB/NLRP3 pathway.

Exploring montelukast in dogs: A preliminary pharmacokinetic study following oral administration under fasted and fed conditions.

This study investigates the pharmacokinetics (PK) of montelukast (MTK), a cysteinyl leukotriene receptor antagonist increasingly being considered in veterinary medicine. In dogs, MTK has found indications mainly for treating atopic dermatitis as an off-label use. Six male Labrador dogs underwent a single oral administration of MTK (40 mg/dog) in both fasted and fed conditions according to an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was withdrawn to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 hr. MTK plasma concentrations were quantified using a validated HPLC method, and the data were analysed using PKanalix™ software with a non-compartmental approach. Concentrations remained quantifiable at 24 hr after administration, under both conditions. No significant differences were observed in the PK parameters between the fasted and fed states. MTK was relatively eliminated slowly, with t1/2 values of 8.10 and 7.68 hr after fasted and fed states, respectively. The attainment of maximum concentration (Cmax) occurred at a Tmax of 4 hr, with mean values of 1.98 µg/mL and 2.80 µg/mL under fasted and fed conditions, respectively. Given the unknown therapeutic range of MTK in dogs and the absence of controlled studies proving its efficacy in this species, further dosing adjustments and refinements should be considered based on both the current PK data and the need to establish an effective therapeutic range, if present. Future research should focus on efficacy studies, multiple-dose investigations, and pharmacodynamic assessments to evaluate the suitability of MTK use in dogs.

Retrospective, observational study of different medication regimens and outcome in children with cough variant asthma.

OBJECTIVE: This retrospective longitudinal cohort study aimed to explore the best therapeutic regimen and treatment duration of cough variant asthma (CVA) in children. METHODS: A total of 314 children with CVA were divided into receive inhaled corticosteroids (ICS) combined with long-acting beta2-agonist (LABA) group, ICS combined with leukotriene receptor antagonists (LTRA) group, ICS monotherapy group and LTRA monotherapy group. All clinical data were statistically analyzed. Logistic regression model was used to compare the advantages and disadvantages of different treatment schemes at each follow-up time point and the best treatment scheme. The Cox proportional hazard regression model based on inverse probability weighting was used to compare the effects of different medication regimens on adverse outcomes with asthma recurrence or progression as the end point. RESULTS: (1) After comprehensive analysis, ICS + LABA group was the preferred control regimen for CVA within 8 weeks. After 8 weeks of diagnosis, the efficacy of ICS group or LTRA group was comparable to that of ICS + LABA group and ICS + LTRA group. (2) The ICS + LABA group showed a significant improvement in cough at an early stage, particularly at 4 weeks; the symptoms of ICS + LTRA and ICS groups were significantly improved at 36 weeks. The LTRA group alone showed significant improvement at 20 weeks. CONCLUSION: ICS + LABA, ICS + LTRA, ICS alone and LTRA alone can effectively treat CVA. ICS + LABA could improve the symptoms most quickly within 8 weeks after CVA diagnosis, followed by ICS + LATR group. After 8 weeks, it can be reduced to ICS alone to control CVA for at least 36 weeks based on the remission of symptoms in children.

[Modern approaches to rational combination pharmacotherapy of allergic rhinitis]. / Sovremennye podkhody k ratsional'noi kombinirovannoi farmakoterapii allergicheskogo rinita.

Allergic rhinitis (AR) can significantly reduce the quality of life of patients leading to increased fatigue, mood changes, cognitive impairment, and depression. In clinical practice, insufficient effectiveness of initial AR monotherapy is often noted, and a significant proportion of patients referring for medical care have moderate-severe AR. In this regard, the issues of optimization of combined pharmacological treatment of AR are becoming more and more urgent. This paper provides analysis of the opportunities of combined pharmacotherapy within the framework of current management strategy of AR. Based on the results of some studies and known pharmacological properties of medications it is being discussed the advantages of combined use of intranasal corticosteroids and leukotriene receptor antagonists, in particular mometasone furoate and montelukast, in the therapy of AR, including such comorbidities as bronchial asthma, chronic polyposis rhinosinusitis and pharyngeal tonsil hyperplasia. Some aspects of combination therapy with montelukast and second-generation systemic antihistamines as an alternative approach in case of inability to take intranasal corticosteroids, including the reasonability of using a fixed combination of montelukast and levocetirizine, are analyzed from the perspective of rational pharmacotherapy. The problem of interchangeability of brand-name and generic drugs for the treatment of AR is discussed, considering the almost complete absence of studies of their therapeutic equivalence.

Protective effect of leukotriene receptor antagonist, montelukast, against cyclophosphamide-induced placental toxicity via modulation of NLRP3/IL-1ß signaling pathway in rats.

BACKGROUNDS & AIM: Placental insufficiency is a serious complication that affects pregnancy and fetal growth. Cyclophosphamide (CYC) is considered one of the chemotherapeutic agents. Unfortunately, CYC not only affects tumor cells but also affects healthy cells causing multiple injuries including the placenta. The present study aimed to evaluate the effect of cysteinyl leukotriene receptor antagonist; montelukast (MK), on CYC-induced placental injury in rats. MATERIALS AND METHODS: Forty-eight female Wister rats were randomly divided into 8 experimental groups. Group 1: control pregnant group; Group 2: MK 5 mg-treated pregnant rats; Group 3: MK 10 mg-treated pregnant rats; Group 4: MK 20 mg-treated pregnant rats; Group 5: pregnant rats received CYC (20 mg/kg, i.p); Group 6: pregnant rats received MK 5 mg and CYC; Group 7: pregnant rats received MK 10 mg and CYC; Group 8: pregnant rats received MK 20 mg and CYC. Placental malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), placental growth factor (PlGF), and Nod-like receptor p3 (NLRP3) inflammasome were measured. Histological changes, interleukin-1ß (IL-1ß), and cleaved caspase-3 immuno-expressions were also evaluated. RESULTS: CYC showed a significant decrease in placental GSH, TAC, and PlGF with a significant increase in placental MDA, NLRP3, and immuno-expression of IL-1ß and caspase-3. MK showed significant improvement in all oxidative stress (MDA, GSH and TAC), inflammatory (NLRP3 and IL-1ß), and apoptotic (caspase-3) parameters. CONCLUSION: According to the findings, MK was proved to have a possible protective role in CYC-induced placental injury via modulation of NLRP3/IL-1ß signaling pathway with anti-oxidant, anti-inflammatory, and anti-apoptotic effects.

Potential of Anti-Leukotriene Drugs as New Therapeutic Agents for Inhibiting Cholangiocarcinoma Progression.

Cholangiocarcinoma (CCA) is a cancer with a poor prognosis due to difficulties in diagnosis and limited treatment options, highlighting the urgent need for new targeted therapies. In a clinical setting, we found that leukotriene levels in bile were higher than in serum. Immunohistochemical analysis of surgically resected samples also revealed that CysLT receptor 1 (CysLTR1) was more highly expressed in CCA than in normal bile duct tissue, prompting us to investigate leukotriene as a potential therapeutic target in CCA. In vitro studies using CCA cell lines expressing CysLTR1 showed that leukotriene D4, a major ligand of CysLTR1, promoted cell proliferation, with increased phosphorylation of AKT and extracellular signal-regulated kinase 1/2 (ERK1/2). Additionally, treatment with two clinically available anti-allergic drugs-zileuton, an inhibitor of CysLT formation, and montelukast, a CysLTR1 inhibitor-had inhibitory effects on cell proliferation and migratory capacity, accompanied by the reduced phosphorylation of AKT and ERK1/2. Furthermore, the simultaneous administration of both drugs synergistically enhanced the inhibitory effect on cell proliferation. Our study suggests that use of these drugs may represent a novel approach to treat CCA through drug repositioning.

Differential effects of montelukast and zafirlukast on MDA­MB­231 triple­negative breast cancer cells: Cell cycle regulation, apoptosis, autophagy, DNA damage and endoplasmic reticulum stress.

Montelukast and zafirlukast, cysteinyl leukotriene receptor antagonists (LTRAs), trigger apoptosis and inhibit cell proliferation of triple­negative breast cancer MDA­MB­231 cells. By contrast, only zafirlukast induces G0/G1 cell cycle arrest. The present study compared the effects of these drugs on proteins regulating cell proliferation, apoptosis, autophagy, and endoplasmic reticulum (ER) and oxidative stress using reverse transcription­quantitative PCR, western blotting and flow cytometry. The expression of proliferating markers, Ki­67 and proliferating cell nuclear antigen, was decreased by both drugs. Zafirlukast, but not montelukast, decreased the expression of cyclin D1 and CDK4, disrupting progression from G1 to S phase. Zafirlukast also increased the expression of p27, a cell cycle inhibitor. Both drugs decreased the expression of anti­apoptotic protein Bcl­2 and ERK1/2 phosphorylation, and increased levels of the autophagy marker LC3­II and DNA damage markers, including cleaved PARP­1, phosphorylated (p)­ATM and p­histone H2AX. The number of caspase 3/7­positive cells was greater in montelukast­treated cells compared with zafirlukast­treated cells. Montelukast induced higher levels of the ER stress marker CHOP compared with zafirlukast. Montelukast activated PERK, activating transcription factor 6 (ATF6) and inositol­requiring enzyme type 1 (IRE1) pathways, while zafirlukast only stimulated ATF6 and IRE1 pathways. GSK2606414, a PERK inhibitor, decreased apoptosis mediated by montelukast, but did not affect zafirlukast­induced cell death. The knockdown of CHOP by small interfering RNA reduced apoptosis triggered by montelukast and zafirlukast. In conclusion, the effects on cell cycle regulator proteins may contribute to cell cycle arrest caused by zafirlukast. The greater apoptotic effects of montelukast may be caused by the higher levels of activated caspase enzymes and the activation of three pathways of ER stress: PERK, ATF6, and IRE1.

Neuromodulatory effects of leukotriene receptor antagonists: A comprehensive review.

Cysteinyl leukotrienes (CysLTs) are central to the pathophysiology of asthma and various inflammatory disorders. Leukotriene receptor antagonists (LTRAs) effectively treat respiratory conditions by targeting cysteinyl leukotriene receptors, CysLT1 and CysLT2 subtypes. This review explores the multifaceted effects of LTs, extending beyond bronchoconstriction. CysLT receptors are not only present in the respiratory system but are also crucial in neuronal signaling pathways. LTRAs modulate these receptors, influencing downstream signaling, calcium levels, inflammation, and oxidative stress (OS) within neurons hinting at broader implications. Recent studies identify novel molecular targets, sparking interest in repurposing LTRAs for therapeutic use. Clinical trials are investigating their potential in neuroinflammation control, particularly in Alzheimer's disease (AD) and Parkinson's diseases (PD). However, montelukast, a long-standing LTRA since 1998, raises concerns due to neuropsychiatric adverse drug reactions (ADRs). Despite widespread use, understanding montelukast's metabolism and underlying ADR mechanisms remains limited. This review comprehensively examines LTRAs' diverse biological effects, emphasizing non-bronchoconstrictive activities. It also analyses plausible mechanisms behind LTRAs' neuronal effects, offering insights into their potential as neurodegenerative disease modulators. The aim is to inform clinicians, researchers, and pharmaceutical developers about LTRAs' expanding roles, particularly in neuroinflammation control and their promising repurposing for neurodegenerative disease management.

Leukotriene receptor antagonists as add-on therapy to antihistamines for urticaria: Systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: The benefits and harms of adding antileukotrienes to H1 antihistamines (AHs) for the management of urticaria (hives, itch, and/or angioedema) remain unclear. OBJECTIVE: We sought to systematically synthesize the treatment outcomes of antileukotrienes in combination with AHs versus AHs alone for acute and chronic urticaria. METHODS: As part of updating American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters urticaria guidelines, we searched Medline, Embase, Central, LILACS, WPRIM, IBECS, ICTRP, CBM, CNKI, VIP, Wanfang, US Food and Drug Administration, and European Medicines Agency databases from inception to December 18, 2023, for randomized controlled trials (RCTs) evaluating antileukotrienes and AHs versus AHs alone in patients with urticaria. Paired reviewers independently screened citations, extracted data, and assessed risk of bias. Random effects models pooled effect estimates for urticaria activity, itch, wheal, sleep, quality of life, and harms. The GRADE approach informed certainty of evidence ratings. The study was registered at the Open Science Framework (osf.io/h2bfx/). RESULTS: Thirty-four RCTs enrolled 3324 children and adults. Compared to AHs alone, the combination of a leukotriene receptor antagonist with AHs probably modestly reduces urticaria activity (mean difference, -5.04; 95% confidence interval, -6.36 to -3.71; 7-day urticaria activity score) with moderate certainty. We made similar findings for itch and wheal severity as well as quality of life. Adverse events were probably not different between groups (moderate certainty); however, no RCT reported on neuropsychiatric adverse events. CONCLUSION: Among patients with urticaria, adding leukotriene receptor antagonists to AHs probably modestly improves urticaria activity with little to no increase in overall adverse events. The added risk of neuropsychiatric adverse events in this population with leukotriene receptor antagonists is small and uncertain.

Cysteinyl leukotriene receptor-1 as a potential target for host-directed therapy during chronic schistosomiasis in murine model.

Schistosomiasis remains the most devastating neglected tropical disease, affecting over 240 million people world-wide. The disease is caused by the eggs laid by mature female worms that are trapped in host's tissues, resulting in chronic Th2 driven fibrogranulmatous pathology. Although the disease can be treated with a relatively inexpensive drug, praziquantel (PZQ), re-infections remain a major problem in endemic areas. There is a need for new therapeutic drugs and alternative drug treatments for schistosomiasis. The current study hypothesized that cysteinyl leukotrienes (cysLTs) could mediate fibroproliferative pathology during schistosomiasis. Cysteinyl leukotrienes (cysLTs) are potent lipid mediators that are known to be key players in inflammatory diseases, such as asthma and allergic rhinitis. The present study aimed to investigate the role of cysLTR1 during experimental acute and chronic schistosomiasis using cysLTR1-/- mice, as well as the use of cysLTR1 inhibitor (Montelukast) to assess immune responses during chronic Schistosoma mansoni infection. Mice deficient of cysLTR1 and littermate control mice were infected with either high or low dose of Schistosoma mansoni to achieve chronic or acute schistosomiasis, respectively. Hepatic granulomatous inflammation, hepatic fibrosis and IL-4 production in the liver was significantly reduced in mice lacking cysLTR1 during chronic schistosomiasis, while reduced liver pathology was observed during acute schistosomiasis. Pharmacological blockade of cysLTR1 using montelukast in combination with PZQ reduced hepatic inflammation and parasite egg burden in chronically infected mice. Combination therapy led to the expansion of Tregs in chronically infected mice. We show that the disruption of cysLTR1 is dispensable for host survival during schistosomiasis, suggesting an important role cysLTR1 may play during early immunity against schistosomiasis. Our findings revealed that the combination of montelukast and PZQ could be a potential prophylactic treatment for chronic schistosomiasis by reducing fibrogranulomatous pathology in mice. In conclusion, the present study demonstrated that cysLTR1 is a potential target for host-directed therapy to ameliorate fibrogranulomatous pathology in the liver during chronic and acute schistosomiasis in mice.

Practice Patterns for Acute Asthma Exacerbation in Adult Patients Admitted to U.S. Intensive Care Units.

Rationale: Guidelines recommend systemic corticosteroids and inhaled ß-agonists for patients with severe asthma exacerbation who are admitted to intensive care units. The benefits and utilization of adjunct treatments after guideline-recommended first-line treatments have been initiated are unclear. Objectives: Examine practice patterns of adjunct interventions in US intensive care units (ICUs) and their associations with outcomes for adults with severe asthma exacerbations. Methods: Using the multicenter PINC AI Healthcare Database of Premier Inc. (2016-2022), we sought to explore the use of adjunct interventions (medications [e.g., magnesium, leukotriene inhibitors, terbutaline, heliox] and procedures [e.g., invasive and noninvasive mechanical ventilation]) for adult patients admitted to U.S. ICUs with acute asthma exacerbations. We used hierarchical generalized linear models to calculate risk-adjusted rates of adjunct interventions and quantified between-hospital variation in adjunct interventions using the intraclass correlation coefficient (ICC; higher values correspond to higher between-hospital variation). We then used K-means clustering to identify groups of hospitals with similar risk-adjusted practice profiles of all adjunct treatments and examined associations between identified hospital clusters and patient outcomes. Results: We identified 62,392 patients from 961 hospitals for inclusion. Adjunct interventions with the highest between-hospital variation after risk adjustment were heliox (ICC, 91%), inhaled steroids (ICC, 23%), invasive mechanical ventilation (ICC, 21%), terbutaline (ICC, 22%), paralytics (ICC, 16%), and noninvasive ventilation (ICC, 15%). K-means clustering identified two distinct hospital clusters: Patients who were admitted to Cluster 1 hospitals (399 hospitals) had higher risk-adjusted rates of noninvasive ventilation (51% vs. 33%), compared with patients who were admitted to Cluster 2 hospitals (234 hospitals), which had higher risk-adjusted rates of invasive mechanical ventilation (63% vs. 30%). Cluster 2 was associated with fewer hospital-free days (ß = -0.75 d; 95% confidence interval [CI] = -0.95, -0.55) and increased in-hospital mortality (adjusted odds ratio, 1.28; 95% CI = 1.17, 1.40). Conclusions: The use of adjunct interventions for patients with severe asthma exacerbations vary widely across U.S. hospitals; however, hospitals generally fall into two clusters differentiated primarily by the use of invasive or noninvasive mechanical ventilation. The cluster favoring noninvasive mechanical ventilation was associated with improved outcomes. Our results help to inform usual-care arms of future comparative effectiveness studies and efforts to standardize asthma practice.

Montelukast Influence on Lung in Experimental Diabetes.

Background and Objectives: The influence of montelukast (MK), an antagonist of cysLT1 leukotriene receptors, on lung lesions caused by experimental diabetes was studied. Materials and Methods: The study was conducted on four groups of six adult male Wistar rats. Diabetes was produced by administration of streptozotocin 65 mg/kg ip. in a single dose. Before the administration of streptozotocin, after 72 h, and after 8 weeks, the serum values of glucose, SOD, MDA, and total antioxidant capacity (TAS) were determined. After 8 weeks, the animals were anesthetized and sacrificed, and the lungs were harvested and examined by optical microscopy. Pulmonary fibrosis, the extent of lung lesions, and the lung wet-weight/dry-weight ratio were evaluated. Results: The obtained results showed that MK significantly reduced pulmonary fibrosis (3.34 ± 0.41 in the STZ group vs. 1.73 ± 0.24 in the STZ+MK group p < 0.01) and lung lesion scores and also decreased the lung wet-weight/dry-weight (W/D) ratio. SOD and TAS values increased significantly when MK was administered to animals with diabetes (77.2 ± 11 U/mL in the STZ group vs. 95.7 ± 13.3 U/mL in the STZ+MK group, p < 0.05, and 25.52 ± 2.09 Trolox units in the STZ group vs. 33.29 ± 1.64 Trolox units in the STZ+MK group, respectively, p < 0.01), and MDA values decreased. MK administered alone did not significantly alter any of these parameters in normal animals. Conclusions: The obtained data showed that by blocking the action of peptide leukotrienes on cysLT1 receptors, montelukast significantly reduced the lung lesions caused by diabetes. The involvement of these leukotrienes in the pathogenesis of fibrosis and other lung diabetic lesions was also demonstrated.

Efficacy of montelukast for adenoid hypertrophy in paediatrics: A systematic review and meta-analysis.

INTRODUCTION: Leukotrienes play a significant role in the pathogenesis of adenoid hypertrophy (A.H.). Therefore, we aimed to analyse the role of montelukast, a leukotriene receptor antagonist, alone or in combination with mometasone, a potent local intranasal steroid, for the treatment of A.H. METHODS: Participants were children with A.H. were treated with montelukast alone or montelukast and mometasone furoate. The main outcome measures were effect of montelukast on clinical symptoms of A.H. A literature review was conducted using online search engines, Cochrane Library, PubMed, Web of Science and Scopus, for randomized clinical trials assessing children with A.H. treated with montelukast alone or montelukast and mometasone furoate. Seven randomized clinical trials (RCTs) were included with 742 children. RESULTS: Our study reveals that montelukast alone or in combination with intranasal mometasone furoate significantly improves clinical symptoms of adenoid hypertrophy such as snoring, sleeping disturbance, mouth breathing and A/N ratio. Montelukast was superior to placebo in decreasing snoring (SMD = -1.00, 95% CI [-1.52, -0.49]), sleep discomfort (SMD = -1.26, 95% CI [-1.60, -0.93]), A/N ratio (MD = -0.11, 95% CI [-0.14, -0.09]) and mouth breathing (SMD = -1.36, 95% CI [-1.70, -1.02]). No difference was detected between montelukast and mometasone versus mometasone alone in snoring (SMD = -0.21, 95%CI [-0.69, 0.27]); however, the combination group was superior to the mometasone alone in mouth breathing (SMD = -0.46, 95% CI [-0.73, -0.19]). CONCLUSIONS: The limitation of studies included a small sample size, with an overall low to medium quality. Thus, further larger, higher-quality RCTs are recommended to provide more substantial evidence.

Eosinophilic granulomatosis with polyangiitis and its association with montelukast: a case-based review.

The association between the use of certain medications (including sulfonamides, hydralazine, and procainamide) and the occurrence of drug-induced lupus or hepatitis is well established. More recently, cases of immune-related adverse events ranging from inflammatory polyarthritis to necrotizing myositis in patients taking checkpoint inhibitors have been reported. However, data linking drugs to systemic vasculitis are scarce and at times debatable. Propylthiouracil, hydralazine, and minocycline have been associated with rare cases of ANCA-associated syndromes, including life-threatening pulmonary-renal syndromes and systemic polyarteritis nodosa-like diseases. Eosinophilic granulomatosis with polyangiitis (EGPA) has been reported in patients taking leukotriene inhibitors. Since the link between the use of leukotriene inhibitors and occurrence of EGPA remains highly controversial, we performed a literature review for cases of EGPA in patients taking montelukast without prior history of oral corticosteroid use. We found 24 cases, along with our own two cases described, making 26 cases in total. The mean age was 43 and a majority (18/26) were female. In majority of cases EGPA-like disease never relapsed after they were taken off leukotriene inhibitors suggesting a clear causal relationship between the use of these drugs and occurrence of eosinophil-rich systemic EGPA.

Montelukast as a repurposable additive drug for standard-efficacy multiple sclerosis treatment: Emulating clinical trials with retrospective administrative health claims data.

BACKGROUND: Effective and safe treatment options for multiple sclerosis (MS) are still needed. Montelukast, a leukotriene receptor antagonist (LTRA) currently indicated for asthma or allergic rhinitis, may provide an additional therapeutic approach. OBJECTIVE: The study aimed to evaluate the effects of montelukast on the relapses of people with MS (pwMS). METHODS: In this retrospective case-control study, two independent longitudinal claims datasets were used to emulate randomized clinical trials (RCTs). We identified pwMS aged 18-65 years, on MS disease-modifying therapies concomitantly, in de-identified claims from Optum's Clinformatics® Data Mart (CDM) and IQVIA PharMetrics® Plus for Academics. Cases included 483 pwMS on montelukast and with medication adherence in CDM and 208 in PharMetrics Plus for Academics. We randomly sampled controls from 35,330 pwMS without montelukast prescriptions in CDM and 10,128 in PharMetrics Plus for Academics. Relapses were measured over a 2-year period through inpatient hospitalization and corticosteroid claims. A doubly robust causal inference model estimated the effects of montelukast, adjusting for confounders and censored patients. RESULTS: pwMS treated with montelukast demonstrated a statistically significant 23.6% reduction in relapses compared to non-users in 67.3% of emulated RCTs. CONCLUSION: Real-world evidence suggested that montelukast reduces MS relapses, warranting future clinical trials and further research on LTRAs' potential mechanism in MS.

Leukotriene-modifying agents may increase the risk of depression: A cross-sectional study.

INTRODUCTION: Post-market monitoring has shown a potential link between the use of leukotriene-modifying agents (LTRAs) and an increased risk of neuropsychiatric events, such as depression. However, observational studies have produced inconsistent findings, offering no definitive conclusions. OBJECTIVE: To assess the potential correlation between LTRAs exposure and depression in US adults. METHOD: This cross-sectional study, based on population data from the National Health and Nutrition Examination Survey (NHANES) 2007-2016 cycle. The Patient Health Questionnaire-9 was used to assess depression. Multivariable regression was used to evaluate the association between LTRAs exposure and depression. Sensitivity and subgroup analyses were conducted, with the calculation of the E-value. Network pharmacology was employed to investigate the influence of LTRAs on mechanisms of depression. RESULTS: Among the 9414 participants, 595 (6.3 %) were classified as having depression. LTRAs exposure was associated with a higher prevalence of depression (16.9 % vs. 6.0 %). The multivariable logistic regression results showed that LTRAs use increased the risk of depression (OR = 1.70; 95 % CI, 1.05-2.75). An association between LTRAs exposure and depression was found in sensitivity analyses conducted regardless of multivariable linear regression with the PHQ-9 score as a continuous variable (ß = 0.97; 95 % CI, 0.44-1.50) or multivariable logistic regression with the PHQ-9 cut-off of 5 (OR = 1.52; 95 % CI, 1.08-2.14). The association between LTRAs and depression was stable in the different subgroups. CONCLUSION: LTRAs exposure is positively associated with depression in US adults. Therefore, the risk for depression in patients receiving long-term LTRAs treatment should be considered.

Myocardial reperfusion injury exacerbation due to ALDH2 deficiency is mediated by neutrophil extracellular traps and prevented by leukotriene C4 inhibition.

BACKGROUND AND AIMS: The Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene is closely associated with myocardial ischaemia/reperfusion injury (I/RI). The effects of ALDH2 on neutrophil extracellular trap (NET) formation (i.e. NETosis) during I/RI remain unknown. This study aimed to investigate the role of ALDH2 in NETosis in the pathogenesis of myocardial I/RI. METHODS: The mouse model of myocardial I/RI was constructed on wild-type, ALDH2 knockout, peptidylarginine deiminase 4 (Pad4) knockout, and ALDH2/PAD4 double knockout mice. Overall, 308 ST-elevation myocardial infarction patients after primary percutaneous coronary intervention were enrolled in the study. RESULTS: Enhanced NETosis was observed in human neutrophils carrying the ALDH2 genetic mutation and ischaemic myocardium of ALDH2 knockout mice compared with controls. PAD4 knockout or treatment with NETosis-targeting drugs (GSK484, DNase1) substantially attenuated the extent of myocardial damage, particularly in ALDH2 knockout. Mechanistically, ALDH2 deficiency increased damage-associated molecular pattern release and susceptibility to NET-induced damage during myocardial I/RI. ALDH2 deficiency induced NOX2-dependent NETosis via upregulating the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/leukotriene C4 (LTC4) pathway. The Food and Drug Administration-approved LTC4 receptor antagonist pranlukast ameliorated I/RI by inhibiting NETosis in both wild-type and ALDH2 knockout mice. Serum myeloperoxidase-DNA complex and LTC4 levels exhibited the predictive effect on adverse left ventricular remodelling at 6 months after primary percutaneous coronary intervention in ST-elevation myocardial infarction patients. CONCLUSIONS: ALDH2 deficiency exacerbates myocardial I/RI by promoting NETosis via the endoplasmic reticulum stress/microsomal glutathione S-transferase 2/LTC4/NOX2 pathway. This study hints at the role of NETosis in the pathogenesis of myocardial I/RI, and pranlukast might be a potential therapeutic option for attenuating I/RI, particularly in individuals with the ALDH2 mutation.