Metabolic pathways of inhaled glucocorticoids by the CYP3A enzymes

Interleukin-13 Treatment of Living Lung Tissue Model Alters the Metabolome and Proteome-A Nano-DESI MS Metabolomics and Shotgun Proteomics Study

Asthma is a chronic respiratory disease with one of the largest numbers of cases in the world; thus, constant investigation and technical development are needed to unravel the underlying biochemical mechanisms. In this study, we aimed to develop a nano-DESI MS method for the in vivo characterization of the cellular metabolome. Using air-liquid interface (ALI) cell layers, we studied the role of Interleukin-13 (IL-13) on differentiated lung epithelial cells acting as a lung tissue model. We demonstrate the feasibility of nano-DESI MS for the in vivo monitoring of basal-apical molecular transport, and the subsequent endogenous metabolic response, for the first time. Conserving the integrity of the ALI lung-cell layer enabled us to perform temporally resolved metabolomic characterization followed by "bottom-up" proteomics on the same population of cells. Metabolic remodeling was observed upon histamine and corticosteroid treatment of the IL-13-exposed lung cell monolayers, in correlation with alterations in the proteomic profile. This proof of principle study demonstrates the utility of in vivo nano-DESI MS for characterizing ALI tissue layers, and the new markers identified in our study provide a good starting point for future, larger-scale studies.

A Roadmap for Using Causal Inference and Machine Learning to Personalize Asthma Medication Selection

Inhaled corticosteroid (ICS) is a mainstay treatment for controlling asthma and preventing exacerbations in patients with persistent asthma. Many types of ICS drugs are used, either alone or in combination with other controller medications. Despite the widespread use of ICSs, asthma control remains suboptimal in many people with asthma. Suboptimal control leads to recurrent exacerbations, causes frequent ER visits and inpatient stays, and is due to multiple factors. One such factor is the inappropriate ICS choice for the patient. While many interventions targeting other factors exist, less attention is given to inappropriate ICS choice. Asthma is a heterogeneous disease with variable underlying inflammations and biomarkers. Up to 50% of people with asthma exhibit some degree of resistance or insensitivity to certain ICSs due to genetic variations in ICS metabolizing enzymes, leading to variable responses to ICSs. Yet, ICS choice, especially in the primary care setting, is often not tailored to the patient's characteristics. Instead, ICS choice is largely by trial and error and often dictated by insurance reimbursement, organizational prescribing policies, or cost, leading to a one-size-fits-all approach with many patients not achieving optimal control. There is a pressing need for a decision support tool that can predict an effective ICS at the point of care and guide providers to select the ICS that will most likely and quickly ease patient symptoms and improve asthma control. To date, no such tool exists. Predicting which patient will respond well to which ICS is the first step toward developing such a tool. However, no study has predicted ICS response, forming a gap. While the biologic heterogeneity of asthma is vast, few, if any, biomarkers and genotypes can be used to systematically profile all patients with asthma and predict ICS response. As endotyping or genotyping all patients is infeasible, readily available electronic health record data collected during clinical care offer a low-cost, reliable, and more holistic way to profile all patients. In this paper, we point out the need for developing a decision support tool to guide ICS selection and the gap in fulfilling the need. Then we outline an approach to close this gap via creating a machine learning model and applying causal inference to predict a patient's ICS response in the next year based on the patient's characteristics. The model uses electronic health record data to characterize all patients and extract patterns that could mirror endotype or genotype. This paper supplies a roadmap for future research, with the eventual goal of shifting asthma care from one-size-fits-all to personalized care, improve outcomes, and save health care resources.

Exploring the influence of the microbiome on the pharmacology of anti-asthmatic drugs

The microbiome is increasingly implicated in playing a role in physiology and pharmacology; in this review, we investigate the literature on the possibility of bacterial influence on the pharmacology of anti-asthmatic drugs, and the potential impact this has on asthmatic patients. Current knowledge in this area of research reveals an interaction between the gut and lung microbiome and the development of asthma. The influence of microbiome on the pharmacokinetics and pharmacodynamics of anti-asthmatic drugs is limited; however, understanding this interaction will assist in creating a more efficient treatment approach. This literature review highlighted that bioaccumulation and biotransformation in the presence of certain gut bacterial strains could affect drug metabolism in anti-asthmatic drugs. Furthermore, the bacterial richness in the lungs and the gut can influence drug efficacy and could also play a role in drug response. The implications of the above findings suggest that the microbiome is a contributing factor to an individuals' pharmacological response to anti-asthmatic drugs. Hence, future directions for research should follow investigating how these processes affect asthmatic patients and consider the role of the microbiome on drug efficacy and modify treatment guidelines accordingly.

Tissue re-distribution of budesonide in rats co-administrated with curcumin by ultra performance liquid chromatography-tandem mass spectrometry

Budesonide (BUD), a locally acting glucocorticoid with low side effects, is recommended in several Crohn's disease (CD) drug treatment guidelines as the first choice for early treatment. Nevertheless, the extensive first-pass effect mediated by P-glycoprotein (P-gp) and Cytochrome P450 3A4 (CYP3A4) leads to low bioavailability and limits further applications. Curcumin (CUR), a natural polyphenol derived from turmeric, has been found to influence the in vivo processes of drugs by affecting the activity of P-gp and CYP3A4. However, the pharmacokinetic interactions between BUD and CUR remains elusive, so an ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of BUD and CUR in the tissue. The results showed that the area under the concentration-time curve 0 to time (AUC0→t) of BUD in the colon and kidney increased by approximately 32.35% and 39.03% respectively in the co-administered group compared to the single-drug group, while the small intestine, liver and plasma decreased by 80.03%, 67.34% and 24.34% respectively compared to the single-drug group. Therefore, long-term treatment with CUR can increase the concentration of BUD in the colonic area without increasing its systemic exposure, thus potentially reducing the incidence of side effects.

Preterm lung and brain responses to mechanical ventilation and corticosteroids

Mechanical ventilation is necessary to maintain oxygenation and ventilation in many preterm infants. Unfortunately, even short periods of mechanical ventilation can cause lung and airway injury, and initiate the lung inflammation that contributes to the development of bronchopulmonary dysplasia (BPD). The mechanical stretch leads to airway cell differentiation and simplification of the alveoli, and releases cytokines that cause systemic response in other organs. Mechanical ventilation also leads to brain injury (IVH, white and gray matter) and neuronal inflammation that can affect the neurodevelopment of preterm infants. In efforts to decrease BPD, corticosteroids have been used for both prevention and treatment of lung inflammation. Corticosteroids have also been demonstrated to cause neuronal injury, so the clinician must balance the negative effects of both mechanical ventilation and steroids on the brain and lungs. Predictive models for BPD can help assess the infants who will benefit most from corticosteroid exposure. This review describes the lung and brain injury from mechanical ventilation in the delivery room and chronic mechanical ventilation in animal models. It provides updates on the current guidelines for use of postnatal corticosteroids (dexamethasone, hydrocortisone, budesonide, budesonide with surfactant) for the prevention and treatment of BPD, and the effects the timing of each steroid regimen has on neurodevelopment.

Enigma of Intramuscular Triamcinolone Acetonide (Kenalog®) Efficacy

Triamcinolone acetonide is a glucocorticosteroid used in standard clinical practice for its anti-inflammatory properties. Although it can be given via different routes of administration, the intramuscular route is unique compared with other corticosteroids-its effects remain potent over a longer period of time. We summarize the existing literature on the pharmacokinetic and pharmacodynamic mechanisms of intramuscular triamcinolone acetonide (Kenalog®). The fascinating nature of the purported efficacy of triamcinolone acetonide may be attributed to differing binding mechanisms, low solubility in blood, a low renal clearance rate, and various metabolites and other yet defined effects on skin. The enigma of the purported efficacy of triamcinolone acetonide may lie in the fact that it has a unique nature of having a long-term effect on dermatologic disease using a seemingly low dose compared with other routes of administration and other corticosteroids. Possible reasons for this may be binding differences at the intramuscular site, low solubility due to acetonide esters, a slow rate of absorption from the injected site, and a low renal clearance rate. There is still much to be learned about its mechanism of action, which may be of clinical and therapeutic significance.

Processed product (Pinelliae Rhizoma Praeparatum) of Pinellia ternata (Thunb.) Breit. Alleviates the allergic airway inflammation of cold phlegm via regulation of PKC/EGFR/MAPK/PI3K-AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Pinelliae Rhizoma Praeparatum (PRP) is a traditional processed product of Pinellia ternata (Thunb.) Berit., which mainly used for treating cold asthma (CA). However, the mechanism of action of PRP for treating CA have not been fully elucidated.

AIM OF THE STUDY

To investigate the core active constituents and the pharmacological mechanism of PRP against CA.

MATERIALS AND METHODS

Ovalbumin (OVA) and cold water-induced cold asthma model were established in male mice. The effects of water extract from PRP were evaluated by general morphological observation, expectorant activity, airway hyperresponsiveness, mucus hypersecretion, inflammatory cytokines, etc. Additionally, the mRNA and protein expression of mucin 5AC (MUC5AC) and aquaporin 5 (AQP5) in vivo and in vitro were detected by immunohistochemistry (IHC), qRT-PCR, and western blotting. The mechanisms of action were investigated through network pharmacology and transcriptomic, and validated through western blotting and molecular docking.

RESULTS

PRP exhibited a favorable expectorant activity, and significantly reduced the airway inflammation, mucus secretion, and hyperresponsiveness in cold asthma model. It also reduced the levels of IL-4, IL-5, IL-8, and IL-13 in bronchoalveolar lavage fluid (BALF) and IL-4 and total IgE in serum, while obviously increased the levels of IL-10 and IFN-γ in serum for asthmatic mice. Meanwhile, PRP also attenuated the pathological changes and mucus production in cold asthmatic mice. Moreover, the downregulation of MUC5AC and upregulation of AQP 5 were detected by western blotting and qRT-PCR after administration with PRP both in vivo and in vitro. PRP expectedly inhibited the protein expression of PKC-α, SRC, p-EGFR, p-ERK1/2, p-JNK, p-p38, p-PI3K, and p-Akt levels in vivo.

CONCLUSIONS

These combined data showed that PRP suppressed the allergic airway inflammation of CA by regulating the balance of Th1 and Th2 cytokines and the possible involvement of the PKC/EGFR/MAPK/PI3K-Akt signaling pathway. Pentadecanoic acid, licochalcone A, β-sitosterol, etc. were considered as main active ingredients of PRP against CA. This study provides a novel perspective of the classical herbal processed product PRP in the treatment of CA.

Biochemical Behaviours of Salmeterol/Fluticasone Propionate in Treating Asthma and Chronic Obstructive Pulmonary Diseases (COPD)

Chronic obstructive pulmonary diseases (COPD) and asthma are fatal. The respiratory tract may be blocked, robbed of the adequate amounts of oxygen; hence, death ensues if a quick medical attention is not provided. The treatment available for the duo are inhaled corticosteroids (ICS). The ICS can work synergically with LABAS (long-acting β 2-antagonists) and so many other medicines like bronchodilators. The drugs used for the treatment of asthma and COPD are metabolised once in the body system and at the same time exerting the therapeutic effect provided the concentration of the drug is within the therapeutic window. The CYP3A isoforms metabolise the ICS, in this case, salmeterol and fluticasone propionate (FP). Methods of administration are not limited to inhalation. Specific doses are prescribed accurately paying attention to factors like age, gender, race, and genetic makeup since these affect drug metabolisms. Generally, the ICS work by translocating glucocorticoid receptors to the nucleus from the cytosol. The mechanism is potentiated by the β-antagonists and this brings about an anti-inflammatory effect which is greater than either of the two drugs alone. Once this happens, it is not necessary to increase ICS dose. The ICS, in addition, cause more production of β-receptors by activating the β-receptor genes. This mode of action begets the LABAs' bronchodilator-effects. The challenge is that ICS are not limited only to "double" therapy. Analysing such therapies is daunting since coadministration interferes with pharmacology and pharmacokinetics of drugs. This work focuses on salmeterol/fluticasone propionate combination and aspects which has to do with administration, monitoring, metabolism, toxicity, and adverse effects.

The Role of Cytochrome P450 Enzymes in COVID-19 Pathogenesis and Therapy

Coronavirus disease 2019 (COVID-19) has become a new public health crisis threatening the world. Dysregulated immune responses are the most striking pathophysiological features of patients with severe COVID-19, which can result in multiple-organ failure and death. The cytochrome P450 (CYP) system is the most important drug metabolizing enzyme family, which plays a significant role in the metabolism of endogenous or exogenous substances. Endogenous CYPs participate in the biosynthesis or catabolism of endogenous substances, including steroids, vitamins, eicosanoids, and fatty acids, whilst xenobiotic CYPs are associated with the metabolism of environmental toxins, drugs, and carcinogens. CYP expression and activity are greatly affected by immune response. However, changes in CYP expression and/or function in COVID-19 and their impact on COVID-19 pathophysiology and the metabolism of therapeutic agents in COVID-19, remain unclear. In this analysis, we review current evidence predominantly in the following areas: firstly, the possible changes in CYP expression and/or function in COVID-19; secondly, the effects of CYPs on the metabolism of arachidonic acid, vitamins, and steroid hormones in COVID-19; and thirdly, the effects of CYPs on the metabolism of therapeutic COVID-19 drugs.

Effectiveness and safety of early combined utilization of budesonide and surfactant by airway for bronchopulmonary dysplasia prevention in premature infants with RDS: A meta-analysis

OBJECTIVE

To address the effectiveness and safety of early airway combined utilization of budesonide and surfactant for bronchopulmonary dysplasia (BPD) prevention in premature infants with respiratory distress syndrome (RDS).

METHODS

Literature retrieval was carried out in the PubMed, Web of Science, EMBASE, Cochrane Library, Wanfang, CQ VIP, and China National Knowledge Infrastructure databases, searching from the inception to September 2021. Stata 16.0 software was used for statistical analysis.

RESULTS

This meta-analysis suggested that early combined utilization of budesonide and surfactant by airway have a superiority on BPD incidence (risk ratio [RR] = 0.62; 95% confidence interval [CI]: 0.54-0.71, p < 0.001], mortality (RR = 0.64; 95%CI: 0.45-0.92, p = 0.016), the composite outcome of BPD or mortality (RR = 0.58; 95%CI: 0.50-0.68, p < 0.001), the additional doses of surfactant (RR = 0.53; 95%CI: 0.44-0.63, p < 0.001), the duration of assisted ventilation (standard mean difference [SMD] = -1.14; 95%CI: -1.58 to -0.70, p < 0.001), duration of invasive ventilation(SMD = -1.77; 95% CI: -2.61 to -0.93, p < 0.001), and hospital stays (SMD = -1.11; 95% CI: -1.73 to -0.49, p = 0.001) in preterm infants with RDS. And these benefits were not associated with increased adverse outcomes. Furthermore, a decreased incidence of patent ducts arterious (PDA) (RR = 0.79; 95% CI: 0.65 to 0.97, p = 0.028) was found in premature infants treated with budesonide and surfactant. Subgroup analysis based on budesonide delivery methods (inhalation or intratracheal instillation) indicated that the decrease of mortality (RR = 0.63; 95% CI: 0.43-0.93, p = 0.019), duration of assisted ventilation (SMD = -0.95; 95% CI: -1.30 to -0.61, p < 0.001), hospital stays (SMD = -1.23; 95% CI: -2.05 to -0.41, p = 0.003) and PDA incidence (RR = 0.80; 95% CI: 0.65 to 0.99, p = 0.044) were mainly in budesonide intratracheal instillation subgroup, rather than in budesonide inhalation subgroup.

CONCLUSIONS

This meta-analysis suggested that early combined utilization of budesonide and surfactant by airway might be an effective and safe clinical practice for BPD prevention in premature infants with RDS, especially when budesonide was delivered by intratracheal instillation. However, many of the included studies were small and were from Asian origin. More well-designed randomized controlled trials with larger sample sizes and longer follow-up from all over the world ought to be conducted in the future.

Pharmacokinetics, plasma protein binding, and metabolism of a potential natural chemosensitizer from Marsdenia tenacissima in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Marsdenia tenacissima (Roxb.) Wight et Arn is a medicinal plant mainly distributed in southwest China. It is used in folk medicine for the treatment of tumors and is synergistic with chemotherapies. In our previous study, 11α-O-2-methybutyryl-12β-O-tigloyl-tenacigenin B (MT2), a main steroid aglycone isolated from the total aglycones of M. tenacissima, significantly enhanced the in vivo antitumor effect of paclitaxel in mice bearing human tumor xenografts, showing its potential as a chemosensitizer. However, the pharmacokinetic characteristics, plasma protein binding rate, and metabolic profile of MT2 remain unclear.

AIM OF THE STUDY

To elucidate the pharmacokinetic characteristics, plasma protein binding rate, and metabolic profile of MT2 in rats.

MATERIALS AND METHODS

MT2 in rat plasma and phosphate-buffered saline was quantified using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method, while the MT2 metabolites in rat liver microsomes were analyzed using UPLC-triple time-of-flight MS/MS.

RESULTS

For intravenously administered MT2, the maximum plasma concentration and the area under the plasma concentration-time curve indicated dose dependency, while the elimination half-life time, the mean residence time, apparent volume of distribution and total apparent clearance values remained relatively unchanged in both the 5 mg/kg and 10 mg/kg groups. For orally administered MT2, the bioavailability was 1.08-1.11%. In rat plasma, MT2 exhibited a protein binding rate of 93.84-94.96%. In rat liver microsomes, MT2 was metabolized by oxidation alone or in combination with demethylation, and five MT2 metabolites were identified.

CONCLUSION

MT2 has low oral bioavailability and a high plasma protein binding rate in rats. After administration, MT2 is transformed into oxidative metabolites in the liver. To achieve a high blood concentration of MT2, it should be administered intravenously. These findings would serve as a reference for further MT2-based pharmacological study and drug development.

Is zebrafish (Danio rerio) water tank model applicable for the assessment of glucocorticoids metabolism? The budesonide assessment

Knowledge of the metabolic profile is essential for doping control analysis in sport since most drugs are excreted after an elaborate biotransformation process. Currently, Zebrafish Water Tank (ZWT) model has been applied to investigate the metabolism of different doping agents. Nevertheless, the class of glucocorticoids has not been subjected to this model for metabolism studies. In the present work, budesonide (BUD) was applied as a pilot to investigate the metabolic pathways of glucocorticoids in the ZWT model. The BUD biotransformation in ZWT model was compared to the described metabolism in humans. Samples from ZWT experiments were collected after BUD administration and analyzed by Liquid Chromatography coupled to High Resolution Mass Spectrometry (LC-HRMS). Following the identification and characterization of all significant metabolites described for humans, it was observed that the ZWT was able to produce in a relevant amount the main target for doping control purposes: the 6β-hydroxy BUD. In addition, prior knowledge about the lack of butyrylcholinesterase activity in the zebrafish organism was considered for the evaluation for the formation of the 16α-hydroxy prednisolone, the most intense BUD metabolite in human urine. Biotransformation of BUD by ZWT focused on metabolites with the acetal fraction preserved, including the intermediate metabolite for the 16α-hydroxy prednisolone pathway. However,analternative metabolic pathway for the complete biotransformation of the 16α-hydroxy prednisolone intermediate was not observed, leading to the absence of the major human metabolite in the ZWT model. The findings reported in this study elucidate for the first time the application and limitations of the ZWT model to evaluate the metabolism of other glucocorticoids.

Comparison of the Effect of Different Local Analgesia Administration Techniques in Total Hip Arthroplasty: A Retrospective Comparative Cohort Study

Objective

To improve postoperative pain management, several authors have described the use of periarticular injection (PAI) or intra-articular injection (IAI) following total hip arthroplasty (THA). However, no comparative studies examining the results between PAI and IAI following THA have been published. This study aimed to evaluate the analgesic and anti-inflammatory effects of PAI and IAI following THA.

Methods

This single-center, retrospective cohort study enrolled patients who underwent unilateral primary THA. A total of 278 patients (281 hips) were included in the final analyses, with 112 patients (113 hips) in the control group, 85 patients (87 hips) in the PAI group, and 81 patients (81 hips) in the IAI group. Numeric rating scale (NRS) scores and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7.

Results

NRS scores, creatine phosphokinase, and C-reactive protein levels in the PAI and IAI groups were significantly lower than those in the control group on POD 1 and 7. D-dimer levels were significantly lower in the PAI and IAI groups than in the control group on POD 7. The white blood cell count was significantly higher in the PAI and IAI groups than in the control group on POD 1 and 7. Aspartate transaminase, alanine aminotransferase, blood urea nitrogen, and creatinine levels were within the reference ranges in all three groups at all time points. NRS scores and laboratory data showed no significant differences between the PAI and IAI groups at all time points.

Conclusion

PAI and IAI have equivalent analgesic and anti-inflammatory effects. Considering the technical challenges of PAI, IAI may be preferable because of its simplicity in the case of using a closed suction drain.

Periarticular analgesic injection containing a corticosteroid after total hip arthroplasty may prevent deep venous thrombosis: a retrospective comparative cohort study

BACKGROUND

Of late, periarticular analgesic injection (PAI) has become a common alternative treatment for pain following total hip arthroplasty (THA). However, the systemic effects of PAI containing corticosteroids in patients subjected to THA have not been investigated. This study evaluated the analgesic efficacy and systemic effects of PAI containing a corticosteroid in patients subjected to THA.

METHODS

This single-center, retrospective cohort study enrolled patients undergoing unilateral, primary THA. A total of 197 patients (200 hips) were included in the final analyses, with 87 hips in the PAI group and 113 hips in the control group. Numeric Rating Scale (NRS) and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7. Pearson's correlation coefficients were obtained to assess the correlations between the D-dimer level on POD 7 and each outcome measure on POD 1.

RESULTS

The postoperative white blood cell count (WBC) was significantly higher in the PAI group than in the control group. Postoperative NRS, creatine phosphokinase (CK), and C-reactive protein (CRP) levels were significantly lower in the PAI group. D-dimer levels were significantly lower in the PAI group on POD 7. Postoperative aspartate transaminase (AST), alanine aminotransferase, blood urea nitrogen, and creatinine levels were within reference ranges. D-dimer levels on POD 7 showed a significant negative correlation with WBC on POD 1 (r=-0.4652) and a significant positive correlation with the NRS score and AST, CK, CRP, and D-dimer levels on POD 1 (r = 0.1558, 0.2353, 0.2718, 0.3545, and 0.3359, respectively).

CONCLUSIONS

PAI containing a corticosteroid may be an effective treatment for pain and inflammation after THA, and it does not seem to cause drug-induced liver or kidney injury. Moreover, corticosteroid PAI can may accelerate early ambulation, which prevents the elevation of postoperative D-dimer levels, and may reduce the risk of deep venous thrombosis.

Dose of budesonide with surfactant affects lung and systemic inflammation after normal and injurious ventilation in preterm lambs

BACKGROUND

The addition of budesonide (Bud) 0.25 mg/kg to surfactant decreased the lung and systemic responses to mechanical ventilation in preterm sheep and the rates and severity of bronchopulmonary dysplasia (BPD) in preterm infants. We hypothesized that lower budesonide concentrations in surfactant will decrease injury while decreasing systemic corticosteroid exposure.

METHODS

Preterm lambs received either (1) protective tidal volume (V_T) ventilation with surfactant from birth or (2) injurious V_T ventilation for 15 min and then surfactant treatment. Lambs were further assigned to surfactant mixed with (i) Saline, (ii) Bud 0.25 mg/kg, (iii) Bud 0.1 mg/kg, or (iv) Bud 0.04 mg/kg. All lambs were then ventilated with protective V_T for 6 h.

RESULTS

Plasma Bud levels were proportional to the dose received and decreased throughout ventilation. In both protective and injurious V_T ventilation, <4% of Bud remained in the lung at 6 h. Some of the improvements in physiology and markers of injury with Bud 0.25 mg/kg were also found with 0.1 mg/kg, whereas 0.04 mg/kg had only minimal effects.

CONCLUSIONS

Lower doses of Bud were less effective at decreasing lung and systemic inflammation from mechanical ventilation. The plasma Bud levels were proportional to dose given and the majority left the lung.

Ultra high-performance liquid chromatography method development for separation of formoterol, budesonide, and related substances using an analytical quality by design approach

The application of the Quality by Design (QbD) principles in developing a new ultra high performance liquid chromatography method for the analysis of formoterol/budesonide and related substances using Fusion QbD® software is explored. The effect of various chromatographic parameters including, column stationary phase, pH, temperature, flow rate, and gradient time on separations were systematically investigated. Results show that optimal separations of these compounds in a standard solution can be achieved using a BEH C₁₈ column (2.1 × 1.7 μm × 10 cm) applying a pH of 8.2, a temperature of 35 °C, a flow rate of 0.35 mL min^-1 and a gradient time of 25 min. Furthermore, the results show that the main parameters affecting the performance of the method were the mobile phase pH, gradient time, and the temperature. For example, the most important factor for peak tailing was the pH of the mobile phase and the critical factors affecting resolution of the analytes were the gradient time and the temperature. As an application, the method was further used to analyze budesonide and formoterol in a sample obtained from a Symbicort® metered dose inhaler and it was found to provide similar separations to those obtained with the standard solution. These findings indicate that applying the QbD principles in analytical method development can be very advantageous not only in obtaining deep understanding of the effect of input parameters but also potential regulatory flexibility.

Cushing's syndrome due to interaction between ritonavir or cobicistat and corticosteroids: a case-control study in the French Pharmacovigilance Database

OBJECTIVES

To explore the frequent interaction between antiretroviral-boosting agents and corticosteroids causing Cushing's syndrome (CS) in the French Pharmacovigilance Database (FPVD).

METHODS

We conducted a retrospective case-control study describing CS recorded in the FPVD between 1996 and 2018. Case was defined as CS occurring in people living with HIV (PLWH) and control was defined as CS in uninfected individuals. Drug-drug interaction (DDI) was defined as an interaction between corticosteroids and CYP3A4 inhibitors. Data concerning the DDI, corticosteroids involved, route of administration and seriousness of the CS were described.

RESULTS

Among the 139 instances of CS identified, 34/35 cases (97%) had DDIs (31 with ritonavir and 3 with cobicistat) and 7/104 controls (7%) had DDIs (6 with itraconazole and 1 with verapamil). The main corticosteroid involved was inhaled fluticasone (28/35, 80%) among the cases and oral prednisone (38/104, 37%) among the controls. More CS cases (30/35, 86%) than CS controls (62/104, 60%) were serious (OR = 4.0, 95% CI = 1.4-14.4; P = 0.007).

CONCLUSIONS

Antiretroviral-boosting agents were responsible for one out of four iatrogenic CS cases in a French national database. Prescribers should be aware of the risk of potentially serious DDIs between antiretroviral-boosting agents and corticosteroids, including single-tablet regimens containing cobicistat.

Phenotypes of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common chronic morbidity in preterm infants. In the absence of effective interventions, BPD is currently a major therapeutic challenge. Several risk factors are known for this multifactorial disease that results in disrupted lung development. Inflammation plays an important role and leads to persistent airway and pulmonary vascular disease. Since corticosteroids are potent anti-inflammatory agents, postnatal corticosteroids have been used widely for BPD prevention and treatment. However, the clinical responses vary to a great degree across individuals, and steroid-related complications remain major concerns. Emerging studies on the molecular mechanism of lung alveolarization during inflammatory stress will elucidate the complicated pathway and help discover novel therapeutic targets. Moreover, with the advances in metabolomics, there are new opportunities to identify biomarkers for early diagnosis and prognosis prediction of BPD. Pharmacometabolomics is another novel field aiming to identify the metabolomic changes before and after a specific drug treatment. Through this "metabolic signature," a more precise treatment may be developed, thereby avoiding unnecessary drug exposure in non-responders. In the future, more clinical, genetic, and translational studies would be required to improve the classification of BPD phenotypes and achieve individualized care to enhance the respiratory outcomes in preterm infants.

Surfactant and budesonide for respiratory distress syndrome: an observational study

BACKGROUND

In preterm infants on moderately high ventilator support, the addition of budesonide to surfactant lowered bronchopulmonary dysplasia (BPD) rates by 20% without increased morbidity or mortality. The aim of this cohort comparison was to determine the safety and efficacy of the combination in infants with milder respiratory distress syndrome (RDS).

METHODS

In August 2016 we began administering budesonide (0.25 mg/kg) mixed with surfactant (Survanta 4 mL/kg) to all infants ≤ 1250 g who failed CPAP and required intubation. Infants were compared to a historical cohort (2013-2016) who received surfactant alone.

RESULTS

BPD or death did not change between the historical surfactant cohort (71%, n = 294) and the budesonide cohort (69%, n = 173). Budesonide was associated with a decrease in the need for continued mechanical ventilation, severe BPD type II or death (19-12%), grade III BPD or death (31-21%), and the median gestational age at discharge was 1 week earlier. Histologic chorioamnionitis was associated with decreased budesonide effects. Secondary morbidities (NEC, IVH, ROP, Sepsis) were similar.

CONCLUSION

Overall BPD rates remained unchanged with the addition of budesonide. Budesonide was associated with decreased severity of BPD, decreased mechanical ventilation use, earlier discharge, and similar short-term outcomes.

Metabolic and Pharmaceutical Aspects of Fluorinated Compounds

The applications of fluorine in drug design continue to expand, facilitated by an improved understanding of its effects on physicochemical properties and the development of synthetic methodologies that are providing access to new fluorinated motifs. In turn, studies of fluorinated molecules are providing deeper insights into the effects of fluorine on metabolic pathways, distribution, and disposition. Despite the high strength of the C-F bond, the departure of fluoride from metabolic intermediates can be facile. This reactivity has been leveraged in the design of mechanism-based enzyme inhibitors and has influenced the metabolic fate of fluorinated compounds. In this Perspective, we summarize the literature associated with the metabolism of fluorinated molecules, focusing on examples where the presence of fluorine influences the metabolic profile. These studies have revealed potentially problematic outcomes with some fluorinated motifs and are enhancing our understanding of how fluorine should be deployed.

Clobetasol Propionate Is a Heme-Mediated Selective Inhibitor of Human Cytochrome P450 3A5

The human cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A5 metabolize most drugs and have high similarities in their structure and substrate preference. Whereas CYP3A4 is predominantly expressed in the liver, CYP3A5 is upregulated in cancer, contributing to drug resistance. Selective inhibitors of CYP3A5 are, therefore, critical to validating it as a therapeutic target. Here we report clobetasol propionate (clobetasol) as a potent and selective CYP3A5 inhibitor identified by high-throughput screening using enzymatic and cell-based assays. Molecular dynamics simulations suggest a close proximity of clobetasol to the heme in CYP3A5 but not in CYP3A4. UV-visible spectroscopy and electron paramagnetic resonance analyses confirmed the formation of an inhibitory type I heme-clobetasol complex in CYP3A5 but not in CYP3A4, thus explaining the CYP3A5 selectivity of clobetasol. Our results provide a structural basis for selective CYP3A5 inhibition, along with mechanistic insights, and highlight clobetasol as an important chemical tool for target validation.

Rational particle design to overcome pulmonary barriers for obstructive lung diseases therapy

Pulmonary delivery of active drugs has been applied for the treatment of obstructive lung diseases, including asthma, chronic obstructive pulmonary disease and cystic fibrosis, for several decades and has achieved progress in symptom management by bronchodilator inhalation. However, substantial progress in anti-inflammation, prevention of airway remodeling and disease progression is limited, since the majority of the formulation strategies focus only on particle deposition, which is insufficient for pulmonary delivery of the drugs. The lack of knowledge on lung absorption barriers in obstructive lung diseases and on pathogenesis impedes the development of functional formulations by rational design. In this review, we describe the physiological structure and biological functions of the barriers in various regions of the lung, review the pathogenesis and functional changes of barriers in obstructive lung diseases, and examine the interaction of these barriers with particles to influence drug delivery efficiency. Subsequently, we review rational particle design for overcoming lung barriers based on excipients selection, particle size and surface properties, release properties and targeting ability. Additionally, useful particle fabrication strategies and commonly used drug carriers for pulmonary delivery in obstructive lung diseases are proposed in this article.

Neonatal cytochrome P450 CYP3A7: A comprehensive review of its role in development, disease, and xenobiotic metabolism

The human cytochrome P450 CYP3A7, once thought to be an enzyme exclusive to fetal livers, has more recently been identified in neonates and developing infants as old as 24 months post-gestational age. CYP3A7 has been demonstrated to metabolize two endogenous compounds that are known to be important in the growth and development of the fetus and neonate, namely dehydroepiandrosterone sulfate (DHEA-S) and all-trans retinoic acid (atRA). In addition, it is also known to metabolize a variety of drugs and xenobiotics, albeit generally to a lesser extent relative to CYP3A4/5. CYP3A7 is an important component in the development and protection of the fetal liver and additionally plays a role in certain disease states, such as cancer and adrenal hyperplasia. Ultimately, a full understanding of the expression, regulation, and metabolic properties of CYP3A7 is needed to provide neonates with appropriate individualized pharmacotherapy. This article summarizes the current state of knowledge of CYP3A7, including its discovery, distribution, alleles, RNA splicing, expression and regulation, metabolic properties, substrates, and inhibitors.

Enhanced Sensitivity Using MALDI Imaging Coupled with Laser Postionization (MALDI-2) for Pharmaceutical Research

Visualizing the distributions of drugs and their metabolites is one of the key emerging application areas of matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) within pharmaceutical research. The success of a given MALDI-MSI experiment is ultimately determined by the ionization efficiency of the compounds of interest, which in many cases are too low to enable detection at relevant concentrations. In this work we have taken steps to address this challenge via the first application of laser-postionisation coupled with MALDI (so-called MALDI-2) to the analysis and imaging of pharmaceutical compounds. We demonstrate that MALDI-2 increased the signal intensities for 7 out of the 10 drug compounds analyzed by up to 2 orders of magnitude compared to conventional MALDI analysis. This gain in sensitivity enabled the distributions of drug compounds in both human cartilage and dog liver tissue to be visualized using MALDI-2, whereas little-to-no signal from tissue was obtained using conventional MALDI. This work demonstrates the vast potential of MALDI-2-MSI in pharmaceutical research and drug development and provides a valuable tool to broaden the application areas of MSI. Finally, in an effort to understand the ionization mechanism, we provide the first evidence that the preferential formation of [M + H]⁺ ions with MALDI-2 has no obvious correlation with the gas-phase proton affinity values of the analyte molecules, suggesting, as with MALDI, the occurrence of complex and yet to be elucidated ionization phenomena.

Solving the interactions of steroidal ligands with CYP3A4 using a grid-base template system

Using over fifty steroidal ligands, CYP3A4 Template system established in our previous study (DMPK 34: 113-125, 2019) has been evaluated for the applicability for prediction of regioselective metabolisms of steroids in the present study. Plural regional interactions near Site of Oxidation of CYP3A4 (Slide-down and Adaptation) are newly defined for steroid ligands in addition to previously characterized Trigger- and IJL-interactions on Template. Interaction of steroids at ring-A with CYP3A4 residue (Front-residue), at the facial side of Ring B of Template, determined the availability of ligand sitting at Rings A and B of Template. Steroids having 3-one-4-ene structures, which are not stacked on Front-residue, thus slide down for their 6-oxidations. Some steroids with 3β-ol structures undergo the further right-side movement (Adaptation) for their 7-oxidations. Similar overpassing phenomena are also expected for steroid 15/16-oxidations and 2/1-oxidations. Allowable width on ligand accommodation was also defined as Width-gauge of Template. Reciprocal comparison of sittings of steroids on Template with experimental data offered idea of CYP3A4-mediated oxidations of steroids through seven distinct types of placements on Template and of the relationship with their usage abundance. The present system would offer practical way for structural identification and verification of CYP3A4-mediated metabolisms of various types of steroids.

Monoclonal antibodies for severe asthma: Pharmacokinetic profiles

Several monoclonal antibodies (mAbs) (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) are currently approved for the treatment of severe asthma. They have complex pharmacokinetic profiles. These profiles are unique in that they are dependent on their structure as well as can be markedly influenced by the biology of their target antigen, but their general behaviour can still be considered a class property, similar to their endogenous IgG counterpart. They cannot be administered by oral route, have a slow distribution into tissue, are metabolized to peptides and amino acids in several tissues but are protected from degradation by binding to protective receptors (the FcRn), which explains their long elimination half-lives. Their clearance is nonlinear because of the saturation of the target-mediated elimination. Also anti-drug antibody (ADA) response and off-target binding, as well as their glycosylation pattern, can influence the pharmacokinetics of mAbs.

Surfactant plus budesonide decreases lung and systemic inflammation in mechanically ventilated preterm sheep

Mechanical ventilation with normal tidal volumes (VT) causes lung and systemic inflammation in preterm sheep. Mechanical ventilation is associated with bronchopulmonary dysplasia (BPD) in preterm infants, and the addition of budesonide to surfactant decreases BPD in clinical trials. Budesonide with surfactant will decrease the lung injury from mechanical ventilation for 24 h in preterm sheep. Lambs at 126 ± 1 day gestational age were delivered and randomized to either: 1) surfactant (200 mg/kg) or 2) surfactant mixed with budesonide (0.25 mg/kg) before mechanical ventilation with VT of 7-8 ml/kg for 2, 6, or 24 h (n = 6 or 7/group). Lung physiology and budesonide levels in the plasma and the lung were measured. Lung tissue, bronchoalveolar lavage fluid (BALF), liver, and brain tissues were evaluated for indicators of injury. High initial budesonide plasma levels of 170 ng/ml decreased to 3 ng/ml at 24 h. Lung tissue budesonide levels were less than 1% of initial dose by 24 h. Although physiological variables were generally similar, budesonide-exposed lambs required lower mean airway pressures, had higher hyperoxia responses, and had more stable blood pressures. Budesonide decreased proinflammatory mRNA in the lung, liver, and brain. Budesonide also decreased total protein and proinflammatory cytokines in BALF, and decreased inducible nitric oxide synthase activation at 24 h. In ventilated preterm lambs, most of the budesonide left the lung within 24 h. The addition of budesonide to surfactant improved physiology, decreased markers of lung injury, and decreased systemic responses in liver and brain.

The early detection of asthma based on blood gene expression

Asthma is a complex heterogeneous disorder with hereditary tendency and the most widely used therapy is inhalation of anti-inflammatory corticosteroids. But it has systemic side effects. If the chronic inflammation can be detected in early stage, the dosage of corticosteroids will be low and the side effects can be avoided. Therefore, to discover the early stage blood biomarkers for asthma, we analyzed the gene expression profiles in the blood of 77 moderate asthma patients and 87 healthy controls. With advanced feature selection methods, minimal Redundancy Maximal Relevance and Incremental Feature Selection, we identified 31 genes, such as MYD88, ZFP36, CCR3 and CYP3A5, as the optimal asthma biomarker. The sensitivity, specificity and accuracy of the 31-gene Support Vector Machine predictor evaluated with Leave-One-Out Cross Validation were 0.870, 0.816 and 0.841, respectively. Through literature survey, many biomarker genes have asthma associated functions. Our results not only provided the easy-to-apply blood gene expression biomarkers for early detection of asthma, but also an explainable qualitative model with biological significance.

Effects of budesonide and surfactant in preterm fetal sheep

Mechanical ventilation causes lung injury and systemic inflammatory responses in preterm sheep and is associated with bronchopulmonary dysplasia (BPD) in preterm infants. Budesonide added to surfactant decreased BPD by 20% in infants. We wanted to determine the effects of budesonide and surfactant on injury from high tidal volume (V_T) ventilation in preterm lambs. Ewes at 125 ± 1 days gestational age had fetal surgery to expose fetal head and chest with placental circulation intact. Lambs were randomized to 1) mechanical ventilation with escalating V_T to target 15 ml/kg by 15 min or 2) continuous positive airway pressure (CPAP) of 5 cmH₂O. After the 15-min intervention, lambs were given surfactant 100 mg/kg with saline, budesonide 0.25 mg/kg, or budesonide 1 mg/kg. The fetuses were returned to the uterus for 24 h and then delivered and ventilated for 30 min to assess lung function. Budesonide levels were low in lung and plasma. CPAP groups had improved oxygenation, ventilation, and decreased injury markers compared with fetal V_T lambs. Budesonide improved ventilation in CPAP lambs. Budesonide decreased lung weights and lung liquid and increased lung compliance and surfactant protein mRNA. Budesonide decreased proinflammatory and acute-phase responses in lung. Airway thickness increased in animals not receiving budesonide. Systemically, budesonide decreased monocyte chemoattractant protein-1 mRNA and preserved glycogen in liver. Results with 0.25 and 1 mg/kg budesonide were similar. We concluded that budesonide with surfactant matured the preterm lung and decreased the liver responses but did not improve lung function after high V_T injury in fetal sheep.

NR3C1 gene polymorphisms are associated with steroid resistance in patients with primary nephrotic syndrome

Aim: The aim of this study was to investigate the role of SNPs of genes involved in the glucocorticoid pathway in the development of steroid resistance in patients with primary nephrotic syndrome. Methods: Sequenom MassARRAY method was used to sequence 25 SNP genotypes in 154 patients. The frequency distribution of the genotypes was compared between patients with steroid-sensitive nephrotic syndrome and those with steroid-resistant nephrotic syndrome. Results: NR3C1 rs6196 G allele carriers had a decreased risk of steroid resistance compared with that of the A allele carriers. The presence of rs10052957 and rs258751 A alleles could reduce the incidence of steroid resistance compared with that with G allele. Haplotype analysis showed AAG and GGA haplotypes that contain NR3C1 rs10052957, rs258751 and rs6196 were associated with steroid resistance. Conclusion: NR3C1 gene polymorphisms are significantly associated with the response to glucocorticoids in patients with primary nephrotic syndrome.

Antiinflammatory Effects of Budesonide in Human Fetal Lung

Lung inflammation in premature infants contributes to the development of bronchopulmonary dysplasia (BPD), a chronic lung disease with long-term sequelae. Pilot studies administering budesonide suspended in surfactant have found reduced BPD without the apparent adverse effects that occur with systemic dexamethasone therapy. Our objective was to determine budesonide potency, stability, and antiinflammatory effects in human fetal lung. We cultured explants of second-trimester fetal lung with budesonide or dexamethasone and used microscopy, immunoassays, RNA sequencing, liquid chromatography/tandem mass spectrometry, and pulsating bubble surfactometry. Budesonide suppressed secreted chemokines IL-8 and CCL2 (MCP-1) within 4 hours, reaching a 90% decrease at 12 hours, which was fully reversed 72 hours after removal of the steroid. Half-maximal effects occurred at 0.04-0.05 nM, representing a fivefold greater potency than for dexamethasone. Budesonide significantly induced 3.6% and repressed 2.8% of 14,500 sequenced mRNAs by 1.6- to 95-fold, including 119 genes that contribute to the glucocorticoid inflammatory transcriptome; some are known targets of nuclear factor-κB. By global proteomics, 22 secreted inflammatory proteins were hormonally regulated. Two glucocorticoid-regulated genes of interest because of their association with lung disease are CHI3L1 and IL1RL1. Budesonide retained activity in the presence of surfactant and did not alter its surface properties. There was some formation of palmitate-budesonide in lung tissue but no detectable metabolism to inactive 16α-hydroxy prednisolone. We concluded that budesonide is a potent and stable antiinflammatory glucocorticoid in human fetal lung in vitro, supporting a beneficial antiinflammatory response to lung-targeted budesonide:surfactant treatment of infants for the prevention of BPD.

Genetic variation in the glucocorticoid pathway involved in interindividual differences in the glucocorticoid treatment

Glucocorticoids (GCs) are widely used for treating asthma, rheumatoid arthritis, nephrotic syndrome, acute lymphoblastic leukemia and other autoimmune diseases. However, in a subgroup of patients, failure to respond to GCs is known as GC resistance or GC insensitivity. This represents an important barrier to effective treatment and a clinical problem requiring an urgent solution. Genetic variation in the GC pathway is a significant factor in interindividual differences in GC treatment. This article reviews the pharmacogenetics of GCs in diverse diseases based on the GC pathway.

Pharmacokinetics of Budesonide Administered with Surfactant in Premature Lambs: Implications for Neonatal Clinical Trials

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of premature human infants, which may persist through adulthood. Airway inflammation has been firmly established in the pathogenesis of BPD. Previous studies to reduce airway inflammation with high-dose dexamethasone demonstrated adverse neurological outcomes, despite lower incidences of BPD. Instillation of budesonide and surfactant can facilitate early extubation and reduce the incidence of BPD and death among very low birth weight infants. However, the pharmacokinetics of budesonide and its distribution into the lung and brain are unknown. Therefore, 5 premature lambs were administered 0.25 mg/kg budesonide, with surfactant as the vehicle. Plasma and tissue samples were taken from the lambs for measurement of budesonide, 16α- hydroxy prednisolone, and budesonide palmitate using LC/MS/MS. Peak plasma budesonide concentrations were inversely correlated with the oxygenation index (correlation coefficient of -0.75). plasma budesonide concentrations were extremely low (~10% of expected) for two lambs that had high oxygenation indices and were excluded from further analyses. For the remaining 5 premature lambs, a non-compartmental analysis demonstrated an AUCinf of 148.77 ± 28.16 h*μg/L, half-life of 4.76 ± 1.79 h, and Cmax of 46.17 ± 17.71 µg/L. Using population pharmacokinetic methods, a onecompartment model with exponential residual error and first-order absorption adequately described the data. The apparent clearance and apparent volume of distribution of budesonide were estimated at 6.29 L/h (1.99 L/h/kg) and 29.1 L (9.2 L/kg), respectively. Budesonide and budesonide palmitate, but not 16α-hydroxy prednisolone, were detected in lung tissue. In this study, budesonide and its metabolites were not detected in the brain, which suggests that intratracheal instillation suggests that after local pulmonary deposition, there is no evidence of budesonide accumulation in the central nervous system. Overall, these results show that peak plasma budesonide concentrations are inversely correlated with the oxygenation index and that lung-specific delivery of budesonide avoids accumulation of budesonide in the brain.

Inhaled corticosteroids and HPA axis suppression: how important is it and how should it be managed?

Inhaled corticosteroids (ICS) are established as a cornerstone of management for patients with bronchoconstrictive lung disease. However, systemic absorption may lead to suppression of the hypothalamic-pituitary-adrenal (HPA) axis in a significant minority of patients. This is more likely in 'higher risk' patients exposed to high cumulative ICS doses, and in those treated with frequent oral corticosteroids or drugs which inhibit cytochrome p450 3A4. Hypothalamic-pituitary-adrenal axis suppression is frequently unrecognized, such that some patients, notably children, only come to light when an adrenal crisis is precipitated by physical stress. To minimize this risk, 'higher risk' patients and those with previously identified suppressed cortisol responses to Synacthen testing should undergo an education programme to inform them about sick day rules. A review of ICS therapy should also be undertaken to ensure that the dose administered is the minimum required to control symptoms.

Predicting anxiety responses to halogenated glucocorticoid drugs using the hexobarbital sleep time test

Glucocorticoids (GCs) are used to treat numerous diseases, but their use in limited by adverse side effects. One such effect is occasional increased anxiety. Since the intensity of hepatic microsomal oxidation has been shown to alter responses to GC, we examined the possibility that rats with lower rates of hepatic GC metabolism would have increased anxiety. We hypothesized that the resulting, excessive GC would stimulate brain monoamine oxidase A (MAO-A), which would reduce brain serotonin, and thereby increase anxiety. Hepatic microsomal oxidative intensity was evaluated by the hexobarbital sleep time (HST) test. Results showed that rats with lower rates of hepatic GC metabolism had elevated brain MAO-A activity, reduced brain serotonin, and more anxiety than rats with higher rates of hepatic GC metabolism. We suggest that the HST test, as an integrative test of microsomal oxidation status, should be useful for predicting individual sensitivity to GC and to other drugs metabolized by the hepatic microsomal oxidation system.

Long-Term Fluticasone Propionate/Formoterol Fumarate Combination Therapy Is Associated with a Low Incidence of Severe Asthma Exacerbations

Background: A primary goal of asthma management is the reduction of exacerbation risk. We assessed the occurrence of oral corticosteroid-requiring exacerbations (OCS exacerbations) with long-term fluticasone/formoterol therapy, and compared it with the occurrence of similar events reported with other inhaled corticosteroid/long acting β₂-agonist (ICS/LABA) combinations.

Methods: The occurrence of OCS exacerbations was assessed in two open-label trials of fixed-dose fluticasone/formoterol administered for between 26 to 60 weeks in adults and adolescents with asthma. The incidence of OCS exacerbations with fluticasone/formoterol was compared with those reported in three recent Cochrane meta-analyses of other ICS/LABAs.

Results: The pooled incidence of OCS exacerbations with long-term fluticasone/formoterol was 2.1% (95% CI: 1.1, 3.2%, n/N = 16/752). In only two of the nineteen treatment arms summarized by Cochrane did OCS exacerbation incidence approximate that seen in the two fluticasone/formoterol trials (single-inhaler fluticasone/salmeterol [2.9%]; separate inhaler budesonide, beclometasone, or flunisolide plus formoterol [3.4%]). In Lasserson's review the pooled incidence of OCS exacerbations for single-inhaler combinations was 9.5% (95% CI: 8.4, 10.6%; n/N = 239/2516) for fluticasone/salmeterol, and 10.6% (95% CI: 9.3, 11.8%; n/N = 257/2433) for budesonide/formoterol. In Ducharme's and Chauhan's meta-analyses (primarily incorporating separate inhaler combinations [fluticasone, budesonide, beclometasone, or flunisolide plus salmeterol or formoterol]), the pooled incidences of OCS exacerbations were 16.0% (95% CI: 14.2, 17.8%, n/N = 258/1615) and 16.7% (95% CI: 14.9, 18.5, n/N = 275/1643), respectively.

Conclusions: The incidence of exacerbations in two fixed-dose fluticasone/formoterol studies was low and less than in the majority of comparable published studies involving other ICS/LABA combinations. This difference could not be readily explained by differences in features of the respective studies and may be related to the favorable pharmacological/mechanistic characteristics of the constituent components fluticasone and formoterol compared to other drugs in their respective classes.

Dosing Recommendations for Concomitant Medications During 3D Anti-HCV Therapy

The development of direct-acting antiviral (DAA) agents has reinvigorated the treatment of hepatitis C virus infection. The availability of multiple DAA agents and drug combinations has enabled the transition to interferon-free therapy that is applicable to a broad range of patients. However, these DAA combinations are not without drug-drug interactions (DDIs). As every possible DDI permutation cannot be evaluated in a clinical study, guidance is needed for healthcare providers to avoid or minimize drug interaction risk. In this review, we evaluated the DDI potential of the novel three-DAA combination of ombitasvir, paritaprevir, ritonavir, and dasabuvir (the 3D regimen) with more than 200 drugs representing 19 therapeutic drug classes. Outcomes of these DDI studies were compared with the metabolism and elimination routes of prospective concomitant medications to develop mechanism-based and drug-specific guidance on interaction potential. This analysis revealed that the 3D regimen is compatible with many of the drugs that are commonly prescribed to patients with hepatitis C virus infection. Where interaction is possible, risk can be mitigated by paying careful attention to concomitant medications, adjusting drug dosage as needed, and monitoring patient response and/or clinical parameters.

Effects of low- versus high-dose fluticasone propionate/formoterol fumarate combination therapy on AMP challenge in asthmatic patients: A double-blind, randomised clinical trial

BACKGROUND

The dose-response relationship between two dose levels of fluticasone/formoterol (flutiform(®), 100/10 μg and 500/20 μg) was evaluated in asthmatic patients. Non-invasive inflammatory markers were used including adenosine monophosphate (AMP) challenge (primary endpoint), and sputum eosinophils and fractional exhaled nitric oxide (FeNO) (secondary endpoints).

METHODS

Patients aged ≥18 years with forced expiratory volume in 1 s (FEV1) ≥60% predicted and who required a dose of <60 mg AMP to elicit a 20% drop in FEV1 (AMP PD20) were randomised in this incomplete block, crossover study to receive 2 of 3 treatments b.i.d.: fluticasone/formoterol 500/20 μg (high dose), 100/10 μg (low dose) or placebo, during 2 periods of 28 ± 3 days each, separated by 2-3 weeks. AMP challenges were performed pre-dose and 12 h after last dose at the end of each treatment period. A series of post hoc analyses were performed only in patients allocated to both fluticasone/formoterol doses, who completed the study and had evaluable AMP PD20 data for both treatments ("fluticasone/formoterol subgroup"). Changes in AMP PD20 FEV1, percentage sputum eosinophils and FeNO levels (Day 1 vs Day 28) between treatments were compared by an analysis of covariance (ANCOVA).

RESULTS

Sixty-two patients were randomised and 46 completed the study. Fifteen patients received both high- and low-dose fluticasone/formoterol (post hoc subgroup). The difference in AMP PD20 for the overall population was not statistically significant between high- and low-dose fluticasone/formoterol (LS mean fold difference: 1.3; p = 0.489), although both dose levels were superior to placebo: high-dose vs placebo LS mean fold difference: 4.4, p < 0.001; low-dose vs placebo LS mean fold difference: 3.5, p < 0.001. In the post hoc subgroup, the difference in AMP PD20 between the doses was statistically significant in favour of the high-dose (LS mean fold difference: 2.4, p = 0.012). Other inflammatory parameters (sputum eosinophil counts and FeNO) showed small differences and statistically non-significant changes between high- and low-dose fluticasone/formoterol.

CONCLUSIONS

A significant dose-response was found between low- and high-dose fluticasone/formoterol in the post hoc subgroup (patients who received both doses), but not in the overall population, with the higher dose demonstrating a greater reduction in airway responsiveness to AMP.

Formation of Δ(1) and Δ(6) testosterone metabolites by human hepatocytes

The existence of urinary testosterone (T) metabolites conjugated with cysteine has been recently reported. The formation of a ring double bond by a phase I metabolic transformation and the subsequent nucleophilic conjugation with glutathione was proposed as a putative metabolic pathway for the occurrence of these metabolites in urine. The main goal of the present study was to confirm the first step of the postulated pathway. For that purpose, human hepatocyte cells systems were incubated with a pure T standard. The cell culture supernatants were analyzed by liquid chromatography coupled to mass spectrometry using a selected reaction monitoring method. Major T metabolites such as androsterone and 4-androstene-3,17-dione, together with the recently reported Δ(1) and Δ(6) metabolites were simultaneously quantified. The formation of 1,4-androstadien-3,17-dione, 4,6-androstadien-3,17-dione, 17β-hydroxy-4,6-androstadien-3-one and 17β-hydroxy-1,4-androstadien-3-one (boldenone) after incubation of T in hepatocyte cell cultures was demonstrated by comparing the retention times and the ion ratios of the metabolites with those obtained by analysis of commercial standards. Thus, the formation of double bonds Δ(1) and Δ(6) by hepatic phase I metabolism of T was confirmed. Analogously to T, this pathway might also be present in other steroids, opening the possibility of targeting additional biomarkers.

Utilization of inhaled corticosteroids for infants with bronchopulmonary dysplasia

OBJECTIVE

To determine demographic and clinical variables associated with inhaled corticosteroid administration and to evaluate between-hospital variation in inhaled steroid use for infants with bronchopulmonary dysplasia (BPD).

DESIGN

Retrospective Cohort Study.

SETTING

Neonatal units of 35 US children's hospitals; as recorded in the Pediatric Health Information System (PHIS) database.

PATIENTS

1429 infants with evolving BPD at 28 days who were born at <29 weeks gestation with birth weight <1500 grams, admitted within the first 7 postnatal days, and discharged between January 2007-June 2011.

RESULTS

Inhaled steroids were prescribed to 25% (n = 352) of the cohort with use steadily increasing during the first two months of hospitalization. The most frequently prescribed steroid was beclomethasone (n = 194, 14%), followed by budesonide (n = 125, 9%), and then fluticasone (n = 90, 6%). Birth gestation <24 weeks, birth weight 500-999 grams, and prolonged ventilation all increased the adjusted odds of ever receiving inhaled corticosteroids (p<0.05). Wide variations between hospitals in the frequency of infants ever receiving inhaled steroids (range: 0-60%) and the specific drug prescribed were noted. This variation persisted, even after controlling for observed confounders.

CONCLUSIONS

Inhaled corticosteroid administration to infants with BPD is common in neonatal units within U.S. Children's hospitals. However, its utilization varies markedly between centers from no treatment at some institutions to the majority of infants with BPD being treated at others. This supports the need for further research to identify the benefits and potential risks of inhaled steroid usage in infants with BPD.

Detection and characterization of triamcinolone acetonide metabolites in human urine by liquid chromatography/tandem mass spectrometry after intramuscular administration

RATIONALE

Glucocorticosteroids are prohibited in sports when used by systemic administrations (e.g. intramuscular, IM), whereas they are allowed using other ways of administration. Strategies to discriminate between administrations routes have to be developed by doping control laboratories. For this reason, the metabolism of triamcinolone acetonide (TA), one of the most used glucocorticosteroids, was studied using liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS).

METHODS

Urine samples obtained after IM administration of TA were analyzed using two sample treatments: (a) hydrolysis with β-glucuronidase enzymes and liquid-liquid extraction under alkaline conditions, and (b) liquid-liquid extraction under acidic conditions. The extracts were analyzed by LC/MS/MS.

RESULTS

TA, commercially available metabolites (6β-hydroxytriamcinolone acetonide, 6β-OH-TA, and triamcinolone), and their C20-reduced derivatives showed characteristic fragmentation behavior. Besides common product ions and neutral losses for corticosteroids containing fluorine, additional characteristic neutral losses (58 Da, loss of acetone; 44 Da, loss of acetaldehyde) were observed in positive electrospray ionization. Based on that behavior, two complementary approaches were applied to detect TA metabolites: (a) open detection by precursor ion and neutral loss scan methods and (b) targeted detection by selected reaction monitoring methods (SRM) containing theoretical ion transitions of the potential metabolites. Two main compounds, TA and 6β-OH-TA, and nine minor potential metabolites, were detected by open screening methods. Using SRM, two additional metabolites were detected. Some of the metabolites were characterized using reference standards and, for the rest of metabolites, feasible structures were proposed based on mass spectrometric data.

CONCLUSIONS

Metabolites resulting from hydroxylation in C-6, oxidation of the 11-hydroxyl group, reduction of the Δ(4) double bond and oxidation of the side chain were detected. Some of them have not been previously described. Excretion profiles of the detected metabolites after IM administration are presented.

Flunisolide for the treatment of asthma

Inhaled corticosteroids (ICSs) are recommended for treatment of persistent asthma. Several ICSs are available and delivered by a variety of devices. After the banning of chlorofluorocarbon (CFC), a formulation of hydrofluoroalkane (HFA)-flunisolide marketed with an in-built spacer has been developed, complying with the request of efficacy and safety for children and adults. It delivers an aerosol with mass median aerodynamic diameter smaller than that of the CFC-formulation (1.2 vs 3.8 m). The extrafine aerosol and the add-on spacer are peculiarities of HFA-flunisolide with respect to the traditional ICSs, assuring larger lung deposition, lower oro-pharyngeal dose and targeting small airways. HFA-flunisolide with the spacer is effective at one-third the dose of CFC-flunisolide delivered without spacer. HFA-flunisolide may be considered an effective alternative to currently available ICSs for asthma management of adult and pediatric patients 6 years of age and older.