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Asymmetric Power Hazard Distribution for COVID-19 Mortality Rate under Adaptive Type-II Progressive Censoring: Theory and Inferences. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2022; 2022:5134507. [PMID: 35463230 PMCID: PMC9021994 DOI: 10.1155/2022/5134507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 02/02/2022] [Indexed: 11/18/2022]
Abstract
This article investigates the estimation of the parameters for power hazard function distribution and some lifetime indices such as reliability function, hazard rate function, and coefficient of variation based on adaptive Type-II progressive censoring. From the perspective of frequentism, we derive the point estimations through the method of maximum likelihood estimation. Besides, delta method is implemented to construct the variances of the reliability characteristics. Markov chain Monte Carlo techniques are proposed to construct the Bayes estimates. To this end, the results of the Bayes estimates are obtained under squared error and linear exponential loss functions. Also, the corresponding credible intervals are constructed. A simulation study is utilized to assay the performance of the proposed methods. Finally, a real data set of COVID-19 mortality rate is analyzed to validate the introduced inference methods.
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Allan R, Haughie S, Ahrens R, Singh S, Ward J. A Dose-Response Study Examining the Use of Methacholine Challenge to Demonstrate Local Therapeutic Equivalence of the Salmeterol Component of Generic Inhaled Fluticasone Propionate/Salmeterol Combination Products. J Aerosol Med Pulm Drug Deliv 2019; 32:352-363. [PMID: 31259673 DOI: 10.1089/jamp.2018.1519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Asthma is widely treated using inhaled corticosteroid/long-acting beta agonist (LABA) combinations, for example, fluticasone propionate/salmeterol (FPS) dry powder inhaler, marketed as Advair® Diskus®. Some regulators require generics to demonstrate local (lung) therapeutic equivalence (LTE) for each component of the FPS reference, ideally with a dose-response within the approved FPS dose range. We sought to develop a methacholine challenge (MeCh) LTE methodology for assessing the LABA (salmeterol) component of FPS. Methods: Forty-six patients with asthma received single doses of albuterol (active control; 90 or 180 μg), FPS (100/50 or 200/100 μg), and placebo on 5 separate study days. Spirometry and MeCh were performed 1, 6, and 10 hours after study drug inhalation. Primary endpoint was provocative concentration of methacholine producing a 20% fall in forced expiratory volume in 1 second (PC20). Study entry required screening PC20 ≤8 mg/mL, with a greater than fourfold increase (and PC20 ≤128 mg/mL) after 180 μg albuterol. Results: Both albuterol (90 and 180 μg) and FPS (100/50 and 200/100 μg) significantly increased PC20 compared with placebo (sustained 6 and 10 hours postdose with FPS but not albuterol). The dose-response slopes (95% confidence interval) estimated 1 hour after treatment were 0.374 (-0.068 to 0.815) and 0.310 (-0.135 to 0.754) between low and high doses of albuterol and FPS, respectively, both nonsignificant. Slopes were shallower than those available in the literature for albuterol and formoterol, but similar to those for salmeterol. Conclusions: These data confirm that the bronchoprotective effect of FPS lasts longer than that of albuterol. The shallow dose-response slope we observed for albuterol is contrary to previous reports, probably due to the measurement of PC20 beginning at 1 hour postdose. The results suggest that use of MeCh to assess LTE for salmeterol formulations may be more difficult to accomplish than it is for albuterol and formoterol products.
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Affiliation(s)
| | | | - Richard Ahrens
- Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Sachinkumar Singh
- Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Jon Ward
- Mylan Pharma UK Limited, Sandwich, United Kingdom
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EL-Sagheer RM, Mahmoud MAW, Abdallah SHM. Statistical inferences for new Weibull-Pareto distribution under an adaptive type-ii progressive censored data. JOURNAL OF STATISTICS & MANAGEMENT SYSTEMS 2018. [DOI: 10.1080/09720510.2018.1467628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Rashad M. EL-Sagheer
- Department of Mathematics, Faculty of Science, Al-Azhar University, Nasr-City 11884 Cairo, Egypt
| | - Mohamed A. W. Mahmoud
- Department of Mathematics, Faculty of Science, Al-Azhar University, Nasr-City 11884 Cairo, Egypt
| | - Samah H. M. Abdallah
- Department of Mathematics, Faculty of Science, Al-Azhar University, Nasr-City 11884 Cairo, Egypt
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Dissanayake S, Suggett J. A review of the in vitro and in vivo valved holding chamber (VHC) literature with a focus on the AeroChamber Plus Flow-Vu Anti-static VHC. Ther Adv Respir Dis 2018; 12:1753465817751346. [PMID: 29378477 PMCID: PMC5937155 DOI: 10.1177/1753465817751346] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 11/20/2017] [Indexed: 11/16/2022] Open
Abstract
Valved holding chambers (VHCs) reduce the need for inhalation-actuation coordination with pressurized metered dose inhalers (pMDIs), reduce oropharyngeal drug deposition and may improve lung deposition and clinical outcomes compared to pMDIs used alone. While VHCs are thus widely advocated for use in vulnerable patient groups within clinical and regulatory guidelines, there is less consensus as to whether the performance differences between different VHCs have clinical implications. This review evaluates the VHC literature, in particular the data pertaining to large- versus small-volume chambers, aerosol performance with a VHC adjunct versus a pMDI alone, charge dissipative/conducting versus non-conducting VHCs, and facemasks, to ascertain whether potentially meaningful differences between VHCs exist. Inconsistencies in the literature are examined and explained, and relationships between in vitro and in vivo data are discussed. A particular focus of this review is the AeroChamber Plus® Flow-Vu® Anti-static VHC, the most recent iteration of the AeroChamber VHC family.
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Affiliation(s)
| | - Jason Suggett
- Trudell Medical International, London, Ontario,
Canada
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Zeng Y, Singh S, Wang K, Ahrens RC. Effect of Study Design on Sample Size in Studies Intended to Evaluate Bioequivalence of Inhaled Short-Acting β-Agonist Formulations. J Clin Pharmacol 2017; 58:457-465. [PMID: 29281130 PMCID: PMC5901014 DOI: 10.1002/jcph.1045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 10/23/2017] [Indexed: 11/15/2022]
Abstract
Pharmacodynamic studies that use methacholine challenge to assess bioequivalence of generic and innovator albuterol formulations are generally designed per published Food and Drug Administration guidance, with 3 reference doses and 1 test dose (3‐by‐1 design). These studies are challenging and expensive to conduct, typically requiring large sample sizes. We proposed 14 modified study designs as alternatives to the Food and Drug Administration–recommended 3‐by‐1 design, hypothesizing that adding reference and/or test doses would reduce sample size and cost. We used Monte Carlo simulation to estimate sample size. Simulation inputs were selected based on published studies and our own experience with this type of trial. We also estimated effects of these modified study designs on study cost. Most of these altered designs reduced sample size and cost relative to the 3‐by‐1 design, some decreasing cost by more than 40%. The most effective single study dose to add was 180 μg of test formulation, which resulted in an estimated 30% relative cost reduction. Adding a single test dose of 90 μg was less effective, producing only a 13% cost reduction. Adding a lone reference dose of either 180, 270, or 360 μg yielded little benefit (less than 10% cost reduction), whereas adding 720 μg resulted in a 19% cost reduction. Of the 14 study design modifications we evaluated, the most effective was addition of both a 90‐μg test dose and a 720‐μg reference dose (42% cost reduction). Combining a 180‐μg test dose and a 720‐μg reference dose produced an estimated 36% cost reduction.
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Affiliation(s)
- Yaohui Zeng
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - Sachinkumar Singh
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA, USA
| | - Richard C Ahrens
- Stead Family Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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Lee SL, Saluja B, García-Arieta A, Santos GML, Li Y, Lu S, Hou S, Rebello J, Vaidya A, Gogtay J, Purandare S, Lyapustina S. Regulatory Considerations for Approval of Generic Inhalation Drug Products in the US, EU, Brazil, China, and India. AAPS JOURNAL 2015; 17:1285-304. [PMID: 26002510 DOI: 10.1208/s12248-015-9787-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/09/2015] [Indexed: 11/30/2022]
Abstract
This article describes regulatory approaches for approval of "generic" orally inhaled drug products (OIDPs) in the United States, European Union, Brazil, China and India. While registration of a generic OIDP in any given market may require some documentation of the formulation and device similarity to the "original" product as well as comparative testing of in vitro characteristics and in vivo performance, the specific documentation approaches, tests and acceptance criteria vary by the country. This divergence is due to several factors, including unique cultural, historical, legal and economic circumstances of each region; the diverse healthcare and regulatory systems; the different definitions of key terms such as "generic" and "reference" drug; the acknowledged absence of in vitro in vivo correlations for OIDPs; and the scientific and statistical issues related to OIDP testing (such as how best to account for the batch-to-batch variability of the Reference product, whether to use average bioequivalence or population bioequivalence in the statistical analysis of results, whether to use healthy volunteers or patients for pharmacokinetic studies, and which pharmacodynamic or clinical end-points should be used). As a result of this discrepancy, there are ample opportunities for the regulatory and scientific communities around the world to collaborate in developing more consistent, better aligned, science-based approaches. Moving in that direction will require both further research and further open discussion of the pros and cons of various approaches.
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Affiliation(s)
- Sau L Lee
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA,
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Zou P, Yu LX. Pharmacodynamic Endpoint Bioequivalence Studies. FDA BIOEQUIVALENCE STANDARDS 2014. [DOI: 10.1007/978-1-4939-1252-0_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Hilton ECY, Baverel PG, Woodcock A, Van Der Graaf PH, Smith JA. Pharmacodynamic modeling of cough responses to capsaicin inhalation calls into question the utility of the C5 end point. J Allergy Clin Immunol 2013; 132:847-55.e1-5. [PMID: 23777849 DOI: 10.1016/j.jaci.2013.04.042] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 03/26/2013] [Accepted: 04/18/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Inhaled capsaicin elicits cough reproducibly in human subjects and is widely used in the study of cough and antitussive therapies. However, the traditional end points C2 and C5 (the concentrations of capsaicin inducing at least 2 or 5 coughs, respectively) display extensive overlap between health and disease and therefore might not best reflect clinically relevant mechanisms. OBJECTIVES We sought to investigate capsaicin dose responses in different disease groups. METHODS Two novel capsaicin cough challenges were compared in patients with chronic cough (CC; n = 20), asthmatic patients (n = 18), and healthy volunteers (HVs; n = 20). Increasing doubling doses of capsaicin (0.48-1000 μmol/L, 4 inhalations per dose) were administered in challenge 1, whereas the order of the doses was randomized in challenge 2. A nonlinear mixed-effects model compared dose-response parameters by disease group and sex. Parameters were also correlated with objective cough frequency. RESULTS The model classified subjects based on maximum cough response evoked by any concentration of capsaicin (Emax) and the capsaicin dose inducing half-maximal response (ED50). HVs and asthmatic patients were not statistically different for either parameter and therefore combined for analysis (mean ED50, 38.6 μmol/L [relative SE, 28%]; mean Emax, 4.5 coughs [relative SE, 11%]). Compared with HVs/asthmatic patients, patients with CC had lower ED50 values (14.7 μmol/L [relative SE, 28%], P = .008) and higher Emax values (8.6 coughs [relative SE, 11%], P < .0001). Emax values highly correlated with 24-hour cough frequency (r = 0.71, P < .001) and were 37% higher in female compared with male subjects, regardless of disease group (P < .001). CONCLUSIONS Nonlinear mixed-effects modeling demonstrates that maximal capsaicin cough responses better discriminate health from disease and predict spontaneous cough frequency and therefore provide important insights into the mechanisms underlying CC.
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Affiliation(s)
- Emma C Y Hilton
- Respiratory Research Group, University of Manchester, Manchester, United Kingdom
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Evans C, Cipolla D, Chesworth T, Agurell E, Ahrens R, Conner D, Dissanayake S, Dolovich M, Doub W, Fuglsang A, García Arieta A, Golden M, Hermann R, Hochhaus G, Holmes S, Lafferty P, Lyapustina S, Nair P, O'Connor D, Parkins D, Peterson I, Reisner C, Sandell D, Singh GJP, Weda M, Watson P. Equivalence considerations for orally inhaled products for local action-ISAM/IPAC-RS European Workshop report. J Aerosol Med Pulm Drug Deliv 2012; 25:117-39. [PMID: 22413806 DOI: 10.1089/jamp.2011.0968] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The purpose of this article is to document the discussions at the 2010 European Workshop on Equivalence Determinations for Orally Inhaled Drugs for Local Action, cohosted by the International Society for Aerosols in Medicine (ISAM) and the International Pharmaceutical Consortium on Regulation and Science (IPAC-RS). The article summarizes current regulatory approaches in Europe, the United States, and Canada, and presents points of consensus as well as ongoing debate in the four major areas: in vitro testing, pharmacokinetic and pharmacodynamic studies, and device similarity. Specific issues in need of further research and discussion are also identified.
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Affiliation(s)
- Carole Evans
- Catalent Pharma Solutions, Research Triangle Park, NC 27709, USA.
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Prabhakaran S, Shuster J, Ahrens R, Hendeles L. Methacholine challenge as a clinical bioassay of pulmonary delivery of a long-acting β₂-adrenergic agonist. Pharmacotherapy 2011; 31:449-57. [PMID: 21923426 PMCID: PMC3845881 DOI: 10.1592/phco.31.5.449] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To determine whether the methacholine challenge method used for albuterol can be applied to assess long-acting β2-adrenergic agonist (LABA) bioequivalence, which would require a sufficiently steep dose-response curve. DESIGN Prospective, unblinded, randomized, 2-way crossover study. SETTING University medical center clinical research laboratory. PATIENTS Ten adults, aged 21-58 years, with mild asthma (forced expiratory volume in 1 sec [FEV(1)] ≥ 70% predicted) and a baseline provocational concentration of methacholine required to decrease FEV(1) by 20% (PC(20)) of 4 mg/ml or less completed the study. INTERVENTION Patients were randomized to receive a single dose of either 12 or 24 μg of formoterol delivered by a dry powder inhaler; 3-7 days later, at the same time of day, they received the other dose. MEASUREMENTS AND MAIN RESULTS The FEV(1) was measured before and 1 hour after dosing, followed by performance of a methacholine challenge. Statistical analysis was performed by the 2-sample regression method for crossover studies. The dose-response curve for bronchodilatation was flat; the mean ± SD increase in FEV(1) after formoterol 12 and 24 μg was 14 ± 5% and 14 ± 8%, respectively (p>0.05). In contrast, the geometric mean PC20 (95% confidence interval) was 7 mg/ml (2-22 mg/ml) after the 12-μg dose and 16 mg/ml (5-45 mg/ml) after the 24-μg dose (p<0.001). CONCLUSION Bioassay by methacholine challenge will be useful for bioequivalence studies of LABAs. A sample of at least 28 patients will be required for formoterol when methacholine challenge is performed in an optimal manner. The sample size may differ for other LABAs.
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Affiliation(s)
- Sreekala Prabhakaran
- Pediatric Pulmonary Division, University of Florida, Gainesville, Florida 32610-0486, USA
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Arieta AG. Bioequivalence assessment of inhalation products: Interchangeability, study design and statistical methods. Pulm Pharmacol Ther 2010; 23:156-8. [DOI: 10.1016/j.pupt.2010.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 07/11/2008] [Accepted: 01/05/2010] [Indexed: 11/24/2022]
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Adams WP, Ahrens RC, Chen ML, Christopher D, Chowdhury BA, Conner DP, Dalby R, Fitzgerald K, Hendeles L, Hickey AJ, Hochhaus G, Laube BL, Lucas P, Lee SL, Lyapustina S, Li B, O'Connor D, Parikh N, Parkins DA, Peri P, Pitcairn GR, Riebe M, Roy P, Shah T, Singh GJP, Sharp SS, Suman JD, Weda M, Woodcock J, Yu L. Demonstrating Bioequivalence of Locally Acting Orally Inhaled Drug Products (OIPs): Workshop Summary Report. J Aerosol Med Pulm Drug Deliv 2010; 23:1-29. [DOI: 10.1089/jamp.2009.0803] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Wallace P. Adams
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | - Richard C. Ahrens
- University of Iowa Hospitals and Clinics, Department of Pediatrics, Iowa City, Iowa
| | - Mei-Ling Chen
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | - Badrul A. Chowdhury
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Dale P. Conner
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | | | | | | | | | - Günther Hochhaus
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida
| | - Beth L. Laube
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Paul Lucas
- Pfizer Global Research and Development, Sandwich, Kent, CT13 9NJ, United Kingdom
| | - Sau L. Lee
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | | | - Bing Li
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
| | - Dennis O'Connor
- Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut
| | | | | | - Prasad Peri
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Gary R. Pitcairn
- Pfizer Limited, Ramsgate Road, Sandwich, Kent, CT13 9NJ, United Kingdom
| | | | - Partha Roy
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | | | - Sandra Suarez Sharp
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | | | - Marjolein Weda
- National Institute for Public Health and the Environment (RIVM) Centre for Quality of Chemical-Pharmaceutical Products, Bilthoven, The Netherlands
| | - Janet Woodcock
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland
| | - Lawrence Yu
- Food and Drug Administration, Center for Drug Evaluation and Research, Office of Pharmaceutical Science, Office of Generic Drugs, Rockville, Maryland
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Frequent mistakes in equivalence studies of generic inhalation products. Respir Med 2008; 102:628-9; author reply 630-1. [DOI: 10.1016/j.rmed.2007.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Accepted: 12/18/2007] [Indexed: 11/19/2022]
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Raissy HH, Harkins M, Esparham A, Kelly HW. Comparison of the dose response to levalbuterol with and without pretreatment with S-albuterol after methacholine-induced bronchoconstriction. Pharmacotherapy 2007; 27:1231-6. [PMID: 17723076 DOI: 10.1592/phco.27.9.1231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
STUDY OBJECTIVE To determine the effect of S-albuterol on the dose response to levalbuterol in patients with moderate bronchoconstriction induced by a methacholine challenge. DESIGN Prospective, randomized, double-blind, placebo-controlled, crossover study. SETTING University-affiliated clinical trial center. PATIENTS Twenty-two adults with mild, stable asthma. INTERVENTION At the screening visit, patients were switched from their beta2-agonist to ipratropium bromide for use as an as-needed rescue therapy. At the baseline visit 2-6 days later, the provocative concentration of methacholine to induce a 30% decrease in forced expiratory volume in 1 second (FEV(1) PC(30)) was determined, followed by a nebulized racemic albuterol dose-response study with three doses of albuterol, to familiarize patients with the procedures. At visits 2 and 3, patients were randomly assigned to receive nebulized normal saline placebo or S-albuterol 5 mg before the methacholine challenge and were administered three escalating doses of levalbuterol after the challenge. MEASUREMENTS AND MAIN RESULTS Area under the curve for FEV(1) over 40 minutes (AUC(0-40)) after administration of levalbuterol was the primary outcome, with slope of FEV(1) as the secondary outcome. In addition, the fraction of exhaled nitric oxide (FeNO) was measured before and after the challenges. In the 17 patients who met criteria for completion, no deleterious effect for S-albuterol was found for FEV(1) PC(30), AUC(0-40) FEV(1), or the FEV(1) slope(0-40). However, S-albuterol reduced the provocative concentration of methacholine to induce a 20% decrease in FEV(1) (PC(20) 0.52 +/- 2.06 vs 0.39 +/- 1.58 mg/ml, placebo vs S-albuterol, p=0.044) but did not affect FeNO. CONCLUSION A single high dose of S-albuterol did not alter the bronchodilator response to levalbuterol. The effect on bronchial responsiveness requires further study.
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Affiliation(s)
- Hengameh H Raissy
- School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131, USA
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Arieta AG. The frequent deficiency of lack of assay sensitivity. Respir Med 2007; 101:2230-1. [PMID: 17596927 DOI: 10.1016/j.rmed.2007.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 05/16/2007] [Indexed: 11/17/2022]
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Lavorini F, Geri P, Mariani L, Marmai C, Maluccio NM, Pistolesi M, Fontana GA. Speed of onset of bronchodilator response to salbutamol inhaled via different devices in asthmatics: a bioassay based on functional antagonism. Br J Clin Pharmacol 2006; 62:403-11. [PMID: 16995861 PMCID: PMC1885153 DOI: 10.1111/j.1365-2125.2006.02641.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 01/24/2006] [Indexed: 11/28/2022] Open
Abstract
AIMS To evaluate the speed of onset of bronchodilation following salbutamol administered via a metered-dose inhaler with a spacer (pMDI + Volumatic) and a dry-powder inhaler (Diskus), as well as the relative potencies of these devices in asthmatic patients with methacholine-induced bronchoconstriction. METHODS Eighteen patients inhaled methacholine (MCh) until FEV(1) decreased by 35% of control. Following administration of placebo, 200 microg salbutamol or 400 microg salbutamol through the pMDI + Volumatic or the Diskus, we calculated the time elapsed from drug administration and the appearance of a 90% increase in post-MCh forced vital capacity (FVC), FEV(1) and volume-adjusted mid-expiratory flow (recovery times). The salbutamol doses to be delivered by the two inhalation devices to achieve similar recovery times and the relative potencies of the devices were calculated by using the 2-by-2 Finney parallel regression method. RESULTS For all functional variables, recovery times were significantly (P < 0.01) shorter in pMDI + Volumatic than Diskus trials. The salbutamol doses to be delivered by the Diskus to achieve recovery times for FVC, FEV(1) and volume-adjusted mid-expiratory flow similar to those obtained with 200 microg salbutamol administered via the pMDI + Volumatic were 558 (95% CI 537, 579) microg, 395 (95% CI 388, 404) microg and 404 (95% CI 393, 415) microg, respectively, and corresponded to relative potencies of 2.79 (95% CI 2.68, 2.90), 1.98 (95% CI 1.94, 2.02), and 2.02 (95% CI 1.96, 2.07). CONCLUSIONS Administration of salbutamol via the pMDI + Volumatic provides faster reversal of induced bronchoconstriction than via the Diskus. The salbutamol dose targeting the lungs with the pMDI + Volumatic is approximately twice that with the Diskus.
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Affiliation(s)
- Federico Lavorini
- Dipartimento di Area Critica Medico Chirurgica, Unità Funzionale di Medicina Respiratoria, Università degli Studi di Firenze, Italia.
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Tomlinson HS, Corlett SA, Allen MB, Chrystyn H. Assessment of different methods of inhalation from salbutamol metered dose inhalers by urinary drug excretion and methacholine challenge. Br J Clin Pharmacol 2005; 60:605-10. [PMID: 16305584 PMCID: PMC1884885 DOI: 10.1111/j.1365-2125.2005.02499.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Indexed: 11/28/2022] Open
Abstract
AIMS Methods to determine the lung delivery of inhaled bronchodilators from metered dose inhalers include urinary drug excretion 30 min post inhalation and methacholine challenge (PD20). We have compared these two methods to differentiate lung delivery of salbutamol from metered dose inhalers using different inhalation methods. METHODS In phase 1 of the study, on randomized study days, 12 mild asthmatics inhaled placebo, one and two 100 microg salbutamol doses from a breath actuated metered dose inhaler, in randomized fashion on different days. In phase 2, they inhaled one 100 microg salbutamol dose from a metered dose inhaler using a SLOW (20 l min(-1)) and a FAST (60 l min(-1)) inhalation technique and a slow inhalation delayed until after they had inhaled for 5 s (LATE). Urinary excretion of salbutamol (0-30 min) and PD20 were measured after each dose. RESULTS Following placebo, one and two 100 microg salbutamol doses, the geometric mean for PD20 was 0.10, 0.41 and 0.86 mg respectively and the mean (SD) urinary drug excretion after one and two doses was 2.25 (0.65) and 5.37 (1.36) microg, respectively. After SLOW, FAST and LATE inhalations the geometric mean for PD20 was 0.50, 0.40 and 0.42 mg, respectively, and mean (SD) salbutamol excretion was 2.67 (0.84), 1.90 (0.70) and 2.72 (0.67) microg, respectively. Only the amount of drug excreted during the FAST compared with the SLOW and LATE inhalations showed a statistical difference (95% confidence interval on the difference 0.12, 1.54 and 0.06, 1.59 microg, respectively). CONCLUSIONS Urinary salbutamol excretion but not PD20 showed differences between the inhalation methods used. When using a metered dose inhaler slow inhalation is better and co-ordination is not essential if the patient is inhaling when they actuate a dose of the drug.
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Affiliation(s)
| | | | - Martin B Allen
- University Hospital of North StaffordshireStoke-on-Trent, ST4 6QG
| | - Henry Chrystyn
- School of Pharmacy and Institute of Pharmaceutical Innovation, University of BradfordBradford, BD7 1DP
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Langley SJ, Allen D, McDonnell B, Wheeler N, Sharma RK, Sykes A, Woodcock A. The effect of reducing the fine-particle mass of salmeterol from metered-dose inhalers on bronchodilatation and bronchoprotection against methacholine challenge: a randomized, placebo-controlled, double-blind, crossover study. Clin Ther 2005; 27:1004-12. [PMID: 16154479 DOI: 10.1016/j.clinthera.2005.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE This study examined the clinical relevance of fine-particle mass (FPM) delivered from metered dose inhalers (MDIs) to bronchodilatation and bronchoprotection against methacholine challenge by comparing a marketed chlorofluorocarbon (CFC) formulation of salmeterol with an investigational hydrofluoroalkane (HFA)formulation. METHODS This was a randomized, double-blind, placebo-controlled, 3-way crossover study in patients with mild to moderate asthma who had a forced expiratory volume in 1 second (FEV (1)) of > or =60% predicted and a base-line provocation dose of inhaled methacholine required to produce a 20% decrease in FEV(1) (PD (20) [methacholine]) of < or =3.2 mg. On separate occasions, patients received 2 inhalations of salmeterol 25 microg from either the CFC MDI (FPM 14 microg), the investigational HFA MDI (FPM 7 microg), or placebo via CFC MDI. Serial measurements of FEV(1) were made over 90 minutes after dosing, followed by methacholine challenge. Efficacy end points were PD(20) (methacholine) and FEV(1) AUC (inc) (incremental area under the FEV(1) curve) over 15 to 90 minutes. The study was designed to demonstrate non-inferiority of the investigational HFA formulation to the CFC formulation in terms of protection against methacholine-induced bronchial hyperresponsiveness; for PD(20) (methacholine), noninferiority was predefined as 1.0 doubling dose of methacholine. RESULTS The study enrolled 40 patients (65% men; mean age, 36.9 years). Both active treatments were significantly better than placebo in terms of PD(20) (methacholine) (P < 0.001). In the per-protocol population, the mean (SE) difference in bronchoprotection between the CFC MDI and placebo was 2.7888 (0.3432) doubling doses of methacholine (n = 32), and the difference between the investigational HFA MDI and placebo was 1.8268 (0.3418) doubling doses(n = 33). The adjusted mean (SE) treatment difference between the CFC MDI and HFA MDI was 0.9621 (0.3454) doubling doses. The upperlimit of the 95% CI (0.2714-1.6527) was greater than the predefined limit for noninferiority. There was no significant difference in FEV(1) AUC(inc) between formulations (mean treatment difference, 1.895 L . min; 95% CI, -4.893 to 8.684); however, both active treatments were significantly different from placebo (P < 0.001). CONCLUSIONS FPM from different MDI formulations may affect the bronchoprotective properties of salmeterol. In this study, the formulation with the smaller FPM was associated with less-effective bronchoprotection, although there was no difference in bronchodilatation. This study did not demonstrate noninferiority of the investigational HFA formulation to the CFC formulation in terms of protection against methacholine-induced bronchial hyperresponsiveness.
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Affiliation(s)
- Stephen J Langley
- Medicines Evaluation Unit, North West Lung Centre, Wythenshawe Hospital, Manchester, UK
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19
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Houghton CM, Langley SJ, Singh SD, Holden J, Monici Preti AP, Acerbi D, Poli G, Woodcock A. Comparison of bronchoprotective and bronchodilator effects of a single dose of formoterol delivered by hydrofluoroalkane and chlorofluorocarbon aerosols and dry powder in a double blind, placebo-controlled, crossover study. Br J Clin Pharmacol 2005; 58:359-66. [PMID: 15373928 PMCID: PMC1884606 DOI: 10.1111/j.1365-2125.2004.02172.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND In response to the phasing out of chlorofluorocarbon (CFC) inhalers, a metered dose hydrofluoroalkane (HFA) formulation, Modulite (Chiesi Farmaceutici S.p.A, Parma, Italy), to be delivered with a pressurized metered dose inhaler (pMDI), has been developed. Modulite is a HFA formulation technology that has been designed to provide stable and uniform dose delivery of HFA-based formulations to enable an easy transition from CFC to HFA inhalers. OBJECTIVES The aim of this study was to compare the bronchoprotective and bronchodilator effects of a single dose of 12 microg of formoterol from the HFA Modulite inhaler with the Foradil Aerolizer (dry powder inhaler, DPI) and the Foradil CFC inhalers (Novartis Health Consumer, Basel, Switzerland). METHODS This was a double blind, double dummy, randomized, placebo-controlled, crossover study conducted in 38 subjects with mild to moderate asthma (mean forced expiratory volume in 1 s [FEV1] 87.5% predicted). The primary endpoint was methacholine challenge provocative dose required for 20% fall in the FEV1 (PD20) 90 min post dose. Bronchodilation was assessed with spirometry (FEV1, FVC, FEF25-75) and impulse oscillometry (resistance at 5 and 20 Hz, reactance at 5 Hz and resonant frequency) over the 90 min post dose. In a subset of 12 subjects formoterol plasma levels, serum potassium and glucose were determined up to 480 min post dose. RESULTS The three formoterol formulations demonstrated significant (P < or = 0.05) improvements in bronchoprotection compared to placebo and non-inferiority of the HFA preparation compared to the CFC and DPI preparations was demonstrated. Geometric mean PD20 values were 0.51 mg with HFA, 0.62 mg with DPI, 0.62 mg with CFC and 0.2 mg with placebo. The log transformed mean differences in PD20 doubling dose between HFA and (a) DPI was -0.28 (95% CI -0.84-0.29, P = 0.57) (b) CFC was -0.28 (95% CI -0.84-0.28, P = 0.57) and (c) placebo was 1.38 (95% CI 0.82-1.94, P < 0.001). Serum potassium, glucose and formoterol plasma profiles were comparable for the CFC, HFA and DPI devices. CONCLUSION Our findings of similar efficacy, pharmacokinetics and systemic effects of the HFA formoterol inhaler compared to the CFC and DPI preparations supports the potential use of this novel formulation in the treatment of asthma.
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Affiliation(s)
- C M Houghton
- Medicines Evaluation Unit, North West Lung Research Centre, Wythenshawe Hospital, Manchester, UK
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