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Zhang C, Ding Y, Wu Z, Wang J, Wu X, Xie W. Does China's competitive generic substitution policy deliver equivalent clinical outcomes? A pilot study with two generic formulations of olanzepine. Front Pharmacol 2023; 14:1097600. [PMID: 36909190 PMCID: PMC9999380 DOI: 10.3389/fphar.2023.1097600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/10/2023] [Indexed: 02/24/2023] Open
Abstract
With the National Centralized Drug Procurement policy gradually applied nationally in China, concerns about the effectiveness and safety of bid-winning generic drugs are growing again, but relevant studies are lacking. This real-world, before-and-after study was conducted to explore the clinical effects of switching between two versions of generic olanzapine (one of them was bid-winning product). Pre-and post-switching serum olanzapine concentrations were compared. A total of 30 patients were included and results showed the log-transformed, dose-adjusted concentration of bid-winning generic olanzapine was significantly lower than that of another generic olanzapine, while no significant differences were shown on Clinical Global Impressions Severity of Illness or Improvement ratings before and after switching. This study suggest that a generic version of a psychotropic medication may not be of therapeutic equivalence or bioequivalence with another generic one. Changes in efficacy or tolerability are possible in every switch. Therapeutic drug monitoring could be a valuable tool during switches between generic drugs. Larger prospective clinical studies for other generic psychotropic medications in target populations are warranted.
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Affiliation(s)
- Chao Zhang
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Yudan Ding
- Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Zhenzhen Wu
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Juan Wang
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Xiangping Wu
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Weiwei Xie
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
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Bird ST, Flowers N, Zhao Y, McKean S, Izem R, Wernecke M, Kozlowski S, MaCurdy TE, Kelman JA, Graham DJ. Healthy User Bias in Comparative Safety Studies for Brand-Name vs. Generic Products: The Example of Warfarin. Clin Pharmacol Ther 2019; 106:1037-1045. [PMID: 31062343 DOI: 10.1002/cpt.1498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/21/2019] [Indexed: 11/11/2022]
Abstract
Warfarin was selected as a case study to examine confounding when comparing a product across different manufacturers because it is a narrow therapeutic index drug with prevalent beliefs for brand-name superiority. Medicare beneficiaries aged ≥65 years with atrial fibrillation and an incident outpatient warfarin prescription from July 2006 through July 2015 were included in the study population (N = 746,098). Substantial imbalances were observed between brand-name warfarin and generics for (i) clinical comorbidity, (ii) socioeconomic status, (iii) prescriber specialty, (iv) recent ambulatory and emergent care, (v) drug adherence, (vi) pharmacy setting (e.g., retail, mail-order), and (vii) risk scores for bleeding and thrombosis. Patients receiving brand-name warfarin were healthier than patients receiving generic manufactured warfarin. Utilization of generic warfarin products also differed by geographic region and pharmacy setting. Manufacturer-level comparative-safety studies for causal inference should carefully consider the presence of these imbalances and their potential for introducing healthy user bias.
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Affiliation(s)
- Steven T Bird
- Office of Surveillance and Epidemiology, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Yueqin Zhao
- Office of Biostatistics, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Rima Izem
- Office of Biostatistics, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | | | - Steven Kozlowski
- Office of Pharmaceutical Quality, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Thomas E MaCurdy
- Acumen, LLC, Washington, DC, USA.,Department of Economics, Stanford University, Stanford, California, USA
| | - Jeffrey A Kelman
- Centers for Medicare & Medicaid Services, Baltimore, Maryland, USA
| | - David J Graham
- Office of Surveillance and Epidemiology, US Food and Drug Administration, Silver Spring, Maryland, USA
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Blier P, Margolese HC, Wilson EA, Boucher M. Switching medication products during the treatment of psychiatric illness. Int J Psychiatry Clin Pract 2019; 23:2-13. [PMID: 30732488 DOI: 10.1080/13651501.2018.1508724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND The common practice of switching between branded (reference) medications and their corresponding generic products, between generic products, or even from a generic product to a branded medication during the treatment of central nervous system (CNS) disorders may compromise efficacy and/or tolerability. METHODS We assessed the published literature from March 1, 2010 through June 30, 2017 via PubMed using the MeSH term 'generics, drugs' alone and in combination with class-specific terms (e.g., 'anticonvulsants', 'mood stabilisers'), for studies detailing outcomes following product switches. RESULTS Although some studies comparing the initiation of reference versus generic drugs suggest equivalence between products, several studies detailing a switch between reference and generic products describe reductions in efficacy, reduced medication adherence and persistence, and increased overall health care resource utilization and costs associated with generic substitution. CONCLUSION When product switches are considered, they should only proceed with the full knowledge of both patient and provider.
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Affiliation(s)
- Pierre Blier
- a University of Ottawa Institute of Mental Health Research , Ottawa , ON , Canada
| | | | | | - Matthieu Boucher
- d Department of Pharmacology & Therapeutics , McGill University, McIntyre Medical Science Building , Montréal , QC , Canada.,e Medical Affairs, Pfizer Canada Inc , Kirkland , QC , Canada
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Hsu CW, Lee SY, Wang LJ. Comparison of the effectiveness of brand-name and generic antipsychotic drugs for treating patients with schizophrenia in Taiwan. Schizophr Res 2018. [PMID: 28629889 DOI: 10.1016/j.schres.2017.06.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this nationwide population-based study is to compare the long-term effectiveness of brand-name antipsychotics with generic antipsychotics for treating schizophrenia. We identified patients with schizophrenia who were prescribed antipsychotics from a random sample of one million records from Taiwan's National Health Insurance database, observed between January 1, 2000 and December 31, 2012. Only those with no prior use of antipsychotics for at least 180days were included. We selected patients who were prescribed brand-name risperidone (N=404), generic risperidone (N=145), brand-name sulpiride (N=334), or generic sulpiride (N=991). The effectiveness of the treatments researched in this study consisted of average daily doses, rates of treatment discontinuation, augmentation therapy, and psychiatric hospitalization. We found that compared to patients treated with generic risperidone, those treated with brand-name risperidone required lower daily doses (2.14mg vs. 2.61mg). However, the two groups demonstrated similar rates of treatment discontinuation, augmentation, and psychiatric hospitalization. On the other hand, in comparison with patients prescribed generic sulpiride, those treated with brand-name sulpiride not only required lower daily doses (302.72mg vs. 340.71mg) but also had lower psychiatric admission rates (adjusted hazard ratio: 0.24, 95% confidence interval: 0.10-0.56). In conclusion, for both risperidone and sulpiride, higher daily doses of the respective generic drugs were prescribed than with brand-name drugs in clinical settings. Furthermore, the brand-name sulpiride is more effective at preventing patients from hospitalization than generic sulpiride. These findings can serve as an important reference for clinical practices and healthcare economics for treating schizophrenic patients.
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Affiliation(s)
- Chih-Wei Hsu
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Sheng-Yu Lee
- Department of Psychiatry, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; Department of Psychiatry, School of Medicine, and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Psychiatry, College of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Liang-Jen Wang
- Department of Psychiatry, College of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Chinese Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Psychiatry, School of Medicine, and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Child and Adolescent Psychiatry, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
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Al-Tabakha MM, Fahelelbom KMS, Obaid DEE, Sayed S. Quality Attributes and In Vitro Bioequivalence of Different Brands of Amoxicillin Trihydrate Tablets. Pharmaceutics 2017; 9:E18. [PMID: 28531119 PMCID: PMC5489935 DOI: 10.3390/pharmaceutics9020018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/03/2017] [Accepted: 05/16/2017] [Indexed: 02/04/2023] Open
Abstract
Bacterial resistance and antibiotic drug effectiveness can be related to administering generic products with a subtherapeutic dose or poor in vivo drug release. The aim of this study was to investigate whether locally marketed amoxicillin tablets have the required chemical and physical attributes, including in vitro bioequivalence performance. Five generic products (T1, T2, T3, T4, and T5) containing combination of amoxicillin trihydrate and potassium clavulanate as 1 g strength present in immediate release tablets were compared to the reference listed drug product Augmentin® (R) for weight variation, friability, resistance to crushing, and chemical content of amoxicillin. Difference (ƒ1) and similarity (ƒ2) factors were calculated to assess in vitro bioequivalence requirements. The tablets from different products have shown compliance with the pharmacopeial requirements of the performed tests. The measured resistance to crushing of tablets did not influence the dissolution time. Three generic products released more than 85% of amoxicillin by the first 15 min as did the reference product and were considered as bioequivalent products. T1 and T4 had ƒ1 values of 16.5% and 25.4% respectively and their ƒ2 values were 44.5 and 34.6 respectively, indicating failure to meet in vitro bioequivalence requirements. Tablet formulations can play an important role in achieving bioequivalence. Independent investigations such as this study serve as an important tool to reveal possible inferior or noncompliant products that may find their way to the market.
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Affiliation(s)
- Moawia M Al-Tabakha
- Pharmaceutics Unit, College of Pharmacy and Health Sciences, Ajman University, P.O. Box 346, Ajman, UAE.
| | - Khairi M S Fahelelbom
- Department of Pharmaceutical Sciences, College of Pharmacy, Al-Ain University of Science and Technology, P.O. Box 64141, Al Ain, UAE.
| | - Dana Emad Eddin Obaid
- Department of Pharmaceutical Sciences, College of Pharmacy, Al-Ain University of Science and Technology, P.O. Box 64141, Al Ain, UAE.
| | - Sadik Sayed
- Department of Pharmaceutical Sciences, College of Pharmacy, Al-Ain University of Science and Technology, P.O. Box 64141, Al Ain, UAE.
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