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Kocur A, Kunicki PK, Pawiński T. Generic Medicinal Products in Immunosuppressive Therapy-Should It be a Challenge for Therapeutic Drug Monitoring? Ther Drug Monit 2023; 45:173-190. [PMID: 36920502 DOI: 10.1097/ftd.0000000000001041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/29/2022] [Indexed: 03/16/2023]
Abstract
ABSTRACT Immunosuppressants have a narrow therapeutic index (NTIDs). Indisputably cyclosporine, tacrolimus, everolimus, and sirolimus have NTIDs, and only in the case of mycophenolic acid, a scientific discussion has not been yet concluded. Their specificities highlight the implications for generics introduced into the drug market, more precisely, with bioequivalence testing. In the European Union, the European Medicines Agency (EMA) released the "Guideline on the Investigation of Bioequivalence." The bioequivalence (BE) of the generic (tested, T) versus original (reference, R) product should be confirmed by obtaining a 90% confidence interval (CI) for the T:R ratio of each of the 2 decisive pharmacokinetic parameters, namely, the area under the curve (AUC) between 90.00% and 111.11%. A similar approach (90.00%-112.00%) for AUC was adopted by the Canadian Agency for Drugs and Technologies in Health (CADTH) for NTIDs; however, the US Food and Drug Administration is still based on classic acceptance criteria: 90% CI between 80.00% and 125.00% but with special requirements of BE testing. A discussion about long-expected global consensus was performed in this study based on the literature concerning BE testing in the case of NTIDs. The narrow acceptance criteria reduce the potential mean difference in bioavailability between generic and original products by a few percent. To identify this problem, special attention has been paid to switching drugs (generic-generic, original-generic) and therapeutic drug monitoring after conversion (TDM). There is no global consensus on the acceptance criteria for the BE of generic drugs; therefore, consensus and harmonization are strictly necessary. This study presents a review of the generic drug market and its classification by manufacturers, drug agencies, and dates of marketing authorization. Guidelines for TDM optimization (during switching/conversion) have been proposed. Physicians and clinical pharmacists should pay special attention to switching immunosuppressive drugs between original versus generic formulations, and generic versus generic formulations. Patients and their families should be educated on the risks associated with uncontrolled conversion.
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Affiliation(s)
- Arkadiusz Kocur
- Department of Drug Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland
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Report from the 2018 consensus conference on immunomodulating agents in thoracic transplantation: Access, formulations, generics, therapeutic drug monitoring, and special populations. J Heart Lung Transplant 2020; 39:1050-1069. [DOI: 10.1016/j.healun.2020.06.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 01/06/2023] Open
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Medeiros M, Lumini J, Stern N, Castañeda-Hernández G, Filler G. Generic immunosuppressants. Pediatr Nephrol 2018; 33:1123-1131. [PMID: 28733752 DOI: 10.1007/s00467-017-3735-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/20/2017] [Indexed: 11/24/2022]
Abstract
Immunosuppressive drugs for solid organ transplantation are critical dose drugs with a narrow therapeutic index. Many of the most commonly used innovator drugs are off patent and have been replicated by generic counterparts, often at substantial cost-savings to the patient. However, serious adverse events caused by the transition from innovator to generic medications, specifically in pediatric solid organ transplant recipients, have questioned these autosubstitutions. The purpose of this review is to summarize the criteria set forth by the regulatory bodies, and to examine how major immunosuppressive drugs conform to these recommendations. Regulatory bodies have established inconsistent criteria to demonstrate bioequivalence between innovator and generic medications, causing approved generic variations to have varying levels of equivalence with the innovator drugs. In order to minimize the risk for under-immunosuppression, the following recommendations have been concluded. Brand prescribing of cyclosporine and tacrolimus are recommended due to evidence of adverse events after conversion to generic formulations and differences in dissolution parameters. Mycophenolate mofetil (MMF) shows better bioequivalence between innovator and generic formulations, however caution should be advised when switching between formulations. The institution of 'innovator only' policies may be appropriate at this time in order to minimize the risk of under-immunosuppressing patients until the evidence of more stringent bioequivalence has been established.
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Affiliation(s)
- Mara Medeiros
- Unidad de Investigacion en Nefrologia, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico.,Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Julia Lumini
- Department of Biomedical Life Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Noah Stern
- Department of Paediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada
| | | | - Guido Filler
- Department of Paediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada. .,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada. .,Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N5A 5A5, Canada. .,Paediatric Nephrology, University of Western Ontario, Children's Hospital, London Health Science Centre, 800 Commissioners Road East, London, ON, N6A 5W9, Canada.
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Rottembourg J, Rostoker G. [The use of generics in transplantation: Towards rational and safe solutions!]. Presse Med 2018; 47:199-210. [PMID: 29555162 DOI: 10.1016/j.lpm.2017.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 11/27/2017] [Accepted: 12/13/2017] [Indexed: 10/17/2022] Open
Abstract
Generic immunosuppressive drugs are available in Europe Canada and the United States. Between countries, there are large differences in penetration of generic drugs in general, and for immunosuppressive drugs in particular. The registration for generic immunosuppressive drugs are slightly different, but the criteria for registration of narrow therapeutic index drugs and bioequivalence studies, performed only in healthy volunteers, will remain in the medical landscape. About 50 studies compare the clinical efficacy and bioequivalence of the generic immunosuppressive drugs in patients with solid organ transplants. To allow for safe substitution, a number of criteria need to be fulfilled. Consensus statements were made by most transplant organizations. Authorities and payers should refrain from forcing pharmacists to dispense generic drugs in patients on maintenance immunosuppressive treatment. Generic substitution could be safe if realized by the treating physician, for a well-informed patient. Substitution must be followed by control visits to check if the patient is taking the medication correctly and if the drug exposure, through a close monitoring, remains stable. Substitution from one generic to another generic should be avoided, in all cases.
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Affiliation(s)
- Jacques Rottembourg
- Groupe hospitalier Pitié-Salpêtrière, service de néphrologie, 83, boulevard de l'Hôpital, 75013 Paris, France.
| | - Guy Rostoker
- Hôpital privé Claude-Galien, Ramsay-Générale de Santé, service de néphrologie et de dialyse, 91480 Quincy-sous-Sénart, France
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Molnar AO, Fergusson D, Tsampalieros AK, Bennett A, Fergusson N, Ramsay T, Knoll GA. Generic immunosuppression in solid organ transplantation: systematic review and meta-analysis. BMJ 2015; 350:h3163. [PMID: 26101226 PMCID: PMC4476317 DOI: 10.1136/bmj.h3163] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To compare the clinical efficacy and bioequivalence of generic immunosuppressive drugs in patients with solid organ transplants. DESIGN Systematic review and meta-analysis of all studies comparing generic with innovator immunosuppressive drugs. DATA SOURCES Medline and Embase from 1980 to September 2014. REVIEW METHODS A literature search was performed for all studies comparing a generic to an innovator immunosuppressive drug in solid organ transplantation. Two reviewers independently extracted data and assessed quality of studies. Meta-analyses of prespecified outcomes were performed when deemed appropriate. Outcomes included patient survival, allograft survival, acute rejection, adverse events and bioequivalence. RESULTS 1679 citations were screened, of which 50 studies met eligibility criteria (17 randomized trials, 15 non-randomized interventional studies, and 18 observational studies). Generics were compared with Neoral (cyclosporine) (32 studies), Prograf (tacrolimus) (12 studies), and Cellcept (mycophenolate mofetil) (six studies). Pooled analysis of randomized controlled trials in patients with kidney transplants that reported bioequivalence criteria showed that Neoral (two studies) and Prograf (three studies) were not bioequivalent with generic preparations according to criteria of the European Medicines Agency. The single Cellcept trial also did not meet bioequivalence. Acute rejection was rare but did not differ between groups. For Neoral, the pooled Peto odds ratio was 1.23 (95% confidence interval 0.64 to 2.36) for kidney randomized controlled trials and 0.66 (0.40 to 1.08) for observational studies. For kidney observational studies, the pooled Peto odds ratios were 0.98 (0.37 to 2.60) for Prograf and 0.49 (0.09 to 2.56) for Cellcept. Meta-analyses for non-renal solid organ transplants were not performed because of a lack of data.There were insufficient data reported on patient or graft survival. Pooling of results was limited by inconsistent study methods and reporting of outcomes. Many studies did not report standard criteria used to determine bioequivalence. While rates of acute rejection seemed similar and were relatively rare, few studies were designed to properly compare clinical outcomes. Most studies had short follow-up times and included stable patients without a history of rejection. CONCLUSIONS High quality data showing bioequivalence and clinical efficacy of generic immunosuppressive drugs in patients with transplants are lacking. Given the serious consequences of rejection and allograft failure, well designed studies on bioequivalence and safety of generic immunosuppression in transplant recipients are needed.
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Affiliation(s)
- Amber O Molnar
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6 Clinical Epidemiology Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Canada, K1H 8L6
| | - Dean Fergusson
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6 Division of Nephrology, Children's Hospital of Eastern Ontario, 401 Smyth Road, Ottawa, Canada, K1H 8L1
| | - Anne K Tsampalieros
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6 Clinical Epidemiology Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Canada, K1H 8L6
| | - Alexandria Bennett
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6 Clinical Epidemiology Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Canada, K1H 8L6
| | - Nicholas Fergusson
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6 Clinical Epidemiology Program, Ottawa Hospital Research Institute, 501 Smyth Road, Ottawa, Canada, K1H 8L6
| | - Timothy Ramsay
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6
| | - Greg A Knoll
- Division of Nephrology, Kidney Research Centre, Department of Medicine, University of Ottawa, 501 Smyth Road, Ottawa, Canada, K1H 8L6
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El Hajj S, Kim M, Phillips K, Gabardi S. Generic immunosuppression in transplantation: current evidence and controversial issues. Expert Rev Clin Immunol 2015; 11:659-72. [DOI: 10.1586/1744666x.2015.1026895] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Heavner MS, Tichy EM, Yazdi M, Formica RN, Kulkarni S, Emre S. Clinical outcomes associated with conversion from brand-name to generic tacrolimus in hospitalized kidney transplant recipients. Am J Health Syst Pharm 2014; 70:1507-12. [PMID: 23943182 DOI: 10.2146/ajhp120783] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The safety of converting kidney transplant recipients on brand-name tacrolimus to generic tacrolimus during hospitalization was evaluated. METHODS A single-center observational study compared tacrolimus dosages and trough tacrolimus levels in kidney transplant recipients who had a kidney transplant more than 90 days before hospital admission. Patients in the "brand" group were maintained on brand-name tacrolimus throughout the entire study period. Patients in the generic group were maintained on brand-name tacrolimus before hospital admission, converted to the generic formulation during hospitalization, and returned to the brand-name product at discharge. Tacrolimus dosages were converted on a milligram-per-milligram basis and adjusted, if needed. Outcomes evaluated included the percentage of patients requiring a dosage change, absolute change in average tacrolimus trough level, and frequency of biopsy-proven acute rejection within six months of discharge. RESULTS A total of 100 patients were evaluated for inclusion in the brand group, with 42 meeting study criteria; 98 patients were evaluated in the generic group, with 36 qualifying for the study. There were no significant differences between the brand and generic groups with respect to dosage adjustments required or trough tacrolimus levels at any point in the transition of care. Mean trough concentrations were similar between groups during all periods of care. The only occurrence of new-onset acute rejection within six months after admission occurred in the brand group. CONCLUSION Substitution of a generic formulation of tacrolimus for the innovator product during hospitalization of kidney transplant recipients was safely implemented. Tacrolimus dosage adjustments were common throughout the transitions of care, regardless of the formulation used.
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Affiliation(s)
- Mojdeh S Heavner
- Department of Pharmacy, Yale-New Haven Hospital, New Haven, CT 06510, USA
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van Gelder T, Gabardi S. Methods, strengths, weaknesses, and limitations of bioequivalence tests with special regard to immunosuppressive drugs. Transpl Int 2013; 26:771-7. [DOI: 10.1111/tri.12074] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 11/12/2012] [Accepted: 01/11/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Teun van Gelder
- Departments of Hospital Pharmacy and Internal Medicine; Erasmus Medical Center; CA; Rotterdam; The Netherlands
| | - Steven Gabardi
- Departments of Transplant Surgery and Pharmacy Services, and the Renal Division; Brigham and Women's Hospital; Harvard Medical School; Boston; MA; USA
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Remport A, Dankó D, Gerlei Z, Czebe K, Kiss I. [Special considerations in generic substitution of immunosuppressive drugs in transplantation]. Orv Hetil 2012; 153:1341-9. [PMID: 22913916 DOI: 10.1556/oh.2012.29429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Long-term success in solid organ transplantation strongly depends on the optimal use of maintenance immunosuppressive treatment. Cyclosporin and tacrolimus are the most frequently administered immunosuppressants and they are designed to narrow therapeutic index drugs. The substitution of the branded formulation by their generic counterparts may lead to economic benefit only if equivalent clinical outcomes can be achieved. There is no published evidence to date on the guarantee of their long-term therapeutic equivalence and cases of therapeutic failures have been reported due to inadvertent drug conversion. The disadvantageous clinical consequences of a non medical, mechanistic forced switch from the original to generic formulation of tacrolimus and the estimated loss of the payer's presumed savings are presented in a kidney transplant recipient population. Special problems related to pediatric patients, drug interactions with concurrent medications and the burden of additional therapeutic drug monitoring and follow up visits are also discussed. The authors are convinced that the implementation of the European Society of Organ Transplantation guidelines on generic substitution may provide a safe way for patients and healthcare payers.
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Affiliation(s)
- Adám Remport
- Szent Imre Kórház Nefrológia-Hypertonia Profil Budapest Tétényi.
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Abstract
The introduction of generic immunosuppressant medications may present an opportunity for cost savings in solid organ transplantation if equivalent clinical outcomes to the branded counterparts can be achieved. An interprofessional working group of the Canadian Society of Transplantation was established to develop recommendations on the use of generic immunosuppression in solid organ transplant recipients (SOTR) based on a review of the available data. Under current Health Canada licensing requirements, a demonstration of bioequivalence with the branded formulation in healthy volunteers allows for bridging of clinical data. Cyclosporine, tacrolimus, and sirolimus are designated as "critical dose drugs" and are held to stricter criteria. However, whether this provides sufficient guarantee of therapeutic equivalence in SOTR remains controversial, and failure to maintain an appropriate balance of immunosuppression may have serious consequences, including rejection, graft loss, and death. Published evidence supporting therapeutic equivalence of generic formulations in SOTR is lacking. Moreover, in the setting of multiple generic formulations the potential for uncontrolled product switching is a major concern, since generic preparations are not required to demonstrate bioequivalence with each other. Although close monitoring is recommended with any change in formulation, drug product switches are likely to occur without prescriber knowledge and may pose a significant patient safety risk. The advent of generic immunosuppression will require new practices including more frequent therapeutic drug and clinical monitoring, and increased patient education. The additional workload placed on transplant centers without additional funding will create challenges and could ultimately jeopardize patient outcomes. Until more robust clinical data are available and adequate regulatory safeguards are instituted, caution in the use of generic immunosuppressive drugs in solid organ transplantation is warranted.
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Hulbert AL, Pilch NA, Taber DJ, Chavin KD, Baliga PK. Generic immunosuppression: deciphering the message our patients are receiving. Ann Pharmacother 2012; 46:671-7. [PMID: 22570436 DOI: 10.1345/aph.1r028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The introduction of generic immunosuppressants elicited controversy within the transplant community and it is unknown whether patient attitudes mirror the ambiguity of provider perceptions. With the current health care economic crisis, it is necessary to consider generic immunosuppression as an option. A greater understanding of patient perceptions would enhance vital communication between providers and patients to facilitate education and appropriate monitoring. OBJECTIVE To evaluate transplant recipients' perceptions of generic versus brand immunosuppressants based on experience with these agents and the willingness of patients to convert treatment from brand to generic formulations based on socioeconomic variables and baseline demographics. METHODS Key informant interviews were conducted to inform the development of the survey instrument. The survey was distributed to solid organ transplant recipients at a large, academic medical center from October to December 2010. RESULTS Nine patients participated in key informant interviews. Financial considerations and provider recommendations were the most commonly identified factors to influence perceptions of generic immunosuppressants. A total of 255 patients completed the survey; treatment in 81 (32%) participants had been converted to a generic immunosuppressant. Those currently receiving a generic immunosuppressant expressed higher beliefs of generic and brand equivalency (75% vs 54%, p = 0.006) and an increased willingness to convert treatment to a generic given equivalent cost (51% vs 32%, p = 0.024). African American participants were found to have a decreased belief of generic and brand equivalency compared to other ethnicities (60% vs 75%, p = 0.013). Participants with an annual income of less than $30,000 had higher beliefs of generic and brand equivalency (60% vs 40%, p = 0.0001). Education level and age did not impact beliefs of generic efficacy or willingness to convert therapy. CONCLUSIONS Patient ethnicity, income, and experience with generic immunosuppressants appear to contribute to perceptions of generic immunosuppressants. The prevalence of generic immunosuppressant use supports the importance of communication of this issue between providers and patients.
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Affiliation(s)
- Amanda L Hulbert
- Department of Pharmacy Services, The Ohio State University Medical Center, Columbus, OH, USA
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Cyclosporine: A Commentary on Brand versus Generic Formulation Exchange. J Transplant 2011; 2011:480642. [PMID: 22174986 PMCID: PMC3235899 DOI: 10.1155/2011/480642] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 09/26/2011] [Indexed: 11/25/2022] Open
Abstract
The evidence for conversion from brand name to generic equivalent cyclosporine is conflicting. Cyclosporine is a narrow therapeutic-range drug for which small variations in exposure may have severe clinical consequences for transplant patients. There is currently a lack of comparative outcome data relating to the pharmacokinetics of the reference formulation, Neoral, and generic formulations in transplant recipients. A major common concern is the potential inability to attain similar trough levels, an issue that can be easily corrected by ongoing therapeutic drug monitoring to ensure that the new steady state falls within an intended target range. Prospective clinical studies investigating the efficacy and safety of generic formulations in both de novo and long-term transplant patients are also awaited. Until further evidence is available on the conversion of transplant patients to or between generic formulations of cyclosporine, any transfer to a different cyclosporine formulation should be undertaken with close supervision. The best available information to date, however, does not support the frequently held but unsubstantiated belief that generic preparations of immunosuppressive drugs are not as effective as brand names or that conversion from brand to generic is associated with significant danger. This paper attempts to initiate a discussion of these issues.
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Ensor CR, Trofe-Clark J, Gabardi S, McDevitt-Potter LM, Shullo MA. Generic Maintenance Immunosuppression in Solid Organ Transplant Recipients. Pharmacotherapy 2011; 31:1111-29. [DOI: 10.1592/phco.31.11.1111] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Al Ameri MN, Whittaker C, Tucker A, Yaqoob M, Johnston A. A survey to determine the views of renal transplant patients on generic substitution in the UK. Transpl Int 2011; 24:770-9. [DOI: 10.1111/j.1432-2277.2011.01268.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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AlAmeri M, Epstein M, Johnston A. Generic and therapeutic substitutions: are they always ethical in their own terms? ACTA ACUST UNITED AC 2010; 32:691-5. [DOI: 10.1007/s11096-010-9429-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Helderman JH, Kang N, Legorreta AP, Chen JY. Healthcare costs in renal transplant recipients using branded versus generic ciclosporin. APPLIED HEALTH ECONOMICS AND HEALTH POLICY 2010; 8:61-68. [PMID: 20038194 DOI: 10.1007/bf03256166] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND Generic ciclosporin A modified (CsA) does not have an equivalent pharmacokinetic profile to branded CsA in some transplant populations, potentially leading to negative clinical consequences and increased long-term costs. OBJECTIVE To assess direct healthcare costs for de novo renal transplant recipients in the US receiving branded versus generic CsA in the first month after transplantation. METHODS Administrative claims data from eight private US health plans were linked to the Organ Procurement and Transplantation Network data. A total of 227 renal transplant cases between 1996 and 2004 were included: 183 were dispensed branded CsA and 44 received generic CsA. Log transformed multiple linear regression was used to model total first-year healthcare costs after the initial CsA claim, controlling for both patient demographics and clinical characteristics and clustering at the transplant centre level. RESULTS After controlling for patient factors and pre-CsA costs, total healthcare costs were significantly higher (p = 0.04) for patients receiving generic CsA versus branded CsA. The main driver for the difference was the cost associated with immunosuppressants other than CsA (p = 0.01). CONCLUSION Despite initial perceived cost savings associated with generic CsA, de novo renal transplant recipients incurred greater total healthcare costs than those treated with branded CsA. Patients receiving generic CsA may need higher doses or other immunosuppressants to maintain the transplanted kidney than patients receiving branded CsA. Providers and payers need to be aware of potential differences in total healthcare costs between formulations of bioequivalent critical-dose drugs to make the best choice for patient care.
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Mendonza AE, Gohh RY, Akhlaghi F. Blood and Plasma Pharmacokinetics of Ciclosporin in Diabetic Kidney Transplant Recipients. Clin Pharmacokinet 2008; 47:733-42. [DOI: 10.2165/00003088-200847110-00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Masri MA, Rizk S, Attia MLE, Barbouch H, Rost M. Bioavailability of a New Generic Formulation of Mycophenolate Mofetil MMF 500 Versus CellCept in Healthy Adult Volunteers. Transplant Proc 2007; 39:1233-6. [PMID: 17524942 DOI: 10.1016/j.transproceed.2007.03.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several studies have revealed a decreased incidence of early graft rejection with the use of mycophenate mofetil (MMF). The cost of the drug is, however, prohibitive especially in developing countries with limited resources. We compared the pharmacokinetic profile of a new MMF generic formulation (MMF 500 batch number: 06T3001; Medis Tunis) with those of Cellcept, (batch number: M1427; Hoffmann La Roche, Switzerland) in healthy volunteers. The study was double-blinded to investigator and volunteers. It had a balanced randomized, two-treatment, two-period, two-sequence, single-dose, crossover, comparative oral bioavailability design in adult healthy human volunteers. The study was designed, performed, and monitored by CRO Transmedical s.a.l International (Beirut, Lebanon) in accordance with the Basic Principals defined in the US 21 CFR Part 312.20, and the principals enunciated in the World Medical Association Declaration of Helsinki. We included nonsmoking healthy volunteers between the ages of 22 and 45 years. The subjects were admitted to the hospital one night prior to blood sampling. After volunteers received the same dinner, they were fasted overnight and for 2 hours postdosing. At 8 am each person received a single oral dose of 500 mg of either formulation. Blood samples were collected to construct the pharmacokinetic profiles as follows: 0, 0.15, 0.30, 0.45 minutes and 1, 1.15, 1.30, 2, 4, 6, 10, 12, and 24 hours. Water and food intake were the same for all volunteers during the whole study period. Following an 8-day washout period, the subjects were crossed over. Plasma mycophenolic acid concentrations were determined using a high-performance liquid chromatography validated enzyme-linked immunosorbent assay-based method (TransMedical, Beirut Lebanon). Physical examinations, hematology, urinanalysis, serum chemistry tests, and liver enzymes were performed at screening and at the end of each period. Subjects were monitored for safety and adverse events throughout the study by two physicians (one from the hospital and one from TransMedical). The Cmax, Tmax, and AUC for MMF 500 were 10.14 ng/mL, 51.82 minutes, and 18.33 ng/mL/h vs 10.94 ng/mL, 49.09 minutes, and 17.46 ng/mL/h for CellCept, respectively. The 90% confidence intervals (LSM) of Cmax, Tmax, and AUC for MMF 500 were 92.7%, 105.6%, and 105%, respectively, which is within the Food and Drug Administration (FDA)-assigned range for immunosuppressive drugs (90% to 111%). These results indicated that the products are equivalent and switchable according to FDA rulings.
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Affiliation(s)
- M A Masri
- TransMedical Drug Evaluation Center, Beirut, Lebanon
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Qazi YA, Forrest A, Tornatore K, Venuto RC. The clinical impact of 1:1 conversion from Neoral to a generic cyclosporine (Gengraf) in renal transplant recipients with stable graft function. Clin Transplant 2006; 20:313-7. [PMID: 16824147 DOI: 10.1111/j.1399-0012.2005.00483.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The introduction of cyclosporine (CYA) to the immunosuppressive armamentarium has had a significant effect on graft survival. An improvement in the formulation from the oil-based to a microemulsion-based form has resulted in better absorption and more predictable CYA bioavailability. Since the introduction of the first microemulsion form (Neoral), several bioequivalent formulations are now available and are switched in a 1:1 fashion at pharmacies to curtail costs. The purpose of our study was to study the effect of a 1:1 switch from Neoral to Gengraf on CYA trough levels and serum creatinine (SRC) in renal transplant recipients with stable graft function. Eighty-two renal transplant recipients with stable graft function were enrolled in the study, and of these, 73 were switched to Gengraf, whereas nine remained on Neoral. The 13 patients switched to Gengraf required a dosage change after the mean CYA trough levels changed from 234 +/- 96 ng/mL at baseline to 289 +/- 102 ng/mL (p < 0.05) at 2 wk. With the adjustments in dosage, the levels approached the baseline trough concentrations (239 +/- 151 ng/dL). The nine patients who remained on Neoral had no change in the CYA levels or SCR. Nearly 20% of patients who switched to a bioequivalent CYA preparation required a dose adjustment to return to pre-conversion CYA trough levels. Our study raises serious concerns regarding the switchability of generic CYA for Neoral without careful follow-up therapeutic drug monitoring.
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Affiliation(s)
- Yasir A Qazi
- Department of Medicine, University at Buffalo, State University at New York, School of Medicine and School of Pharmacy, NY, USA
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23
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Hibberd AD, Trevillian PR, Roger SD, Wlodarczyk JH, Stein AM, Bohringer EG, Milson-Hawke SM. Assessment of the bioequivalence of a generic cyclosporine A by a randomized controlled trial in stable renal recipients. Transplantation 2006; 81:711-7. [PMID: 16534473 DOI: 10.1097/01.tp.0000181198.98232.0c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The aim of this study was to determine the bioequivalence of Cysporin, a generic cyclosporine A, compared with Neoral in stable renal transplant recipients. METHODS Study design consisted of an open label, two-way crossover, randomized controlled trial of Cysporin versus Neoral in stable renal transplant recipients. In all, 33 patients were enrolled; 31 were randomized and 28 were evaluable. AUCs(0-12) were done on day 14 and 28; C(0) and C(2) were done on days 0, 7, 21 and 35. Dose conversion was 1:1. Outcome measures for serum cyclosporin A concentrations expressed as the mean+/-SD were AUC(0-12) (microg x hr/L), C(max) (microg/L), C(2) (microg/L), T(max) (hr) and T(1/2) (hr). Mean and 90% CI of the ratio Cysporin/Neoral of log-transformed data were calculated using a general linear model. RESULTS The main pharmacokinetic features were: AUC(0-12): Cysporin 3495+/-1319, Neoral 3853+/-1378 (P<0.05); C(max): Cysporin 755+/-301, Neoral 881+/-368 (P<0.05); C(2): Cysporin 613+/-235, Neoral 672+/-255 (P>0.05); T(max): Cysporin 1.9+/-0.8, Neoral 1.4+/-0.6 (P<0.005); and T1/2: Cysporin 8.8+/-4.3, Neoral 8.7+/-6.2 (P>0.05). Estimated ratios of Cysporin/Neoral were: AUC 0.93 (90% CI 0.88-0.98; P<0.05); C(max) 0.88 (90% CI 0.80-0.97; P<0.05); and T(max) 1.32 (90% CI 1.14-1.53; P<0.005). CONCLUSIONS Both the extent and rate of absorption of Cysporin are significantly less than those of Neoral. The 90% CI for the ratios of Cysporin/Neoral for AUC and C(max) lie within 0.80-1.25. Hence in this clinical context Cysporin is pharmacologically bioequivalent with Neoral. This study illustrates the importance of testing bioequivalence of generic cyclosporine A products in transplant recipients not healthy volunteers.
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Affiliation(s)
- Adrian D Hibberd
- Newcastle Transplant Unit, Division of Surgery, John Hunter Hospital, Newcastle, New South Wales, Australia.
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24
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Masri MA, Haberal M, Rizvi A, Stephan A, Bilgin N, Naqvi A, Barbari A, Kamel G, Zafar N, Emiroğlu R, Colak T, Manzoor K, Matha V, Kamarad V, Rost M, Rizk S, Hazime A, Perlik F. Switchability of neoral and equoral according to Food and Drug Administration rules and regulations. Transplant Proc 2006; 37:2988-93. [PMID: 16213282 DOI: 10.1016/j.transproceed.2005.07.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.
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25
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Taber DJ, Baillie GM, Ashcraft EE, Rogers J, Lin A, Afzal F, Baliga P, Rajagopalan PR, Chavin KD. Does Bioequivalence Between Modified Cyclosporine Formulations Translate into Equal Outcomes? Transplantation 2005; 80:1633-5. [PMID: 16371936 DOI: 10.1097/01.tp.0000188688.15639.03] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neoral was replaced with a generic cyclosporine formulation on our hospital formulary. We compared outcomes for de novo kidney transplant recipients who either received Gengraf (n=88) or Neoral (n=100) in a single-center, retrospective review. As compared to patients who received Neoral, patients who received Gengraf were significantly more likely to have an acute rejection episode (39% vs. 25%, P=0.04), more likely to have a second rejection episode (13% vs. 4%; P=0.03), or to have received an antibody preparation to treat acute rejection (19% vs. 8%; P=0.02). Patients treated with Gengraf had a higher degree of intrapatient variability for cyclosporine trough concentrations as determined by %CV (P<0.05). The incidence of acute rejection at 6 months posttransplant was significantly higher in patients who received Gengraf compared to Neoral. A larger, prospective analysis is warranted to compare these formulations of cyclosporine in de novo kidney transplant recipients.
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Affiliation(s)
- David J Taber
- School of Pharmacy, Wingate University, Wingate, NC, USA
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26
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Formea CM, Evans CG, Karlix JL. Altered Cytochrome P450 Metabolism of Calcineurin Inhibitors: Case Report and Review of the Literature. Pharmacotherapy 2005; 25:1021-9. [PMID: 16006281 DOI: 10.1592/phco.2005.25.7.1021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A 19-year-old woman was admitted to receive a kidney transplant from a nonliving donor. At the time of transplantation, she was taking oral phenytoin 300 mg every morning, 100 mg at noon, and 300 mg every evening (total of 700 mg/day) to treat seizures secondary to hemodialysis. Immediately after the transplantation, phenytoin treatment was resumed, and immunosuppressive therapy consisting of antithymocyte globulin, cyclosporine, mycophenolate mofetil, and corticosteroids was started. Her cyclosporine blood levels varied over the first 10 days after transplantation. Cyclosporine was discontinued, and tacrolimus was begun after acute rejection was discovered. The rejection was treated with antithymocyte globulin, plasmapheresis, and intravenous immunoglobulin, and subsequently resolved; however, the patient's blood concentrations of tacrolimus varied widely. Phenytoin is an antiepileptic drug that induces hepatic enzymes, affecting the cytochrome P450 3A family. These enzymes metabolize approximately 50% of all prescribed drugs, including cyclosporine and tacrolimus. According to the Naranjo adverse drug reaction probability scale, this patient's adverse drug reaction probably occurred from altered metabolism of cyclosporine and tacrolimus due to phenytoin therapy. Clinicians must identify drug interactions between metabolic enzyme inducers or inhibitors and drug substrates with narrow therapeutic ranges, closely monitor drug concentrations, and observe patients for clinical signs and symptoms of therapeutic failure or toxicity. In daily practice, clinicians should explore the metabolic characteristics of drugs and their biotransformation pathways to identify patients who require alternative therapy.
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Affiliation(s)
- Christine M Formea
- Department of Pharmacy Practice, College of Pharmacy, University of Florida, Gainesville, Florida, USA.
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27
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Abstract
The introduction of cyclosporine (CsA) in clinical practice has significantly improved patient and allograft survival after organ transplantation. The new microemulsion CsA formulation, Neoral, has been associated with a more reproducible absorption and a better patient outcome as compared to the old formulation Sandimmune. Recently, several generic CsA formulations have been tested as bioequivalent to Neoral. Bioequivalence tests have been performed in selected groups of young, healthy male volunteers usually in single-dose studies, and then extended to completely different population, such as transplant recipients. However, growing body of evidence shows that CsA pharmacokinetics in healthy subjects is different from that of transplant patients, treated chronically with CsA. Therefore, converting patients from Neoral to the new generic formulations could be detrimental, exposing patients to increased risk of graft function deterioration and graft loss. Thus, more research and more accurate bioequivalence tests are required to address the unanswered problems dealing with the generic CsA formulations.
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Affiliation(s)
- Dario Cattaneo
- Department of Medicine and Transplantation, Ospedali Riuniti di Bergamo, Mario Negri Institute for Pharmacological Research, Italy.
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28
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Abstract
The introduction of cyclosporine into clinical practice improved transplant outcome. However, the use of cyclosporine is not without problems. A narrow therapeutic index (the drug causes irreversible kidney damage when given in too high a dose) coupled with variable absorption and unpredictable pharmacokinetics has resulted in the need to measure cyclosporine blood concentrations to enable the dose of the drug to be individualised to the patient. When this is done correctly therapeutic efficacy can be maximised while toxicity is kept to a minimum. The evolution of cyclosporine dose optimisation started with the adjustment of empirical fixed doses by clinical "judgement;" progressed to therapeutic drug monitoring of trough, predose, C0 concentration with non specific assays that measured parent drug and metabolite; then on to "specific" cyclosporine C0 measurements; through area under curve monitoring using full profile measurements and limited sampling scheme procedures; and finally ending up with absorption profiling that targets AUC in the first 4 hours or the 2 hour blood cyclosporine concentration, C2. At the same time the formulation of cyclosporine has changed from Sandimmune to Neoral and now generic forms of the latter are available. The evidence base supporting C2 monitoring continues to grow and the technique will need to be customised as new combination therapies emerge. Therapeutic drug monitoring of cyclosporine may also need to be tailored to avoid the potential negative impact of switching patients to generic forms of the drug.
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Affiliation(s)
- A Jorga
- Clinical Pharmacology Barts and The London, Charterhouse Square, London, UK
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29
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David-Neto E, Kakehashi E, Alves CF, Pereira LM, de Castro MCR, de Mattos RM, Sumita NM, Romano P, Mendes ME, Nahas WC, Ianhez LE. Bioequivalence of a new cyclosporine a formulation to Neoral. Ther Drug Monit 2004; 26:53-7. [PMID: 14749551 DOI: 10.1097/00007691-200402000-00012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
New cyclosporine A (CsA) formulations must prove their bioequivalence to Neoral, the reference CsA formulation, to allow free prescription for the patients. The aim of this study was to compare the pharmacokinetics (PK) of a new CsA formulation (Zinograf-ME), produced by Strides-Arcolab, to Neoral and to demonstrate their interchangeability in stable renal transplant recipients. Twelve-hour PK studies were obtained from 18 (13 M/5 F) adult patients (mean age 44.7 +/- 12 years). They received their renal allografts from 13 cadaver and 5 living donors. Before enrollment, all patients were receiving a third generic CsA for a mean of 48 months. Nine patients were also under azathioprine and 9 under mycophenolate mofetil; 17 received prednisone. A single oral dose of either Zinograf or Neoral was administered. The first PK study was performed with one formulation, and 1 week later, a second PK was done with the other formulation. During the washout period, patients continued taking the third CsA formulation. The drug substitution was done milligram-for-milligram. The CsA whole-blood level was measured by TDx immunoassay. Mean +/- SD of area under the curve (AUC), maximum concentration (C(max)), and concentration at the second hour (C2) of Zinograf were not statistically different from those with Neoral (4019 +/- 1466 vs 3971 +/- 1325 ng x h/mL, 998 +/- 376 vs 1021 +/- 356 ng/mL, and 707 +/- 254 vs 734 +/- 229 ng/mL, respectively). In the same way, the Zinograf 90% confidence interval for either C(max) (-123, +77 ng/mL) or AUC (-214, +311 ng.mL/h) were within the Neoral bioequivalence interval for the same parameters (+/-204 ng/mL and +/-794 ng x mL/h, respectively). These data demonstrate that the ZinografME CsA formulation is bioequivalent to Neoral.
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Affiliation(s)
- Elias David-Neto
- Unidade de Transplante Renal, Divisão de Clínica Urológica das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
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30
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Langone AJ, Helderman JH. Experience with cyclosporine. Transplant Proc 2004; 36:59S-63S. [PMID: 15041308 DOI: 10.1016/j.transproceed.2004.01.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- A J Langone
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical School, Nashville, TN 37232-3272, USA.
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31
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Alloway RR, Isaacs R, Lake K, Hoyer P, First R, Helderman H, Bunnapradist S, Leichtman A, Bennett MW, Tejani A, Takemoto SK. Report of the American Society of Transplantation conference on immunosuppressive drugs and the use of generic immunosuppressants. Am J Transplant 2003; 3:1211-5. [PMID: 14510694 DOI: 10.1046/j.1600-6143.2003.00212.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Considerable economic and health-related costs are associated with the life-long maintenance immunosuppressive therapy required to prevent transplant rejection. Generic medications have the potential of providing equivalent therapeutic efficacy at a lower economic cost. In 2001, the American Society of Transplantation invited experts to review the data and issues associated with the approval and use of generic immunosuppressants. A summary of that meeting is reported here. The generic medication approval process has been in effect for more than 30 years. All marketed generic cyclosporin formulations have met FDA criteria demonstrating bioequivalence in healthy subjects, and some were also tested in transplant recipients. Most participants agreed that generic narrow therapeutic index immunosuppressive agents provide adequate de novo immunosuppression in low-risk transplant recipients. However, some participants expressed concern regarding the currently unquantified risk that may be associated with switching immunosuppressive agents under uncontrolled circumstances. There was broad agreement among the participants that generic medications should be clearly labeled and distinguishable from innovator drugs, and that patients should be educated to inform their physicians of any switch to or among generic alternatives. There was also strong support in favor of requiring studies to demonstrate bioequivalence in potentially at-risk patient populations, specifically African-Americans and pediatric patients.
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Affiliation(s)
- Rita R Alloway
- University of Cincinnati, College of Medicine, Cincinnati OH, USA
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32
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TSANG WK, WONG SH, CHU KH, LEE W, CHEUK A, TANG HL, FUNG SKS, CHAN HWH, TONG MKL. The pharmacokinetics and bioequivalence of Gengraf and Neoral in stable renal transplant recipients. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1561-5413(09)60102-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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33
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Ouyang J, Baeyens WRG, Duan J, Delanghe J. Improvement of cyclosporin A determination in whole blood by reversed-phase high-performance liquid chromatography. Biomed Chromatogr 2003; 17:404-10. [PMID: 13680852 DOI: 10.1002/bmc.262] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A chromatographic method was developed for the determination of cyclosporin A in human whole blood using reversed-phase HPLC at room temperature. Most previous reports carried out this liquid chromatographic separation at temperatures above 70 degrees C. The present procedure greatly improves the detection limit by controlling peak broadening effects, as well as the lifetime of the column at room temperature. Under optimal conditions and using ketoconazole as an internal standard, the calibration graph was linear in the range of 16-1000 microg/L with a relative standard deviation of 3.72% at 150 microg/L and 2.45% at 300 microg/L (n = 11) of cyclosporin A. The detection limit was of 5.0 microg/L cyclosporin A. By this procedure, cyclosporin A pharmacokinetic parameters in healthy Chinese subjects were studied. The developed method could be applied to the quantification of cyclosporin A in human blood samples and allows the study of its pharmacokinetics in routine laboratories.
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Affiliation(s)
- Jin Ouyang
- Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium
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