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Clinical and economic impact of generic versus brand name meropenem use in an intensive care unit in Colombia. Braz J Infect Dis 2019; 23:237-245. [PMID: 31344357 PMCID: PMC9427813 DOI: 10.1016/j.bjid.2019.06.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 06/13/2019] [Accepted: 06/16/2019] [Indexed: 01/08/2023] Open
Abstract
Background Recent studies suggest that sustained use of generic antibiotics may be associated with clinical failure and emergence of antibacterial resistance. The present study was designed to determine the clinical outcome between the use of generic meropenem (GM) and brand-name meropenem (BNM). Additionally, this study evaluated the economic impact of GM and BNM to determine if the former represents a cost-effective alternative to the latter. Methods Patients treated between January 2011 and May 2014 received GM while patients treated between June 2014 and March 2017 received BNM. Mortality was compared between groups. Total infection cost was defined by the cost of antimicrobial consumption, length of stay, and laboratory and imaging exams until infection resolution. Findings A total of 168 patients were included; survival rate for the 68 patients treated with GM was 38% compared to 59% in the patients treated with BNM. Multivariate analysis showed that the variables most strongly-associated with mortality were cardiovascular disease (OR 18.18, 95% CI 1.25–262.3, p = 0.033) and treatment with generic meropenem (OR 18.45, 95% CI 1.45–232.32, p = 0.024). On the other hand, total infection cost did not show a significant difference between groups (BNM $10,771 vs. GM $11,343; p = 0.91). Interpretation The present study suggests that patients treated with GM have a risk of death 18 times higher compared to those treated with BNM. Furthermore, economic analysis shows that GM is not more cost effective than BNM. Summary More studies measuring clinical outcomes are needed to confirm the clinical equivalence of brand-name versus generic antibiotics, not only for meropenem but also for other molecules.
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Agudelo M, Rodriguez CA, Zuluaga AF, Vesga O. Nontherapeutic equivalence of a generic product of imipenem-cilastatin is caused more by chemical instability of the active pharmaceutical ingredient (imipenem) than by its substandard amount of cilastatin. PLoS One 2019; 14:e0211096. [PMID: 30726248 PMCID: PMC6364906 DOI: 10.1371/journal.pone.0211096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/02/2019] [Indexed: 11/25/2022] Open
Abstract
Background We demonstrated therapeutic nonequivalence of “bioequivalent” generics for meropenem, but there is no data with generics of other carbapenems. Methods One generic product of imipenem-cilastatin was compared with the innovator in terms of in vitro susceptibility testing, pharmaceutical equivalence, pharmacokinetic (PK) and pharmacodynamic (PD) equivalence in the neutropenic mouse thigh, lung and brain infection models. Both pharmaceutical forms were then subjected to analytical chemistry assays (LC/MS). Results and conclusion The generic product had 30% lower concentration of cilastatin compared with the innovator of imipenem-cilastatin. Regarding the active pharmaceutical ingredient (imipenem), we found no differences in MIC, MBC, concentration or potency or AUC, confirming equivalence in terms of in vitro activity. However, the generic failed therapeutic equivalence in all three animal models. Its Emax against S. aureus in the thigh model was consistently lower, killing from 0.1 to 7.3 million less microorganisms per gram in 24 hours than the innovator (P = 0.003). Against K. pneumoniae in the lung model, the generic exhibited a conspicuous Eagle effect fitting a Gaussian equation instead of the expected sigmoid curve of the Hill model. In the brain infection model with P. aeruginosa, the generic failed when bacterial growth was >4 log10 CFU/g in 24 hours, but not if it was less than 2.5 log10 CFU/g. These large differences in the PD profile cannot be explained by the lower concentration of cilastatin, and rather suggested a failure attributable to the imipenem constituent of the generic product. Analytical chemistry assays confirmed that, besides having 30% less cilastatin, the generic imipenem was more acidic, less stable, and exhibited four different degradation masses that were absent in the innovator.
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Affiliation(s)
- Maria Agudelo
- GRIPE: Grupo Investigador de Problemas en Enfermedades Infecciosas, University of Antioquia (UdeA) Medical School, Medellín, Colombia
- Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia
| | - Carlos A. Rodriguez
- GRIPE: Grupo Investigador de Problemas en Enfermedades Infecciosas, University of Antioquia (UdeA) Medical School, Medellín, Colombia
- CIEMTO: Centro de Información de Medicamentos y Tóxicos, University of Antioquia (UdeA) Medical School, Medellín, Colombia
| | - Andres F. Zuluaga
- GRIPE: Grupo Investigador de Problemas en Enfermedades Infecciosas, University of Antioquia (UdeA) Medical School, Medellín, Colombia
- CIEMTO: Centro de Información de Medicamentos y Tóxicos, University of Antioquia (UdeA) Medical School, Medellín, Colombia
| | - Omar Vesga
- GRIPE: Grupo Investigador de Problemas en Enfermedades Infecciosas, University of Antioquia (UdeA) Medical School, Medellín, Colombia
- Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia
- * E-mail:
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Machado-Alba JE, Gaviria-Mendoza A, Machado-Duque ME. Results of the effectiveness of two piperacillin-tazobactam molecules in the real world. Int J Infect Dis 2018; 76:91-96. [PMID: 30244077 DOI: 10.1016/j.ijid.2018.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/03/2018] [Accepted: 09/13/2018] [Indexed: 10/28/2022] Open
Abstract
OBJECTIVE The objective was to determine the effectiveness of two piperacillin-tazobactam molecules in terms of all-cause mortality, mortality by infection, and hospital stay. METHODS A cohort study was performed involving patients treated with piperacillin-tazobactam at a clinic in Colombia. The patients were divided into those who received the innovator piperacillin-tazobactam (from July to December 2014) and those who received the generic piperacillin-tazobactam (from January to June 2015). Socio-demographic, clinical (all-cause mortality, death by infection, days of hospitalization), microbiological, pharmacological, and comorbidity variables were evaluated. Multivariate analyses were performed. RESULTS A total of 279 patients were included: 140 treated with the innovator piperacillin-tazobactam and 139 with the generic piperacillin-tazobactam. The median age was 63 years, and 56% of the patients were male. There was no statistically significant difference in death from all causes (22.9% vs. 14.4%, p=0.069), death by infection (7.9 vs. 10.8%, p=0.399), or hospital stay (18.1±16.2 vs. 15.7±11.6 days, p=0.178) between the innovator and generic piperacillin-tazobactam, respectively. CONCLUSIONS The generic piperacillin-tazobactam was equivalent to the innovator piperacillin-tazobactam with regards to all-cause mortality, mortality by infection, hospital stay, and safety, and at a lower cost, which may be useful for decision-makers in hospitals.
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Affiliation(s)
- Jorge Enrique Machado-Alba
- Grupo de Investigación en Farmacoepidemiología y Farmacovigilancia, Universidad Tecnológica de Pereira-Audifarma S.A., Pereira, Risaralda, Colombia.
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Katayama B, Ozawa T, Morimoto K, Awazu K, Ito N, Honda N, Oiso N, Tsuruta D. Enhanced sterilization and healing of cutaneous pseudomonas infection using 5-aminolevulinic acid as a photosensitizer with 410-nm LED light. J Dermatol Sci 2018; 90:323-331. [PMID: 29534858 DOI: 10.1016/j.jdermsci.2018.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 02/14/2018] [Accepted: 03/02/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Pseudomonas aeruginosa (PA) frequently develops antibiotic-resistant characteristics, which is clinically problematic. The main reason behind the rise of antibiotic-resistant PA is the extensive use of antibiotics. Therefore, a novel technique is needed to treat PA infections. Photodynamic therapy (PDT) is thought to have the potential to be a non-antibiotic treatment for infections. 5-Aminolevulinic acid (ALA), which works as a photosensitizer after being metabolized into protoporphyrin IX (PpIX) in the heme synthetic pathway, is used for PDT. Thus far, the in vivo effectiveness of PDT using ALA against PA is unknown. OBJECTIVE In this study, we investigated PDT using ALA both in vitro and in vivo. METHODS AND RESULTS Although PDT with ALA alone did not show a bactericidal effect on PA, PDT with both ALA and EDTA-2Na had a bactericidal effect in vitro. In in vivo experiments, wounds healed faster in PA-infected mice treated with PDT using both EDTA-2Na and ALA compared to non-PDT. CONCLUSION These results suggest that PDT with EDTA-2Na and ALA is a potential novel treatment option for PA-infected wounds.
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Affiliation(s)
- Bunpei Katayama
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Toshiyuki Ozawa
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan; Research Center for Infectious Disease Sciences, Osaka City University Graduate School of Medicine, Osaka, Japan.
| | - Kuniyuki Morimoto
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Kunio Awazu
- Medical Beam Physics Laboratory, Osaka University Graduate School of Engineering, Osaka, Japan
| | - Nobuhisa Ito
- Medical Beam Physics Laboratory, Osaka University Graduate School of Engineering, Osaka, Japan
| | - Norihiro Honda
- Medical Beam Physics Laboratory, Osaka University Graduate School of Engineering, Osaka, Japan; Institute for Academic Initiatives, Osaka University, Osaka, Japan
| | - Naoki Oiso
- Department of Dermatology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Daisuke Tsuruta
- Department of Dermatology, Osaka City University Graduate School of Medicine, Osaka, Japan; Research Center for Infectious Disease Sciences, Osaka City University Graduate School of Medicine, Osaka, Japan
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Rodriguez CA, Agudelo M, Zuluaga AF, Vesga O. In vivo pharmacodynamics of piperacillin/tazobactam: implications for antimicrobial efficacy and resistance suppression with innovator and generic products. Int J Antimicrob Agents 2016; 49:189-197. [PMID: 27988068 DOI: 10.1016/j.ijantimicag.2016.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/20/2022]
Abstract
Recent studies have shown that the pharmacodynamic (PD) index driving the efficacy of β-lactam/β-lactamase inhibitor combinations such as ceftazidime/avibactam and ceftolozane/tazobactam is the percentage of time the free inhibitor concentration is above a threshold (fT>threshold). However, data with piperacillin/tazobactam (TZP) are scarce. Here we aimed to assess the relationship between fT>threshold and TZP antibacterial efficacy by a population pharmacokinetic study in mice and dose-effect experiments in a neutropenic murine thigh infection model with two isogenic strains of Escherichia coli differentially expressing TEM-1 β-lactamase. We also explored the dynamics of resistance selection with the innovator and a non-equivalent generic, extrapolated the results to the clinic by Monte Carlo simulation of standard TZP doses, and estimated the economic impact of generic-selected resistance. The fT>threshold index described well the efficacy of TZP versus E. coli, with threshold values from 0.5 mg/L to 2 mg/L and mean exposures of 42% for stasis and 56% for 1 log10 kill. The non-equivalent generic required a longer exposure (fT>threshold 33%) to suppress resistance compared with the innovator (fT>threshold 22%), leading to a higher frequency of resistance selection in the clinical simulation (16% of patients with the generic vs. 1% with the innovator). Finally, we estimated that use of TZP generics in a scenario of 25% therapeutic non-equivalence would result in extra expenses approaching US$1 billion per year in the USA owing to selection of resistant micro-organisms, greatly offsetting the savings gained from generic substitution and further emphasising the need for demonstrated and not assumed therapeutic equivalence.
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Affiliation(s)
- Carlos A Rodriguez
- GRIPE (Grupo Investigador de Problemas en Enfermedades Infecciosas), Facultad de Medicina, Universidad de Antioquia, Medellín, Antioquia, Colombia
| | - Maria Agudelo
- GRIPE (Grupo Investigador de Problemas en Enfermedades Infecciosas), Facultad de Medicina, Universidad de Antioquia, Medellín, Antioquia, Colombia; Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia
| | - Andres F Zuluaga
- GRIPE (Grupo Investigador de Problemas en Enfermedades Infecciosas), Facultad de Medicina, Universidad de Antioquia, Medellín, Antioquia, Colombia
| | - Omar Vesga
- GRIPE (Grupo Investigador de Problemas en Enfermedades Infecciosas), Facultad de Medicina, Universidad de Antioquia, Medellín, Antioquia, Colombia; Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia.
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Impact on Bacterial Resistance of Therapeutically Nonequivalent Generics: The Case of Piperacillin-Tazobactam. PLoS One 2016; 11:e0155806. [PMID: 27191163 PMCID: PMC4871539 DOI: 10.1371/journal.pone.0155806] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/04/2016] [Indexed: 11/19/2022] Open
Abstract
Previous studies have demonstrated that pharmaceutical equivalence and pharmacokinetic equivalence of generic antibiotics are necessary but not sufficient conditions to guarantee therapeutic equivalence (better called pharmacodynamic equivalence). In addition, there is scientific evidence suggesting a direct link between pharmacodynamic nonequivalence of generic vancomycin and promotion of resistance in Staphylococcus aureus. To find out if even subtle deviations from the expected pharmacodynamic behavior with respect to the innovator could favor resistance, we studied a generic product of piperacillin-tazobactam characterized by pharmaceutical and pharmacokinetic equivalence but a faulty fit of Hill's Emax sigmoid model that could be interpreted as pharmacodynamic nonequivalence. We determined the impact in vivo of this generic product on the resistance of a mixed Escherichia coli population composed of ∼99% susceptible cells (ATCC 35218 strain) and a ∼1% isogenic resistant subpopulation that overproduces TEM-1 β-lactamase. After only 24 hours of treatment in the neutropenic murine thigh infection model, the generic amplified the resistant subpopulation up to 20-times compared with the innovator, following an inverted-U dose-response relationship. These findings highlight the critical role of therapeutic nonequivalence of generic antibiotics as a key factor contributing to the global problem of bacterial resistance.
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Demonstration of Therapeutic Equivalence of Fluconazole Generic Products in the Neutropenic Mouse Model of Disseminated Candidiasis. PLoS One 2015; 10:e0141872. [PMID: 26536105 PMCID: PMC4633286 DOI: 10.1371/journal.pone.0141872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 10/14/2015] [Indexed: 11/25/2022] Open
Abstract
Some generics of antibacterials fail therapeutic equivalence despite being pharmaceutical equivalents of their innovators, but data are scarce with antifungals. We used the neutropenic mice model of disseminated candidiasis to challenge the therapeutic equivalence of three generic products of fluconazole compared with the innovator in terms of concentration of the active pharmaceutical ingredient, analytical chemistry (liquid chromatography/mass spectrometry), in vitro susceptibility testing, single-dose serum pharmacokinetics in infected mice, and in vivo pharmacodynamics. Neutropenic, five week-old, murine pathogen free male mice of the strain Udea:ICR(CD-2) were injected in the tail vein with Candida albicans GRP-0144 (MIC = 0.25 mg/L) or Candida albicans CIB-19177 (MIC = 4 mg/L). Subcutaneous therapy with fluconazole (generics or innovator) and sterile saline (untreated controls) started 2 h after infection and ended 24 h later, with doses ranging from no effect to maximal effect (1 to 128 mg/kg per day) divided every 3 or 6 hours. The Hill’s model was fitted to the data by nonlinear regression, and results from each group compared by curve fitting analysis. All products were identical in terms of concentration, chromatographic and spectrographic profiles, MICs, mouse pharmacokinetics, and in vivo pharmacodynamic parameters. In conclusion, the generic products studied were pharmaceutically and therapeutically equivalent to the innovator of fluconazole.
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Pharmacodynamics of nine generic products of amikacin compared with the innovator in the neutropenic mouse thigh infection model. BMC Res Notes 2015; 8:546. [PMID: 26445936 PMCID: PMC4596513 DOI: 10.1186/s13104-015-1507-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/21/2015] [Indexed: 11/21/2022] Open
Abstract
Background Previously, we validated the mouse thigh infection model to test the therapeutic equivalence of generic antibiotic products. Here, our aim was to compare the in vivo efficacy of amikacin products in clinical use in Colombia using this animal model. Results All except one generic product had the same in vitro potency, judging by the lack of differences on MIC and MBC compared with the innovator. However, eight of nine generic products failed in the neutropenic mouse thigh infection model to achieve the innovator’s maximum effect (Emax ≤ 5.65 for the generics vs. 6.58 log10 CFU/g for the innovator) against Escherichia coli SIG-1, after subcutaneous treatment every 6 h with doses ranging from 1.5 to 3072 mg/kg per day. Conclusion As we demonstrated previously with other antibiotics such as vancomycin, gentamicin and oxacillin, the generic products of amikacin failed the in vivo efficacy testing. The therapeutic equivalence should be assessed in vivo before clinical approval of generic products.
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Zuluaga AF, Salazar BE, Agudelo M, Rodriguez CA, Vesga O. A strain-independent method to induce progressive and lethal pneumococcal pneumonia in neutropenic mice. J Biomed Sci 2015; 22:24. [PMID: 25890037 PMCID: PMC4474571 DOI: 10.1186/s12929-015-0124-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 02/26/2015] [Indexed: 11/10/2022] Open
Abstract
Background Experimental models of pneumonia with penicillin non-susceptible Streptococcus pneumoniae (PNSSP) are hard to reproduce because the majority of strains with clinical relevance (like serotypes 6B, 9 V and 19 F) have low murine virulence. By optimization of culture and inoculum conditions of PNSSP (using porcine mucin), our aim was to develop a suitable, reliable and reproducible pneumonia mouse model for anti-infective pharmacology research. Results Seven PNSSP strains, including serotypes 6B, 9 V, 14 and 19 F were included. Strain INS-E611 displayed the highest murine virulence and was chosen to validate the lung model. Nose-instilled pneumococci grew between 2.1 and 2.5 log10 CFU/g of lung in 24 hours when an optimized culture of bacterial cells was used, but animals were all alive and recovered of infection after 36 h. In contrast, inoculum supplementation with mucin led to 100% mortality related to a successful lung infection confirmed by histopathology. These findings were reproduced with all seven PNSSP strains in neutropenic mice. Immunocompetent animals cleared all strains spontaneously. Conclusions This pneumonia model produces a progressive and uniformly fatal lung infection with diverse serotypes of PNSSP independently of their intrinsic murine virulence.
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Affiliation(s)
- Andres F Zuluaga
- GRIPE [Grupo Investigador de Problemas en Enfermedades infecciosas], Medellín, Colombia. .,Department of Pharmacology and Toxicology, Medellín, Colombia.
| | | | - Maria Agudelo
- GRIPE [Grupo Investigador de Problemas en Enfermedades infecciosas], Medellín, Colombia. .,Department of Pharmacology and Toxicology, Medellín, Colombia. .,Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia.
| | - Carlos A Rodriguez
- GRIPE [Grupo Investigador de Problemas en Enfermedades infecciosas], Medellín, Colombia. .,Department of Pharmacology and Toxicology, Medellín, Colombia.
| | - Omar Vesga
- GRIPE [Grupo Investigador de Problemas en Enfermedades infecciosas], Medellín, Colombia. .,Department of Pharmacology and Toxicology, Medellín, Colombia. .,Department of Internal Medicine, Universidad de Antioquia, Calle 70 No. 52-21, Medellín, Colombia. .,Infectious Diseases Unit, Hospital Universitario San Vicente Fundación, Medellín, Colombia.
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