Efficacy and safety of generic cefoperazone/sulbactam versus branded cefoperazone/sulbactam in the treatment of bacterial infections: a systematic review and meta-analysis

This study aim to assess the clinical efficacy and safety of generic cefoperazone/sulbactam compared to the branded cefoperazone/sulbactam (Sulperazon) in treating bacterial infections through a meta-analysis. Searches were conducted across PubMed, Embase, Cochrane Library, CNKI, WanFang, VIP databases, and Clinical Trials database, resulting in the inclusion of 11 studies comprising 7 randomized controlled trials (RCTs) and 4 retrospective cohort studies (RCSs). Meta-analysis of the RCTs indicated no statistical differences in clinical success rates, clinical cure rates, microbiological eradication rates, and incidence of adverse reactions between the generic cefoperazone/sulbactam and the branded version. Findings from the RCSs aligned with those from the RCTs, demonstrating that generic versions of cefoperazone/sulbactam are equivalent in efficacy and safety to their branded counterparts in treating bacterial infections.

Antibiotic prescribing practices of medical doctors in a resource-limited setting and the influence of individual perceptions and stewardship support: a survey in three tertiary hospitals in Vietnam

Objectives

To understand antibiotic prescribing and influencing factors to inform antimicrobial stewardship (AMS) interventions to reduce unwanted consequences of antibiotic use in hospitals in Vietnam, a lower-middle-income country in Asia.

Methods

We conducted a cross-sectional study of doctors at three tertiary hospitals using non-probability convenience sampling, through a paper-based (Hospitals 1 and 2) or electronic (Hospital 3) survey. Questions included items on perceptions regarding antibiotic resistance and AMS, prescribing practices, knowledge, demographics and training. We used principal components analysis and mixed-effects models to examine practices and identify influencing factors.

Results

Among 314 surveyed participants, 61%, 57% and 59% in Hospitals 1, 2 and 3, respectively, felt certain about the appropriateness of their antibiotic prescriptions. In total, 9% reported sometimes prescribing antibiotics when not needed to meet patients' expectations, and 13% reported doing so to avoid perceived complications. Higher prescribing confidence was found among those with positive perceptions about AMS (P < 0.0001), whereas negative perceptions about colleagues' practices reduced this confidence (P < 0.0001). Individual preference for branded antibiotics was associated with more unnecessary prescribing whereas having higher prescribing confidence decreased the habits of prescribing when not needed.

Conclusions

This study provides important implications for design of hospital interventions to address influencing factors on antibiotic prescribing in Vietnam and similar resource-limited settings. Specific interventions should target improving knowledge through education and training for doctors, enhancing the support from the AMS team, and promoting guidelines and policies for appropriate antibiotic use in hospital.

Quality equivalence and in-vitro antibiotic activity test of different brands of amoxicillin/clavulanic acid tablets in Mwanza, Tanzania: A cross sectional study

Background

Each film coated tablet of amoxicillin/clavulanic acid contains 500 mg of amoxicillin as an active pharmaceutical ingredient and 125 mg of clavulanic acid. Different brands have the same active ingredients but different excipients, which may cause differences in efficacy. With the emergence of generic antibiotics post-patent expiration, the antibiotic activity of generics is in question in comparison to the innovator. This study aims at determining the pharmaceutical quality and in-vitro antimicrobial activity of different brands of amoxicillin/clavulanate.

Method

ology: The study was a cross-sectional laboratory-based experimental study conducted at the TMDA (Tanzania Medicines and Medical Devices Authority) Lake Zone laboratory and the CUHAS Microbiology Laboratory from in May 2021. The study samples were four brands of amoxicillin/clavulanate and sixty archived isolates, thirty of which were E. coli and the remaining thirty K. pneumoniae. Determination of minimum inhibitory concentrations, assay and dissolution test results were used to make conclusions for the study.

Results

All tablets samples complied with the British pharmacopeia (BP) specifications, however sixty archived isolates which were tested in this study showed resistance towards the standard AMC disc (68 %). The innovator brand (AC1) showed significant mean difference from 2 out of 3 generics (p-values <0.05) while the first generic brand (AC2) showed significant superiority among the generics.

Conclusion

Thus, the four samples that were used all complied with the specifications according to BP on dissolution and assay tests but there was an overall resistance towards amoxicillin/clavulanate, and this was moreover seen by generic brands in comparison to the innovator which proved to be of superior activity.

Clinical Equivalence between Generic Versus Branded Antibiotics: Systematic Review and Meta-Analysis

Regulatory authorities authorize the clinical use of generic drugs (GD) based on bioequivalence studies, which consist of the evaluation of pharmacokinetics after a single dose in vitro or in healthy individuals. There are few data on clinical equivalence between generic and branded antibiotics. Our aim was to synthesize and analyze the available evidence on the clinical efficacy and safety of generic antibiotics compared to their original formulations. A systematic review was performed on Medline (PubMed) and Embase and validated through Epistemonikos and Google Scholar. The last search was conducted on 30 June 2022. Meta-analyses of clinical cure and mortality outcomes were performed. One randomized clinical trial (RCT) and 10 non-randomized intervention studies were included. No differences in clinical cure were observed between groups in the meta-analysis (OR = 0.89, 95% CI [0.61-1.28]; I² = 70%, p = 0.005). No difference was observed between groups when considering the use of carbapenems for overall mortality (OR = 0.99, 95% CI [0.63-1.55]; I² = 78%) or death associated with infections (OR = 0.79, 95% CI [0.48-1.29], I² = 67%). Most of the studies were observational, and the duration of follow-up, the characteristics of the participants, and the sites of infections were heterogeneous. Due to the uncertainty of the evidence, it is not possible to contraindicate the use of generics, which is an important strategy to expand access.

Comparison of pharmacokinetics and stability of generics of cefepime, linezolid and piperacillin/tazobactam with their respective originator drugs: an intravenous bioequivalence study in healthy volunteers

OBJECTIVES

The efficacy and quality of generic antibacterial drug formulations are often questioned by both healthcare specialists and patients. Therefore, the present study investigated the interchangeability of generic drugs with their originators by comparing bioequivalence parameters and stability data of generic cefepime, linezolid and piperacillin/tazobactam with their respective originator drugs.

METHODS

In this open-label, randomized, crossover bioequivalence study, three groups of 12 healthy volunteers each received a single intravenous infusion of either 2 g of cefepime or 4.5 g of piperacillin/tazobactam and two generic formulations, or 600 mg of linezolid and one generic formulation. Plasma sampling was performed, with a 5 day washout period between study days. Stability was tested by storing reconstituted generic and originator products according to their own storage specifications and those of the comparator products. All concentrations were measured by LC-MS.

RESULTS

Similar ratios of generic/originator (90% CI) Cmax were observed for Cefepime-MIP/Maxipime [93.7 (88.4-99.4)], Cefepime Sandoz/Maxipime [95.9 (89.1-103.2)], Linezolid Kabi/Zyvoxid [104.5 (91.1-119.9)], Piperacillin Kabi/Tazobac [95.9 (90.4-101.7)], Piperacillin Aurobindo/Tazobac [99.7 (84.9-104.7)], Tazobactam Kabi/Tazobac [93.4 (87.4-99.8)] and Tazobactam Aurobindo/Tazobac [97.4 (89.7-105.8)]. Accordingly, similar ratios of AUC0-t were observed for Cefepime-MIP/Maxipime [91.1 (87.6-94.8)], Cefepime Sandoz/Maxipime [97.9 (92.5-103.5)], Linezolid Kabi/Zyvoxid [99.7 (93.3-106.6)], Piperacillin Kabi/Tazobac [92.2 (88.3-96.3)], Piperacillin Aurobindo/Tazobac [99.9 (97.0-102.8)], Tazobactam Kabi/Tazobac [91.4 (86.4-96.7)] and Tazobactam Aurobindo/Tazobac [98.8 (94.3-103.6)]. Stable and similar concentrations were measured for all contiguous substances, regardless of storage conditions.

CONCLUSIONS

Compared with their respective originator drugs, generic cefepime, linezolid and piperacillin/tazobactam met the predetermined bioequivalence criteria. All formulations were stable under the storage conditions of their respective comparators.

Impact of Generic Entry on Hospital Antimicrobial Use: A Retrospective Quasi-Experimental Interrupted Time Series Analysis

Background: The impact of antimicrobials generic entry (GE) is controversial. Their introduction could provide an economic benefit yet may also increase their consumption, leading to a higher risk of resistance. Our aim was to analyze the impact of GE on trends of antimicrobial consumption in an acute-care hospital. Methods: A retrospective quasi-experimental interrupted time series analysis was conducted at a 400-bed tertiary hospital in Barcelona, Spain. All antimicrobials for systemic use for which a generic product entered the hospital from January 2000 to December 2019 were included. Antimicrobial consumption was expressed as DDD/100 bed days. Results: After GE, the consumption of cefotaxime (0.09, p < 0.001), meropenem (0.54, p < 0.001), and piperacillin-tazobactam (0.13, p < 0.001) increased, whereas the use of clindamycin (−0.03, p < 0.001) and itraconazole (−0.02, p = 0.01) was reduced. An alarming rise in cefepime (0.004), daptomycin (1.02), and cloxacillin (0.05) prescriptions was observed, despite not achieving statistical significance. On the contrary, the use of amoxicillin (−0.07), ampicillin (−0.02), cefixime (−0.06), fluconazole (−0.13), imipenem–cilastatin (−0.50) and levofloxacin (−0.35) decreased. These effects were noticed beyond the first year post GE. Conclusions: GE led to an increase in the consumption of broad-spectrum molecules. The potential economic benefit of generic antibiotics could be diluted by an increase in resistance. Antimicrobial stewardship should continue to monitor these molecules despite GE.

Real-World Use of Generic Meropenem: Results of an Observational Study

Background: To determine the therapeutic effect and tolerability of meropenem in routine clinical practice, in terms of clinical and microbiological response. Methods: A real-world, observational, descriptive, longitudinal study with daily monitoring of clinical history records was conducted on all patients who were medically prescribed meropenem during a period between October 2015 and March 2016 at a university hospital in Bucaramanga (Colombia). Results: The study evaluated 84 patients with an average age of 63.2 years, mostly older adults with multiple comorbidities, of whom 54.8% were men. A positive clinical or microbiological response was obtained in 98.8% of the patients. At the end of the treatments, significant improvements in dysthermia (0% vs. 29% at the beginning, p = 0.000), tachycardia (13% vs. 47%, p = 0.049), and leukocytosis (39% vs. 15% at the beginning, p = 0.008) were evidenced. The improvement in the indicator that combines all the Systemic Inflammatory Response Syndrome (SIRS) criteria was also significant (p = 0.000). The treatment was well tolerated, although we identified some non-serious and expected adverse reactions. Conclusions: Generic meropenem proved to be effective and well tolerated for different types of infection in routine clinical practice. The results are consistent with the findings of the clinical studies with the innovator drug.

Acceptability of generic versus innovator oral medicines: not only a matter of taste

Optimum use of generic products would require equivalence, not only in terms of quality, safety, and efficacy in clinical studies, but also patient acceptability to not jeopardize treatment success because of non-adherence which would de facto limit the potential cost saving anticipated by their use. Although acceptability is a requirement for the authorization of pediatric innovator products, a survey of European Union (EU) regulatory authorities showed that few have a formal process for assessing patient acceptability of generic products during the registration processes. The current International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) focus on unifying guidance for the development and scrutiny of generics but should include acceptability alongside the other factors being considered for harmonization.

Efficacy of generic meropenem products in combination with colistin in carbapenemase-producing Klebsiella pneumoniae experimental osteomyelitis

Guidelines for the management of carbapenemase-producing Enterobacterales (CPE) infections recommend a combination of two active agents, including meropenem if the minimum inhibitory concentration (MIC) is ≤8 mg/L. The therapeutic equivalence of meropenem generics has been challenged. We compared the bactericidal activity of meropenem innovator (AstraZeneca) and four generic products (Actavis, Kabi, Mylan and Panpharma), both in vitro and in vivo, in association with colistin. In vitro time-kill studies were performed at 4 × MIC. An experimental model of KPC-producing Klebsiella pneumoniae osteomyelitis was induced in rabbits by tibial injection of a sclerosing agent followed by 2 × 10⁸ CFU of K. pneumoniae KPC-99YC (meropenem MIC = 4 mg/L; colistin MIC = 1 mg/L). At 14 days after inoculation, treatment for 7 days started in seven groups of ≥10 rabbits, including a control group, a colistin group, and one group for each meropenem product (i.e. the innovator and four generics), in combination with colistin. In vitro, meropenem + colistin was bactericidal with no viable bacteria after 6 h, and this effect was similar with all meropenem products. In the osteomyelitis model, there was no significant difference between meropenem generics and the innovator when combined with colistin. Colistin-resistant strains were detected after treatment with colistin + meropenem innovator (n = 3) and generics (n = 3). The efficacy of four meropenem generics did not differ from the innovator in vitro and in an experimental rabbit model of KPC-producing K. pneumoniae osteomyelitis in terms of bactericidal activity and the emergence of resistance.

The Use of Generic Medications for Glaucoma

The use of generic medicines has grown considerably in recent years providing considerable cost savings. In England, generic items represented 11.7% of prescriptions for glaucoma and ocular hypertension in 2009, increasing to 55.2% of prescriptions in 2018. Generics can be brought to the market quickly and at low cost as manufacturers are not required to repeat animal or clinical research on active ingredients already approved for safety and efficacy. Although there is no regulatory requirement for studies comparing branded and generic eye drops, several randomised crossover studies have been performed comparing branded and generic prostaglandin analogues. While most have shown similar intraocular pressure lowering, studies are of short duration and have not evaluated visual field endpoints. Furthermore, differences in inactive ingredients, pH, viscosity, levels of particulate matter, and degradation over time have been reported. Other potential problems with generic eye drops include differences in bottle design affecting adherence, problems with supply, and the possibility that reduced revenue for innovator companies will lead to reduced investment in new drug development. This article reviews the potential advantages and disadvantages of generic antiglaucoma medications.

Comparison of In Vivo Pharmacokinetics and Pharmacodynamics of Vancomycin Products Available in Korea

PURPOSE

Few studies have been investigated the in vivo efficacy of generic vancomycin products available outside of the United States. In this study, we aimed to compare the in vivo pharmacokinetics (PK) and pharmacodynamics (PD) of five generic vancomycin products available in Korea with those of the innovator.

MATERIALS AND METHODS

The in vitro vancomycin purity of each product was examined using high-pressure liquid chromatography. Single-dose PK analyses were performed using neutropenic mice. The in vivo efficacy of vancomycin products was compared with that of the innovator in dose-effect experiments (25 to 400 mg/kg per day) using a thigh-infection model with neutropenic mice.

RESULTS

Generic products had a lower proportion of vancomycin B (range: 90.3-93.8%) and a higher proportion of impurities (range: 6.2-9.7%) than the innovator (94.5% and 5.5%, respectively). In an in vivo single-dose PK study, the maximum concentration (C_max) values of each generic were lower than that of the innovator, and the geographic mean area under the curve ratios of four generics were significantly lower than that of the innovator (all p<0.1). In the thigh-infection model, the maximum efficacies of generic products reflected in maximal effect (E_max) values were not significantly different from the innovator. However, the PD profile curves of some generic products differed significantly from that of the innovator in mice injected with a high level of Mu3 (all p≤0.05).

CONCLUSION

Some generic vancomycin products available in Korea showed inferior PK and PD profiles, especially in mice infected with hetero-vancomycin-resistant Staphylococcus aureus.

Clinical and economic impact of generic versus brand name meropenem use in an intensive care unit in Colombia

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.

Vancomycin-Associated Acute Kidney Injury in a Large Veteran Population

BACKGROUND

To determine the association of vancomycin with acute kidney injury (AKI) in relation to its serum concentration value and to examine the risk of AKI in patients treated with vancomycin when compared with a matched cohort of patients receiving non-glycopeptide antibiotics (linezolid/daptomycin).

METHODS

From a cohort of > 3 million US veterans with baseline estimated glomerular filtration rate ≥60 mL/min/1.73 m2, we identified 33,527 patients who received either intravenous vancomycin (n = 22,057) or non-glycopeptide antibiotics (linezolid/daptomycin, n = 11,470). We examined the association of the serum trough vancomycin level recorded within the first 48 h of administration with subsequent AKI in all patients treated with vancomycin and association of vancomycin vs. non-glycopeptide antibiotics use with the risk of incident AKI.

RESULTS

The overall multivariable adjusted ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptides were 1.1 (1.1-1.2), 1.2 (1-1.4), and 1.4 (1.1-1.7), respectively. When examined in strata divided by vancomycin trough level, the odds of AKI were similar or lower in patients receiving vancomycin compared to non-glycopeptide antibiotics as long as serum vancomycin levels were ≤20 mg/L. However, in patients with serum vancomycin levels > 20 mg/L, the ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptide antibiotics were 1.5 (1.4-1.7), 1.9 (1.5-2.3), and 2.7 (2-3.5), respectively.

CONCLUSIONS

Vancomycin use is associated with a higher risk of AKI when serum levels exceed > 20 mg/L.

Drug utilization study of two generic antibiotics in a tertiary hospital in Bogotá

Introduction: The Colombian national pharmaceutical policy establishes as a strategy the generation of greater pharmaco-epidemiological research at the national level, especially in the case of antibiotic drugs. Objective: To provide local pharmaco-epidemiological evidence regarding the effectiveness, conditions of use and safety of generic meropenem and cefepime in a tertiary hospital in Bogotá. Materials and methods: We conducted a descriptive, longitudinal and retrospective drug utilization study. The data were collected from the medical histories of all the patients who had cefepime or meropenem prescribed. Results: We included 82 patients treated with cefepime and 91 treated with meropenem in the study. Most of the patients were in services different from the intensive care unit (taking cefepime: 59.8%, and meropenem: 52.7%). Only 21.9% of the patients treated with cefepime and 49% of those treated with meropenem were seen by an infectious disease specialist. The antibiogram was performed for 47% and 60% of the patients treated with cefepime and meropenem, respectively. The most frequent indication for cefepime were respiratory infections and for meropenem, genitourinary ones. Therapeutic success rates were 61.7% for cefepime and 63.0% for meropenem. Conclusions: This study contributes evidence regarding the therapeutic performance of two generic antibiotics used in tertiary hospitals. There were no reports of therapeutic failure during the study period. In the cases of non-response, pharmacokinetic alterations, unfavorable clinical conditions, and inappropriate choice of antimicrobial treatment were identified as frequent factors.

Assessing the risk of false positive serum galactomannan among patients receiving piperacillin/tazobactam for febrile neutropenia

Galactomannan (GM) assay is commonly used as an early diagnostic tool for invasive fungal infection (IFI) in high-risk hematology patients. False positivity is frequently observed in GM with the use of piperacillin/tazobactam. The usage of generic drugs over the original brand has a significant cost advantage. The aim of this study was to assess the performance of GM test among patients receiving original and generic piperacillin/tazobactam formulations. The study included 85 adult patients; 62.4% were male with hematological malignancy currently receiving piperacillin/tazobactam. The study group was divided into two groups: patients receiving original and generic piperacillin/tazobactam. Serum GM index was positive in one of 35 patients receiving original piperacillin/tazobactam, whereas it was positive in 46 out of 50 patients receiving generic piperacillin/tazobactam (P < .001). However, the patients receiving generic piperacillin/tazobactam underwent computed tomography (CT) scans more frequently than those receiving original piperacillin/tazobactam (P = .047). In addition, in vitro analysis of GM was performed in two generics and one original piperacillin/tazobactam vials. One generic piperacillin/tazobactam vial included high GM level. False positivity of serum GM with generic formulations of piperacillin/tazobactam is still an ongoing issue in hematology patients. A high rate of serum GM index false positivity may unexpectedly lead to a higher rate of CT scan. Selected piperacillin/tazobactam vials in each batch should be checked for GM to identify a false positivity of GM before purchase.

A prospective, observational study comparing the PK/PD relationships of generic Meropenem (Mercide®) to the innovator brand in critically ill patients

Introduction

Clinicians’ skepticism, fueled by evidence of inferiority of some multisource generic antimicrobial products, results in the underutilization of more cost-effective generics, especially in critically ill patients. The aim of this observational study was to demonstrate equivalence between the generic or comparator brand of meropenem (Mercide^®) and the leading innovator brand (Meronem^®) by means of an ex vivo technique whereby antimicrobial activity is used to estimate plasma concentration of the active moiety.

Methods

Patients from different high care and intensive care units were recruited for observation when prescribed either of the meropenem brands under investigation. Blood samples were collected over 6 hours after a 30 minute infusion of the different brands. Meropenem concentration curves were established against United States Pharmacopeia standard meropenem (Sigma-Aldrich) by using standard laboratory techniques for culture of Klebsiella pneumoniae. Patients’ plasma samples were tested ex vivo, using a disc diffusion assay, to confirm antimicrobial activity and estimate plasma concentrations of the two brands.

Results

Both brands of meropenem demonstrated similar curves in donor plasma when concentrations in vials were confirmed. Patient-specific serum concentrations were determined from zones of inhibition against a standard laboratory Klebsiella strain ex vivo, confirming at least similar in vivo concentrations as the concentration curves (90% confidence interval) overlapped; however, the upper limit of the area under the curve for the ratio comparator/innovator exceeded the 1.25-point estimate, i.e., 4% higher for comparator meropenem.

Conclusion

This observational, in-practice study demonstrates similar ex vivo activity and in vivo plasma concentration time curves for the products under observation. Assay sensitivity is also confirmed. Current registration status of generic small molecules is in place. The products are therefore clinically interchangeable based on registration status as well as bioassay results, demonstrating sufficient overlap for clinical comfort. The slightly higher observed comparator meropenem concentration (4%) is still clinically acceptable due to the large therapeutic index and should ally fears of inferiority.

Comparative analysis of the cost and effectiveness of generic and brand-name antibiotics: the case of uncomplicated urinary tract infection

PURPOSE

Generic medications used for chronic diseases are beneficial in containing healthcare costs and improving drug accessibility. However, the effects of generic drugs in acute and severe illness remain controversial. This study aims to investigate treatment costs and outcomes of generic antibiotics prescribed for adults with a urinary tract infection in outpatient settings.

METHODS

The data source was the Longitudinal Health Insurance Database of Taiwan. We included outpatients aged 20 years and above with a urinary tract infection who required one oral antibiotic for which brand-name and generic products were simultaneously available. Drug cost and overall healthcare expense of the index consultation, healthcare cost during a 42-day follow-up period, and treatment failure rates were the main dependent variables. Data were compared between brand-name and generic users from the entire cohort and a propensity score-matched samples.

RESULTS

Results from the entire cohort and propensity score-matched samples were similar. Daily antibiotic cost was significantly lower among generic users than brand-name users. Significant lower total drug claims of the index consultation only existed in patients receiving the investigated antibiotics, while the drug price between brand-name and generic versions were relatively large (e.g., >50%). The overall healthcare cost of the index consultation, healthcare expenditure during a 42-day follow-up period, and treatment failure rates were similar between the two groups.

CONCLUSIONS

Compared with those treated with brand-name antibiotics, outpatients who received generic antibiotics had equivalent treatment outcomes with lower drug costs. Generic antibiotics are effective and worthy of adoption among outpatients with simple infections indicating oral antibiotic treatment. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison between liposomal formulations of amphotericin B

Given the clinical success of commercial amphotericin B lipid products, investigators have begun making generic formulations of liposomal amphotericin B. Generic medicines are an attractive approach to help decrease the cost and accessibility to healthcare, provided that appropriate studies are performed to ensure bioequivalence with the parent product. This is of particular concern for liposomal drugs such as amphotericin B where liposomes are used as a carrier system to reduce the toxicity of the active agent. A favorable therapeutic profile for this form of the drug has to include the proper chemical composition along with strictly controlled manufacturing processes. Studies have shown that a comparison of liposomal amphotericin B products with different or the same chemical compositions, using different methods of production, will vary in size, and have significantly dissimilar in vitro and in vivo toxicities along with reduced efficacy. These results underscore the importance of establishing appropriate bioequivalence testing for liposome products to ensure uniformity of their therapeutic index.

What do people really think of generic medicines? A systematic review and critical appraisal of literature on stakeholder perceptions of generic drugs

BACKGROUND

Considerable emphasis is presently being placed on usage of generic medicines by governments focussed on the potential economic benefits associated with their use. Concurrently, there is increasing discussion in the lay media of perceived doubts regarding the quality and equivalence of generic medicines. The objective of this paper is to report the outcomes of a systematic search for peer-reviewed, published studies that focus on physician, pharmacist and patient/consumer perspectives of generic medicines.

METHODS

Literature published between January 2003 and November 2014, which is indexed in PubMed and Scopus, on the topic of opinions of physicians, pharmacists and patients with respect to generic medicines was searched, and articles within the scope of this review were appraised. Search keywords used included perception, opinion, attitude and view, along with keywords specific to each cohort.

RESULTS

Following review of titles and abstracts to identify publications relevant to the scope, 16 papers on physician opinions, 11 papers on pharmacist opinions and 31 papers on patient/consumer opinions were included in this review. Quantitative studies (n = 37) were the most common approach adopted by researchers, generally in the form of self-administered questionnaires/surveys. Qualitative methodologies (n = 15) were also reported, albeit in fewer cases. In all three cohorts, opinions of generic medicines have improved but some mistrust remains, most particularly in the patient group where there appears to be a strongly held belief that less expensive equals lower quality. Acceptance of generics appears to be higher in consumers with higher levels of education while patients from lower socioeconomic demographic groups, hence generally having lower levels of education, tend to have greater mistrust of generics.

CONCLUSIONS

A key factor in improving confidence in generic products is the provision of information and education, particularly in the areas of equivalency, regulation and dispelling myths about generic medicines (such as the belief that they are counterfeits). Further, as patient trust in their physician often overrules their personal mistrust of generic medicines, enhancing the opinions of physicians regarding generics may have particular importance in strategies to promote usage and acceptance of generic medicines in the future.

Nephrotoxicity comparison of two commercially available generic vancomycin products

To date, no comparative clinical studies have investigated the effects of different vancomycin products on nephrotoxicity. The objective of this single-center, retrospective, matched-cohort study was to investigate the impact of two different vancomycin products on the development of nephrotoxicity. The study population included adults receiving a single vancomycin product, from either Pfizer or Hospira, for their entire course of therapy. Patients were matched based on underlying nephrotoxicity risk factors. Secondary outcomes included the need for renal replacement therapy, length of hospital stay, and in-hospital mortality. One-hundred forty-six matched pairs (n = 292) were included, and they had no significant differences in demographics, comorbid conditions, severity of illness, or vancomycin-associated nephrotoxicity risk factors. The frequency of nephrotoxicity was 8.9% in the Pfizer group and 11.0% in the Hospira group as defined by the 2009 consensus vancomycin guidelines (P = 0.56), 17.1% in the Pfizer group and 13.0% in the Hospira group as defined by the Acute Kidney Injury Network (AKIN) (P = 0.33), and 10.3% in the Pfizer group and 11.6% in the Hospira group as defined by RIFLE (risk, injury, failure, loss, and end-stage renal disease) criteria (P = 0.71). There were no differences between groups in regard to nephrotoxicity by any definition or in secondary outcomes. In multivariate analysis of overall nephrotoxicity risk factors, the type of vancomycin product was not independently associated with increased odds of developing nephrotoxicity according to the RIFLE criteria. Based on our results, there are no discernible differences between Pfizer and Hospira vancomycin products in the frequency of nephrotoxicity. Confirmation of these results with other types of vancomycin and different patient populations is warranted.

Relevance of various animal models of human infections to establish therapeutic equivalence of a generic product of piperacillin/tazobactam

After demonstrating with diverse intravenous antibacterials that pharmaceutical equivalence (PE) does not predict therapeutic equivalence, we tested a single generic product of piperacillin/tazobactam (TZP) in terms of PE, pharmacokinetics and in vitro/vivo pharmacodynamics against several pathogens in neutropenic mouse thigh, lung and brain infection models. A generic product was compared head-to-head against the innovator. PE was evaluated by microbiological assay. Single-dose serum pharmacokinetics were determined in infected mice, and the MIC/MBC were determined by broth microdilution. In vivo experiments were done in a blind fashion. Reproducibility was tested on different days using different infecting organisms and animal models. Neutropenic MPF mice were infected in the thighs with Staphylococcus aureus GRP-0057 or Pseudomonas aeruginosa PA01 and in the lungs or brain with Klebsiella pneumoniae ATCC 10031. Treatment started 2h (thigh and brain) or 14 h (lung) after infection and was administered every 3h over 24h (thigh and lung) or 48 h (brain). Both products exhibited the same MIC/MBC against each strain, yielded overlaid curves in the microbiological assay (P>0.21) and were bioequivalent (IC90 83-117% for AUC test/reference ratio). In vivo, the generic product and innovator were again undistinguishable in all models and against the different bacterial pathogens involved. The relevance of these neutropenic murine models of infection was established by demonstrating their accuracy to predict the biological response following simultaneous treatment with a generic product or the innovator of TZP. Therapeutic equivalence of the generic product was proved in every model and against different pathogens.

Vancomycin-associated renal dysfunction: where are we now?

Vancomycin has been in clinical use for over 60 years, during which time renal toxicity has been well documented. Multiple risk factors and outcomes are associated with vancomycin-related nephrotoxicity. Risk factors include vancomycin exposure (trough levels 15 mg/L or higher, larger area under the curve, duration of therapy), host susceptibility to vancomycin (increased body weight, preexisting renal dysfunction, critical illness), and concurrent nephrotoxin therapy. Nephrotoxicity is associated with prolonged hospital stays, mortality, and the need for renal replacement therapy. To what degree vancomycin-associated nephrotoxicity exacerbates these adverse clinical outcomes remains unclear. This article reviews the current evidence on vancomycin-associated nephrotoxicity and explores future research directions with potential implications for improved patient safety.