Bioequivalence and other unresolved issues in generic drug substitution

Use of DOACs in frail elderly patients in light of class genericization

BACKGROUND

Frailty and comorbidity influence the therapeutic approach in everyday clinical practice. The DOACs genericization opens a reflection on their differences from a pharmacological and bioavailability point of view, particularly in elderly frail patients. The aim of this project was to create a national Delphi consensus on the topic of the use of DOACs for atrial fibrillation (AF) in such patients, in light of the genericization of the class.

METHODS AND RESULTS

The consensus dealt with 3 main topics: a) efficacy and safety of DOACs in elderly and/or frail patients; b) therapeutic choice in specific frailty scenarios; c) DOACs genericization. 56 cardiologists, two internists and two neurologists from Italy expressed their level of agreement on each statement by using a 5-point Likert scale (1: strongly disagree, 2: disagree, 3: uncertain, 4: agree, 5: strongly agree). A positive consensus was reached if the percentage of agreement (vote 1-2, positive consensus) or disagreement (votes 4-5, negative consensus) was >66%; otherwise, no consensus was reached. Results are displayed accordingly.

CONCLUSIONS

After 10 years of everyday clinical management of DOACs for AF, specific elements differentiating a molecule from another, either for efficacy or for safety, are consolidated. However, some uncertainties still exist in particular contexts, such as chronic kidney disease or cancer patients. Clinicians have an unsure attitude towards generic drugs, because clinical practice is lacking as well as a proper knowledge of the topic. Albeit being an alternative, the choice of the generic drug must remain the responsibility of the clinician.

Metal-Organic Frameworks/Heterojunction Structures for Surface-Enhanced Raman Scattering with Enhanced Sensitivity and Tailorability

Metal-organic frameworks (MOFs), which are composed of crystalline microporous materials with metal ions, have gained considerable interest as promising substrate materials for surface-enhanced Raman scattering (SERS) detection via charge transfer. Research on MOF-based SERS substrates has advanced rapidly because of the MOFs' excellent structural tunability, functionalizable pore interiors, and ultrahigh surface-to-volume ratios. Compared with traditional noble metal SERS plasmons, MOFs exhibit better biocompatibility, ease of operation, and tailorability. However, MOFs cannot produce a sufficient limit of detection (LOD) for ultrasensitive detection, and therefore, developing an ultrasensitive MOF-based SERS substrate is imperative. To the best of our knowledge, this is the first study to develop an MOFs/heterojunction structure as an SERS enhancing material. We report an in situ ZIF-67/Co(OH)2 heterojunction-based nanocellulose paper (nanopaper) plate (in situ ZIF-67 nanoplate) as a device with an LOD of 0.98 nmol/L for Rhodamine 6G and a Raman enhancement of 1.43 × 107, which is 100 times better than that of the pure ZIF-67-based SERS substrate. Further, we extend this structure to other types of MOFs and develop an in situ HKUST-1 nanoplate (with HKUST-1/Cu(OH)2). In addition, we demonstrate that the formation of heterojunctions facilitates efficient photoinduced charge transfer for SERS detection by applying the Mx(OH)y-assisted (where M = Co, Cu, or other metals) MOFs/heterojunction structure. Finally, we successfully demonstrate the application of medicine screening on our nanoplates, specifically for omeprazole. The nanoplates we developed still maintain the tailorability of MOFs and perform high anti-interference ability. Our approach provides customizing options for MOF-based SERS detection, catering to diverse possibilities in future research and applications.

Generic orphan drug substitution: a critical analysis of global practices and Saudi Arabia's perspective

In an era of cost pressure, substituting generic drugs represents one of the main cost-containment strategies of healthcare systems. Despite the obvious financial benefits, in a minority of cases, substitution may require caution or even be contraindicated. In most jurisdictions, to obtain approval, the bioequivalence of generic products with the brand-name equivalent needs to be shown via bioavailability studies in healthy subjects. Rare diseases, defined as medical conditions with a low prevalence, are a group of heterogenous diseases that are typically severe, disabling, progressive, degenerative, and life-threatening or chronically debilitating, and disproportionally affect the very young and elderly. Despite these unique features of rare diseases, generic bioequivalence studies are typically carried out with single doses and exclude children or the elderly. Furthermore, the excipients and manufacturing processes for generic/biosimilar products can differ from the brand products which may affect the shelf-life of the product, its appearance, smell, taste, bioavailability, safety and potency. This may result in approval of generics/biosimilars which are not bioequivalent/comparable in their target population or that meet bioequivalence but not therapeutic equivalence criteria. Another concern relates to the interchangeability of generics and biosimilars which cannot be guaranteed due to the phenomenon of biocreep. This review summarizes potential concerns with generic substitution of orphan drugs and discusses potentially problematic cases including narrow therapeutic index drugs or critical conditions where therapeutic failure could lead to serious complications or even death. Finally, we put forward the need for refining regulatory frameworks, with emphasis on Saudi Arabia, for generic substitution and recent efforts toward this direction.

Contrastive analysis on the safety of brand and generic nebivolol: a real-world pharmacovigilance study based on the FDA adverse event reporting system

Background: The equivalence of generic drugs to their brand-name counterparts is a controversial issue. Current literature indicates disparities between the generic nebivolol (GN) and the brand nebivolol (BN). Aim: The study is designed to investigate the safety difference between GN and BN and provide reference information for clinical practice. Methods: We reviewed adverse event (AE) reports that recorded nebivolol as the primary suspect drug in the FDA Adverse Event Reporting System (FAERS) database from 2004 to 2022, conducted a disproportional analysis to detect signals for the GN and BN respectively, and compared the AE heterogeneity between them using the Breslow-Day test. Results: A total of 2613 AE reports of nebivolol were recorded in the FAERS database from 2004 to 2022, of which 2,200 were classified as BN, 346 as GN, and 67 unclassifiable AE reports were excluded. The signals of 37 AEs distributed in cardiac, gastrointestinal, psychiatric, and nervous systems were detected in disproportional analysis. 33 out of 37 AEs were positive signals, with 21 not previously listed on the drug label, indicating an unrecognized risk with nebivolol. In the heterogeneity analysis of AE signals between GN and BN, the GN generally showed a higher AE signal value than BN, especially 15 AEs distributed in the cardiac, neurological, and psychiatric systems that showed statistically significantly higher risk by taking GN. Conclusion: Our study shows some previously overlooked adverse effects of nebivolol. It suggests that the risk of GN's adverse effects may be higher than those in BN, which deserves further attention and investigation by healthcare professionals, regulators, and others.

Post-market quality assessment of 22 ciprofloxacin brands by HPLC available in Bangladesh market

Antibiotic resistance has been recognized as a public health threat in recent years, and mortality due to resistance is increasing alarmingly every year. Antibiotic resistance, among many factors, may arise due to the consumption of substandard antibiotic brands that provide subnormal levels of the drug in the blood. Post-market evaluation can provide important information in assessing pharmaceutical products in terms of quality, purity, and therapeutic aspects. Ciprofloxacin, a broad-spectrum antibiotic, has been used against a wide range of infectious diseases in Bangladesh. The present study aimed to determine the quality attributes of twenty-two commonly prescribed brands of ciprofloxacin 500 mg tablet collected from Dhaka city and the rural regions of Jessore. RP-HPLC coupled with UV-visible spectrophotometry was used to determine the potency of ciprofloxacin in tablets, and the zone of inhibition was determined using Kirby-Bauer's disc diffusion method to assess the antimicrobial efficacy against different strains of microorganisms. We found that 95.45% of brands (21 out of 22 brands) of ciprofloxacin tablets met United States Pharmacopoeia (USP) and British Pharmacopoeia (BP) specified potency, whereas one brand failed. From dissolution studies, we observed that 68.2% of brands (15 out of 22 brands) followed USP/NF dissolution test specifications, whereas 31.8% (7 out of 22 brands) failed to release 80% of the labeled amount of drug within 30 min. Drug release kinetics data showed that most brands followed the Weibull drug release kinetic model. Fit factor analysis exhibited that 8 brands out of 22 (36.4%) failed to comply similar dissolution profiles with the reference product. Minimum inhibitory concentrations, assessed against five bacterial strains, further showed good antimicrobial sensitivity by all brands.

Health professionals' perceptions on local production and bioequivalence study of generic medicines: A cross-sectional survey of physicians and pharmacy professionals in Addis Ababa, Ethiopia

Local production of generic medicines in developing countries has a critical role to meet public health needs by ensuring the availability of essential medicines and providing patients' relief from the burden of unaffordable medical bills. Compliance with bioequivalence (BE) requirements increase the quality and competitiveness of generic drugs regardless of the source. In this regard, a regional BE center has been established in Addis Ababa, Ethiopia to serve the needs of Ethiopia and neighbouring countries. The present study aimed to assess the knowledge and perceptions of health professionals working in Addis Ababa regarding local production and BE studies of generic medicines. A cross-sectional survey was employed and physician participants working at public hospitals and pharmacists from various practice settings were selected using convenient sampling technique. Data was collected using self-administered structured questionnaire. Descriptive statistics was used to summarize the data and multinomial logistic regression analyses was used to assess predictors of health professionals' perception towards the source of drugs. Statistically significant association was declared at p-value < 0.05. A total of 416 participants responded and 272 (65.4%) of them were male. Nearly half of the study participants (n = 194) preferred the imported products. Compared to physicians, participants with diploma (AOR = 0.40; 95%CI: 0.18-0.91, p = 0.028) and bachelor degree and above holders (AOR = 0.32; 95%CI: 0.15-0.68, p = 0.003) in pharmacy were more likely to prefer locally produced products. Participants who practiced in pharmaceutical industries (AOR = 0.40, 95%CI: 0.22-0.77, p = 0.006) preferred locally manufactured products as compared to those practicing in the hospital. While a majority (321, 77.2%) believed in the advantages of doing BE studies locally, only 106 (25.5%) recognized that local pharmaceutical manufacturers did not implement BE studies for their generic products and lack of enforcement by the national regulatory body was raised as a reason for not conducting BE studies by most of the participants (67.9%). The present study revealed a modest preference by physicians and pharmacy professionals towards locally produced products. Majority of participants supported the idea of doing BE studies locally. However, manufacturers and regulators should devise ways to increase health professionals' confidence in local products. Strengthening local BE study capacity is also highly recommended.

In vitro Efficacy Evaluation of Leading Brands of Ciprofloxacin Tablets Found in Bishoftu City Against Salmonella Isolates, Central Ethiopia

Purpose

Salmonella Enteritidis (SE) and Salmonella Typhimurium (STM) are the serovars most frequently associated with human illness. Ciprofloxacin is most widely used to manage cases in adults. The present study aimed to evaluate the in vitro antibacterial activity of leading brands of ciprofloxacin (tablets) marketed in Bishoftu city against SE and STM serovars, and field isolates of Salmonella (non-serotyped) from dairy milk in central Ethiopia.

Methods

Five most widely prescribed ciprofloxacin brands (A-E) were subjected to in vitro efficacy evaluation against Salmonella isolates by using the disc diffusion method. The zone of inhibition (ZI) of the tested brands was compared with the standard disc and interpreted as susceptible, intermediate, and resistant.

Results

Out of 27 replicates (SE, STM, and field Salmonella isolates each = 9) tested for efficacy, the result revealed the mean ZI of the brands varies for all tested isolates (p < 0.05). The highest mean was recorded for Brand E (24.7±0.71, 24.3±0.50, and 19.5±2.69) and lowest for Brand A (22.0±0.87, 21.0±0.87, and 10.7±1.4) for field Salmonella isolates, STM and SE, respectively. All SE were resistant to four brands (Brand A-D) whereas 67% and 33% of them were resistant and intermediate to Brand E, respectively. Similarly, 33% of STM were resistant to Brand A while all the STM were intermediate to other brands. Furthermore, all non-serotyped field isolates of Salmonella were intermediate to all five tested ciprofloxacin brands with variable ranges of mean of ZI (p<0.05).

Conclusion

The study revealed that Brand E was found to have relatively better efficacy against SE than other brands. The current study warrants a need for periodic surveillance of both the quality and efficacy of antibiotics to improve patient well-being and minimize the risk of antimicrobial resistance.

Detecting falsified oral contraceptives by visual assessment and diffuse reflectance spectroscopy (350–2500 nm): the need for supplementing traditional pharmacopeia techniques and the public health implications

Objectives

Substandard and falsified pharmaceuticals can present a major health risk, particularly for low- and middle-income countries. In a Sub-Saharan African market, United States Agency for International Development (USAID) staff found an oral contraceptive product (0.15 mg levonorgestrel/0.03 mg ethinyl estradiol) labeled with a logo (and brand name) visually matching one historically used by USAID but purportedly manufactured by an unauthorized source. Additional assessment was conducted to determine if more evidence of falsification was present to better understand the public health impact.

Study design

Relative to a control, the suspect sample was assessed visually for tablet features and with United States and International Pharmacopeia methods for levonorgestrel/ethinyl estradiol tablets. Diffuse reflectance spectra (350–2500 nm) were collected to further characterize the sample.

Results

Although the suspect sample aligned with pharmacopeia tests, visual examination of tablet characteristics and diffuse reflectance spectroscopy (350–2500 nm) assessments supported the tablets were not the same as control samples, confirming the suspect sample was falsified. These results raised concerns for the overall regulatory oversight available for the market with uncertainty regarding the true clinical bioequivalence levels (although adequate dissolution levels were observed).

Conclusions

Comprehensive characterization of suspect pharmaceuticals from the field can often be required depending on the nature of the sample and can have dramatic implications for understanding the public health risks to the end user within the local market. Simple visual assessment and spectroscopic techniques to screen a sample can help to supplement traditional pharmacopeia approaches.

Implications

Proper characterization of suspect pharmaceuticals is necessary to best understand their potential public health impact. Situations can occur where traditional pharmacopeial techniques may not adequately characterize a sample. Visual assessments and diffuse reflectance spectroscopy can be supplemented to provide a more holistic analysis.

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.

Comparison of Paliperidone Palmitate from Different Crystallization Processes and Effect on Formulations In Vitro and In Vivo

The quality of active pharmaceutical ingredients (APIs) is an important factor which can affect the safety and efficacy of pharmaceuticals. This study was designed to investigate the nature of paliperidone palmitate (PP) obtained by different crystallization processes, then compare the characteristics between test formulations which prepared PP of different crystallization and reference formulations (Invega Sustenna^®) in vitro and in vivo. Two different PPs, namely PP-1 and PP-2, were prepared by different crystallization methods. Contact angle, morphology, and crystallinity of the PPs were characterized. Taking the particle sizes and distribution of Invega Sustenna^® as reference, test formulations were prepared by the wet milling method using either a PP-1 or PP-2 sample. Their release behavior, stability in vitro, and pharmacokinetics in vivo were subsequently investigated. The results indicated that PP-2 had a higher surface free energy (SFE). More small particles were attached to the PP-1 surface under the influence of crystallization temperature. Different crystallization processes did not change the crystal of PP, but changed the crystallinity of PP. There was no obvious difference in in vitro releases between test formulations. However, the stability and state of formulation containing PP-2 were better compared to formulations containing PP-1, indicated by differences in crystallinity and SFE. Meanwhile, pharmacokinetic in vivo results demonstrated that the pharmacokinetic profiles and parameters of formulation containing PP-2 and Invega Sustenna^® tended to be consistent, but those of formulations containing PP-1 were significantly different from those of formulations containing PP-2 or Invega Sustenna^®, and there was burst release phenomenon of formulations containing PP-1 in rats. PP made by different crystallization processes could induce changes in appearance, SFE, and crystallinity, and further affect the stability, state, and pharmacokinetic in vivo formulation.

Raman Mapping-Based Reverse Engineering Facilitates Development of Sustained-Release Nifedipine Tablet

The development of generic preparations that are bioequivalent to a reference listed drug (RLD) is faced with challenges because some critical attributes of RLDs are commonly unknown to developers. In order to determine these attributes, Raman mapping-based reverse engineering in this study to analyze a model sustained-release tablet of nifedipine. The Raman mapping results indicate that the size and size distribution of nifedipine are critical to its release pattern and bioavailability. The tablets with a particle size of nifedipine comparable to that of a commercial product, Adalat^®-L, showed similar in vitro release profiles to the RLD. Moreover, a pharmacokinetic study in human volunteers proved the bioequivalence of the two preparations. In conclusion, Raman mapping-based reverse engineering has the potential to facilitate the development of generic preparations.

Risk of hospitalized depression and intentional self-harm with brand and authorized generic sertraline

BACKGROUND

Recent suggestions of therapeutic inequivalence of brand and generic sertraline have raised concerns about disproportionately higher adverse events among generic users.

OBJECTIVE

To assess the impact of confounding in a comparison of the risks of worsening depression and intentional self-harm (ISH) between users of brand name sertraline and its pharmaceutically equivalent authorized generic (AG).

METHODS

Using a retrospective new-user cohort design, we identified patients with a diagnosis code for depression aged ≥12 years who were continuously enrolled in a Sentinel Data Partner health plan for ≥180 days before their first sertraline dispensing between June 30, 2006 and September 30, 2015. New use was defined as no evidence of sertraline dispensing in the 180 days before index date. We matched each brand name user to up to 10 AG users using propensity scores (PS) and conducted case-centered logistic regression to assess the risks of hospitalized depression and ISH.

RESULTS

Before PS matching, brand name users were significantly less likely to be hospitalized for depression [Hazard Ratio (HR) = 0.70 (95% confidence interval (CI): 0.53-0.94)]. However, in the matched analysis, we observed no statistical difference between brand and AG users [HR = 0.84 (95% CI: 0.59-1.21)]. The risk of ISH did not significantly differ between the exposure groups in unmatched (HR = 0.99 (95% CI: 0.60-1.62) and matched analyses [HR = 0.91 (95% CI: 0.49-1.70).

CONCLUSION

In depressed patients receiving brand versus AG sertraline, patient characteristics confounded the association with hospitalization. Baseline differences were ameliorated by PS matching resulting in no statistical difference between brand and AG sertraline users.

Branded vs. Generic drugs: the role of self-perceived seriousness of disease

Purpose

This study aims at exploring the role of perceived disease seriousness in consumers’ preference for generic versus branded drugs, by shedding light on new factors impacting consumer purchase behaviour for pharmaceutical products.

Design/methodology/approach

An exploratory study based on a quantitative analysis has been conducted with a sample of 100 participants who have been presented with two different scenarios: one related to more serious disease (as in cardiological disease) and one related to less serious disease (as in the seasonal flu). This paper considered Italy as a research setting where the recent mandatory prescription of the active ingredient by doctors leaves the final purchase decision in consumers’ hands

Findings

Results show that, although consumers are free to choose whether to buy a branded or a generic prescribed active ingredient, their choice is mainly driven by the role of the brand. Consumers’ intention to buy generic drugs is higher in the case of diseases perceived as less serious, while the intention to buy branded drugs is higher in the case of disease perceived as more serious.

Originality/value

This study contributes to marketing research and practice by proposing that consumers’ perceived seriousness of their disease should be considered as a further factor in identifying new marketing strategies in those contexts in which the choice between branded or generic drugs is free.

What to Do for Increasing Cancer Burden on the African Continent? Accelerating Public Health Diagnostics Innovation for Prevention and Early Intervention on Cancers

No other place illustrates the increasing burden of cancer than in Africa and in particular, sub-Saharan Africa. Many of the individuals to be diagnosed with cancer will be in low-resource settings in the future due to, for example, an increase in populations and aging, and high co-morbidity with infections with viruses such as human immunodeficiency virus (HIV) and human papillomavirus (HPV), as well as the presence of infectious agents linked to cancer development. Due to lack of prevention and diagnostic innovation, patients present with advanced cancers, leading to poor survival and increased mortality. HIV infection-associated cancers such as B cell lymphomas, Kaposi's sarcoma, and HPV-associated cancers such as cervical cancer are particularly noteworthy in this context. Recent reports show that a host of other cancers are also associated with viral infection and these include lung, oral cavity, esophageal, and pharyngeal, hepatocellular carcinoma, and anal and vulvar cancers. This article examines the ways in which diagnostic innovation empowered by integrative biology and informed by public health priorities can improve cancer prevention or early intervention in Africa and beyond. In addition, I argue that because diagnostic biomarkers can often overlap with novel therapeutic targets, diagnostics research and development can have broader value for and impact on medical innovation.

Effects of anxiety on preferences for generic medicines in Australia

Generic medicines have been available to consumers for ∼40 years, with varying degrees of uptake in different countries. Despite offering equivalent therapeutic qualities, generic medicines still struggle to be accepted by consumers. This study examines the role of a consumer's affective state and framing effects on the purchase of a branded versus a generic pharmaceutical product. These issues are examined in an experiment, with independent manipulations of consumer anxiety levels and the framing of generic alternatives by the pharmacist. The sample comprised 426 men and women within Australia who completed an online survey with a scenario of purchasing a pharmaceutical after visiting a General Practitioner. Results indicate that those consumers experiencing higher levels of anxiety and where the doctor prescribed the branded medicine are more likely to choose branded medicines over cheaper, generic alternatives. The effect of framing the generic alternative as either 'generic' or 'cheaper' was not significant.

Current Bioequivalence Study Designs in South Korea: A Comprehensive Analysis of Bioequivalence Study Reports Between 2013 and 2019

Demonstration of bioequivalence (BE) is mandatory while developing generic drugs. The scientific concept of BE applies equally to different regulatory agencies. However, the application of the concept may differ for each agency, which can affect the design of BE studies. To evaluate the study practices in terms of the BE concept in South Korea, we retrospectively analyzed BE study reports available from Ministry of Food and Drug Safety between 2013 and 2019. Statistical estimation of the pharmacokinetic parameters, including peak concentration and area under the concentration-time curve to the last measurable concentration, as well as study design, number of subjects in a study, study duration, fasting status, and formulation of specific drugs were obtained. The drugs were classified per World Health Organization Anatomical Therapeutic Chemical Classification and Biopharmaceutics Classification System. Post-hoc intrasubject coefficient of variation and corresponding sample sizes were calculated from the 90% confidence intervals of pharmacokinetic parameters. A total of 143 generic drugs in 588 BE studies were analyzed. The largest number of studies were performed in the area of Cardiovascular system (172 studies), followed by Nervous system (143 studies) and Alimentary tract and metabolism (92 studies). Overall, BE studies in South Korea were conducted in accordance with the global guideline despite the differences in details. BE studies were focused on the several therapeutic areas and conducted in a similar manner. The number of subjects was generally larger than that estimated with 90% power.

The Impacts of National Centralized Drug Procurement Policy on Drug Utilization and Drug Expenditures: The Case of Shenzhen, China

In 2019, the Chinese government implemented the first round of the National Centralized Drug Procurement (NCDP) pilot (so-called “4 + 7” policy) in mainland China, in which 25 drugs were included. We conducted this study to examine the impacts of NCDP policy on drug utilization and expenditures, and to clarify the main factors contributing to drug expenditure changes. This study used drug purchasing order data from the Centralized Drug Procurement Survey in Shenzhen 2019. Drugs related to the “4 + 7” policy were selected as study samples, including 23 “4 + 7” policy-related varieties and 15 basic alternative drugs. Driving factors for drug expenditures changes were analyzed using A.M. index system analysis (Addis A. & Magrini N.’ method). After the implementation of the NCDP policy, the volume of “4 + 7” policy-related varieties increased by 73.8%, among which winning products jumped by 1638.2% and non-winning products dropped by 70.8%; the expenditures of “4 + 7” policy-related varieties decreased by 36.9%. Structure effects (0.47) and price effects (0.78) negatively contributed to the increase in drug expenditures of “4 + 7” policy-related varieties, while volume effects (1.73) had positive influence. NCDP policy successfully decreased drug expenditures of “4 + 7” policy-related varieties with structure effects playing a leading role. However, total drug expenditures were not effectively controlled due to the increasing use of alternative drugs.

Knowledge, attitude, and practice of pharmacy professionals on generic medicines in Eastern Ethiopia: A cross-sectional study

Background

Generic medicines are similar to innovator medicine in terms of safety, quality, efficacy, dosage form, strength, and route of administration. They have the same therapeutic use to innovator medicines and available at a far lower price. However, health professionals' poor knowledge and attitude may limit its utilization. The present study aimed at assessing the knowledge, attitude, and practice of pharmacy professionals towards generic medicines in Harar city, Eastern Ethiopia.

Methods

A cross-sectional survey was conducted among community pharmacists in Harar city. A self-administered thirty-three item questionnaire on Knowledge, attitude, and practice of community pharmacists was utilized. Logistic regression analysis was performed to predict the determinants of knowledge and attitude of pharmacists. An odds ratio at 95% confidence interval along with a p-value < 0.05 was considered significant.

Results

Among 80 community pharmacists’ approached, 74 completed the survey, providing a response rate of 92.5%. Sixty-seven percent of the respondents knew that generic drugs are bioequivalent to brand drugs and claimed generic medicines are cheaper (86.5%). Nearly half (48.6%) of participants believe that generic medicines are less effective and slower in the onset of action (58.1%). More than half (54.1%) of study participants revealed their lack of belief in generic medicine as a factor hindering the selection and dispensing of generic medicines. In multivariate logistic regression, experience in community pharmacy practice (Adjusted odds ratio (AOR = 2.18, 95%CI: 1.21–63.1) and Sex (AOR = 3.88, 95%CI: 2.12–39.62) were significantly associated with knowledge and attitude toward generic medicines, respectively.

Conclusion

The current study revealed that there is a gap in the knowledge and attitude of community pharmacists towards generic and brand drugs. More than averages of the respondents have known the concept of generic medicine including their right to perform generic substitution and had a positive attitude toward generics. Female pharmacists were more likely to have a positive attitude and the overall knowledge was higher in those who have more than 5 years of work experience.

Low quality of some generic cardiovascular medicinal products represents a matter for growing concern

AIMS

Generic medicinal products (GMPs) are low-priced copies of off-patent medicines that reduce healthcare costs and broaden access to healthcare. Thus, healthcare authorities, professionals, and providers recommend their use. In recent years, the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) approved hundreds of GMPs based on specific bioequivalent trials. The question is whether the brand name drugs and GMPs or the different GMPs similar in purity, efficacy, and safety.

METHODS AND RESULTS

We have reviewed the progressive increasing recalls and warning letters of cardiovascular GMPs issued recently by the FDA/EMA. Both Agencies found numerous irregularities in the purity, safety, effectiveness, and current good manufacturing practices in some GMPs widely used in cardiovascular therapy. This evidence and the recent identification of nitrosamine impurities classified as probable human carcinogens in several angiotensin receptor blockers confirm that the presence of low-quality/substandard GMPs represents a serious public health problem with significant impact on national clinical and economic burden.

CONCLUSION

A global strategy that unifies the efforts of all the stakeholders, including drug manufacturers, healthcare providers, governments, health professionals, patients, and judicial systems are needed to protect the drug chain supply and ensure that only high-quality GMPs are available for use.

Has the Time Come to Employ Population and Individual Bioequivalence for the Evaluation of Generics?

BACKGROUND

Bioequivalence studies are a vital part of drug development. The average bioequivalence approach is the standard method of assessment to conclude whether the generic product is bioequivalent to the innovator product. Of late, debates are on whether the average bioequivalence approach adequately addresses drug interchangeability as it considers only population mean for the evaluation especially when highly variable drug products and narrow therapeutic index drugs are dealt with. Hence, the alternative approaches like population bioequivalence and individual bioequivalence assessment approaches emerge as they consider inter/intra-subject variance and subject- by-formulation variance along with population mean.

OBJECTIVES

The objective of the study was to apply different bioequivalence assessment approaches in a replicate bioequivalence study to evaluate the drug interchangeability.

METHODS

This was an open-label, single-dose, randomized, balanced, two-treatment, three-period, three-sequence, partial replicate crossover bioequivalence study of omeprazole enteric-coated tablet 20 mg conducted on 48 normal healthy subjects under fed conditions. The plasma concentration of omeprazole was analyzed by a validated bioanalytical method to determine the pharmacokinetic and statistical parameters to assess average bioequivalence, population bioequivalence, and individual bioequivalence.

RESULTS

In this study, test formulation was shown to be bio-inequivalent to the reference formulation by average bioequivalence, population bioequivalence, and individual bioequivalence approaches.

CONCLUSION

The outcome of the evaluation clearly states that the bioequivalence outcome of all these approaches are the same. Obviously, it does not mean that these three approaches provide the same outcome though the consideration of variances varies. Certainly, population bioequivalence and individual bioequivalence approach will be more accurate for the assessment of drug interchangeability.

Factors Contributing to Drug Release From Enteric-Coated Omeprazole Capsules: An In Vitro and In Vivo Pharmacokinetic Study and IVIVC Evaluation in Beagle Dogs

This study was performed to explore factors influencing the release of the proton pump inhibitor omeprazole from enteric-coated capsules in vitro and absorption in vivo in beagle dogs. Enteric-coated pellets with different enteric coating materials and coating levels were designed and prepared. All self-prepared formulations were characterized in vitro as well as in vivo and compared to the brand and generic commercial products. Evaluation of the corresponding release profiles suggested that coating material was the most critical factor. Enteric coating level determined the lag time before initiation of drug release, and subcoating level affected the drug release rate. Pharmacokinetic studies were performed in beagle dogs to further confirm the influence of formulation factors on drug absorption. Medium at pH 6.8 was a more biorelevant condition for in vitro drug release tests, although medium at pH 6.0 was better for discriminating release profiles of different formulations. A multiple level C in vitro/in vivo correlation was preliminarily established by which T_max and C_max of omeprazole formulations could be predicted with release parameters such as T_lag and T₂₅. These results may facilitate quality evaluation and potentially improve the clinical efficacy of generic omeprazole products.

Predicting Cost-Effectiveness of Generic vs. Brand Dabigatran Using Pharmacometric Estimates Among Patients with Atrial Fibrillation in the United States

Generic entry of newer anticoagulants is expected to decrease the costs of atrial fibrillation management. However, when making switches between brand and generic medications, bioequivalence concerns are possible. The objectives of this study were to predict and compare the lifetime cost‐effectiveness of brand dabigatran with hypothetical future generics. Markov microsimulations were modified to predict the lifetime costs and quality‐adjusted life years of patients on either brand or generic dabigatran from a US private payer perspective. Event rates for generics were predicted using previously developed pharmacokinetic‐pharmacodynamic models. The analyses showed that generic dabigatran with lower‐than‐brand systemic exposure were dominant. Meanwhile, generic dabigatran with extremely high systemic exposure was not cost‐effective compared with the brand reference. Cost‐effectiveness of generic medications cannot always be assumed as shown in this example. Combined use of pharmacometric and pharmacoeconomic models can assist in decision making between brand and generic pharmacotherapies.

Current Regulatory Standpoint on Evaluating the Bioequivalence of Different Classes of Generic Drugs - Is the Evaluation in the Right Direction?

BACKGROUND

The concept of evaluating bioequivalence has changed over a period of time. Currently, the Average Bioequivalence approach (ABE) is the gold standard tool for the evaluation of generics. Of late, many debates had arisen about employing ABE approach for the appraisal of all drug categories. This review aims to examine the limitations of ABE approach and the significances of Population Bioequivalence (PBE) and Individual Bioequivalence (IBE) approach, current regulatory thinking for assessing different categories of the drug, whether they are adequately assessed, and the evaluation is in the right direction.

METHODS

We carried out an organized search of bibliographic databases for peer-reviewed research literatures, regulatory recommendations, guidance documents using a focused review question and eligibility criteria. The standard tools were used to appraise the quality of retrieved documents and to make sure the authenticity of the data.

RESULTS

In total 73 references were used in the review, the majority of the references (guidance documents) were from the different regulatory agencies and product-specific guidance. There were 29 product-specific guidance from USFDA and EMA. The limitations of the ABE approach were discussed in detail along with the significances of Population Bioequivalence (PBE) approach and Individual Bioequivalence (IBE) approaches.

CONCLUSION

It is apparent from the review that IBE approach is a precise method for evaluating the drugs as it answers drug interchangeability (prescribability and switchability). IBE approach is followed by PBE approach and ABE approach for the evaluation of different categories of drugs in terms of precision.

Generics in transplantation medicine: Randomized comparison of innovator and substitution products containing mycophenolate mofetil

Objective: Mycophenolate mofetil (MMF) is widely used as an immunosuppressant for the prophylaxis of acute organ rejection in recipients of solid organ transplants. Materials and methods: We have compared, in healthy subjects, the pharmacokinetics of mycophenolic acid when MMF was administered in the form of the innovator product CellCept (F. Hoffmann-La Roche Ltd.) or one of three commercially available generics, Renodapt (Biocon Ltd.), Mycept (Panacea Biotec), or Cellmune (Cipla Ltd.). The study was powered to detect a 20% difference in mean formulation performance measures, but not to formally evaluate bioequivalence. Geometric mean ratios of maximum concentrations (C_max) and areas under plasma concentration-time curves were calculated. Results: Comparing generics against each other, the differences in point estimates of the geometric mean ratios of C_max of two of the comparisons were either borderline within (Renodapt/Cellmune) or clearly outside (Mycept/Cellmune) a region of 80 – 125% around the reference mean, indicating that bioequivalence between these generics may be difficult to show. Conclusion: Physicians in the field of transplantation should be aware of the potential risk of altering the therapeutic outcome when switching from one preparation of MMF to another. ClinicalTrials.gov identifier: NCT02981290.

Generic Substitution of Orphan Drugs for the Treatment of Rare Diseases: Exploring the Potential Challenges

Generic drugs are important components of measures introduced by healthcare regulatory authorities to reduce treatment costs. In most patients and conditions the switch from a branded drug to its generic counterpart is performed with no major complications. However, evidence from complex diseases suggests that generic substitution requires careful evaluation in some settings and that current bioequivalence criteria may not always be adequate for establishing the interchangeability of branded and generic products. Rare diseases, also called orphan diseases, are a group of heterogeneous diseases that share important characteristics: in addition to their scarcity, most are severe, chronic, highly debilitating, and often present in early childhood. Finding a treatment for a rare disease is challenging. Thanks to incentives that encourage research and development programs in rare diseases, several orphan drugs are currently available. The elevated cost of orphan drugs is a highly debated issue and a cause of limited access to treatment for many patients. As patent protection and the exclusivity period of several orphan drugs will expire soon, generic versions of orphan drugs should reach the market shortly, with great expectations about their impact on the economic burden of rare diseases. However, consistent with other complex diseases, generic substitution may require thoughtful considerations and may be even contraindicated in some rare conditions. This article provides an overview of rare disease characteristics, reviews reports of problematic generic substitution, and discusses why generic substitution of orphan drugs may be challenging and should be undertaken carefully in rare disease patients.

Greek students' attitudes, perception and knowledge regarding generic medicines in times of economic crisis: a cross-sectional study

BACKGROUND

The penetration of generic medicines in the pharmaceutical market is influenced, among others, by the consumer's attitude upon them. The attitude of students in health management and recent alumni is particularly important, as they constitute tomorrow's policymakers. The aim of our study was to assess their attitude, perception and knowledge towards generic medicines.

METHODS

A cross-sectional study was undertaken, involving students in Health Management and recent alumni. The ATtitude TOwards GENerics (ATTOGEN) validated questionnaire was used, which consists of 18 items, yielding 6 scales (trust, state audit, knowledge, drug quality, drug substitution and fiscal impact), with all item responses expressed on a 5-point Likert scale and higher scores denoting greater disagreement. Correlation coefficients were computed and independent sample tests were performed using non-parametrical statistical methods.

RESULTS

A total of 1402 students were interviewed, with a female predominance (62.88%). The mean (SD) scores for the six scales of the ATTOGEN questionnaire were: Trust: 2.877 (0.940), State audit: 3.251 (0.967), Knowledge: 1.537 (0.688), Drug quality: 2.708 (0.971), Drug substitution: 3.828 (1.127) and Fiscal impact: 2.299 (0.860). Trust over generics was statistically significantly associated with all ATTOGEN scales (all p < 0.001). In addition, the increased level of knowledge about generics was associated with recognition of the generic medicines' quality equivalence (p < 0.001) and positive fiscal impact (p = 0.018). Pharmacists declared having a superior knowledge of generic medicines, being more satisfied with the information they receive about them and strongly believing in drug substitution (p < 0.001). Comparatively to other professionals, pharmacists also indicated substantial differences between branded and generic medicines more often (p < 0.001). They also argued to a greater extent that generic medicines were invented and promoted to resolve the financial crisis of social security institutions at the expense of citizens (p < 0.001).

CONCLUSIONS

This study demonstrated a mixed attitude of students regarding generic medicines. Trust and knowledge emerged as key factors shaping the students' attitude towards generics. Among students, pharmacists exhibited a distinct response pattern. This study underlines the importance of addressing and correcting health management students' misbeliefs about generics' quality and utility.

Relative Oral Bioavailability of Two Amoxicillin-Clavulanic Acid Formulations in Healthy Dogs: A Pilot Study

The use of human generic amoxicillin-clavulanic acid formulations in veterinary medicine is currently lacking supportive evidence. This pilot study was conducted to determine preliminary pharmacokinetic parameters and relative oral bioavailability of a human generic and veterinary proprietary 4:1 amoxicillin-clavulanic acid formulation in healthy dogs to evaluate whether drug exposure was similar and to determine if further comparative investigation is warranted. Each dog received a single oral dose of each formulation containing 500:125 mg of amoxicillin-clavulanic acid at two separate instances with a 2 wk washout period between product administration. Following drug administration, blood was collected at fixed times over 24 hr to measure plasma amoxicillin and clavulanic acid concentrations using liquid chromatography-mass spectrometry. There were no statistically significant differences between pharmacokinetic parameters of either formulation. Clavulanic acid showed greater between-dog variation in drug exposure between formulations compared with amoxicillin and was also observed to be more variable within the veterinary proprietary formulation. The average relative oral bioavailability was 98.2% (23.6% coefficient of variation) for amoxicillin and 152.6% (64.3% coefficient of variation) for clavulanic acid between formulations. This pilot investigation supports the need for further bioequivalence studies regarding these formulations before commenting on product interchangeability.

Factors influencing the use of the "not for generic substitution" mention for prescriptions in primary care: a survey with general practitioners

BACKGROUND

Generic drug substitution is a public health policy challenge with high economic potential. Generic drugs are generally cheaper than brand-name drugs. Drugs are a significant part of the total health expenditure, especially in ambulatory care. We conducted a cross-sectional study with general practitioners in the Champagne-Ardenne region to determine physician-related factors and beliefs causing doctors to use the Not for Generic Substitution (NGS) mention.

METHODS

Questionnaires were sent to General Practitioners (GPs) practicing in Champagne-Ardenne via 3 shipments, from January 2015 to May 2015. Prescriber characteristics and beliefs influencing the use of the NGS mention were assessed for frequent (≥ 5%) and less frequent (< 5%) users of the NGS mention.

RESULTS

Factors associated with above average NGS mention use in bivariate analysis included patient comorbidity, polypharmacy, a concern that generic and brand-name drugs are not bioequivalent and belief in higher efficacy of the brand name drug. The use of an e-prescribing system (EPS) and medical practice in rural areas appeared to be associated with lower use of NGS mention in bivariate analysis but not in multivariable analysis. In multivariable analysis, patient request was associated with a higher use of the NGS mention (NGS ≥ 5%, adjusted Odds Ratio (aOR) = 2.52; 95% CI = [1.46-4.35]; p = 0.001), which was also linked to patient age over 65 (NGS ≥ 5%, aOR = 2.33; 95% CI = [1.03-5.30]; p = 0.04). The NGS mention was often used for drugs where substitution is debated in the literature (thyroid hormones, antiepileptic drugs).

CONCLUSION

This work highlights the involvement of the doctor-patient pair for the use of the NGS mention. Patient request was the major reason for using the NGS mention, even though it was not always endorsed by prescribers. Further studies are needed to assess patient views on generic drugs and drug substitution, accounting for their health status and socio-economic condition, to help improve the relevance of the information available to them.

Registered Randomized Trials Comparing Generic and Brand-Name Drugs: A Survey

OBJECTIVES

To evaluate the research agenda of registered randomized trials comparing generic and brand-name drugs in terms of who sponsors them, whether they are published promptly, and whether they find favorable results.

METHODS

We included randomized trials comparing the safety or efficacy of brand-name vs generic medications that were registered in ClinicalTrials.gov or other registries from January 1, 2000, through July 31, 2015. To identify published articles or results generated from such trials, we searched PubMed, Scopus, Google, and registry databases. Data were compared across sponsorship categories ("inbred" if the compared drugs were owned by the same company or its partners/subsidiaries, "competitive" if the compared drugs were owned by competing companies, and "apparently nonprofit"), and time to publication was evaluated with Cox analysis.

RESULTS

We found 207 registered protocols reporting on 186 completed trials. Among those trials, 37 had published their results and another 56 had posted results in registries, for a total of 93 trials with available results. Four years after trial completion, results were available for 64 of 138 trials (46.4%), with substantial differences by sponsor: 70.8% (34 of 48), 28.1% (18 of 64), and 46.2% (12 of 26) of the inbred, competitive, and nonprofit trials, respectively. In multivariate modeling, inbred trials had a 1.73-fold risk of having results available compared with competitive trials (P=.04). Almost all trials reported favorable results, with the exception of 4 (4.3% of the 93 trials with results).

CONCLUSION

Despite the importance of generic drugs, relatively few registered randomized trials have compared the health effects of generic vs brand-name medicines, and there is an associated unsatisfactory publication rate and almost ubiquitous favorable results. The overall literature on the topic is at high risk of bias, possibly in favor of generic drugs. Higher nonprofit funding and stronger pressure to register trials and publish results are needed.

The use of generics to treat chronic hepatitis C: not quite ready for the big stage

Recently developed direct acting antivirals have been highly effective in treating patients with chronic hepatitis C infection. Due to their expense, there has been development of generic formulations of these medications in many countries. However, there has been controversy regarding the bioequivalence of generics when compared to brand name medications. Inactive ingredients, which may differ in generic medications, can alter the bioequivalence of the active ingredient as well as provoke intolerance or confusion among patients. There is also concern regarding the quality control and assessment of the manufacturing process of generics. When taken together these issues have the potential to lead to treatment failure. The use of generics to treat chronic hepatitis C will remain controversial, until these issues are adequately addressed.

Potential problems and recommendations regarding substitution of generic antiepileptic drugs: a systematic review of literature

Despite the availability of generic antiepileptic drugs (AEDs), still patients and neurologists hesitate to make a switch due to assorted reasons. The objectives of this review were to evaluate the risks associated with the generic substitution of AEDs. In this context, we also summarized the recommendations of various international societies to treat epileptic patients. We used a number of electronic databases to identify the relevant published studies which demonstrated the potential problems and recommendations regarding generic substitution of AEDs. Of 204 articles found initially, 153 were selected for additional review. Subsequently, 68 articles were finally selected. This review concluded that potential problems linked with the generic substitution of AEDs could be bioequivalence issues, failure of drug therapy, emergence of adverse events and increase in the frequency of seizures. The reasons could be the pharmacokinetics properties of AEDs and unique characteristics of some epilepsy patients. Consequently, the generic substitution of AEDs affects the successful treatment and quality of life of the patients. Various guidelines recommend the well-controlled epileptic patients to avoid switching from brand-to-generic products, generic-to-brand products or generic to some other generic products.

Pharmacodynamics of nine generic products of amikacin compared with the innovator in the neutropenic mouse thigh infection model

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 (E_max ≤ 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.

Comparing the Efficacy of 8 Weeks Treatment of Cipram® and its Generic Citalopram in Patients With Mixed Anxiety-Depressive Disorder

Background:

Patients with mixed anxiety-depressive disorder (MADD) suffer both anxiety and depression. Antidepressants, especially, selective serotonin reuptake inhibitors are among agents of choice for treating this condition.

Objectives:

This study compared the efficacy of Cipram® with its generic, citalopram.

Patients and Methods:

Forty adult outpatients (between 18 to 55 years of age) with a diagnosis of MADD who met the trial criteria, entered this double-blind, randomized study. Subjects were assigned to receive either generic citalopram or Cipram® for 8 weeks. Hamilton Rating Scale for Depression (HAM-D) and Hamilton Rating Scale for Anxiety (HAM-A) were utilized to assess depression and anxiety at baseline, weeks 4 and 8 of the study. Statistical analysis was performed using SPSS 14.0.

Results:

Twenty patients received citalopram (mean dosages of 22 mg/day during the first 4 weeks and 33 mg/day during weeks 4 to 8) and 20 received Cipram® (mean dosages of 22 mg/day during the first 4 weeks and 29 mg/day during weeks 4 to 8). Both treatments were noted to be effective in improving the symptoms of MADD at weeks 4 and 8. The mean differences of HAM-D and HAM-A between Citalopram and Cipram® groups were significantly different at the end of week 4 (HAM-D: P = 0.038, HAM-A: P = 0.025), but not at the end of week 8 (HAM-D: P = 0.239, HAM-A: P = 0.204). Both medications were tolerated well by the patients.

Conclusions:

This study suggests that the efficacy of citalopram is similar to that of Cipram® in the treatment of MADD after 8 weeks. Meanwhile, Cipram® may reduce depression and anxiety quicker than its generic, citalopram.

Generic immunosuppression in solid organ transplantation: systematic review and meta-analysis

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.

Efficacy and Safety of Glaucoma Patients' Switch from a 2% Dorzolamide/0.5% Timolol Fixed-Combination Brand-Name Drug to Its Generic Counterpart

PURPOSE

To compare the efficacy and safety of the brand-name and generic 2% dorzolamide/0.5% timolol fixed-combination (DTFC) drugs in glaucoma patients.

METHODS

This was a prospective single-center study, in which patients using only the brand-name DTFC (Cosopt(®); Merck and Co, Inc.) drug and those using Cosopt with prostaglandin analogs (PGs) were enrolled. In the patients using Cosopt (Group A) and Cosopt with PGs (Group B), Cosopt was switched to its generic counterpart (Batidor(®); Bausch & Lomb, Inc.). The intraocular pressure (IOP) was measured before the switch and 4, 8, and 12 weeks after the switch in both groups. The questionnaire on the discomfort symptoms and on the discomfort score for the use of eye drops was answered by the patients in both groups before the switch and 12 weeks after the switch.

RESULTS

A total of 112 patients were enrolled in the study, 62 in Group A and 50 in Group B. The IOPs before the switch and 4, 8, and 12 weeks after the switch showed no statistical difference in both groups (P>0.05). There were higher incidences of bitter taste and blurring with Cosopt, and there was a higher incidence of headache with Batidor in both groups, but no significant differences (P>0.05) were noted. There was, likewise, no significant difference in the discomfort score between 2 drugs in both groups (P>0.05).

CONCLUSIONS

After the switch, the IOP-lowering effect of the generic drug Batidor was similar to that of the brand-name drug Cosopt in the monotherapy and combination therapy with PGs. No significant differences were found in terms of the discomfort symptoms and discomfort score between the 2 drugs.

Bioequivalence evaluation of two amlodipine salts, besylate and orotate, each in a fixed-dose combination with olmesartan in healthy subjects

A fixed-dose combination of amlodipine and olmesartan is used to treat high blood pressure in patients whose hypertension is not sufficiently controlled with either drug alone. The objective of this study was to evaluate the bioequivalence of two fixed-dose combinations, ie, amlodipine orotate/olmesartan medoxomil 10/40 mg and amlodipine besylate/olmesartan medoxomil 10/40 mg, in healthy subjects. A randomized, open-label, single-dose, two-sequence, two-period, crossover study was conducted in 30 healthy adult volunteers. Blood samples were collected for up to 72 hours post-dose in each period. Safety data included the results of physical examinations, clinical laboratory tests, vital signs, an electrocardiogram, and adverse events. For both amlodipine and olmesartan, the 90% confidence intervals for the geometric mean ratios of AUC_last and time to peak plasma concentration fell within the bioequivalence acceptance criteria. The two fixed-dose combinations showed similar safety profiles. Amlodipine orotate/olmesartan medoxomil 10/40 mg was bioequivalent to amlodipine besylate/olmesartan medoxomil 10/40 mg.

Narrow therapeutic index drugs: a clinical pharmacological consideration to flecainide

PURPOSE

The therapeutic index (TI) is the range of doses at which a medication is effective without unacceptable adverse events. Drugs with a narrow TI (NTIDs) have a narrow window between their effective doses and those at which they produce adverse toxic effects. Generic drugs may be substituted for brand-name drugs provided that they meet the recommended bioequivalence (BE) limits. However, an appropriate range of BE for NTIDs is essential to define due to the potential for ineffectiveness or adverse events. Flecainide is an antiarrhythmic agent that has the potential to be considered an NTID. This review aims to evaluate the literature surrounding guidelines on generic substitution for NTIDs and to evaluate the evidence for flecainide to be considered an NTID.

METHODS

A review of recommendations from various regulatory authorities regarding BE and NTIDs, and publications regarding the NTID characteristics of flecainide, was carried out.

RESULTS

Regulatory authorities generally recommend reduced BE limits for NTIDs. Some, but not all, regulatory authorities specify flecainide as an NTID. The literature review demonstrated that flecainide displays NTID characteristics including a steep drug dose-response relationship for safety and efficacy, a need for therapeutic drug monitoring of pharmacokinetic (PK) or pharmacodynamics measures and intra-subject variability in its PK properties.

CONCLUSIONS

There is much evidence for flecainide to be considered an NTID based on both preclinical and clinical data. A clear understanding of the potential of proarrhythmic effects or lack of efficacy, careful patient selection and regular monitoring are essential for the safe and rational administration of flecainide.

Opinions of Czech general practitioners on generic drugs and substitution

The aim of the study was to map and analyze general practitioners` opinions of, attitudes towards and experiences with generic drugs and generic substitution (GS) in the Czech Republic. General practitioners (GPs) who took part in the annual and regional professional conferences of the Society of General Practice in the period from November 2008 until March 2009 were asked to complete the 28-item questionnaire concerning the issue of generic drugs and GS. Questions were organized in 5 sections aimed at assessing the attitude towards GS, understanding the legislation and opinions on statements related to GS. All data were analyzed using descriptive statistics and correlations were tested by selected parametric and non-parametric tests. Total of 263 completed questionnaires were returned (mean age of 52.2 years (SD=13.7), 177 (67.3%) females and 248 (94.3%) GPs having a practice specialization). 99 (37.6%) respondents have considered generic drugs to be bioequivalent to the respective brand name drugs. 121 (46.0%) respondents believed that generic drugs are of lower quality than brand name drugs. None of respondent showed acquaintance with all the legal rules for GS. Awareness of the legislation and attitude towards GS correlated with the age (p<0.001). In conclusion, distrust among GPs in generic drugs derives from poor knowledge and personal experiences.

Variation in the availability of cancer drug generics in the United States of America

While most of the attention and spending in the oncology community in the United States has been focused on the remarkable scientific inventions of the newer targeted drugs, the shortage of the older essential cancer drugs that are off patent, mostly generics and injectables, has a threatening impact on the health of cancer patients, the execution of clinical trials and the identification of newer drugs and thus impacts upon the burden of costs and pressures on the health system in the United States. It is a part of the problem of the scarcity of generics across all medical specialties, but its oncology is particularly vulnerable. The problem in The United States has been increasing since the beginning of the 21st century until the 2011; since then there has been some improvement in 2012 and the first two quarters of 2013. In the second quarter of 2012, there were 211 active shortages, down from 246 reports of active shortages in the same quarter of 2011. The Food and Drug Administration (FDA) officials ascribe the improvement to efforts that the agency made after President Obama issued an executive order in 2012 that impel the FDA to obtain early reports from companies about potential shortages. The drivers of the shortages are multi-factorial. But are largely economic and are due to the lack of incentives to produce generics. There are efforts from the US government, politicians and the medical, pharmacy and oncology communities. However, the problem is still serious. There is a general agreement that efforts so far have not been adequate, and that there is a need for addressing effectively the fundamentals and the underlying causes. There is a lot that could be done in the United States and across the world to improve the accessibility of economically sustainable better value cancer drugs regardless of whether they are brand or generics and aiming at a win-win outcome for all stakeholders.

Knowledge, attitudes, and practices of community pharmacists on generic medicines in Qatar

BACKGROUND

The practice of generic medicines prescribing, dispensing and substitution in developing countries has been controversial among healthcare professionals, particularly due to issues on quality, safety and efficacy. These controversies are as a result of inter-country differences in policies and laws as well as individualized knowledge and attitudes of pharmacists pertaining to generic medicines.

OBJECTIVE

This study primarily aims to assess the knowledge, attitudes, and practices of community pharmacists in Qatar towards generic medicines.

SETTING

Community pharmacy settings throughout the State of Qatar.

METHOD

A cross-sectional study using a pretested paper-based survey was conducted among a random sample of community pharmacists in Qatar. The data were analyzed using IBM-SPSS(®) version 20. Both descriptive and inferential statistical analyses were applied.

MAIN OUTCOME MEASURE

Knowledge, attitudes, and practices of generic medicines pertaining to regulatory standards, safety, efficacy, quality, and future policies. Results A total of 160 surveys were distributed to community pharmacists of which 118 were returned (response rate, 74 %). The mean total score of generic medicines knowledge among the pharmacists was 6.8 ± 1.6 (maximum possible score was 10). Years of practice as well as place of obtaining academic degree did not influence knowledge score. Approximately 72 % of the pharmacists supported generic substitution for brand name drugs in all cases where a generic medicine is available and the majority (93 %) agreed that pharmacists should be given generic substitution right. Nearly 61 % of the pharmacists considered lack of proven bioequivalence to original brands as an important barrier for selecting generic medicines and 55 % rated "lack of policy for directing the practice of generic medicine" as an important barrier.

CONCLUSION

In order to enhance the quality use of and to promote the practice of generic medicines in Qatar, an educational program should be implemented. A national generic medicine policy and guidelines are warranted in the State of Qatar.

A critical review of brand and generic alendronate for the treatment of osteoporosis

Objective

Compare in vitro and in vivo characteristics and clinical outcomes of brand and generic alendronate.

Research design and methods: Relevant search terms were input into Medline ("alendronate" AND "generic" up to August 5, 2013) and any abstracts deemed possibly relevant selected for full paper review and abstraction.

Results

Multicentre, randomized, placebo-controlled Phase III clinical trials of substantial size and duration have established the anti-fracture efficacy and safety of brand amino-bisphosphonates. For regulatory approval, generic versions of brand drugs need to demonstrate bioequivalence in young, healthy volunteers and have similar dissolution times. While the potency and amount of active drug within generic formulations must be identical to the brand, differences are permitted in the excipients. Significant differences in tablet disintegration time among different versions of generic and brand alendronate have been reported. Rapidly disintegrating alendronate pills may increase oesophageal bioadhesion and adverse event risk. Oesophageal-bound alendronate or slow disintegrating alendronate tablets may be made inert and ineffective by subsequently ingested food or drink. Investigations have reported a lower persistence to therapy with generic brands of alendronate as compared to brand bisphosphonates and patients switched from brand to generic alendronate have increased adverse event rates and losses in bone mineral density.

Conclusion

Numerous differences exist between brand and generic alendronate including: disintegration time, bioadhesion to the oesophagus, patient persistence to therapy, adverse event incidence, and maintenance of bone mineral density. Generic forms of alendronate warrant closer clinical study before they are ascribed the clinical effectiveness and tolerability of brand alendronate.

Electronic supplementary material

The online version of this article (doi:10.1186/2193-1801-2-550) contains supplementary material, which is available to authorized users.