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Objectives: To determine the relationship between consumer cost sharing for branded antidepressants and the initiation of branded therapy among patients with major depressive disorder (MDD) filling a prescription for generic MDD medication., Study Design: Retrospective cross-sectional analyses., Methods: Patients aged 18 to 64 years with MDD who filled a generic antidepressant were identified in commercial claims data for 2012 to 2014. For each year-specific analysis, an average cost-sharing index for branded antidepressants at the level of the plan was computed. Multivariable models were used to estimate the relationship between plan-level cost sharing for branded antidepressant medications and the filling of branded prescriptions, with demographic and clinical variables as covariates., Results: For patients with MDD filling a generic prescription, increases in branded cost sharing were associated with significant decreases in the likelihood of filling a branded antidepressant in each year (P <.001). Results in 2012 imply that a shift from the 0th to 90th percentile in the branded cost-sharing index corresponded with a 9.5% decrease in the relative likelihood of a branded fill among patients receiving a generic antidepressant. The corresponding figures for 2013 and 2014 were 9.3% and 3.5%, respectively., Conclusions: In MDD, patients and clinicians who dutifully adhere to guidelines requiring a trial of first-line medication may ultimately require therapy with alternate agents to achieve adequate disease control. A "reward the good soldier" benefit design would lower cost sharing for higher-tier evidence-based therapies when clinically indicated. Results suggest that narrowing the gap in cost sharing between branded and generic medications following a trial of a generic agent might improve access to second-line treatment in MDD.

We measured and compared the physicochemical properties (pH, yield value, and squeeze force) of a drug for dermatomycosis, terbinafine hydrochloride-containing cream (brand-name product), and 12 generic products to clarify the characteristics of each product. On pH measurement, the pH value of the brand-name product, Lamisil, was 4.8, and those of the generic products ranged from 4.3 to 5.5, showing no marked difference. Furthermore, the yield value of Lamisil, as an index of cream ductility, was 122.2 dyn/cm 2 , and those of the generic products ranged from 42.1 to 1,621.5 dyn/cm 2 . In particular, the value of a generic product, Taiyo (42.1 dyn/cm 2 ), was significantly lower, whereas that of another one, Viras (1,621.0 dyn/cm 2 ), was significantly higher. In addition, the squeeze force was measured by attaching a HapLog ® to the thumb and second finger. The value of Lamisil was 12.9 N, and those of the generic products ranged from 8.0 to 15.4 N. The values of generic products, Mylan (8.6 N), Tebinaceil (9.0 N), and Kelger (8.0 N), were significantly lower, whereas that of another one, Viras (15.4 N), was significantly higher. These results showed that there were marked differences in the pharmaceutical properties between the generic and brand-name products. The above pharmaceutical characteristics of drugs facilitated the presentation of reasons for differences in the sense of use, which characterizes external preparations, suggesting that products appropriate for individual patients can be recommended.

Class III antiarrhythmics are preferred therapy for managing atrial fibrillation/flutter. Dofetilide 0.5-mg capsules were US Food and Drug Administration (FDA) approved in 1999 to treat atrial fibrillation/flutter. Bioequivalence of generic dofetilide is important for treating arrhythmias because drug concentrations must be consistent to maintain normal sinus rhythm. Generic dofetilide 0.5-mg capsule pharmacokinetics were compared with branded product in 2 open-label, 2-way crossover, single-dose studies - 1 study each in fasted and fed healthy subjects. Blood samples were collected before and up to 48 hours after dosing. Safety was assessed by tabulating adverse events and vital signs. Seventy-three subjects were enrolled; 59 completed the studies. In fasted subjects, the 90% confidence intervals (CIs) for generic dofetilide 0.5 mg versus the reference formulation were 0.996-1.026 for the area under the plasma concentration-time curve from 0 to infinity (AUC) and 0.974-1.066 for the maximum observed concentration (C max ). In fed subjects, the 90%CIs for AUC and C max were 0.988-1.015 and 0.928-0.992, respectively. All ratios were within the FDA-established bioequivalence range. Twenty-six subjects experienced 37 adverse events (generic, 15; reference, 22); all but 1 were mild or moderate in severity. Generic dofetilide 0.5-mg capsules can be considered bioequivalent to the reference product., (© 2017, The American College of Clinical Pharmacology.)

Background: Observational studies of switching from branded to generic formulations of the same drug substance often lack appropriate comparators for the subjects who switched. Three generic formulations were deemed equivalent to Concerta: an authorized generic (AG) identical except for external packaging, and two other generics (EG)., Objective: Compare the incidence of a combined endpoint (switching back to Concerta, changing the use of immediate release methylphenidate (MPH), stopping all long-acting methylphenidate, or starting a new medication) among people switched from Concerta to the AG versus the EG., Methods: Cohort study from the Truven CCAE database of people aged 6 to 65 diagnosed with ADHD, treated with Concerta, and switched to the EG or to the AG formulation., Results: In the EG arm 24.6% and in the AG arm 19.7% of subjects switched back to Concerta. The proportion of subjects meeting the combined endpoint was 39.5% in the EG arm, 32.9% in the AG arm, a crude risk ratio of 1.20 (95% CI 0.94, 1.54). After adjustment by propensity score stratification, the adjusted odds ratio (OR) was 1.23 (95% CI 0.90, 1.70). In an unplanned analysis using a different method of adjustment, the adjusted OR was 1.00 (95% CI 0.69, 1.44)., Discussion: This study did not detect a difference between the proportion of people who met the study endpoint in the two study arms, i.e. between those who switched to a generic formulation that was identical to Concerta except for external packaging and those who switched to the comparison generics. The high incidence of the combined endpoint in the AG arm demonstrates the need for an appropriate comparator in studies of this type., Trial Registration: ClinicalTrials.gov NCT02730572.

Objectives: To analyze the cost effectiveness of short-cycle therapy (SCT), where patients take antiretroviral (ARV) drugs 5 consecutive days a week and have 2 days off, as an alternative to continuous ARV therapy for young people infected with human immunodeficiency virus (HIV) and taking efavirenz-based first-line ARV drugs., Methods: We conduct a hierarchical cost-effectiveness analysis based on data on clinical outcomes and resource use from the BREATHER trial. BREATHER is a randomized trial investigating the effectiveness of SCT and continuous therapy in 199 participants aged 8 to 24 years and taking efavirenz-based first-line ARV drugs in 11 countries worldwide. Alongside nationally representative unit costs/prices, these data were used to estimate costs and quality adjusted life years (QALYs). An incremental cost-effectiveness comparison was performed using a multilevel bivariate regression approach for total costs and QALYs. Further analyses explored cost-effectiveness in low- and middle-income countries with access to low-cost generic ARV drugs and high-income countries purchasing branded ARV drugs, respectively., Results: At 48 weeks, SCT offered significant total cost savings over continuous therapy of US dollar (USD) 41 per patient in countries using generic drugs and USD 4346 per patient in countries using branded ARV drugs, while accruing nonsignificant total health benefits of 0.008 and 0.009 QALYs, respectively. Cost-effectiveness estimates were similar across settings with access to generic ARV drugs but showed significant variation among high-income countries where branded ARV drugs are purchased., Conclusion: SCT is a cost-effective treatment alternative to continuous therapy for young people infected with HIV in countries where viral load monitoring is available.

Introduction: Generic inhalers are often perceived as inferior to their branded counterparts; however, they are safe and effective if they can meet the regulatory requirements. The approach to assess bioequivalence (BE) in oral dosage form products is not sufficient to address the complexities of inhalational products (e.g., patient-device interface); hence, more considerations are needed and caution should be applied in determining BE of inhaled compounds., Areas Covered: This review outlines the evaluation process for generic inhalers, explores the regulatory approaches in BE assessment, and highlights the considerations and challenges in the current in vitro and in vivo approaches (lung deposition, pharmacokinetic, pharmacodynamic/clinical studies, and patient-device interface) for establishing BE of inhaled compounds., Expert Opinion: The ultimate goals in this field are to establish uniformity in the regulatory approaches to speed the drug submission process in different regions, clear physicians' misconception of generic inhalers, and have meaningful clinical endpoints such as improvement in patient quality of life when compared to placebo and brand name drugs. As inhalational drugs become more common for other indications such as antibiotics, the technologies developed for inhaled compounds in the treatment of chronic pulmonary diseases may be extrapolated to these other agents.

Background: Treatment of chronic hepatitis C using combination of sofosbuvir (SOF) and daclatasvir (DCV) was used in several clinical trials and multicentre studies, which were somewhat limited to genotypes 1-3. The national program in Egypt is using SOF-DCV combination for large scale treatment., Aim: To assess the efficacy and safety of combined SOF-DCV in treating patients with HCV-G4 in a real-world setting., Methods: Data and outcome of chronic HCV patients who were treated for 12 weeks with generic medications: DCV 60 mg plus SOF 400 mg ± ribavirin (RBV) within the national hepatitis C treatment program in Egypt are presented. Treatment-naïve patients without cirrhosis were treated without RBV, and those who had cirrhosis or were treatment-experienced (interferon experienced or SOF experienced) received RBV. Efficacy and safety were assessed, and baseline factors associated with sustained virological response at post-treatment week 12 (SVR12) were explored., Results: During the first 2 months of the programme, 18 378 patients with HCV-G4 started treatment with SOF-DCV with or without RBV. Overall, 95.1% achieved SVR12 (95.4% among patients treated without RBV and 94.7% for patients treated with RBV, P = .32). Treatment was prematurely discontinued in only 1.5% of patients. The most common events leading to discontinuation were patient withdrawal (n = 76) and pregnancy (n = 5). Five deaths occurred within this group., Conclusions: Real-world experience of generic SOF-DCV in patients with chronic HCV-G4 proved to be safe and associated with a high SVR12 rate, in patients with different stages of fibrosis., (© 2017 John Wiley & Sons Ltd.)

To be considered bioequivalent to their branded counterparts, generic drugs must meet the standards for bioequivalence (BE) described by the regulatory agencies. While BE of generic inhalational drugs can be evaluated using a similar approach as that for oral dosage from products or drugs that are delivered systemically, the approach is insufficient to address the complexities of inhalational products (e.g., localized site of action, device-patient interface). Therefore, more considerations are needed and caution should be applied when evaluating BE of inhaled compounds. The purpose of this review is to highlight the considerations and challenges in establishing BE of inhaled compounds by (1) outlining the current regulatory approaches (from Health Canada, the U.S. Food and Drug Administration, and the European Medicines Agency) to assess BE for subsequent entry inhaled products (SEIPs) and (2) reviewing the literature pertaining to testing considerations of SEIPs to establish BE.

There are several drug products that bind phosphate or bile acid in the gastrointestinal (GI) tract to exert their therapeutic efficacy. In vitro binding studies are used to assess bioequivalence (BE) of these products. The objective of this study is to identify the common deficiencies in Abbreviated New Drug Applications (ANDAs) for these products. Deficiencies were compiled from ANDAs containing in vitro binding BE studies. The deficiencies were classified into eight categories: Pre-Study Method Validation, During-Study Sample Analysis, Study Design, Study Procedure, Dissolution/Disintegration, Analytical Site Inspection, Data Submission, and Formulations. Within each category, additional subcategories were defined to characterize the deficiencies. A total of 712 deficiencies from 95 ANDAs for 11 drug products were identified and included in the analysis. The four categories with the most deficiencies were During-Study Sample Analysis (27.8%), Pre-Study Method Validation (17.3%), Data Submission (16.7%), and Study Design (15.7%). For the During-Study Sample Analysis category, failure to submit complete raw data or analytical runs ranked as the top deficiency (32.8%). For the Study Design category, using an unacceptable alternate study design (26.8%) was the most common deficiency. Within this category, other commonly occurring deficiencies included incorrect/insufficient number of absorbent concentrations, failure to pre-treat drug product with acid, insufficient number of replicates in study, incorrect calculation of k1 and k2 values, incorrect dosage form or pooled samples used in the study, and incorrect pH of study medium. The review and approval of these products may be accelerated if these common deficiencies are addressed in the original ANDA submissions.

Background: Scrupulous comparison of the pharmacokinetic and clinical characteristics of generic tacrolimus formulations versus the reference drug (Prograf) is essential. The pharmacokinetics of the Tacrolimus Hexal (TacHexal) formulation is similar to Prograf in stable renal transplant patients, but data in de novo patients are lacking., Methods: De novo kidney transplant patients were randomized to generic tacrolimus (TacHexal) or Prograf in a 6-month open-label study., Results: The primary end point, the dose-normalized area under the curve0-12h at month 1 posttransplant, was similar with TacHexal or Prograf; back-transformed geometric means of adjusted log-transformed values (analysis of variance) were 18.99 ng·h·L (TacHexal) and 20.48 ng·h·L (Prograf) (ratio, 1.08; 90% confidence interval, 0.84-1.38; P = 0.605). The dose-normalized peak concentration geometric means at month 1 was also comparable between treatments (ratio, 1.16; 90% confidence interval, 0.88-1.54; P = 0.377). There were no relevant differences in other pharmacokinetic parameters at month 1 or in area under the curve0-4h and trough concentration when measured at months 3 and 6. The adjusted change in mean estimated glomerular filtration rate from baseline to month 6 (Nankivell) was noninferior for TacHexal versus Prograf using observed values (47.7 vs 38.6 mL/min per 1.73 m, P < 0.001) and was superior based on observed values (P = 0.044) but not using last observation-carried forward method. Rates of biopsy-proven acute rejection (5.7% vs 7.9%), adverse events, and serious adverse events were similar with TacHexal or Prograf., Conclusion: Tacrolimus pharmacokinetics is similar with TacHexal and Prograf early after kidney transplantation. Efficacy and safety in this limited data set were comparable, with at least equivalent graft function under TacHexal.

Administration of proton pump inhibitors (PPIs) through nasogastric tubes may present risks. If the PPI drug products are not prepared properly, clogging or obstruction of nasogastric tubes can pose a safety concern. In addition, the integrity of the enteric coating of the drug product may be damaged resulting in reduced bioavailability of the active moiety. From the perspective of administration of generic PPIs when compared to the reference drug product, differences in formulation can potentially result in a greater relative risk for the generic drug product. As part of the assessment of bioequivalence, the Office of Generic Drugs (OGD) has developed a suite of in vitro testing to compare the delivery of the generic and reference products via nasogastric tubes. These in vitro tests assess essential attributes associated with the likelihood of clogging and maintenance of the enteric coating. These in vitro tests include studies evaluating sedimentation, granule size distribution, drug recovery, and acid resistance. One of the challenges is that while the administration of PPIs through nasogastric tubes is common in clinical practice, this issue is not uniformly addressed in the FDA approved label of the reference drug products. This paper discusses the design and rationale for in vitro testing of PPI formulations with respect to bioequivalence via nasogastric tube administration and in addition, it summarizes commonly occurring deficiencies in the in vitro nasogastric tube testing of 14 recent Abbreviated New Drug Applications (ANDA) submitted for five generic PPI drug products.

Background: Bioequivalence between Tacrolimus Prograf® and generic tacrolimus formulations has been demonstrated in adult populations, however clinical experience and safety data regarding generic tacrolimus in pediatric transplant recipients is limited. This study aimed to evaluate conversion from Tacrolimus Prograf® to Sandoz® in pediatric renal transplant recipients nationwide. The primary outcome was a change in mean trough tacrolimus concentration. Additionally, changes in tacrolimus intra-patient coefficient of variation (CoV), allograft function, requirement for dose adjustments, and episodes of biopsy-proven rejection were evaluated., Methods: Retrospective cohort study in 37 pediatric renal transplant recipients who switched to Tacrolimus Sandoz®. Each patient had three pre-conversion tacrolimus trough and creatinine concentrations within the 4 months prior and three post-conversion concentrations on day 3, 10, and the next subsequent level. Mean pre- and post-conversion tacrolimus trough concentrations and glomerular filtration rate (eGFR) were calculated. Tacrolimus concentration, CoV, and creatinine differences were compared by paired t test., Results: Thirty-seven patients (41% females, age 3-18 years) were included. Average intra-patient difference in trough tacrolimus concentration was 0.05μg/l (95% CI -0.37 to 0.47). Average intra-patient difference in eGFR was -1.20 ml/min/1.73 2 (95% CI -3.53 to 1.13). Three patients had acute rejection during 12 months post-conversion compared to none during 12 months pre-conversion., Conclusions: Pediatric renal transplant recipients can be converted from Tacrolimus Prograf® to Sandoz® with negligible change in trough concentration, dose adjustments, or immediate allograft function. Of concern was the number of acute rejection episodes, however non-adherence contributed to at least one episode and this difference was determined clinically and statistically not significant.

This study aimed to demonstrate interchangeability between 2 lornoxicam tablet formulations under fasting conditions among Mediterranean Arabs by using a newly validated high-pressure liquid chromatography-tandem mass spectrometry method. A single-oral solid dosage form (8 mg/tablet), randomized, open-label, 2-way crossover study was conducted on 30 healthy male volunteers. Blood samples were collected prior to dosing and over a 24-hour period, and the washout period was 9 days. Statistical comparison of the main pharmacokinetic parameters showed no significant difference between generic and branded products. The point estimates (ratios of geometric mean %) were 90.91, 96.34, and 94.86 for C max, AUC 0-last , and AUC 0-∞ , respectively. The 90% confidence intervals were within the predefined limits of 80.00%-125.00%, as specified by the international guidelines. This study showed that both formulations met the regulatory criteria for bioequivalence., (© 2017, The American College of Clinical Pharmacology.)

Purpose: Our study evaluated adverse events of therapeutic failure (and specifically reduced duration of action) with the use of a branded product, Osmotic Release Oral System (OROS) methylphenidate, which is approved for the treatment of attention deficit/hyperactivity disorder, and a generic product (methylphenidate, methylphenidate ER-C), which was approved for marketing in Canada based on bioequivalence to OROS methylphenidate. This study was initiated following reports that some US-marketed generic methylphenidate ER products had substantially higher reporting rates of therapeutic failure than did the referenced brands., Methods: Through methodology similar to that used by the US Food and Drug Administration to investigate the issue with the US-marketed generic, reporting rates were calculated from cases of therapeutic failure identified in the Canadian Vigilance Adverse Reaction Online database for a 1-year period beginning 8 months after each product launch. Corresponding population exposure was estimated from the number of tablets dispensed. An in-depth analysis of narratives of individual case safety reports (ICSRs) with the use of the generic product was conducted in duplicate by 2 physicians to assess causality and to characterize the potential safety risk and clinical pattern of therapeutic failure. Similar secondary analyses were conducted on the US-marketed products., Findings: Reporting rates of therapeutic failure with the use of methylphenidate ER-C (generic) and OROS methylphenidate (brand name) were 411.5 and 37.5 cases per 100,000 patient-years, respectively (reporting rate ratio, 10.99; 95% CI, 5.93-22.21). In-depth analysis of narratives of 230 ICSRs of therapeutic failure with the Canadian-marketed generic determined that all ICSRs were either probably (60 [26%]) or possibly (170 [74%]) causally related to methylphenidate ER-C. Clinical symptoms suggestive of overdose were present in 31 reports of loss of efficacy (13.5%) and occurred primarily in the morning, and premature loss of efficacy (shorter duration of action) was described in 98 cases (42.6%) and occurred primarily in the afternoon. Impacts on social functioning, such as disruption in work or school performance or adverse social behaviors, were found in 51 cases (22.2%)., Implications: The ~10-fold higher reporting rate of therapeutic failure with the generic product relative to its reference product in the present Canadian study resembles findings with US-marketed generic products. While these results should be interpreted with caution due to the limitations of spontaneous adverse event reporting, which may confound comparisons across products, similar findings nonetheless led the US Food and Drug Administration to declare in 2014 that 2 methylphenidate ER generic products in the United States were neither bioequivalent nor interchangeable with OROS methylphenidate-their reference product. Our results indicate a potential safety issue with the Canadian-marketed generic and suggest a need for further investigation by Health Canada., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: The approval of injectable generic drugs does not require bioequivalence testing. However, although generic products contain the same level of the active compound, the levels and types of additives present can differ from those used in the original product. Since docetaxel is highly lipophilic, polysorbate 80 (PS80), polyethylene glycol (PEG), and ethyl alcohol are employed to solubilize this anticancer agent. This retrospective study compared the safety of five docetaxel products (Taxotere ® , Docetaxel Hospira, Docetaxel Sandoz, Docetaxel Sawai, and Docetaxel EE)., Methods: The incidence and severity of adverse events were analyzed using the medical records of operable breast cancer patients (n = 363) treated with docetaxel (75 mg/m 2 ) in Showa University Hospital, Japan, from Jan 2013 to Mar 2016. Toxicities were graded using the Common Terminology Criteria for Adverse Events, version 4.0., Results: Significant product-related differences were observed in the following non-hematological adverse events: injection site reaction (P = 0.0012), hand-foot syndrome (≥grade 3) (P = 0.0003), and oral mucositis (≥grade 3) (P = 0.0080). Multivariate logistic regression analyses of the associations between these adverse events and the total additive administered (g/m 2 ) identified significant negative effects of PS80 and ethyl alcohol., Conclusions: Injectable docetaxel products had different adverse event profiles, which showed negative associations with the amounts of PS80 and ethyl alcohol present. This finding indicated that there might be additive-related pharmacokinetic and physiochemical differences among these products, suggesting a need for further pre- or post-approval testing of injectable generic products containing noticeable different levels of additives.

Background: The American College of Cardiology recommends considering initiation of cholesterol-lowering therapy in normal cholesterol adults aged 45-70, who are either diabetic or have a 10 year atherosclerotic cardiovascular disease risk higher than 7.5%. Although this policy was shown to be cost-effective, the multi-billion dollar budget impact may limit the adoption, diffusion and overall clinical impact of this therapy., Objectives: We examined whether using a substantially lower cost statin (Simvastatin) in a much wider population, while accepting almost-as-good per-patient outcomes can provide better outcomes for the entire intended use population (IUP) under a pre-specified budget constraint., Methods: We built a model to compare the outcomes on the entire IUP, and compared branded Rosuvastatin to Simvastatin. Outcomes measured were major adverse cardiovascular events (MACE): cardiovascular death, stroke, myocardial infarction, and hospitalization for revascularization or unstable angina., Results: The branded Rosuvastatin alternative resulted in the prevention of 6,571 MACE compared to 311,698 MACE with Simvastatin, and 83,120 MACE with generic Rosuvastatin., Conclusions: Under budget constraints, using Simvastatin instead of branded Rosuvastatin resulted in a 47 fold increase of prevention of MACE for the entire IUP. These results should be considered while initiating statin therapy in this target population.

Purpose: Generic drugs are assuming an increasingly important role in sustaining modern healthcare systems, as the cost of healthcare, including drug usage, is gradually expanding around the world. To date, published articles comparing generic drug reviews between different countries are scarce., Objective: The objective of this study was to examine generic drug reviews in Japan and Canada., Methods: We surveyed generic drug reviews from Japan and Canada and compared the following points: general matter (application types, type of partial change or Supplement to an Abbreviated New Drug Submission, application and approval numbers, review period, application format, review report, responsibility for review), bioequivalence studies for solid oral dosage forms, and bioequivalence guidelines, guidance, or basic principles regarding various dosage forms., Results: This survey described the many similarities and differences in generic drug reviews between the two countries and points that should be improved to promote better generic drug reviews. In particular, regulations for the definition of the same or different active pharmaceutical ingredients (APIs) are similar for both authorities., Conclusions: The results clarified the future challenges of generic drug reviews, and the differences highlighted by this survey will be important considerations for the future. This is the first article to present and discuss the details of generic drug reviews between Japan and Canada.

Introduction: Although generic drugs constitute approximately 88% of drugs prescribed in the US, there are no reliable methods to identify generic drugs in the US FDA Adverse Event Reporting System (FAERS)., Objective: The aim of this study was to develop an algorithm for identifying generic drugs in the FAERS., Data Source: We used 1237 adverse event reports for tamsulosin, levothyroxine, and amphetamine/dextroamphetamine from the publicly available FAERS from 2011-2013, and 277 source case narratives obtained from the FDA., Methods: Two reviewers independently and in duplicate used a three-item algorithm including the following criteria: manufacturer name, New Drug Application (NDA) number/abbreviated NDA (ANDA), and specific use of the term 'generic' or 'brand' to classify the focal drug of each case report as definitely generic (two of three criteria), probably generic (one of three criteria), brand, and cannot be assessed. Inter-rater reliability was estimated using kappa coefficients, and internal consistency was estimated using Cronbach's alpha. We compared the classification of the drugs as generic versus non-generic in publicly available FAERS compared with the original case reports (reference)., Results: The focal drug was classified as generic (definite or probable) in 15.8% (39/234), 9% (67/742), and 16.7% (42/261) of tamsulosin, levothyroxine and amphetamine/dextroamphetamine cases, respectively (overall kappa 0.89, 95% confidence interval 0.85-0.93), while 37% of reports could not be classified due to incomplete information. Among the drugs classified as generics using the publicly available FAERS, we categorized 95.3% as generic drugs using the original case reports. Among those drugs that did not meet the algorithm-based definition of generic in the publicly available data, 20.9% were reclassified as generics using the original case reports., Conclusions: The algorithm demonstrated high inter-rater reliability with moderate internal consistency for identifying generic drugs in the FAERS, in our sample. Future efforts should focus on improving the reliability and validity of identifying generics through improving the completeness of reporting in the FAERS.

Background: No published studies have assessed the efficacy and safety of rosuvastatin generics., Objectives: Primary objective to assess the safety and efficacy of a generic rosuvastatin in reducing plasma low-density-lipoprotein cholesterol (LDL-C) in Lebanese dyslipidemic patients. Changes in high-density lipoprotein cholesterol, triglycerides and adverse effects were secondary objectives., Design: Prospective, observational, non-comparative., Setting: Multiple outpatient clinics in Lebanon., Patients and Methods: Dyslipidemic patients requiring statin therapy were followed for 2 months after prescription of a generic rosuvastatin at the physician's discretion. Efficacy and safety measurements were collected from medical records., Main Outcome Measures: Efficacy was assessed based on the evaluation of mean and percent change in LDL-C between baseline and week 8 as well as the proportion of patients reaching target LDL-C levels. Safety was assessed based on the evaluation of the incidence of adverse events (AEs) during the study period., Results: Two months after initiation of generic rosuvastatin, LDL-C levels in the 313 eligible patients who completed the study significantly decreased from 4.3 (0.8) mmol/L (168.2 [31.3] mg/dL) at baseline to 2.7 (0.7) mmol/L (105.9 [25.5] mg/dL) (P < .001). The mean percent change in LDL-C level was highest in subjects receiving generic rosuvastatin at a dose of 40 mg/day (-47.4%), followed by 20 mg/day (-36.8%), and 10 mg/ day (-31.4%); 82.5% of patients reached the target LDL-C level as set by their physician at baseline. Thirteen patients (4%) reported six AEs during treatment: abdominal pain, headache, stomach ache, insomnia, musculoskeletal pain/myalgia and nausea. No clinically significant changes in serum creatinine, serum creatine kinase, or liver function tests were reported. One patient withdrew because of an adverse event., Conclusions: Generic rosuvastatin was efficacious and safe in reducing LDL-C levels and helping the majority of patients achieve LDL-C targets after a short treatment period., Limitations: The observational nature, and a control group, and the relatively short duration of follow-up limit the generalizability of results. The authors received fees for study activities at patient visits from an independent clinical research organization subcontracted by the sponsor.

Objective: To assess the bioequivalence of generic formulation of rivastigmine (test) and Exelon (reference)., Methods: This randomized, open-label, 2-period, single-dose, 2-treatment, 2-sequence, crossover study was conducted in 40 healthy men under fed condition. Participants were randomized to receive a single dose of Exelon or rivastigmine capsule., Results: A total of 31 participants completed the study. Area under the concentration-time curve from time zero to time t (AUC 0- t ) and area under the concentration-time curve from time zero to infinity (AUC 0-∞ ) for Exelon (mean [standard deviation], h·ng/mL) were 126.40 (56.95) and 129.46 (59.94), respectively, while they were 122.73 (43.46) and 125.08 (45.39) for rivastigmine. Geometric mean ratios of rivastigmine/Exelon were 99.17% for AUC 0- t , 98.81% for AUC 0-∞ , and 105% for maximum observed plasma concentration ( C max ). The 90% confidence intervals (CIs) were 94.14% to 104.46%, 93.77% to 104.12%, and 93.08% to 118.44%, respectively. Both formulations were well tolerated., Conclusion: The generic and reference formulations were bioequivalent, as the 90% CIs for C max , AUC 0- t , and AUC 0-∞ were within the range of 80% to 125%.

Two bioavailability/bioequivalence studies were carried out to evaluate the pharmacokinetics of candesartan cilexetil 16-mg tablet formulations. A pilot study was used to optimize the formulation and manufacturing process prior to conducting the definitive study. The pilot study was a single-dose, randomized, 2-period crossover, and the definitive study was a single-dose, randomized, 3-period, 6-sequence crossover study in healthy adults. In the pilot study the test formulation was 24% and 18% greater for C max and AUC, respectively, compared with the innovator product. Following optimization two 16-mg candesartan cilexetil tablet formulations were taken forward into the second bioavailability study.  Eighteen healthy fasted adult subjects were dosed with either the test formulations or the innovator. The pharmacokinetic parameters C max , AUC 0-t , and AUC 0-∞ of candesartan were investigated together with safety and tolerability. The geometric mean ratios (GMRs) and 90% confidence intervals (CIs) for candesartan, C max , AUC 0-t , and AUC 0-∞ were within the boundary of 0.8-1.25 for one of the test formulations (formulation 2). For test formulation 3 the 90%CI of GMR for C max was above (133%) the upper limit of 125% for bioequivalence. Test formulation 2 was found to be bioequivalent and met internationally acceptable regulatory requirements., (© 2016, The American College of Clinical Pharmacology.)

Importance: Rising pharmaceutical costs in the United States are an increasing source of financial burden for payers and patients. Although topical steroids are among the most commonly prescribed medications in dermatology, there are limited data on steroid-related spending and utilization., Objective: To characterize Medicare and patient out-of-pocket costs for topical steroids, and to model potential savings that could result from substitution of the cheapest topical steroid from the corresponding potency class., Design, Setting, and Participants: This study was a retrospective cost analysis of the Medicare Part D Prescriber Public Use File, which details annual drug utilization and spending on both generic and branded drugs from 2011 to 2015 by Medicare Part D participants who filled prescriptions for topical steroids., Main Outcomes and Measures: Total and potential Medicare and out-of-pocket patient spending. Costs were adjusted for inflation and reported in 2015 dollars., Results: Medicare Part D expenditures on topical steroids between 2011 and 2015 were $2.3 billion. Patients' out-of-pocket spending for topical steroids over the same period was $333.7 million. The total annual spending increased from $237.6 million to $775.9 million, an increase of 226.5%. Patients' annual out-of-pocket spending increased from $41.4 million to $101.8 million, an increase of 145.9%. The total number of prescriptions were 7.7 million in 2011 and 10.6 million in 2015, an increase of 37.0%. Generic medication costs accounted for 97.8% of the total spending during this time period. The potential health care savings and out-of-pocket patient savings from substitution of the cheapest topical steroid within the corresponding potency class were $944.8 million and $66.6 million, respectively., Conclusions and Relevance: Most topical steroids prescribed were generic drugs. There has been a sharp increase in Medicare and out-of-pocket spending on topical steroids that is driven by higher costs for generics. Use of clinical decision support tools to enable substitution of the most affordable generic topical steroid from the corresponding potency class may reduce drug expenditures.

Since the enforcement of Generics Act (1999), three types of pharmaceutically equivalent products are marketed in Brazil: innovative reference (REF), "similar" (S) and generic (G) drugs. The S (brand name) and G (generic name) borrow from REF (brand name) clinical data on safety and efficacy and dosage regimen. G (but not S) is bioequivalent to and interchangeable with REF. Starting in 2003, Brazilian Sanitary Surveillance Agency (Anvisa) has required data on relative bioavailability tests (with REF) to approve (or renew registration of) S drugs. In 2014, Anvisa extended interchangeability notion to similar drugs with a "comparable" bioavailability, i.e., an "equivalent" similar drug (EQ). Drugs for chronic diseases and "critical dose medicines" are listed among the EQ drugs approved. Interchangeability of nonbioequivalent medicines raises deep concerns regarding therapeutic failures and adverse events. Concerns are even more worrisome if patients switch from one drug to another during an ongoing treatment for illnesses such as epilepsy, congestive heart failure, hypertension, diabetes and/or substitutable drugs have a narrow therapeutic index.

We demonstrate the use of modeling and simulation to investigate bioequivalence (BE) concerns raised about generic warfarin products. To test the hypothesis that the loss of isopropyl alcohol and slow dissolution in acidic pH has significant impact on the pharmacokinetics of warfarin sodium tablets, we conducted physiologically based pharmacokinetic absorption modeling and simulation using formulation factors or in vitro dissolution profiles as input parameters. Sensitivity analyses indicated that warfarin pharmacokinetics was not sensitive to solubility, particle size, density, or dissolution rate in pH 4.5, but was affected by dissolution rate in pH 6.8 and potency. Virtual BE studies suggested that stressed warfarin sodium tablets with slow dissolution rate in pH 4.5 but having similar dissolution rate in pH 6.8 would be bioequivalent to the unstressed warfarin sodium tablets. A four-way, crossover, single-dose BE study in healthy subjects was conducted to test the same hypothesis and confirmed the simulation conclusion., (© 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Purpose: Recently, generic drugs of paclitaxel have been commonly used mainly by economic reasons; however, predictive factors for toxicities are not fully determined. Hypersensitivity reaction (HSR) is one of the most important adverse events in the paclitaxel-based therapy, and sometimes leads to lethal condition. The aim of the study was to identify predictors for HSR in patients treated with paclitaxel-based regimens., Methods: All the patients treated with chemotherapy including paclitaxel at our hospital between 1998 and 2013 were retrospectively evaluated. Clinicopathological factors of the patients that developed HSR and those without HSR were compared, and predictive factors for HSR were identified., Results: Among 414 patients enrolled in the study, 26 patients (6.3%) developed HSR. Multivariate analyses showed that younger age (odds ratio 6.31), a history of allergy (odds ratio 3.79), and short-course premedication (odds ratio 14.1) were identified as predictive factors for HSR. There was no significant difference in the incidence of HSR between original paclitaxel and generic drug. The incidence of HSR was higher as the number of these predictors was accumulated., Conclusions: Three factors were identified as predictive factors for HSR: younger age, a history of allergy, and short-course premedication. Accumulation of these factors increased the incidence of HSR; however, the use of generic drug was not associated HSR in gynecologic cancer patients.

Purpose: Pharmaceutical companies paid at least $3.91bn to prescribers in 2013, yet evidence indicating whether industry payments shift prescribing away from generics is limited. This study examined the association between amount of industry payments to prescribers and generic drug prescribing rates among Medicare Part D prescribers., Methods: A cross-sectional analysis was conducted among 770 095 Medicare Part D prescribers after linking the 2013 national Open Payments data with 2013 Medicare Provider Utilization and Payment data. The exposure variable was the categorized amount of total industry payments to prescribers (i.e., meals, travel, research, and ownership). The outcome was prescriber's annual generic drug prescribing rate. Multivariable generalized linear regression models were used to examine the association between the amount of industry payments and prescriber's annual generic drug prescribing rates, controlling for prescriber's demographic and practice characteristics., Results: In this sample, over one-third (38.0%) of Medicare Part D prescribers received industry payments in 2013. The mean annual generic drug prescribing rate was highest among prescribers receiving no payments and lowest among those receiving more than $500 of industry payments (77.5% vs. 71.3%, respectively; p < 0.001). The receipt of industry payments was independently associated with prescribers' generic drug prescribing rate; higher payments corresponded with lower generic drug prescribing rates. Other prescriber characteristics associated with higher annual generic drug prescribing rate included male sex, non-northeast region, specialty, and patient volume., Conclusions: Receipt of industry payments was associated with a decreased rate of generic drug prescribing. How this affects patient care and total medical costs warrants further study. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Background: Generic immunosuppressants may be cost-effective if clinical outcomes are equivalent to the brand-name medications. Mycophenolate mofetil in the form of My-rept may be cost-effective being a generic immunosuppressant, which is available as a 500-mg tablet as well as a 250-mg capsule (Chong Kun Dang Pharmaceutical Corporation, Seoul, Korea)., Objective: This study aimed to evaluate the efficacy, safety, cost-effectiveness, and convenience of My-rept 500-mg tablets in liver transplant recipients., Setting: The setting was an outpatient liver transplantation clinic of a tertiary hospital in Korea., Method: A phase 4, single-center, open-label, noncomparative study was undertaken. A total of 50 patients were recruited. Acute transplant rejection, changes in blood chemistry, white blood cell count, assessments of renal function, occurrence of adverse drug reactions, and other characteristics of the patients were recorded for 24 weeks. After study termination, a satisfaction survey was conducted., Results: All enrolled patients and their liver grafts had survived for 24 weeks post-transplantation. No episodes of acute rejection were reported. Nine patients (18.8%) presented with adverse drug reactions that had been commonly reported with the use of other mycophenolate mofetil products, and no serious adverse drug reactions were reported., Conclusion: In conclusion, the My-rept 500-mg tablet appears to be feasible and convenient for administration to recipients of a liver transplant., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Warfarin is a commonly used anticoagulant. Whether a given dose of the different formulations of Brazilian warfarin will result in the same effect on the international normalized ratio (INR) is uncertain. The aim of the WARFA trial is to determine whether the branded and two generic warfarins available in Brazil differ in their effect on the INR., Methods: WARFA is a cross-over RCT comparing three warfarins. The formulations tested are the branded Marevan® (Uniao Quimica/Farmoquimica) and two generic warfarin (manufactured respectively by Uniao Quimica Farmaceutica Nacional and Laboratorio Teuto Brasileiro). All of them were manufactured in Brazil, are available in all settings of the Brazilian healthcare system and were purchased from retail drugstores. Eligible participants had atrial fibrillation or flutter, had been using warfarin for at least 2 months with a therapeutic range of 2.0-3.0 and had low variability in INR results during the 1st period of the trial. Our primary outcome, for which we have an equality hypothesis, is the difference between warfarins in the mean absolute difference between two INR results, obtained after three and 4 weeks with each drug. Our secondary outcomes, that will be tested for inequality (except for the mean INR, which will be tested for equality), include the difference in the warfarin dose, and time in therapeutic range. Clinical events and adherence were also recorded and will be reported., Discussion: To our knowledge, WARFA will be the first comparison of the more readily applicable INR results between branded and generic warfarins in Brazil. WARFA is important because warfarins are commonly switched between in the course of a chronic treatment in Brazil. Final results of WARFA are expected in May 2017., Trial Registration: ClinicalTrials.gov NCT02017197 . Registered 11 December 2013.

Background & Aims: Few patients from developing countries can afford brand name direct-acting antiviral agents for treating hepatitis C virus (HCV) infection, and controversy regarding the bioequivalence of generics exists. This study aimed to observe the safety and efficacy of 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin for Chinese genotype 1b HCV-infected patients., Methods: In this open-labelled observational study, 63 cirrhotic (group 1) and 65 non-cirrhotic (group 2) patients were administered generic ledipasvir-sofosbuvir plus 1000-1200mg of ribavirin daily for 12 and 8weeks, respectively; and 64 non-cirrhotic patients (group 3) received ledipasvir-sofosbuvir for 8weeks. The primary efficacy endpoint was undetectable HCV RNA at week 12 (SVR12) after cessation of therapy. Safety and pharmacokinetic data were collected., Results: One hundred and eighty-seven patients completed treatment, and the latest undetectable HCV RNA was observed in three patients with cirrhosis at week 5 during treatment. Intention-to-treat analysis revealed 96.8% (61/63), 96.9% (63/65), and 96.9% (62/64) of SVR12 rates in groups 1, 2, and 3, respectively. One patient in group 3 relapsed at post-treatment week 4. The regimens were generally well-tolerated. The most common adverse events were fatigue (17.8%), diarrhea (10.9%), and headache (9.9%). Four patients discontinued therapy due to diarrhea and vomiting. One patient from group 2 discontinued treatment on day 29 because of drug-unaffordability; fortunately, she achieved SVR12., Conclusion: This study demonstrated that 8 or 12weeks of generic ledipasvir-sofosbuvir with or without ribavirin are safe and effective for patients with genotype 1b HCV infection., Lay Summary: The price of Harvoni® has led to restrictions and access limitations in many developing and even developed countries with limited healthcare budgets. Gilead approved generic ledipasvir-sofosbuvir costs far less than Harvoni® and presents a similar cure rate for patients with chronic hepatitis C., (Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: Generic drugs are considered the best alternative for the originator brand drugs because they have the same quality, safety, and efficacy yet offered at considerbaly lower cost. Prior research has developed instrumentation to assess patients' perceptions of generic drugs; however, little has been done to translate these measures in other languages., Objectives: This study's aim was to translate and validate an Arabic version of the generic drug scale (GMS) in a Jordanian sample. This was a cross-sectional study., Methods: The English version of the GMS was translated to an Arabic version using the standard "forward-backward" procedure of translation. The questionnaire was distributed to 225 patients. The translated version was then validated in a sample of patients. Face validity of the translated GMS was confirmed with pilot testing. Content validity of the translated GMS was evaluated by a number of pharmacists and academicians. Confirmatory factor analysis (CFA) was used to test a pre-specified relationship of observed measures., Results: The GMS consisted of two subscales: efficacy, and similarity of generic drugs to originator brand drugs. The efficacy subscale consisted of ten items while the similarity subscale consisted of six. The responses to the items were framed on five-point, Likert-type scales. The instrument demonstrated good internal consistency (Cronbach's alpha = 0.83). The range model fit was good for some fit indices. The RMSEA value was 0.08, which indicates good fit. Also, CMIN/DF indicated a good fit model with a value of 2.7, as well as GFI and CFI values of 0.95 and 0.91, respectively. NFI and CFI values were 0.92 and 0.93, respectively. Factor loadings were over 0.30 for all items, which means the scale has CFA validity indictors., Conclusions: The Arabic version of GMS was proved to be a reliable and valid measure to investigate patients' belief regarding generic drugs as it showed acceptable, internal consistency reliability, face and content validity., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Introduction: Since the introduction of tyrosine kinase inhibitors (TKIs), the treatment of patients with chronic myelogenous leukemia (CML) has resulted in significant improvement in patient survival but at a higher pharmaceutical cost to payers. The recent introduction of generic imatinib presents an opportunity to lower pharmacy costs within a population that is growing due to improved survival. Recent literature has focused on the likely benefits to payers of step therapy through generic imatinib. Areas covered: This review provides a perspective that is broader than the evaluation of financial savings or narrowly defined health economic metrics by incorporating factors such as CML patient heterogeneity, including varying levels of disease progression risk, comorbidities and genetic mutation status, differences in TKI product profiles, clinical guideline recommendations, and the importance of individualized patient care. A focused literature review evaluating the real-world impact of utilization management programs is presented. Expert commentary: The findings indicate that payers can achieve substantial savings without the need to implement utilization management policies. Compromises in the ability to provide individualized patient care and unwanted economic consequences resulting from increased costs of disease progression, adverse events, and lack of response to treatment due to utilization management are summarized.

Study Objective: Generic drugs contain identical active ingredients as their corresponding brand drugs and are pharmaceutically equivalent and bioequivalent, whereas authorized generic drugs (AGs) contain both identical active and inactive ingredients as their corresponding brand drugs but are marketed as generics. This study compares generic-to-brand switchback rates between generic and AGs., Design: Retrospective cohort study., Data Source: Claims and electronic health record data from a regional U.S. health care system., Patients: The full cohort consisted of 5542 unique patients who received select branded drugs during the 6 months prior to their generic drug market availability (between 1999 and 2014) and then were switched to an AG or generic drug within 30 months of generic drug entry. For these patients, 5929 unique patient-drug combinations (867 with AGs and 5062 with generic drugs) were evaluated., Measurements and Main Results: Ten drugs with AGs and generics marketed between 1999 and 2014 were evaluated. The date of the first generic prescription was considered the index date for each drug, and it marked the beginning of follow-up to evaluate the occurrence of generic-to-brand switchback patterns over the subsequent 30 months. Switchback rates were compared between patients receiving AGs versus those receiving generics using multivariable Cox proportional hazards models, controlling for individual drug effects, age, sex, Charlson Comorbidity Score, pre-index drug use characteristics, and pre-index health care utilization. Among the 5542 unique patients who switched from brand to generic or brand to AG, 264 (4.8%) switched back to the brand drug. Overall switchback rates were similar for AGs compared with generics (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.65-1.15). The likelihood of switchback was higher for alendronate (HR 1.64, 95% CI 1.20-2.23) and simvastatin (HR 1.81, 95% CI 1.30-2.54) and lower for amlodipine (HR 0.27, 95% CI 0.17-0.42) compared with the other drugs evaluated., Conclusion: Overall switchback rates were similar between AG and generic drug users, indirectly supporting similar efficacy and tolerability profiles for brand and generic drugs. Reasons for differences in switchback rates among specific products need to be explored further., (© 2017 Pharmacotherapy Publications, Inc.)

Because generic medicines reduce the financialburden on patients and medicalinsurance providers, they have become increasingly popular. However, there are only a few reports that have analyzed the efficacy and safety of generic medicines, especially in terms of their characteristics and side effects. Gemcitabine is an antineoplastic drug that is frequently used with good results in the treatment of lung cancer, pancreatic cancer, breast cancer, ovarian cancer, and malignant lymphoma. However, its fat solubility is high, and several adverse events, such as myelosuppression, are known to develop during its use. We investigated the efficacy, characteristics, and the incidence of adverse events for the generic versions of gemcitabine. We found differences between the generic versions in terms of the characteristics and preparation time; however, the incidence of adverse events was not significantly different, suggesting that the generic versions could be a reasonable substitute.

Oral modified-release (MR) products are dosage forms administered through the mouth and designed to release drug in a controlled manner to achieve maximum efficacy, minimal side effects, and better patient compliance. With significant progress in pharmaceutical technologies and favored therapeutic benefit, more and more oral MR products including the generic versions of these products are being developed, marketed, and used in the USA. Because different types of MR products may exhibit unique drug release modes and specific pharmacokinetic profiles, a better understanding of the regulation and evaluation of these generic MR products can help development and marketing of generic MR products that are therapeutically equivalent to the corresponding reference product. This review summarizes the general regulatory requirements for establishing bioequivalence between generic and reference oral MR products. In addition, some special regulatory considerations for bioequivalence evaluation are highlighted with examples of specific oral MR drug products.

In Japan, the development of generic oral dry powder inhaler (DPI) drug products for marketing approval has recently increased. The Pharmaceuticals and Medical Devices Agency (PMDA) considers the required data for each drug product in the consultation meeting. However, guidelines for DPI drug products have been published by the US Food and Drug Administration and the European Medicines Agency. Recently, the basic principles of bioequivalence evaluations of generic DPI drug products were published in March 2016 by the Ministry of Health, Labour and Welfare. The document mainly outlines the current understanding regarding the bioequivalence evaluations of generic DPI drug products based on knowledge from PMDA consultation meetings. In this review, we compared the bioequivalence evaluations of DPI drug products among Japan, USA, and the European Union and discuss future development of generic DPI drug products in Japan.

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., (Copyright © 2016 John Wiley & Sons, Ltd.)

Objective: We sought to examine rates of clinical outcomes among patients before and after market introduction of generic versions of five drugs approved using product-specific equivalence determinations., Methods: We used data from a large national insurer to identify patients who initiated a study (acarbose tablets, salmon calcitonin nasal spray, enoxaparin injection, vancomycin capsules, venlafaxine extended-release tablets) or control drug (nateglinide, glimepiride, alendronate, fondaparinux, metronidazole, sertraline, paroxetine) in each calendar month between 2003 and 2012 and to determine rates of claims-based proxies for lack of effectiveness outcomes following initiation. We used segmented time-series analyses to evaluate level (short-term) and slope (longer-term) changes in outcomes upon introduction of a generic study or control drug., Results: Among study drugs, we observed three increases (one with p < 0.05) and three decreases (two with p < 0.05) in the level of outcome rates. All changes in slope indicated decreases in outcomes from the brand-only to the generic period; four had p < 0.05. For control drugs, we observed positive level changes for eight of nine drug-outcome pairs; two had p < 0.05. We observed negative slope changes for eight out of nine pairs; six had p < 0.05. We observed a significant increase in level change following the introduction of generic bupropion versions that were later found to be not bioequivalent (p < 0.01)., Conclusions: We did not find evidence that introduction of generic drugs approved using product-specific therapeutic equivalence determinations was associated with worse clinical outcomes than those among initiators of the brand-name versions of the same products. We observed similar patterns for control drugs.

Objective: Clopidogrel is a commonly used antiplatelet aggregation agent. Compared with the reference clopidogrel product, most commercially available generic clopidogrel products contain different crystalline forms of clopidogrel. This study was aimed to compare the pharmacodynamics of a commonly used generic clopidogrel product in Thailand with the reference clopidogrel product under steady state conditions., Methods: A multiple-dose, randomized 2-way crossover study was conducted in 32 healthy male Thai volunteers. The subjects were assigned to receive 75 mg once daily of the test or the reference product for 7 days with a 2-week wash out period. Blood samples were collected on days 1, 5, 6, and 7 prior to drug administration and at 1, 2, 3, 4, 8, 12, and 24 hours after the last dose administered. The antiplatelet aggregation effects of clopidogrel were determined by using two different ex-vivo platelet aggregation tests including the whole blood impedance assay (WBA) and the VerifyNow ® P2Y12 assay. Both pharmacodynamic parameters, the maximal antiplatelet effect (E max ) and the areas under the antiplatelet effect-time curve (AUEC 0-24h ), were calculated., Results: Neither the mean values of E max (90.70 ± 15.15 vs. 89.50 ± 10.71% inhibition) nor of AUEC 0-24h (1,892.84 ± 657.22 vs. 1,853.58 ± 673.95% inhibition × h) under steady-state conditions obtained using the WBA method of these two clopidogrel products were significantly different. The results obtained using the VerifyNow ® P2Y12 assay were consistent with those of the WBA assay., Conclusion: This study clearly demonstrated that ex-vivo antiplatelet aggregation effect under steady-state conditions of the test product was not significantly different from the reference product.
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Recent studies have shown that the pharmacodynamic (PD) index driving the efficacy of β-lactam/β-lactamase inhibitor combinations such as ceftazidime/avibactam and ceftolozane/tazobactam is the percentage of time the free inhibitor concentration is above a threshold (fT >threshold ). However, data with piperacillin/tazobactam (TZP) are scarce. Here we aimed to assess the relationship between fT >threshold and TZP antibacterial efficacy by a population pharmacokinetic study in mice and dose-effect experiments in a neutropenic murine thigh infection model with two isogenic strains of Escherichia coli differentially expressing TEM-1 β-lactamase. We also explored the dynamics of resistance selection with the innovator and a non-equivalent generic, extrapolated the results to the clinic by Monte Carlo simulation of standard TZP doses, and estimated the economic impact of generic-selected resistance. The fT >threshold index described well the efficacy of TZP versus E. coli, with threshold values from 0.5 mg/L to 2 mg/L and mean exposures of 42% for stasis and 56% for 1 log 10 kill. The non-equivalent generic required a longer exposure (fT >threshold 33%) to suppress resistance compared with the innovator (fT >threshold 22%), leading to a higher frequency of resistance selection in the clinical simulation (16% of patients with the generic vs. 1% with the innovator). Finally, we estimated that use of TZP generics in a scenario of 25% therapeutic non-equivalence would result in extra expenses approaching US$1 billion per year in the USA owing to selection of resistant micro-organisms, greatly offsetting the savings gained from generic substitution and further emphasising the need for demonstrated and not assumed therapeutic equivalence., (Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

As lower-cost versions of original biologic drugs made by different manufacturers, follow-on biologics offer the promise of meaningful savings for the US health care system and improved patient health outcomes through greater medication adherence. Fulfillment of this promise, however, is predicated on the prescribing of such products. Under state drug product selection laws, pharmacists may substitute prescriptions for brand name, small-molecule drugs with their generic equivalents, but will be indefinitely prohibited from substituting prescriptions for original biologics with their follow-on biologic counterparts given a lack of product-specific guidance on demonstrating interchangeability. Even when interchangeable follow-on biologics become available, they will face heightened barriers to substitution following the enactment of so-called carve-outs in several states. Data collected to date suggest that a substantial proportion of US physicians remain skeptical of follow-on biologics despite their long record of safe and effective use in Europe. Active surveillance of follow-on biologics within the US market using insurance claims databases can help address this skepticism and help answer key questions concerning the safety of switching between original and follow-on products or between different follow-on products, and of extrapolating to broader indications. Funding is needed to support such surveillance activities and to disseminate the findings to key stakeholders.

Background: Drugs that exhibit close margins between therapeutic and toxic blood concentrations are considered to have a narrow therapeutic index (NTI). The Food and Drug Administration has proposed that NTI drugs should have more stringent bioequivalence standards for approval of generic formulations. However, many immunosuppressant drugs do not have a well-defined therapeutic index (TI)., Methods: We sought to determine whether safety, efficacy, and pharmacokinetic data obtained from the medical literature through a comprehensive literature search could be used to estimate the TI of cyclosporine, tacrolimus, and sirolimus. In this analysis, we considered TI ≤2 as a criterion to define a drug as having an NTI., Results: Published literature indicates that cyclosporine has a TI of 2-3, which falls just short of our criteria to be classified as having an NTI. We found sirolimus and tacrolimus to have a therapeutic range of 5-12 ng/mL and of 5-20 ng/mL, respectively, but were unable to calculate the TI., Conclusions: Although the current literature does not provide a clear indication that these drugs have an NTI, the routine use of therapeutic drug monitoring in clinical practice suggests that more stringent testing of their pharmacokinetic and pharmacodynamic properties should be performed before the approval of generic formulations.

This study aimed to evaluate the long-term efficacy and safety of a generic tacrolimus (Tacrobell [TCB]) compared to the original tacrolimus (Prograf [PGF]) in kidney transplant recipients. In this retrospective observational study, we analyzed the data from 444 patients who took TCB as a first-line immunosuppressive drug and 245 patients who took PGF. The 5-year graft survival rate was 92% for patients in the PGF group and 97% for patients in the TCB group, respectively. Cox proportional hazards for a one-sided, noninferiority model showed noninferiority (upper confidence interval [CI] limit of the hazard ratio [HR]<1.2) for TCB compared to PGF (HR: 0.58; 95% CI: 0-1.14). The 5-year patient survival rate was 96% for patients in the PGF group and 97% for patients in the TCB group. Cox proportional hazards for a one-sided, noninferiority model showed noninferiority (upper confidence interval limit of the HR<2.0) for TCB compared to PGF (HR: 0.83; 95% CI: 0-1.95). The 5-year acute rejection-free graft survival rate was not significantly different between the groups (TCB 67%, PGF 68.8%; P =0.6286). The incidence of adverse events including adverse cardiovascular or cerebrovascular events, malignancies, new-onset diabetes after transplantation, and infection events did not differ significantly between the two groups. We conclude that TCB is a comparable alternative to the original tacrolimus as a first-line immunosuppressive drug. Producers of generics should support further study of their products after approval to assure physicians of their efficacy and safety., Competing Interests: The authors report no conflicts of interest in this work.

Background: Manufacturers provide free sample medications as a means to increase use of branded medications. Sample use varies year-to-year as branded product patents expire and new products come to market., Objective: This study sought to describe the use of sample medications during 2009-2013 and assess individual characteristics associated with sample use., Methods: Data from the 2009-2013 U.S. Medical Expenditure Panel Survey (MEPS) were used. MEPS asks participants whether they received each medication they are taking as a sample. The top 10 medications and medication classes used each year by volume were identified as well as the proportion of people who used at least one sample medication. The proportion of new initiators of medications were also classified as the percent who received a sample for the specific medication. Logistic regression was used to assess individual demographics, insurance, and medication characteristics associated with use., Results: Prevalence of sample use ranged from 9.3% in 2009 to 6.2% in 2013. The most widely used sample medications included statins during 2009-2011, which changed to inhaled β-agonists in 2012-2013, as atorvastatin became available as a generic. The overall volume of the top 10 free sample medications decreased by one-third over this study period. In 2013, 12.6% of new insulin analog users and 11.0% of new oral contraceptive users receive these medications through samples. Regression analysis showed that U.S. Medicaid- and Medicare-insured persons were less likely to use samples compared to those with private insurance., Conclusions: Sample medication use has decreased as generic medications are becoming more used in the U.S., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Morniflumate is a nonsteroid anti-inflammatory drug (NSAID) that inhibits cyclooxygenase-1, 2 (COX-1, 2)., Objective: This study aimed to compare the pharmacokinetics (PKs) and assess the bioequivalence of two different formulations of morniflumate 350-mg tablets in healthy Korean male subjects., Methods: A randomized, single-dose, two-period, two-sequence crossover study was conducted with 38 subjects. Subjects received a single dose of two tablets of either a test or a reference formulation and the alternated formulation in the next period. Serial blood samples for the PK analysis were collected over 12 hours. PK parameters were determined by a noncompartment analysis. PK parameters, including the maximum concentration (Cmax) and the area under-the-concentration-time curve from time zero to the time of the last quantifiable concentration (AUClast) were compared in bioequivalence tests., Results: The Cmax of the test and reference formulations were 985.72 ± 6.80 mg/L and 947.09 ± 6.73 mg/L, respectively, while the AUClast values were 2675.92 ± 7.84 mg×h/L and 2653.06 ± 7.78 mg×h/L, respectively. The geometric mean ratios (90% confidence interval) of the test formulation to the reference formulation for Cmax and AUClast were 1.0715 (0.9469 - 1.2124) and 1.0592 (0.9592 - 1.1695), respectively., Conclusions: The new formulation of morniflumate 350-mg tablet showed a PK profile similar to that of the marketed formulation, and the results of this study fell within in the conventional criteria of bioequivalence.
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Purpose: Generic formulations are by far the most prescribed drugs. This scenario is highly beneficial for society because medication expenses are significantly reduced after expiration of the exclusivity period conceded to the branded name drug. Correspondingly, these formulations must be adequately evaluated to avoid drug inefficacy and toxicity in the overall patient population. Bioequivalence studies are the only in vivo evaluation that a generic drug must overcome to reach the market. These clinical trials have not been exempt from underrepresentation of female subjects and a lack of sex-based analysis. Frequently, conclusions obtained in men are extrapolated to women. Furthermore, the obtained results are not analyzed to determine sex differences. The aim of this study was to discuss the effect that male and female differences in gastrointestinal physiology can have on bioequivalence conclusions and to show why a sex-based analysis must be conducted in these studies to improve the evaluation of generic drugs., Methods: This discussion was based on observed sex differences in product bioavailability discrimination (sex-by-formulation interaction) and on residual variability through an analysis of average bioequivalence data previously reported by other researchers and data collected by our center. Bioequivalence studies of oral formulations, with a 2-period, 2-sequence, 2-treatment random crossover design performed in healthy subjects with at least 6 subjects of each sex, were included. In addition, the bioequivalence conclusion that would have been reached in each study if performed with only 1 sex was estimated., Findings: The data reveal that differences in both product bioavailability discrimination and residual variability occur with a significant incidence in bioequivalence studies. In either C max or AUC, a significant sex-by-formulation interaction was present in 1 of 3 reviewed studies, whereas differences in residual variability between sexes were significant for >50% of studies. Moreover, the performed estimations suggest that the reported bioequivalence conclusions were not verified in at least 1 sex for 1 of 3 studies and were not verified in men and in women for 1 of 6 studies., Implications: This research shows that extrapolation of bioequivalence results from the male population to the female population is not always valid. Bioequivalence studies must therefore be performed with both male and female subjects in similar proportions. Sex-based analysis in bioequivalence can improve study design, enhance the representativeness of conclusions, and provide important information regarding formulation performance, thereby promoting the efficacy and safety of generic drugs., (Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.)

Generic medicines were developed to increase population access to health treatment, to reduce costs and to allow drugs with the same outcomes to be purchased at lower prices. They are therapeutically equivalent to their brand-name counterparts and are interchangeable with them. However, the acceptance of generic medicines by physicians and general consumers is often affected by distrust related to quality and efficacy. In this study three different brands of generic amoxicillin were tested. The results showed that two of them were indistinguishable from the innovator in terms of microbiological potency; however, generic B was unable to reach the Brazilian Pharmacopoeia specifications for potency limits. In contrast, generic B was bioequivalent to the innovator amoxicillin in pharmacokinetic assessment and, surprisingly, generic A, which was approved in the microbiological potency assay, lacked pharmacokinetic equivalence compared with the innovator. Both tests, when used singly, may not be effective at detecting quality deviations in antimicrobial medicines, which indicates that pharmacokinetic tests in rats in association with microbiological potency assays are a valuable tool for post-marketing surveillance of generic antibiotics., (Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)