Are Generic Drugs Used in Cardiology as Effective and Safe as their Brand-name Counterparts? A Systematic Review and Meta-analysis

Choice intention for the national volume-based procurement drug and its associated factors: a cross-sectional study on patients with late-life depression in China

BACKGROUND

The national volume-based procurement (NVBP) policy has significantly decreased prices and increased the accessibility of NVBP drugs. Nevertheless, issues such as heightened adverse reactions and suboptimal efficacy have arisen. Concerns regarding the quality of low-cost medications and the absence of long-term research have been widely recognized. This has led to caution among patients with late-life depression (LLD) due to their delicate health and the severity of their condition. This study evaluated the choice intention for NVBP drugs and associated factors in older patients with LLD.

METHODS

A weighted sample of 408 participants between December 2022 and March 2023 were included. Data were collected via face-to-face interviews and questionnaires. To identify significant associated factors of choice intention, a multilevel logistic regression model was employed.

RESULTS

Over half (53.68%) of older patients with LLD intended to choose NVBP drugs. Associated factors included self-assessed poor economy, higher out-of-pocket expenses, monthly household income exceeding CNY 6000, absence of other non-communicable chronic diseases, ordinary registration, urban employee medical insurance, no requirements for brand-name drugs, adverse reactions after using NVBP drugs, and rejection of physicians' recommendation for NVBP drugs. The interaction effect between the real economic condition and patients self-assessed economy significantly influences choice intention for NVBP drugs. Among 124 patients with self-assessed poor economy, 75 showed a higher intention to use NVBP drugs. In these patients, age, medical insurance reimbursement, and brand awareness were significantly associated with choice intention.

CONCLUSION

Economic factors, physical conditions, medical needs, and physician recommendations significantly influenced the choice intention for NVBP drugs. The choice intention can be improved by strengthening physician-patient communication, increasing the scope and proportion of medical insurance reimbursement, improving substitution studies, and conducting post-marketing re-evaluations of NVBP drugs.

Generic substitution of amlodipine is not associated with increased risk of mortality or adverse cardiovascular events: An observational cohort study

This study aims to assess clinical outcomes following switching from originator to generic amlodipine. This population-based, matched, cohort study included users of originator amlodipine using claims data during 2018-2020 from a health system in Tianjin, China, in which usage of generic amlodipine was promoted by a drug procurement policy, the national volume-based procurement. Non-switchers refer to those remained on originator after the policy, while pure-switchers were those who switched to and continued using generic amlodipine, and back-switchers were those switched to generic amlodipine but then back to the originator. Propensity score matching generates comparable non-switchers and pure-switchers pairs, and non-switchers and back-switchers pairs. The primary outcome was major adverse cardiovascular events (MACEs), defined as all-cause mortality, stroke, and myocardial infarction during follow-up (April 1, 2019 to December 30, 2020). Secondary outcomes included heart failure, atrial fibrillation, and adherence to amlodipine. The hazard ratio (HR) for each clinical outcome was assessed through Cox proportional hazard regression. In total, 5943 non-switchers, 2949 pure-switchers, and 3061 back-switchers were included (mean age: 62.9 years; 55.5% men). For the matched pairs, pure-switchers (N = 2180) presented no additional risks of clinical outcomes compared to non-switchers (N = 4360) (e.g., MACEs: 2.86 vs. 2.95 events per 100 person-years; HR = 0.97 [95%CI: 0.70-1.33]). Back-switchers (N = 1998) also presented no additional risk compared to non-switchers (N = 3996) for most outcomes except for stroke (HR = 1.55 [95%CI: 1.03-2.34]). Pure-switchers and back-switchers all had better amlodipine adherence than non-switchers. Generic substitution of amlodipine is not associated with increased risk of cardiovascular events or all-cause mortality, but improves medicine adherence.

Real-World Clinical Equivalence of Generic and Branded Tofacitinib: A Prospective Longitudinal Cohort Study in Patients With Rheumatoid Arthritis

OBJECTIVES

To explore the clinical efficacy and safety of generic tofacitinib vs brand name tofacitinib in patients with rheumatoid arthritis (RA) in a single-center comparative study based on a prospective real-world cohort.

METHODS

Patients with RA receiving tofacitinib, either generic (Kelejia) or branded (Xeljanz), from March 2017, to December 31, 2022, were enrolled. The primary outcome was the simplified disease activity index (SDAI)-defined remission rate at month 6. Secondary outcomes included the rates of remission and low disease activity defined by other composite scores; European Alliance of Associations for Rheumatology response rate, and ultrasonic synovitis scores at months 1, 3, 6, and 12. Cost-effectiveness was investigated. Propensity score-based inverse probability of treatment weighting was adopted to reduce selection bias.

RESULTS

A total of 204 patients were enrolled: 59 in the generic group and 145 in the branded group. An SDAI-defined remission was achieved in 41.1% and 39.2% of patients in the generic and branded groups, respectively, at month 6 (P=.85). Rates of remission and low disease activity achievement, changes in clinical disease activity scores, and power Doppler and gray scale synovitis scores at months 1, 3, 6, and 12 were comparable between the 2 groups. Similar proportions of patients in the groups achieved moderate/good response at months 1, 3, 6, and 12. Rates of drug retention and adverse effects were also similar in the 2 groups. Both Kelejia and Xeljanz were cost-effective, but Kelejia had a lower average cost-effectiveness ratio.

CONCLUSION

Generic tofacitinib (Keljia) had equivalent clinical efficacy and safety and better cost-effectiveness compared with its originator (Xeljanz).

Clinical outcomes of generic versus brand-name clopidogrel for secondary prevention in patients with acute myocardial infarction: A nationwide cohort study

Skepticism exists among healthcare workers and patients regarding the efficacy and safety of generic medication, despite its potential to lower healthcare costs. This study aimed to compare the outcomes of a generic clopidogrel and its brand-name counterpart for secondary prevention in patients with acute myocardial infarction (AMI). Using the Taiwan National Health Insurance Research Database, we identified 49,325 patients who were hospitalized for AMI between January 1, 2008 and December 31, 2013 and prescribed either generic or brand-name clopidogrel. Among them, 2419 (4.9%) were prescribed the generic clopidogrel. After propensity score matching, both the generic and brand-name groups consisted of 2382 patients. The primary efficacy outcome was a composite of myocardial infarction, coronary revascularization, ischemic stroke, and all-cause death. The primary safety outcome was major bleeding requiring hospitalization. At a mean follow-up of 2.5 years, the generic and brand-name clopidogrel groups had comparable risks of primary efficacy outcome (41.9% vs. 42%; hazard ratio [HR] 0.96; 95% confidence interval [CI] 0.88-1.04), and the risks of the individual components were also similar. There were no significant differences between the two groups in major bleeding (7.9% vs. 7.9%; HR 0.99; 95% CI 0.81-1.21). Subgroup analyses also revealed no statistically significant interactions between the treatment effect and various subgroups. In this retrospective database analysis, the generic clopidogrel was comparable to its brand-name counterpart regarding cardiovascular and bleeding outcomes for the treatment of patients with AMI.

Comparative effectiveness of generic nifedipine versus Adalat long-acting nifedipine for hypertension treatment: A multi-institutional cohort study

This retrospective multi-institutional database analysis aimed to evaluate the blood-pressure-lowering efficacy and clinical outcomes of a generic versus brand-name nifedipine for hypertension management. A total of 12 693 patients who were prescribed a generic or brand-name nifedipine between January 1, 2011, and December 31, 2018, were identified from the Chang Gung Research Database of Chang Gung Memorial Hospitals, Taiwan. Among them, 2112 (21.4%) were prescribed generic nifedipine. After propensity score matching, both the generic and brand-name groups consisted of 2102 patients. At a mean follow-up of 3 years, the changes in office systolic (p for interaction = .791) and diastolic blood pressure (p for interaction = .689) did not differ significantly between the patients who received the generic and the brand-name nifedipine. There was no significant difference between the two study groups regarding the composite of all-cause mortality, acute myocardial infarction, stroke, coronary revascularization, or hospitalization for heart failure (hazard ratio 0.98, 95% confidence interval 0.85-1.13; p = .774). In conclusion, the generic nifedipine was comparable to its brand-name counterpart regarding office blood pressure reduction and the composite cardiovascular outcome for the treatment of patients with hypertension.

Clinical Outcome and Medical Cost of Originator and Generic Antihypertensive Drugs: A Population-Based Study in Yinzhou, China

Background: The substitution of generic drugs can effectively alleviate the rapid growth of drug costs; however, the clinical effectiveness and medical costs of originator products and generics were barely studied in China.

Objectives: To compare the effectiveness of antihypertensive drugs and hypertension-related medical costs between originator and generic initiators in Yinzhou, China.

Methods: We conducted a population-based retrospective cohort study using the Chinese Electronic Health Records Research in Yinzhou (CHERRY), from July 1, 2011, to December 31, 2018. Hypertension patients initiating with originator products were compared with patients initiating with generic counterparts. We used 1:1 propensity score matching to pair the two groups based on sociodemographic, clinical, and health service utilization variables. Cox proportional regression was adopted to compare the rate of hospitalization for hypertension-related cardiovascular disease between matched originator and generic initiators. Wilcoxon matched-pairs signed-rank test was used to compare annual hypertension-related medical costs.

Results: Matched pairs (10,535) of patients were included in the comparative study of originator products and generics, corresponding to seven antihypertensive drugs including amlodipine, felodipine, nifedipine, irbesartan, losartan, valsartan, and metoprolol. The average age of patients included in the analysis was around 60 years (originator vs. generics initiators: from 59.0 vs. 59.1 years in losartan to 62.9 vs. 63.6 years in nifedipine). Higher hospitalization rates among originator initiators were observed for three calcium channel blockers (hazard ratio[95% CI]: amlodipine, 3.18[1.43, 7.11]; felodipine, 3.60[1.63, 7.98]; and nifedipine, 3.86[1.26, 11.81]; respectively). The remaining four out of seven drugs of the clinical endpoint estimates showed comparable outcomes between originator products and generics (hazard ratio[95% CI]: irbesartan, 1.19[0.50, 2.84]; losartan, 1.84[0.84, 4.07]; valsartan, 2.04[0.72, 5.78]; and metoprolol, 1.25[0.56, 2.80]; respectively). Higher median annual hypertension-related medical costs were observed in originator initiators (all p < 0.001), except for metoprolol (p = 0.646).

Conclusion: We observed comparable or even better clinical outcomes and less medical cost associated with the use of antihypertensive generics compared to originator counterparts. This could help increase patient and provider confidence in the efficacy of generic medicines to manage hypertension diseases.

Clinical equivalence of generic and brand-name drugs used in cardiology: what do we know?

The problem of using generics in the treatment of patients with cardiovascular diseases remains relevant for more than a decade. The concern of doctors, pharmacists and patients is not diminishing with the constant rise in cardiovascular morbidity and mortality worldwide. Based on a systematic review of 186 publications, physicians identified concerns about the quality, reliability and replaceability of original drugs; pharmacists have shown the highest level of generic approval. Patients distrust of generics was revealed, caused by a lack of information, concerns about packaging, and negative experience of replacing the original drug. Three meta-analyzes compared generic and original drugs of cardiovascular groups in terms of efficacy and safety. A 2008 meta-analysis (47 studies, 9 classes of cardiovascular drugs) assessed the effect on mild outcomes, a 2016 meta-analysis (74 studies, 7 classes of drugs) also assessed side effects. The cumulative effect revealed a small and nonsignificant difference, which indicated that there was no superiority of original drugs over generics; there were no differences in the frequency and severity of side effects between generics and original drugs. A 2020 meta-analysis (72 studies, 9 drug classes) assessed the frequency of hospital admissions (including emergency department consultations, hospitalizations) and found a significant increase in the risk for generics for any reason (14%), but not for cardiac vascular diseases. A review of 8 cohort studies evaluating antihypertensive drugs for long-term cardiovascular outcomes, duration of retention, and substitution effect did not find significant differences between generics and brands. In a systematic review of studies comparing warfarin and generics, there were no significant differences in international normalized ratio and the incidence of thromboembolic and hemorrhagic complications; however, in one study, the frequency of hospital visits was 10% higher for generics. A systematic review of studies comparing clopidogrel versus generics shows drug comparability for major cardiovascular events and mortality. A review of 5 cohort studies evaluating originator statins and generics showed comparable rates of all-cause mortality and major cardiovascular events, except for one study with conflicting results. Meta-analyzes and large observational studies indicate that generics are not the worst efficacy, sometimes even surpass that of original drugs and can be justifiably used in clinical practice.

Pharmacokinetics and Generic Drug Switching: A Regulator's View

There appears to be a mismatch between the assumed therapeutic equivalence of generic drugs, their interchangeability, and reported clinical discomfort following generic drug use and drug switches. In this article, we describe why we are of the opinion that the current regulatory approach to the evaluation of generic drugs based on average bioequivalence is sufficient to expect therapeutic equivalence in the clinical setting. This has often been debated, specifically as adverse drug reactions related to generic drug switches are regularly reported. We agree that clinical discomfort during a bioequivalent drug switch may indeed be caused by different exposures to the active substance. However, this difference in exposure is not a result of the characteristics or quality of generic drugs; it is caused by the pharmacokinetic within-subject variability of the active substance, i.e., the variability on the bioavailability of the active substance, when comparing two occasions of administration of the same drug product, to the same patient. Therefore, reported clinical discomfort following generic drug use and drug switches does not warrant a change in the regulatory approach to the evaluation of the bioequivalence of generic drugs. Switching from a brand-name drug to currently approved generic drugs, or between different generic drugs, will in principle result in comparable exposure, within boundaries determined by the within-subject variability of the pharmacokinetics of the active substance involved.

Using Data from the Canadian Post-marketing Spontaneous Pharmacovigilance System for Drug Safety Research: A Feasibility Study

INTRODUCTION

Post-marketing studies involve the detection and interpretation of potential problems associated with the use of a given drug. Post-marketing spontaneous pharmacovigilance systems, such as the Canada Vigilance program, may constitute a gold mine of free data for drug safety research. However, the quantity and the quality of data remain to be demonstrated.

OBJECTIVE

To assess the feasibility to use the Canada Vigilance database for academic drug safety research, and to document the characteristics of data that are extractable.

METHODS

This is a descriptive retrospective analysis study design. The beta-blocker and anticoagulant adverse reactions (AR) in Canada were analyzed. Tests for data extraction from the Canada Vigilance database were performed in October 2019; data were then available from January 1, 1966 to June 30, 2019.

RESULTS

There were 41 variables with extractable data. For anticoagulants, data were extracted in Excel and.pdf file format, while it was only plain text.pdf files for beta-blockers. Overall, there were 4707 reported ARs with the use of anticoagulants and 6332 cases reported for beta-blockers. The trend of ARs related to anticoagulants steadily increased in the study period, with a notable increase in 2009 while direct oral anticoagulants were marketed. The proportion of missing data varied from 0 to 98%, but most important variables were all available. It was not possible to distinguish brand names and generic drugs in the database.

CONCLUSION

It seems feasible to use data from the Canadian Post-marketing Spontaneous Pharmacovigilance System for academic drug safety research. Upcoming studies should validate the quality of reports compared to actual medical charts.