Salts of Clopidogrel: Investigation to Ensure Clinical Equivalence: A 12-Month Randomized Clinical Trial

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

BACKGROUND

Previous systematic reviews (2008; 2016) concluded similarity in outcomes between brand-name and generic drugs in cardiology, but they included ≥ 50% comparative bioavailability studies, not designed or powered to detect a difference in efficacy or safety between drug types. We aimed to summarise best-evidence regarding the effectiveness and safety of generic versus brand-name drugs used in cardiology.

METHODS

For this systematic review of the literature, scientific databases (MEDLINE and EMBASE) were searched from January 1984 to October 2018. Original research reports comparing the clinical impact of brand-name versus generic cardiovascular drugs on humans treated in a real-life setting, were selected. Meta-analyses and subgroup analyses were performed. Heterogeneity (I²) and risk of bias were tested.

RESULTS

Among the 3148 screened abstracts, 72 met the inclusion criteria (n ≥ 1,000,000 patients, mean age 65 ± 10 years; 42% women). A total of 60% of studies showed no difference between drug types, while 26% concluded that the brand-name drug was more effective or safe, 13% were inconclusive and only 1% concluded that generics did better. The overall crude risk ratio of all-cause hospital visits for generic versus brand-name drug was 1.14 (95% confidence interval: 1.06-1.23; I²: 98%), while it was 1.05 (0.98-1.14; I²: 68%) for cardiovascular hospital visits. The crude risk ratio was not statistically significant for randomised controlled trials only (n = 4; 0.92 [0.63-1.34], I²: 35%).

CONCLUSION

The crude risk of hospital visits was higher for patients exposed to generic compared to brand-name cardiovascular drugs. However, the evidence is insufficient and too heterogeneous to draw any firm conclusion regarding the effectiveness and safety of generic drugs in cardiology.

The incidence of recurrent cardiovascular events among acute coronary syndrome patients treated with generic or original clopidogrel in relation to their sociodemographic and clinical characteristics. The Aegean study

INTRODUCTION

The use of generic drugs is continuously growing; however, there are limited epidemiological data regarding the therapeutic equivalence of each original drug formulation with its generic counterparts. We evaluated the 12-month composite endpoint of recurrent acute myocardial infarction, ischaemic stroke, cardiac deaths, or hospitalisation due to a major bleeding in acute coronary syndrome (ACS) patients treated with original clopidogrel or a generic clopidogrel formulation, in relation to sociodemographic and clinical characteristics.

MATERIAL AND METHODS

Consecutive Greek ACS patients (n = 1194) hospitalised in the Aegean islands and the Attica region were enrolled. Clopidogrel treatment was recorded either as original clopidogrel hydrogen sulphate (Plavix^®/Iscover^®) or as a generic clopidogrel besylate formulation (Clovelen^®). The composite endpoint was recorded at 12-month follow-up.

RESULTS

The 12-month composite endpoint was 3.9% (4.6% in the Aegean islands and 3.5% in the Attica area, p > 0.05). The respective incidence in men was 4.0% and in women 3.8% (p > 0.05). Overall, generic and original clopidogrel use was 87% and 13% of patients, respectively. No significant differences were observed between original and generic clopidogrel use and 12-month composite endpoint incidence. Subgroup analysis with gender, region of residence, and clinical and lifestyle factors as strata did not reveal any significant outcomes. Haemorrhage incidence did not exceed 1% in the total sample.

CONCLUSIONS

The use of a generic clopidogrel besylate formulation was quite high in both urban and insular areas of Greece and had similar efficacy and safety profile with the original clopidogrel salt, supporting the routine use of this low-cost generic clopidogrel in the management of cardiovascular disease patients.

Did Generic Clopidogrel Commercialization Affect Trends of ER Consultations and Hospitalizations in the Population Treated with Clopidogrel?

BACKGROUND

Clopidogrel has been widely used to prevent atherothrombotic events. Since 2011, pharmacists have offered their patients the opportunity to switch to generic clopidogrel, an economic alternative. Whether bioequivalence of generic cardiovascular drugs translates into clinical equivalence at a population level remains unclear and needs to be further documented.

OBJECTIVE

We aimed to evaluate the impact of generic clopidogrel commercialization on adverse events (AEs): hospitalizations or emergency room (ER) consultations.

METHODS

This is an interrupted time series analysis using the Quebec Integrated Chronic Disease Surveillance System. We included all patients ≥ 66 years old who were users of the brand-name clopidogrel or a generic version (n = 6) 24 months before and up to 12 months after generics commercialization. Rates of AEs were computed, and periods before and after generics commercialization were analyzed by segmented regression models along with exploratory analyses (generic vs. brand name). Sensitivity analyses were also performed using stratification of the time series by (1) sex, (2) the number of prevalent cardiovascular comorbidities, and (3) socioeconomic status.

RESULTS

Time series were constituted of 89,525 clopidogrel users (mean age 78 years, 45% women, 71% ischemic heart disease, 34% stroke). For all users, there was a mean rate of 157 AEs per 1000 user-months, stable trend before (-0.1% [95% confidence interval -0.3 to 0.1] and after (0.0% [- 0.5 to 0.6]) generics commercialization. In exploratory analyses, once generic clopidogrel versions were commercialized, rates of AEs were 19.2% (95% CI 11.7-26.7) higher for generic versus brand-name users. This difference persisted up to 1 year. Sensitivity analyses yielded similar results.

CONCLUSIONS

The population treated with clopidogrel had similar rates of hospitalizations or ER consultations before and after generics commercialization. However, differences in rates of hospitalizations or ER consultations between generic and brand-name clopidogrel users may represent a drug safety signal which remains to be validated. Using a different study design, permitting adjustment for potential confounders, could be useful in this regard.

Comparison of 4 different strategies of DAPT after PCI in ACS real world population from a Northern Italy registry

Aim of the study was to compare four different strategies of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes (ACS) treated with PCI. DAPT with Clopidogrel, Ticagrelor and Prasugrel has proved to be effective in patients with ACS treated with percutaneous coronary intervention (PCI) by reducing major adverse cardiovascular outcomes (MACE). However, the effect of the different strategies in a real-world population deserves further verification. A retrospective analysis of 2404 discharged ACS patients treated with PCI was performed, with a median follow-up of 1 year. The study population was stratified in four drug treatment cohorts: ASA + Clopidogrel (A-C), ASA + Plavix (A-PLx), ASA + Ticagrelor (A-T), ASA + Prasugrel (A-P). We assessed the incidence of net adverse cardiovascular events (NACE): all-cause death, myocardial infarction (MI), target vessel revascularization (TVR), stroke and bleeding during follow-up. At 1-year, the use of A-C and A-PLx was associated with the highest cumulative incidence of NACE in comparison with A-T and A-P therapies (respectively 14.8 and 29.6% vs. 9.2 and 6%). This difference was mainly driven by the mortality and TVR outcomes. Considering selection bias and differences in the patients baseline characteristics, the association of A-T and A-P seems to be superior in comparison with a DAPT strategy of A-C and A-PLx in low risk ACS-PCI patients from real world. In our Region the prescription is consistent with guidelines recommendations and Clopidogrel and Plavix are still predominantly used in older patients with more comorbidities, and this could partially explain the inferiority of this association.