Brand-name Users Research Articles

Public Health Outcomes May Differ After Switching from Brand-Name to Generic Angiotensin II Receptor Blockers.

BackgroundIt is unclear whether generics are as safe as brand-name drugs in cardiology. For public health surveillance purposes, we evaluated if switching from the brand-name losartan, valsartan, or candesartan impacted the occurrence of the following outcomes: emergency room (ER) consultations, hospitalizations, or death.Study DesignThis was a retrospective cohort study.MethodsThis study was conducted in the Quebec Integrated Chronic Disease Surveillance System, including healthcare administrative data of the population of Quebec, Canada. We included brand-name users of losartan, valsartan, or candesartan aged ≥ 66 years who had undergone ≥ 30 days of stable treatment on the brand-name drug prior to cohort entry (substitution time-distribution matching was used to prevent immortal time bias). Outcomes up to 1 year were compared between groups using multivariable Cox proportional hazards regression models (validity assumptions were verified).ResultsIn our cohorts (losartan, n =15,783; valsartan, n =16,907; candesartan, n =26,178), mean age was 76–78 years, 59–66% were female, 90–92% had hypertension, and 13–15% had heart failure. Validity assumptions were violated for losartan only. For patients switched to generic valsartan, the hazard ratio (95% confidence interval) was 1.07 (0.99–1.14) for ER consultation, 1.26 (1.14–1.39) for hospitalization, and 1.01 (0.61–1.67) for death. The corresponding rates for candesartan were 1.00 (0.95–1.05), 0.96 (0.89–1.03), and 0.57 (0.37–0.88), respectively.ConclusionsWe observed an increased risk of hospitalizations for patients switched to generic valsartan, and a decreased risk of death for patients switched to generic candesartan, compared with those who continued taking the brand-name drug. The differences between generic and brand-name drugs may lead to some differences in public health outcomes, but this safety signal must be further studied using other cohorts and settings.Electronic supplementary materialThe online version of this article (10.1007/s40268-020-00307-2) contains supplementary material, which is available to authorized users.

The effect of inertia on brand-name versus generic drug choices

Consumers’ tendency to repurchase products is called inertia. This study investigates inertia in brand-name and generic drug choices, which is manifested by the slow and limited adoption of generic drugs despite their lower prices. We use claims data from Japan and focus on the generic entry of a widely prescribed lipid-lowering drug, Pitavastatin. Observing the periods before and after the generic entry gives us a unique opportunity to identify the effect of inertia. We construct a choice model that incorporates price, heterogeneous brand preferences, and inertia to quantify each component's magnitude. We find that both inertia and heterogeneity in brand preferences have substantial effects. Counterfactual simulations suggest that a nudging policy that removes inertia from previous brand-name users, such as by alerting the patients to switch to cheaper generic drugs, may have substantial effects and enable patients to choose optimally.

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

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. We aimed to evaluate the impact of generic clopidogrel commercialization on adverse events (AEs): hospitalizations or emergency room (ER) consultations. This is an interrupted time series analysis using the Quebec Integrated Chronic Disease Surveillance System. We included all patients ≥ 66years old who were users of the brand-name clopidogrel or a generic version (n = 6) 24months before and up to 12months 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 usingstratification of the time series by (1) sex, (2) the number of prevalent cardiovascular comorbidities, and (3) socioeconomic status. Time series were constituted of 89,525 clopidogrel users (mean age 78years, 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 1year. Sensitivity analyses yielded similar results. The population treated withclopidogrel 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.

PUBLIC HEALTH SURVEILLANCE REVEALS AN INCREASE IN HEALTH CARE UTILIZATION FOR GENERIC VS. BRAND-NAME WARFARIN USERS

Even with nowadays many direct oral anticoagulant options, brand-name or generic warfarin is still widely used to prevent atherothrombotic events in cardiology. Federal standards regulate bioequivalence of generic vs. brand-name drugs through comparative bioavailability studies but do not regulate clinical equivalence or tolerability in “real-life” settings. Through our public health surveillance system, we have evaluated the impact of the generic warfarin commercialization on health care utilization: emergency room (ER) consultations or hospitalizations. We did an interrupted time series analysis using the Québec Integrated Chronic Disease Surveillance System, a surveillance system of the second most populous province in Canada (∼8.3 million in 2016). Rates of health care utilization for warfarin users (n=280,158) aged ≥ 66 years were calculated for six-month periods, five years before and up to 15 years after warfarin commercialization (from January 1996 to January 2016). Periods before and after generic warfarin commercialization were compared by negative binomial segmented regression models for all users with a specific variable for generic or brand-name users. Sensitivity analyses were also conducted. Generic warfarin analogs were first reimbursed on January 2, 2001. Over the 20-year period, there was a mean rate of 113 ER or hospitalizations for 100 brand-name or generic users per six-month period, similar before and after generics arrival. After onset of generics reimbursement, there was an immediate increase in rates of health care utilization for generic vs. brand-name users (difference-hospitalizations: 8.0% [95% confidence interval: 1.5% to 14.6%]; ER consultations: 9.1% [4.2% to 14.1%]). Rates of health care utilization remained higher for generic vs. brand-name users up to 15 years after generic warfarin reimbursement, with parallel trends for both outcomes (difference: 0.0% [0.0% to 0.1%]). Sensitivity analyses confirmed the results. Among generic warfarin users, we observed increased rates of health care utilization six months after generics commercialization. Risk and survival analysis studies controlling for potential confounders are required to better characterize generic substitution, as stricter licensing process may be required.

Abstract P146: Public Health Surveillance Reveals an Increase in Health Care Utilization for Generic versus Brand-name Warfarin Users

Background: Even with many direct oral anticoagulant options, brand-name or generic warfarin is still widely used to prevent atherothrombotic events in cardiology. Federal standards regulate bioequivalence of generic vs. brand-name drugs through comparative bioavailability studies but does not regulate clinical equivalence nor tolerability in a “real-life” settings. Through public health surveillance, we have evaluated the impact of the generic warfarin commercialization on health care utilization: emergency room (ER) consultations or hospitalizations. Methods: We used an interrupted time series analysis using the Quebec Integrated Chronic Disease Surveillance System, a surveillance system from the second populous province in Canada (~8.3 million in 2017). Rates of health care utilization for warfarin users (n=280,158) aged ≥ 66 years were calculated for 6-month periods, 5 years before up to 15 years after warfarin commercialization (from January 1996 to January 2016). Periods before and after generic warfarin commercialization were compared by negative binomial segmented regression models for all users with a specific variable for generic or brand-name users. Sensitivity analyses were also conducted. Results: Generic warfarin analogs (n=5) were commercialized from January 2001. There was an approximated mean rate of 1134 ER or hospitalizations for 1000 brand-name and generic users per 6-month period, similar before and after generics commercialization. After generics commercialization, there was an immediate increase in rates of health care utilization for generic (9.9%) vs. brand-name users (0%), a statistically significant difference (9.9% [95% confidence interval: 4.4% to 15.5%], p = 0.0001). Rates of health care utilization remained stable and higher for generic vs. brand-name users throughout the period after generics commercialization. Conclusion: Among generic warfarin users, we observed an increased rates of health care utilization soon after generics commercialization. Risk and survival analysis studies controlling for potential confounders are required to deepen this pharmacovigilance signal as stricter licensing process may be required.

Abstract P250: Emergency Room Consultations and Hospitalizations Following Generic Clopidogrel Commercialization in Quebec, Canada

Background: Clopidogrel is widely used to prevent atherothrombotic events. Federal standards regulate bioequivalence of generic and brand-name drugs through comparative bioavailability studies but does not regulate clinical equivalence nor tolerability in “real-life” settings. We evaluated the impact of the generic clopidogrel commercialization on some adverse events: emergency room consultations (ER) or hospitalizations. Methods: This is an interrupted time series analysis using the Quebec Integrated Chronic Disease Surveillance System. Rates of adverse events for clopidogrel users (n=75,130) aged ≥ 66 years were calculated monthly, 12 months before and 12 months after generics commercialization. Periods before and after generics commercialization were compared by negative binomial segmented regression models for all users with a specific variable for generic and brand-name users after generics commercialization. Results: Generic clopidogrel analogs (n=6) were commercialized in 2012. There was an approximated monthly mean rate of 157 adverse events per 1000 brand-name and generic users-month. After generics commercialization, there was an immediate increase in rates of adverse events for generic vs. brand-name users (22 vs. 2%, p < 0.0001, Figure 1). This was explained by increased rates of ER (+22%) and hospitalizations (+20%) the month of generic clopidogrel commercialization. Hospitalization trend up to 1 year after generics commercialization was stable for generic users but reduced for brand-name users (-0.9 vs. -2.9%, p = 0.01), while ER trends were comparable (-1.1 vs. -1.8%, p = 0.2443). Conclusion: Among generic clopidogrel users, increased rates of ER and hospitalizations were observed soon after generics commercialization. The trend of hospitalizations was also affected following generic clopidogrel commercialization. Risk and survival analysis studies controlling for potential confounding are required to better characterize generic substitution.

Abstract 12799: Hospitalizations and Emergency Consultations Following Generic Antihypertensive Drugs Commercialization in Quebec

Introduction: Once patent of a brand-name drug expires, generic drugs are commercialized and substitution may occur. Few studies have assessed clinical impacts of generic drugs commercialization at a population level. Objective: We evaluated the impact for three generic versions of antihypertensive drugs on adverse events: hospitalizations and emergency room consultations. Methods: This is an interrupted time series analysis using the Quebec Integrated Chronic Disease Surveillance System. The rate of adverse events for losartan (brand-name and 8 generics), valsartan (brand-name and 5 generics) and candesartan (brand-name and 3 generics) users aged ≥ 66 years (all: N=121 185 citizens) were calculated monthly, 12 months before and 12 months after generics commercialization. Periods before and after generics commercialization were compared with negative binomial segmented regression models for all users with a specific variable for generic and brand-name users. Results: There was an approximated monthly mean rate of 100 adverse events for 1000 exposed person-months to losartan, valsartan and candesartan. Monthly trend of adverse events was affected by generics commercialization. Generic users of losartan, valsartan and candesartan showed increased rate of adverse events of 11% (p=0.0034), 9% (p=0.0024) and 13% (p=0.0008) respectively right after generics commercialization (Figure 1) which was always higher compared to brand-name users (p<0.05). The monthly trend of hospitalizations was affected for losartan users up to 1 year after generics commercialization (generics: +1.2%, brand-name: -2.2, p=0.0094). Conclusion: Generics commercialization impacted population rates of adverse events. A significant adverse events increase was observed right after generics commercialization for all antihypertensive drugs studied, among generic users. More studies are required to identify differences in drugs or users, which could explain this increase.

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

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. 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 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. 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.