Comparison of Outcomes Following a Switch From a Brand to an Authorized Versus Independent Generic Drug

Abstract

Authorized generics are identical in formulation to brand drugs, manufactured by the brand company but marketed as a generic. Generics, marketed by generic manufacturers, are required to demonstrate pharmaceutical and bioequivalence to the brand drug, but repetition of clinical trials is not required. This retrospective cohort study compared outcomes for generics and authorized generics, which serves as a generic vs. brand proxy that minimizes bias against generics. For the seven drugs studied between 1999 and 2014, 5,234 unique patients were on brand drugs prior to generic entry and 4,900 (93.6%) switched to a generic. During the 12 months following the brand-to-generic switch, patients using generics vs. authorized generics were similar in terms of outpatient visits, urgent care visits, hospitalizations, and medication discontinuation. The likelihood of emergency department (ED) visits was slightly higher for authorized generics compared with generics. These data suggest that generics were clinically no worse than their proxy brand comparators.

Bioequivalence and Therapeutic Equivalence of Generic and Brand Bupropion in Adults With Major Depression: A Randomized Clinical Trial

“…In addition, single‐dose studies in healthy volunteers may not predict steady‐state bioequivalence in patients, particularly for modified‐release forms . Administrative claims data and health records can be used to surveil health services use and drug discontinuation after brand‐to‐generic switching, along with other postmarketing data, as surrogates for equivalence testing. However, there are relatively few randomized trials, like the present one, comparing clinical outcomes of generic and brand drugs …”

Impact of brand drug discount cards on private insurer, government and patient expenditures

“…This occurs despite the fact that, in most cases, it is not necessary to use the brand name version of a drug molecule when a generic alternative is available, as evidenced by many studies showing clinical equivalence between branded products and their generic counter parts. [14][15][16] Finally, we observed much heterogeneity in the impact on cash payments by patients, which likely resulted from different adjudication rules for different medications.…”

Healthy User Bias in Comparative Safety Studies for Brand‐Name vs. Generic Products: The Example of Warfarin

“…A recent study contrasting Authorized Generics vs. their generic counterparts found similar rates of outpatient visits, urgent care visits, hospitalizations, and medication discontinuation. 22 This contrasts with the comparison of brand-name warfarin to generic warfarin, where no Authorized Generic was available, and large differences in patient characteristics were observed between users of different warfarin products.…”