Patient perceptions of different generic products may influence the rates of switchbacks to branded drugs. A recent study published in the BMJ analyzed which type of generic drugs demonstrated higher switchback rates.
Generic drugs contain the same active ingredients as their branded counterparts but may have a different appearance. Authorized generic drugs have identical appearances and contain the same non-medicinal ingredients compared to their branded counterparts because they are manufactured by the same pharmaceutical company. Patient negative perceptions towards generic drug efficacy and safety, due to their lower cost, influences their decision to stick to branded products only. This may lead to non-adherence to medication therapy and an important financial burden.
Authorized generic drugs vs. generic drugs
Authorized generic drugs are prescription drugs manufactured by pharmaceutical companies and marketed under a private label and sold at generic prices. It is an approved brand-name drug that is marketed without the brand-name label. Generic drugs are the same as a brand-name drug in its dosage, strength, safety, quality, performance, intended use, and method of administration, but it may have small differences, like the composition of its inactive ingredients.
Researchers at the Division of Pharmacoepidemiology and Pharmacoeconomics at the Brigham and Woman’s Hospital in the United States hypothesized that there would be lower switchback rates between authorized generic drugs compared with generic drugs with a different appearance. They collected switchback data for eight drug products from 2004-2013 from a large national US health insurance database. The results of this study were published in the British Medical Journal.
Within the six-month period after market entry of a generic equivalent, the use of authorized generic and generic drug products represent the majority of drug use in the United States. For the switchback analysis, they included data from a large US commercial health insurance database from the years 2004 to 2013.
Identical appearance and non-medicinal ingredients list was one reason for a lower rate of switchback from branded to authorized generic drugs
As hypothesized, the switchback rates between authorized generic drugs back to branded drugs were lower than the switchback from generic drug products. In fact, there was a 28% lower rate of switchback between authorized generic drugs compared with generic drugs. Although this study lacks the patients’ reasons for the switchbacks, one major reason for a lower rate of switchback from branded to authorized generic drug products could be the authorized generic drugs’ identical appearances and non-medicinal ingredient list to the branded counterpart.
Numerous studies have demonstrated equivalent clinical outcomes between branded and generic products for various drug classes. Drugs with a narrow therapeutic window are usually excluded from these studies since small changes in dose may cause important clinical changes. For drugs with a narrow therapeutic range, changing from branded to the generic counterpart is usually not recommended. These results, therefore, cannot be generalized to drugs with a narrow therapeutic index.
Perception of cheaper prices of generic drugs influence many patients to stay with branded medications
In conclusion, generic drugs have repeatedly demonstrated a clinical equivalency to their branded counterpart. Patient perceptions of generic drugs as a cheaper alternative to branded products influences their decision to stay on a branded medication. This choice comes with an important financial burden. Authorized generic drugs demonstrate a lower rate of switchback to the branded product most likely due to the identical appearance and non-medicinal ingredient list.
Written by Jessica Caporuscio, PharmD
Reference: Desai RJ, Sarpatwari A, Dejene S, et al. Differences in rates of switchbacks after switching from branded to authorized generic and branded to generic drug products: cohort study. BMJ. 2018