Patients who switch from branded drugs are more likely to switch back from generic drugs than from authorized generic drugs, according to a study published in the BMJ.
Rishi J. Desai, PhD, of the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine at Brigham and Women’s Hospital and Harvard Medical School in Boston, and associates conducted an observational study to determine the likelihood of switchbacks from generic or authorized generic drug products to branded drugs.
The study consisted of private and public insurance programs in the US with private health (a large commercial health plan) being the primary group and the public (Medicaid) health insurance studied as a replication group.
Volunteers taking branded drugs for alendronate tablets, amlodipine tablets, amlodipine-benazepril capsules, calcitonin salmon nasal spray, escitalopram tablets, glipizide extended-release tablets, quinapril tablets, and sertraline tablets switched to either an authorized generic or generic drug product and monitored for switchbacks.
Authorized generic drugs were defined as drugs that contained both active and inactive ingredients, as well as appearance of the branded version, while generic drugs only contained the same active ingredients and varied in inactive ingredients and appearance.
A total of 94,909 individuals switched from branded to authorized generic drugs, and 116,017 individuals switched from branded to generic drugs. Switchbacks ranged between drug types: the lowest rate was 3.8 per 100 person years (for alendronate tablets), and the highest rate was 17.8 per 100 person years (for amlodipine-benazepril capsules). The overall rate was 8.2 per 100 person years.
The investigators noted a thorough reduction in switchback in authorized generic drugs compared with generic drugs in patients with private insurance (pooled hazard ratio [HR], 0.72) and public insurance (HR, 0.75).
“Interventions to improve patient-provider communication to increase patient awareness regarding similarity between branded and generic drug products in terms of quality, safety, and efficacy may be crucial to prevent brand switchbacks,” reported the authors. “Consistency in appearance between branded and generic drug products may also help in preventing brand switchbacks.”
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;361:k1180