The effect of generic market entry on antibiotic prescriptions in the United States

When patented, brand-name antibiotics lose market exclusivity, generics typically enter the market at lower prices, which may increase consumption of the drug. To examine the effect of generic market entry on antibiotic consumption in the United States, we conducted an interrupted time series analysis of the change in the number of prescriptions per month for antibiotics for which at least one generic entered the US market between 2000 and 2012. Data were acquired from the IQVIA Xponent database. Thirteen antibiotics were analyzed. Here, we show that one year after generic entry, the number of prescriptions increased for five antibiotics (5 to 406%)-aztreonam, cefpodoxime, ciprofloxacin, levofloxacin, ofloxacin-and decreased for one drug: cefdinir. These changes were sustained two years after. Cefprozil, cefuroxime axetil and clarithromycin had significant increases in trend, but no significant level changes. No consistent pattern for antibiotic use following generic entry in the United States was observed. Generics contribute to increased availability of antibiotics, benefiting healthcare systems but potentially leading to increased consumption with implications for antibiotic stewardship and resistance. Here, the authors found no consistent changes in prescribing patterns of the 13 antibiotics that entered the US market as generics from 2000-2012.

Automated summary

The study found that one year after the entry of generics into the market, the number of prescriptions increased for five antibiotics (by 6% to 406%), while it decreased for one drug. These changes were sustained two years after.