Efficacy and Quality of Antibacterial Generic Products Approved for Human Use: A Systematic Review

Background. Concerns have recently emerged about the efficacy and the quality of antibacterial generic products approved for use in humans. Methods. We searched Medline and Embase for original research articles on antibacterial generic products published in English or French before July 2013. Results. We selected 37 original research articles: 15 on beta-lactams, 10 on glycopeptides, and 12 on other antibacterial agents. The majority of articles (73.0%) were published during 2008-2012. Study designs included analytical chemistry (n = 9), in vitro susceptibility studies (n = 14), animal experiments (n = 6, including 5 using the neutropenic mouse thigh infection model), and clinical studies in humans (n = 15). Of the 37 studies, 14 (37.8%) suggested that some generic products may be inferior to the innovator in terms of purity (n = 2), in vitro activity (n = 3), in vivo efficacy in experimental models (n = 4), clinical efficacy (n = 2), taste (n = 2), or compliance and acceptability in children (n = 1). The majority of in vitro studies (78.6%) found no significant difference between generic products and the innovator. Most (5/6) in vivo studies suggesting a difference between generic products and the innovator were performed in an animal model that is not validated for the evaluation of the efficacy of antibacterial agents. The level of evidence was constantly low in clinical studies. Conclusions. Published data on antibacterial generic products are limited and heterogeneous, thus precluding any attempt to generalize the study results. This systematic review suggests that additional evidence would be needed before considering a revision of the marketing authorization process for antibacterial generic products.