PPI general practitioners’prescribing in the treatment of acid-related disorders: the impact of generic PPI launch into the pharmaceutical market in Italy

OBJECTIVES: To investigate the phenomenon of PPI switching in the acid related disorders treatment in an Italian primary care setting during 2005–2008 (before and after PPIs’ patents expired) and to estimate the costs of health care resources consumption associated with this phenomenon. METHODS: Retrospective cohort study was performed analyzing data from 127 GPs of Naples in the south of Italy. PPI users for ARD treatment within each study year were selected from source population. Switchers were defi ned patients changing from one PPI to another within each study year. Multivariate logistic regressions were used to assess the potential predictors of PPI switching and to investigate the factors infl uencing the direction of the switch. Cost was expressed as Euro 2008 per PPI user. RESULTS: The phenomenon of PPI switching rose from 13.0% in 2005 to 16.7% in 2008 with a peak of 18.8% in 2006. Calendar years, long-term treatments and GERD diagnosis were positive predictors of PPI switching. All years analyzed (versus 2005) were associated with switching to lansoprazole while the 2008 year was strongly associated with switching to omeprazole and pantoprazole. Very long-term treatment (>11 pack/years) group accounted for 66.3% of the total primary care cost. Switchers increased primary care costs by c61.1 compared with no switchers, reaching an incremental cost of c133.1 per useryear in the case with more than 1 switch. CONCLUSIONS: In Italy the launch of generic PPIs in the national market generates the increasing amount of chronic treatments and therapeutic substitution that will probably have had a negative impact on the total savings on PPIs, achievable by the introduction of generic products. Policy rules favouring generic PPIs prescribing can often infl uence physicians’ decision to select the appropriate treatment for each patient