Résumé en anglais

The purpose of this paper is to investigate how the brand name’s market shares in Tunisia are affected by generic competition during the pre-reform period of the Tunisian health insurance system following the methodological approach developed by Aronsson et al. (2001). In this study we use data for three molecules Captopril (antihypertensive) Glibenclamide (antidiabetic) and Carbamazepine (antiepileptic) from IMS Health database. The data span from the third quarter 2002 to second quarter 2007. Statistical results indicate that the impact of generic competition seems to be not different across markets (Captopril, Glibenclamide and Carbamazepine) in Tunisia. In addition, the relative price has a positive and significant effect on the change of market share of the brand name drug in Tunisia for the three active molecules. The higher the price of the brand name product relative to the average price of the generic substitutes, the smaller the decrease of market share of the brand name product. In Tunisian pharmaceutical market, brand- names charge a higher price than their generic versions and still obtain positive market shares. Thus, from a policy perspective, the large market share of higher priced brand-names relative to their generic versions is an unsatisfactory outcome taking into account that brand name drug and generics are identical products and provide similar health gains to patients.