[Generic substitution in primary care in 2011: differences according to pharmacological classes?].

Background: Generic substitution has been permitted for several years in France and is promoted in order to reduce health expenditures. However, reluctance concerning use of generic drugs exists for different reasons: suspicions about their efficacy and/or safety, differences in content (excipients) and discussions about bioequivalency. The aim of our study was to determine whether or not the substitution ratio differs according to pharmacological classes used in primary care.