Differences between prescription and dispensing of generic medicines in primary care. When the exception is the rule

To quantify the frequency and cost of switching prescribed generic brand drugs for others at dispensation in pharmacies. We performed a descriptive cross-sectional study to compare prescription and dispensation of generic drugs in a primary care quota by using computerized data from medical consulting rooms and the Pharmaceutical Service Management Program in 2005. Of 16,181 prescriptions, 3,759 generic prescriptions were included in the study, with a mean price of 7.61 euros as opposed to 8.01 euros for those dispensed in the retail pharmacy. In 62.9% of drugs, the brand prescribed by the doctor was not dispensed. In 65.1% of cases in which the brand was switched, the drug was changed for another generic drug with a higher price. Changing the prescribed generic drug was common in the quota studied with a tendency to dispense another drug that was more expensive, thereby increasing costs.