[Evaluation of information for generic drugs based on importance and necessity].

Limited use of generics in Japan has been justified on the basis of problematic quality, distribution and information. Of these three problem areas, the state of provision of information in particular has never been objectively evaluated. We therefore sought to evaluate information according to its necessity and importance to medical practice. To establish criteria for evaluation, we weighted 36 separate pieces of drug information found in package inserts and interview forms according to necessity and importance, based on the results of a survey of nationwide medical institutions with DI offices. We then used the evaluation criteria to evaluate currently available drugs with 20 or more products per formulation. We evaluated 14 formulations (324 products). Generic drugs were found to have 25.3+/-18.7 to 46.1+/-14.2% (Mean+/-S.D.) the information of brand name drugs when products were compared for quantity of information by formulation. However, comparison according to manufacturer returned a larger range of variation at 14.4+/-8.6 to 64.3+/-14.2% (Mean+/-S.D.). These data reveal that manufacturer differences play a large role in the provision of drug information. Drug information was also compared separately by category for both brand name and generic drugs. Generic drugs were found to have insufficient information on clinical data, pharmacokinetics, safety, side effects, and nonclinical tests. Brand name drugs also scored low points for information on pharmacokinetics. It is imperative that both brand name and generic drugs provide more information on pharmacokinetics.