ABSTRACT
BACKGROUND: All drug marketing authorization holders have the legal obligation to collect data on the use of the products they market and to keep the labels of those products updated. As demonstrated by previous studies, many generic products have labels that are discrepant from the labels of their reference (originator) products. This fact may cause inconsistent messages to be disseminated to healthcare professionals and patients for the same active ingredient. OBJECTIVE: These potential label discrepancies led us to investigate the degree of difference between labels for generic and originator products, the possible consequences of this discrepancy for patients, and its implications for risk minimization. PRODUCTS AND METHODS: Drugs from different Anatomical Therapeutic Chemical classes were randomly selected from the Electronic Medicines Compendium. For each drug, the consistency and discrepancies between the summaries of product characteristics (SmPCs) for originator and generic products were analyzed for each safety-relevant section of the SmPC separately as well as across all of its sections. The percentile distribution of discrepancy classifications was calculated. The same method was applied when determining the potential impact of label discrepencies on patients. RESULTS: Among the 50 drugs selected initially, 31 were eligible for the study and were analyzed further. Of those 31 drugs, 13 (41.9%) presented critical label differences between originator and generic products, 6 (19.4%) showed major label differences, 7 (22.6%) exhibited minor label differences, and 5 (16.1%) showed very minor label differences. Over 60% of the selected drugs (19, 61.3%) presented important (critical, major) label differences between originator and generic products. None of the selected drugs had fully aligned labels of originator and generic products. Label misalignments that could potentially have a fatal or life-threatening impact on the patient were observed for 4 (12.9%) of the selected drugs. Label misalignments that could have a severe patient outcome were noted for 11 (35.5%) of the selected drugs, and label misalignments that could have a medium impact on the patient were seen for 6 (19.35%) of the selected drugs. The label misalignments observed for 10 (32.25%) of the selected drugs would potentially lead to only a minor or no effect on the patient. Almost half (15, 48.4%) of the selected drugs presented label misalignments that could have a critical (fatal, life-threatening, severe) influence on the patient. CONCLUSIONS: In this sample, SmPC alignment between generic and originator medicinal products was found to be inefficient for established drugs, and could lead to the diffusion of discrepant messages to healthcare professionals and patients. In order to address this SmPC alignment problem, health authorities such as the EMA and the FDA must conduct retrospective analyses of all drugs on the market as a first step towards realigning labels. These analyses could be performed during the evaluation of aggregate reports.
ABSTRACT
The present study provides results on the influence of humic substance (HS) photoalteration on lead availability to the freshwater microalga Chlorella kesslerii . The evolution of the free lead-ion concentrations measured by the ion exchange technique [Pb](IET) and intracellular lead contents was explored in the presence of Suwannee River humic (SRHA) and fulvic (SRFA) acids, as well as Aldrich humic acid (AHA) exposed at increasing radiance doses under a solar simulator. Modifications of HS characteristics highly relevant to Pb complexation and accumulation of HS to algal surfaces, including Fourier transform infrared spectroscopy, were followed. It was demonstrated that simulated sunlight exposure of HS increased [Pb](IET) in the medium for SRFA and SRHA, but had no effect for AHA. No clear relationship was observed between the changes in free lead-ion concentrations and intracellular content in alga for all studied HS, suggesting that HS photodegradation products also exhibit Pb complexation properties, and that direct interactions between HS and alga are affected. Indeed, photoalteration of humic substances reduced the adsorption of HS to the algal surface; the effect was more pronounced for SRFA and AHA and less significant for SRHA. The bioavailability results were consistent with the characterization of the phototransformation of humic substances: Pb speciation changes followed the modification of the relative abundance of the carboxylic groups and their molecular environment, while the reduced HS adsorption to the alga correlated with losses of the double bond abundance and aromaticity.
