The anatomical therapeutic chemical classification is flexible enough to describe the innovation in biotechnological drugs?

OBJECTIVES The Anatomical-Therapeutic-Chemical Classification (ATC) - defined by the WHO as a “ tool for drug utilization monitoring and research in order to improve quality of drug use ” - codes active substances and groups them according to the target organ or system and their therapeutic, pharmacological and chemical properties. However, the classification could include inconsistencies, mostly evident for biotechnological products, resulting in possible inappropriate use. The work aimed at determining whether drugs (in particular biologics) are appropriately described by their ATC code,investigating evidence on their use and suggesting solutions to improve the classification pattern. METHODS: Twelve experts critically analyzed the ATC classification and proposed possible solutions. The results were summarized in statements, which were voted to reach a consensus through the Nominal Group Technique. Each expert voted on the statements, and the agreement was defined at 75% of the highest scores. Additionally, to investigate the use of ATC in scientific research, a literature review of its use was also performed. RESULTS: Based on a literature review, a total of 75 studies were analyzed; 99% concerned the appropriate use of ATC classification. Then, based on their experience, the experts identified the following inconsistencies in the ATC code: use of a single ATC code for more than one indication; lack of identification of differences among drug formulations deriving from their pharmacokinetic profile and differences attributable to further characteristics, beyond indication of use and mechanism of action (e.g., blood coagulation factors). Ten statements were identified: 5 regarding critical issues in the ATC code (structural limits at the ATC fifth code level; time-consuming, complex, imprecise coding request/modification procedure) and 5 possible solutions (telematic procedures to modernize the request/modification ATC code process; unique form to request/modify codes, specifying manufacturing process and reference to therapeutic equivalence among active principles; further levels beyond the V to differentiate drug peculiarities). Agreement among experts was reached for all statements. CONCLUSIONS The ATC code classification pattern should be partially changed to incorporate the peculiarities of biotechnologies to promote their appropriate use.