Precision medicine requires precision prescribing: rethinking antiseizure medication regulation in Europe.

Epilepsy care increasingly combines biologically informed precision medicine with individualized prescribing, yet routine personalization based on age, comorbidities, reproductive considerations, tolerability, interactions, and patient preference is good clinical care and should not, by itself, be labelled precision medicine. The unresolved problem is not a general absence of prescribing freedom in Europe. It is the mismatch that may arise among dynamic therapeutic trajectories, formal indications, reimbursement or access rules, and the evidence captured in routine datasets. We propose structured flexibility as a predefined, prospective, and auditable learning pathway operating within or alongside existing mechanisms. A key example is conversion to secondary monotherapy after a meaningful and well-tolerated response to an ASM introduced as adjunctive treatment: simplification may benefit the patient, while structured follow-up can generate otherwise limited standalone data on drug-specific effectiveness, tolerability, functioning, and retention. Layered diagnoses, in which syndrome and aetiology coexist, provide a second example of why clinical information should be preserved rather than forced into mutually exclusive administrative categories. Structured flexibility would not create a new authorization category, lower evidentiary standards, or transform observational response into an unrestricted monotherapy indication. Its purpose is to connect patient-centered optimization with cumulative evidence generation for comparative research, treatment-response prediction, and appropriately validated artificial-intelligence-assisted prescribing. We propose "precision regulation": an adaptive framework that supports individualized prescribing when predefined clinical, pharmacological, evidentiary, monitoring, and patient-centered criteria are met. Precision medicine should extend beyond diagnosis to access, reimbursement, deprescribing, and longitudinal therapeutic optimization.