Autor(s): F. Albani, M. Contin, R. Riva, A. Baruzzi
Therapeutic drug monitoring (TDM) of antiepileptic drugs is an established tool in the medical treatment of epilepsies. The field of epilepsy is particularly suited to the application of TDM, both for the clinical presentation of the pathology (seizures occur irregularly and unpredictably; clinical efficacy and/or toxicity is often difficult to ascertain) and of the features of the drugs used in therapy, characterized by a narrow therapeutic index, a variable intersubject pharmacokinetics, a high potential for pharmacological interactions. In this review we describe the rationale and the procedures for best use of TDM of antiepileptic drugs in the setting of the current therapy of epilepsy. In the last 10-15 years, many new antiepileptic drugs have been marketed in Italy (vigabatrin, lamotrigine, gabapentin, felbamate, oxcarbazepine, tiagabine, topiramate, levetiracetam, pregabalin and zonisamide), doubling the therapeutic arsenal of the clinical epileptologist. In many cases, pharmaceutical companies claimed that these new compounds, for their improved kinetic characteristics and low interaction potential, did not need the support of TDM, simplifying therapy management, and with significant savings in term of time and money. However, in the post-marketing phase, experimental evidences showed for some of these drugs a level of inter-patient kinetic variability and a potential for drug interaction comparable to those of the older drugs, supporting the rationale for TDM of at least some of them.