title: [Therapeutic drug monitoring of primidone and                                     phenobarbital].
abstract: Primidone is a minor first-generation antiepileptic drug, little                               currently prescribed for this indication, but except marketing                               authorization, remains a first-line treatment of essential tremor.                               Although it is metabolized in phenyl-ethyl-malondamide and                               phenobarbital, active metabolites that contribute also to its action,                               primidone is not a prodrug and is active by itself. The rate of                               conversion of primidone to phenobarbital is highly variable according                               to the subject. Generally accepted therapeutic range for primidone is                               between 5 and 10 mg/L (23-46 mmol/L). The therapeutic drug monitoring                               (TDM) of primidone must be accompanied by the determination of                               phenobarbital concentrations. The level of proof of the interest of                               the TDM primidone was estimated to be "probably useless".                               Phenobarbital, a very ancient anticonvulsant, is much less used today,                               for the benefit of other more recent compounds. It remains prescribed                               in neonatology and is one of the compounds used in status epilepticus.                               It is a molecule with a long half-life, metabolized in                               p-hydroxy-phenobarbital. It is a potent inducer of CYP3A4. Several                               side effects, especially drowsiness, are concentration-dependent.                               Generally accepted therapeutic range for phenobarbital is between 10                               and 40 mg/L (43 - 172 mmol/L), without considering the type of crise.                               The level of proof of the interest of TDM of phenobarbital was                               evaluated as "recommended".
authors.affiliation: CHU Pontchaillou, Laboratoire de Pharmacologie BiologiqueRennesFrance.
authors.forename: Danièle
authors.initials: D
authors.lastname: Bentué-Ferrer
authors.forename: Marie-Clémence
authors.initials: MC
authors.lastname: Verdier
authors.forename: Olivier
authors.initials: O
authors.lastname: Tribut
mesh_terms: D000927:Anticonvulsants / Q000627:therapeutic use; D016903:Drug Monitoring; D006207:Half-Life; D011324:Primidone
chemical_list: D000927:Anticonvulsants; D011324:Primidone