[Therapeutic drug monitoring of cyamemazine: How to interpret a concentration? A review of literature].

Cyamemazine is the most prescribed antipsychotic drug in France, often in combination with another antipsychotic, for its sedative and anxiolytic component. Providing to physicians serum concentrations of cyamemazine in different contexts (compliance checking, ineffectiveness, adverse effects, intoxication, modification of pharmacokinetic parameters…) requires to interpret them correctly. This article presents an update on how to interpret a concentration of cyamemazine, wich remains poorly documented. The anxiolysis occurs at steady-state serum trough concentrations of 4 to 5μg/L; the antipsychotic effect from 18-20μg/L. Cyamemazine is not a drug with a narrow therapeutic window and concentrations up to 400μg/L may be sought in cases of partial efficacy; concentrations of 1800μg/L might be fatal; lower concentrations might be fatal if association with high others concentrations of drugs.