Evidence of clonazepam abuse liability: results of the tools developed by the French Centers for Evaluation and Information on Pharmacodependence (CEIP) network.

Recent observations suggest the existence of clonazepam abuse. To determine its importance in France, a quantitative and systematic synthesis of all clonazepam data of several epidemiological tools of the Centers for Evaluation and Information on Pharmacodependence (CEIP) network has been performed in comparison with data on others benzodiazepines (BZD). Data on clonazepam and other BZD have been analysed from different epidemiological tools: OSIAP survey that identifies drugs obtained by means of falsified prescriptions, Observation of Illegal Drugs and Misuse of Psychotropic Medications (OPPIDUM) survey that describes modalities of use and data from regional French health reimbursement system. In OSIAP survey, the proportion of clonazepam falsified prescriptions among all BZD falsified prescriptions increased. During the 2006 OPPIDUM survey, the analysis of the BZD modalities of use highlights clonazepam abuse liability (for example 23% of illegal acquisition), in second rank after flunitrazepam. Studies based on data from the French health reimbursed system show that 1.5% of subjects with clonazepam dispensing had a deviant behaviour. Among BZD, clonazepam has the second most important doctor-shopping indicator (3%) after flunitrazepam. All these data provide some arguments in favour of clonazepam abuse liability in real life and the necessity to reinforce its monitoring.