Has Previous Abuse of Flunitrazepam Been Replaced by Clonazepam?

Abstract

Background and Aims: For many years, flunitrazepam was the benzodiazepine of choice among users of illegal drugs. The aim of this study was to investigate to which extent clonazepam use has increased in this population, and whether this was related to increased prescription or because of illegal availability. Methods: We used data from three sources to study the changes in the use of clonazepam: (1) Presence and concentrations of clonazepam and flunitrazepam in blood samples collected from Norwegian drugged drivers; (2) Sales numbers (legal market) for clonazepam, extracted from the Norwegian prescription database (NorPD), and (3) Specific seizures (illegal market) for clonazepam in Norway. Results: In 2004, 13.0% of the analysed blood samples from drugged drivers contained clonazepam, whereas this proportion had increased to 27.7% in 2013. In the same period, the frequency of flunitrazepam in drugged drivers decreased from 16.6% in 2004 to 3.2% in 2013. The number of clonazepam prescriptions decreased, while the number of seized tablets containing clonazepam increased considerably from 2004 to 2013. Conclusions: For the last 10 years, a significant increase in the illegal use of clonazepam has been seen, now replacing flunitrazepam as the most used illegal benzodiazepine in Norway.

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“…A study found that 12% of clonazepam redemptions in Norway were reimbursed [ 21 ], indicating frequent ‘off-label’ use. For the last 10 years, a significant increase in the illegal use of clonazepam has been seen in Norway [ 22 ].…”

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“…Another key finding is the continuing emergence of clonazepam and decline of flunitrazepam as a benzodiazepine of misuse in heroin users. Clonazepam was found to be the most common benzodiazepine, although this is largely due to the fact that a large proportion of the study data originated from Oslo, where clonazepam was found to be the most commonly used benzodiazepine [27]. In addition, the use of flunitrazepam was rarely reported by patients in this study.…”

Initiation and long‐term use of benzodiazepines and Z‐drugs in bipolar disorder

“…Out of the 6307 patients who initiated benzodiazepine or Z‐drug treatment, 3.5% used clonazepam or alprazolam, both of which are among the most common drugs of abuse worldwide . Alprazolam has long been known for causing more severe physical dependence than other benzodiazepines, due to its high potency .…”

“…Out of the 6307 patients who initiated benzodiazepine or Z-drug treatment, 3.5% used clonazepam or alprazolam, both of which are among the most common drugs of abuse worldwide. [31][32][33] Alprazolam has long been known for causing more severe physical dependence than other benzodiazepines, due to its high potency. 34 Similarly, warnings about the highly addictive properties of clonazepam have emerged in recent years, 35,36 indicating that the high rates of longterm use of these drugs may be due to patients becoming dependent.…”