Phenazepam is a long-acting
benzodiazepine that, unlike other
benzodiazepines, is currently not scheduled as a
narcotic in Finland, most other European countries or the USA. It is used as an
anxiolytic,
sedative-
hypnotic and anti-epileptic, mainly in Russia. In Finland, as well as in some other countries, an increase in the unauthorized use of
phenazepam has been observed in recent years. In the one year period between July 1, 2010 and June 30, 2011 the prevalence of
phenazepam in Finland was assessed among drivers apprehended for driving under the influence of drugs (DUID), in medico-legal autopsy cases and in police confiscations of
illicit drugs. In DUID cases an LC-MS/MS method preceded by solid phase extraction was used for the determination of
phenazepam. In the post-mortem investigations the sample preparation consisted of liquid-liquid extraction followed by derivatization and the determination was carried out by GC-MS. The police confiscations were analysed by GC-MS. There were 141 positive
phenazepam cases among apprehended drivers, representing approximately 3.5% of all confirmed
drug cases (n=4007) in this time period. The median (range)
phenazepam blood concentration in DUID cases was 0.061 mg/L (0.004-3.600 mg/L). The median
phenazepam concentration in cases with no concomitant stimulant use was significantly higher than the overall median concentration.
Phenazepam was found in 17 medico-legal autopsy cases and the median (range) blood concentration was 0.048 mg/L (0.007-1.600 mg/L).
Phenazepam was not considered by the medico-legal team to be the sole cause of death in any of the cases, the majority of them being accidental opiod overdoses. There were 26
seizures of
phenazepam by the Police in the time period studied, some of the batches consisted of a mixture of
phenazepam and stimulant
designer drugs. The data show that
phenazepam abuse is a widespread phenomenon in Finland. A typical user was a male multi-drug user in his 30s. The concentration range of
phenazepam among apprehended drivers and medico-legal autopsy cases was wide and the
drug was usually found along with other
psychoactive drugs. Therefore, although it seems likely that
phenazepam contributed to impairment of driving in some DUID cases, the extent of its effect remains unclear and further studies are needed to define the concentrations causing impairment and toxicity.