High-dose lormetazepam dependence: strange case of Dr. Jekyll and Mr. Hyde.

High-dose benzodiazepine (BZD) abuse is emerging as a substance use disorder (SUD). The aim of the study is to explore the impact of high-dose lormetazepam (LMZ) abuse and the characteristics of patients affected by this SUD in a tertiary referral addiction unit. We have retrospectively evaluated 1112 patients admitted to the Addiction Medicine Unit, Verona University Hospital, Italy for detoxification from high-dose BZD dependence. LMZ was the most common BZD, with an increasing prevalence from January 2003 to June 2018. Socio-demographic (more women; higher age and education) and clinical features (higher daily diazepam dosage equivalent, BZD abuse duration, age of first BZD intake; BZD prescribed more frequently for sleep disorders; less frequent history of other SUDs, previous/active alcohol, previous opioids abuse; more frequent overall major psychiatric diseases and major depression; less-frequent bipolar disorders and other psychoses, personality disorders, and more than one psychiatric disease) of LMZ vs. other BZD abusers significantly differed. 96.7% LMZ abusers took oral solution, while two-thirds of other BZD abusers took tablets. Oral solution, BZD abuse duration and prescription of BZD for sleep disorders increased, while history of other SUDs, previous/active alcohol and active cannabinoids SUD reduced the risk of high-dose LMZ vs. other BZDs abuse. The large prevalence of high-dose LMZ abusers in Italy may be strongly related to the availability and characteristics of oral formulation that may transform the innocuous Dr. Jekyll tablets into an evil Mr. Hyde. Restriction to the market of LMZ oral formulation might reduce the risk of high-dose abuse.