Treating conditions such as anxiety, depression, and sleeping disorders might help opioid-maintained patients reduce their use of benzodiazepines, a study of 193 patients suggests.
The study, conducted to assess the motives and patterns of benzodiazepine (BZD) use and psychiatric comorbidity among patients on injectable heroin or oral opioids, found that nearly half of patients reported prolonged use of benzodiazepines in the past 5 years. Led by Dr. Marc Vogel, the investigators also found that the patients reported prolonged use most often to reduce anxiety, forget problems, feel relaxed, and feel secure (Addict. Behav. 2013;38:2477-84). Prolonged use also was associated with negative affect regulation and "somato-medical" motives.
Dr. Vogel, of the Psychiatric Hospital of the University of Basel in Switzerland, surveyed patients in two of the hospital’s outpatient clinics about their psychiatric family history and patterns of benzodiazepine use; the clinics specialized in either oral opioid agonist treatment or heroin-assisted treatment. Sixty-six percent of participants were male; the mean age was 42.
Patterns of benzodiazepine use were collected only among participants who reported "prolonged use of BZD," defined as regular benzodiazepine use several times per week for longer than 2 months. Patients underwent urinalysis on the same day to confirm their self-reported data, Dr. Vogel and his colleagues reported.
Most patients were maintained on a single agonist, but many of the 80 patients maintained on diacetylmorphine received additional opioids for issues such as avoiding night-time withdrawal. The average daily agonist dose was 111 mg methadone-equivalent; the daily methadone-equivalent dose was 60 mg or higher in 163 patients (84%). Overall, 164 (85%) participants reported lifetime use of benzodiazepines, 108 (56%) reported use in the past 30 days, and 107 (56%) had positive urinalysis. The investigators classified the 117 (62%) subjects with either positive urinalysis or self-reported use in the past 30 days as current users. There were 52 (31%) former users; only 24 participants (12%) did not fulfill the criteria for lifetime use.
"Patients need to be informed about the risks, particularly in light of our finding that many users ingest their daily dose in one portion, regardless of prescription."
Both opioid agonist treatment and diacetylmorphine patients reported similar proportions of lifetime use – about 85% – but diacetylmorphine patients had lower proportions of prolonged benzodiazepine use (37% vs. 54%) and current use (51% vs. 67%), and higher proportions of former use (40% vs. 25%). Diacetylmorphine patients also were less likely to test positive for benzodiazepine use in urinalysis. All of these findings were significant (P less than .05).
Ninety participants (47%) reported prolonged benzodiazepine use in the past 5 years. Diazepam was used most commonly, followed by flunitrazepam and midazolam – all agents with a rapid onset of action. Twenty percent of patients reported using combinations of different benzodiazepines, and 76% combined benzodiazepines with other drugs. Nineteen percent used parenteral routes of administration, and almost half acquired benzodiazepines on the black market. The most common reasons for initially using benzodiazepines included searching for a high (19%), out of curiosity (16%), or because of sleeping problems (13%).
The study "shows that high-risk behaviors associated with BZD use are common, such as parenteral use, purchasing on the black market, or [using them in] combination with other respiratory depressant substances like other BZDs, heroin, or methadone," the authors said.
The investigators cited several limitations of the study, including its cross-sectional design and the use of self-report. "Use of structured clinical interviews for diagnostic purposes would be desirable for future studies," they said.
Because benzodiazepines often are involved in overdose-related deaths, "patients need to be informed about the risks, particularly in light of our finding that many users ingest their daily dose in one portion, regardless of prescription," Dr. Vogel and his colleagues wrote.
The authors reported no conflicts of interest.