The dependence potential of benzodiazepines

Area of Science:

• Pharmacology
• Neuroscience
• Psychology

Background:

• Benzodiazepines are commonly prescribed but their potential for reinforcement and dependence is not fully understood.
• Previous research indicates diazepam, a benzodiazepine, is not an effective reinforcer in human subjects.
• Understanding benzodiazepine reinforcement properties is crucial for assessing abuse potential.

Purpose of the Study:

• To investigate the reinforcing properties of lorazepam, a short-acting benzodiazepine, in adult human volunteers.
• To compare the reinforcing effects of lorazepam with placebo and diazepam.
• To evaluate the dose-dependent effects of lorazepam on drug preference.

Main Methods:

• A choice procedure was used with 12 healthy adult volunteers.
• Four experiments were conducted, comparing three doses of lorazepam (0.5, 1.0, 2.0 mg) against placebo.
• One experiment directly compared 1.0 mg lorazepam to 5.0 mg diazepam; subjective effects were also monitored.

Main Results:

• Subjects did not prefer 0.5 mg lorazepam over placebo.
• No preference was observed between 1.0 mg lorazepam and 5.0 mg diazepam.
• A clear preference for placebo over 1.0 mg and 2.0 mg lorazepam was found.
• Lorazepam produced expected anxiolytic and sedative effects, with a longer duration than anticipated (up to 6 hours).

Conclusions:

• Lorazepam does not appear to be an effective reinforcer in this experimental paradigm.
• The reinforcing potential of shorter-acting benzodiazepines remains to be determined due to lorazepam's prolonged effects.
• Further research is needed to fully elucidate the relationship between benzodiazepine pharmacokinetics and their reinforcing properties.