Performance studies with diazepam and its hydroxylated metabolites

Area of Science:

• Pharmacology
• Neuroscience
• Human Performance

Background:

• Visuo-motor coordination is a sensitive measure for assessing drug effects.
• Benzodiazepines are commonly prescribed for sleep disturbances, necessitating an understanding of their residual effects.

Purpose of the Study:

• To evaluate the immediate and residual effects of various benzodiazepines on visuo-motor performance.
• To determine dose- and time-response relationships for performance impairment.

Main Methods:

• Participants ingested specific doses of benzodiazepines (flurazepam, nitrazepam, diazepam, temazepam, oxazepam) either overnight or in the morning.
• Visuo-motor coordination tests were administered at various time points post-ingestion to assess performance.
• Dose and time response data were collected to quantify performance decrements and their duration.

Main Results:

• Overnight ingestion of flurazepam (30 mg) and nitrazepam (10 mg) impaired performance for 16 and 19 hours, respectively.
• Diazepam (5-10 mg), temazepam (10-30 mg), and oxazepam (15-30 mg) did not cause significant impairment after overnight ingestion, though higher doses showed trends or short-term impairment.
• Morning ingestion of diazepam (10 mg), temazepam (20 mg), and oxazepam (30 mg) resulted in temporary performance impairment for several hours.

Conclusions:

• Lower doses of diazepam, temazepam, and oxazepam may be suitable for managing sleep disturbances without causing significant next-day performance impairment.
• The choice of benzodiazepine and dosage is critical for minimizing residual effects on psychomotor function.