Table 2

Potencies (mean ED50) and number of monkeys reaching 90% drug-appropriate responding for zolpidem and typical BZ receptor agonists in zolpidem-trained squirrel monkeys

DrugED50, mg/kgNo. ≥90%2-aTotal no. TestedRange2-b
% Drug-Lever RespondingResponse Rate
responses/s %
Triazolam0.0073 (0.0015)0.016 (0.020)3464–100
Lorazepam0.15 (0.083)2.2 (0.61)2423–90
Zolpidem0.23 (0.051)0.87 (0.19)4485–100
Midazolam0.67 (0.033)2.2 (0.45)3450–100
N-desmethyldiazepam1.9 (0.10)2.7 (0.88)2347–93
Diazepam2.0 (1.7)1.6 (1.1)3442–100
Chlordiazepoxide9.9 (2.4)15 (1.9)2425–100
Oxazepamn.d.2-c 6.9 (2.4)1312–100

Numbers in parentheses are SECs.

  • 2-a Number of animals for which the test drug engendered zolpidem-lever responding within the lower 95% CI for the group mean zolpidem-lever responding (mean = 90%, CI = 6).

  • 2-b Range corresponds to the maximum % drug-lever responding observed for all animals, regardless of dose.

  • 2-c n.d., did not engender an average at or above 50% drug-lever responding.