Table 1.
Residual effects of zaleplon and zopiclone (4 h after ingestion) on performance, memory, and subjective sedation (means ± s.d.).
| Zopiclone | Zaleplon | |||
|---|---|---|---|---|
| Measure | Placebo (n = 13) | 7.5 mg (n = 13) | 10 mg (n = 13) | 20 mg (n = 12) |
| Digit symbol substitution (Number of substitutions) | 59.3 (8.9) | 52.8 ± 9.8a | 58.3 ± 12.0 | 55.6 ± 12.5 |
| 95% CI | −10.5, −2.1 | −4.9, 3.5 | −7.7, 0.9 | |
| Choice reaction time (ms) | ||||
| Recognition reaction time | 344.3 ± 38.6 | 375.0 ± 47.3b | 339.6 ± 35.2 | 347.8 ± 41.2 |
| 95% CI | 11.9, 48.2 | −22.6, 13.7 | −20.0, 17.1 | |
| Motor reaction time | 260.3 ± 64.3 | 292.8 ± 87.3a | 257.0 ± 74.8 | 268.6 ± 77.1 |
| 95% CI | 10.1, 51.0 | −24.9, 16 | −7.1, 34.8 | |
| Total reaction time | 604.6 ± 68.9 | 667.8 ± 86.7b | 596.6 ± 78.7 | 616.6 ± 98.0 |
| 95% CI | 29.9, 91.3 | −39.5, 21.8 | −19.1, 43.8 | |
| Immediate word recall (Number correctly recalled) | 14.8 ± 4.1 | 11.9 ± 4.2 | 13.3 ± 4.1 | 13.4 ± 4.5 |
| 95% CI | −5.0, −0.7 | −3.6, 0.7 | −4.1, 0.4 | |
| Delayed word recall (Number correctly recalled) | 13.2 ± 4.8 | 7.9 ± 4.6b | 11.0 ± 4.8 | 10.6 ± 5.6 |
| 95% CI | −7.6, −2.5 | −4.5, 0.6 | −5.5, −0.3 | |
| Critical flicker fusion (Hz) | 29.9 ± 2.9 | 28.7 ± 2.0 | 30.0 ± 2.7 | 29.9 ± 3.3 |
| 95% CI | −2.2, −0.1 | −0.9, 1.1 | −1.1, 1.1 | |
| Subjective assessment of sedation (LARS+) | 61.9 ± 11.6 | 62.8 ± 12.0 | 64.4 ± 12.9 | 63.0 ± 15.0 |
| 95% CI | −6.1, 7.9 | −4.3, 9.7 | −6.0, 8.4 | |
a
P < 0.0167,
b
P < 0.0033 (the 5% and 1% significance levels, respectively, adjusted for multiple comparisons) compared with placebo.
+
LARS: Leeds Analogue Rating Scale.
95% CI: Confidence interval of individual differences between placebo and each drug treatment.