Table 3.
ED50 values and 95% confidence limits determined before and 1 day after Δ9-tetrahydrocannabinol (Δ9-THC) treatment (1 mg·kg−1 per day, s.c. for up to 6 days) in monkeys discriminating Δ9-THC
| ED50 in mg·kg−1 (95% confidence limits) | Potency ratio† (95% confidence limits) | |
|---|---|---|
| Δ9-THC | ||
| 1 day Δ9-THC | ||
| Before | 0.041 (0.013–0.13) | |
| 1 day after | 0.030 (0.0097–0.093) | 0.7 (0.2–2.9) |
| 3 days Δ9-THC (First) | ||
| Before | 0.046 (0.021–0.097) | |
| 1 day after | 0.13* (0.068–0.24) | 2.8 (1.3–6.4) |
| 3 days Δ9-THC (Second) | ||
| Before | 0.021 (0.012–0.037) | |
| 1 day after | 0.057* (0.030–0.11) | 2.7 (1.3–5.7) |
| 6 days Δ9-THC | ||
| Before | 0.037 (0.022–0.069) | |
| 1 day after | 0.11* (0.080–0.16) | 3.0 (1.6–5.4) |
| 7 days after | 0.042 (0.025–0.077) | 1.1 (0.5–2.7) |
| CP 55940 | ||
| 3 days Δ9-THC | ||
| Before | 0.0045 (0.0020–0.010) | |
| 1 day after | 0.0047 (0.0025–0.0090) | 1.0 (0.4–2.4) |
| WIN 55212-2 | ||
| 3 days Δ9-THC | ||
| Before | 0.12 (0.032–0.44) | |
| 1 day after | 0.083 (0.029–0.24) | 0.7 (0.2–2.7) |
†
Potency ratios and 95% confidence limits are equal to the ED50 values determined 1 day after Δ9-THC treatment divided by the ED50 value determined before daily Δ9-THC treatment.
*
Significantly different from before.