Table 2.

ED₅₀ values and 95% confidence limits for rimonabant, alone and in combination with Δ⁹-THC, anandamide and URB 597, in Δ⁹-THC-treated (1 mg·kg⁻¹12 h⁻¹) monkeys discriminating rimonabant (1 mg·kg⁻¹ i.v.)

Drug	ED50 value (95% CL) in mg·kg−1	Potency ratio (95% CL)†
Rimonabant (cumulative dosing)	0.35 (0.30–0.40)
+Δ9-THC (0.32 mg·kg−1)	0.52 (0.25–1.1)	1.5 (0.9–2.7)
+Δ9-THC (1 mg·kg−1)	1.3 (0.89–1.9)*	3.7 (2.5–5.7)
+Δ9-THC (3.2 mg·kg−1)	3.4 (2.3–5.0)*	9.7 (6.7–14)
+URB 597 (3.2 mg·kg−1)	0.27 (0.18–0.44)	0.8 (0.5–1.2)
Rimonabant (single bolus dosing)	0.18 (0.07–0.46)
+Anandamide (10 mg·kg−1)	0.35 (0.22–0.55)	1.9 (0.9–4.2)
+Anandamide (32 mg·kg−1)	1.24 (0.66–2.3)*	6.9 (2.6–17)
+Anandamide (10 mg·kg−1) +URB 597 (3.2 mg·kg−1)	0.71 (0.38–1.3)*	3.9 (1.6–9.7)

^*Significant decrease in potency.

^†Potency ratios and 95% confidence limits (CL) are the ED₅₀ value of rimonabant in combination with test drug divided by the control ED₅₀ value of rimonabant.