TABLE 5.

ED₅₀ values (95% CL) of 2-BFI alone and in combination with the varied-efficacy opioids and the dose ratios between them in female rats

Treatment	ED50 (95% CL)	Dose Ratio
2-BFI alone	7.62 (6.10, 9.55)
0.01 Fentanyl + 2-BFI	5.25 (4.68, 5.88)a	1.45
0.01 Bup + 2-BFI	2.86 (2.05, 3.99)a	2.66
0.1 Bup + 2-BFI	1.95 (1.50, 2.54)a	3.91
3.2 NAQ + 2-BFI	4.21 (3.23, 5.51)a	1.81
10 NAQ + 2-BFI	2.40 (1.89, 3.06)a	3.18

Bup, buprenorphine.

^aConfidence limits of combination do not overlap with confidence limits of 2-BFI alone.