. Author manuscript; available in PMC: 2010 Jan 5.

Published in final edited form as: Eur J Pharmacol. 2008 Nov 11;602(1):92–100. doi: 10.1016/j.ejphar.2008.11.004

Table 4.

Predicted Zadd and experimentally determined Zmix values (95%CL) for mixtures of fentanyl and a delta opioid in the assay of thermal nociception. ^abIndicates Zmix confidence limits do not overlap with Zadd confidence limits. ^aZmix lower than Zadd (superadditivity). ^bZmix higher than Zadd (subadditivity).

Mixture	Zadd (95%CL)	Zmix (95%CL)

5:1 SNC243A/Fentanyl	0.088 (0.060-0.128)	0.026 (0.018-0.038) ^a
15:1 SNC243A/Fentanyl	0.234 (0.160-0.342)	0.067 (0.042-0.107) ^a
45:1 SNC243A/Fentanyl	0.672 (0.460-0.982)	0.256 (0.253-0.259) ^a
30:1 MSF61/Fentanyl	0.53 (0.41-0.70)	0.59 (0.40-0.87)
89:1 MSF61/Fentanyl	1.54 (1.18-2.03)	1.49 (1.21-1.85)
267:1 MSF61/Fentanyl	4.60 (3.50-6.04)	5.73 (4.84-6.80)
4:1 Naltrindole/Fentanyl	0.09 (0.06-0.11)	0.12 (0.12-0.12) ^b
12:1 Naltrindole/Fentanyl	0.22 (0.17-0.29)	0.30 (0.26-0.36)
36:1 Naltrindole/Fentanyl	0.64 (0.48-0.83)	>2.56†