Table 2.
Apparent pA2 or pKB values for naltrexone in the presence of CTAP, CTAP in the presence of naltrexone, and CTOP in the presence of naltrexone and CTAP
| Antagonist | pA2 (+95% CL) | Slope (+95% CL) | Slope constrained pA2 (+95% CL) |
|---|---|---|---|
| Naltrexone s.c. | 8.9 (5.1–13) | −0.72 (−1.9 to 0.48) | 8.3 (7.6–9.0) |
| +1.0 μg CTAP | 6.6 (6.4–6.8) | −3.7c (−6.0 to −1.4) | —d |
| +10 μg CTAP | 7.3 (5.0–9.7) | −0.88 (−3.6 to 1.9) | 7.3 (6.9–7.7) |
| +1 μg Naltrexone | 8.6a | —d | —d |
| CTAP i.c.v. | 9.0 (2.6–15) | −0.80 (−6.0 to 4.4) | 8.8 (8.2–9.4) |
| +0.1 mg kg−1 naltrexone | 9.7b | −0.46 | —d |
| CTOP i.c.v. | 8.9 | −1.54 | —d |
| +Naltrexone and CTAP | 9.5a | —d | —d |
a
Apparent pKB calculation using a dose of antagonist or antagonist combination.
b
Apparent pA2 and slope values determined using only two dose–response curves.
c
Slope significantly different than naltrexone s.c. in the presence of 10 μg CTAP i.c.v.
d
Value cannot be determined.