Table 1

ED₅₀ (milligram per kilogram) for stimulus and rate altering effects of morphine before, during, and after treatment with clocinnamox

	Maximal S.D.	ED₅₀^1-a	95% CL	Dose Ratio vs. Control^1-b	95% CL	Dose Ratio vs. 20 MS^1-c	95% CL
Stimulus effects
⁺ 10 C-Cam (n = 5)
Control	100	0.99	0.52–1.9
10 mg/kg C-Cam	100	6.4^1-150	2.6–16	6.5	2.7–15
Chronic MS ⁺ 3.2 C-Cam (n = 7)
Control	100	0.58	0.40–0.85
20 mg/kg per day MS	100	1.4^1-150	0.84–2.3	2.4	1.6–3.5
3.2 mg/kg C-Cam	91	10^1-150 ^1-151	4.1–25	18	6.8–45	7.3	3.7–14
Recovery, week 1	95	2.3^1-150	0.97–5.5	4.0	1.8–8.8	1.7	0.93–2.9
Recovery, week 2	93	1.3^1-150	0.63–2.8	2.3	0.98–5.4	0.96	0.50–1.8
Chronic MS ⁺ 10 C-Cam (n = 6)
Control	98	0.56	0.31–1.0
20 mg/kg per day MS	99	1.9^1-150	1.2–3.0	3.4	2.4–4.8
10 mg/kg C-Cam	86	12^1-150 ^1-151 ^1-d	4.9–32	22	9.0–54	6.5	2.9–15
Recovery, week 1	86	1.1	0.078–16	2.0	0.12–31	0.58	0.034–9.9
Recovery, week 2	100	0.68	0.31–1.5	1.2	0.50–2.9	0.36	0.14–0.95
Rate effects
⁺ 10 C-Cam
Control		2.8	1.3–6.2
10 mg/kg C-Cam		18^1-150	10–34	6.5	3.3–13
Chronic MS ⁺ 3.2 C-Cam
Control		3.3	2.6–4.0
20 mg/kg per day MS		6.1^1-150	4.4–8.2	1.9	1.4–2.4
3.2 mg/kg C-Cam		35^1-150 ^1-151	24–52	11	8.6–14	5.8	4.3–7.9
Recovery, week 1		9.3^1-150 ^1-151	6.8–13	2.8	2.1–3.8	1.5	1.2–2.0
Recovery, week 2		4.0^1-151	3.3–4.9	1.2	0.99–1.5	0.67	0.58–0.77
Chronic MS ⁺ 10 C-Cam
Control		2.3	1.2–4.3
20 mg/kg per day MS		4.1	2.8–6.1	1.8	0.95–3.4
10 mg/kg C-Cam		77^1-150 ^1-151	41–145	34	17–65	19	9.8–36
Recovery, week 1		20^1-150 ^1-151	12–36	8.9	4.4–18	5.0	2.8–8.6
Recovery, week 2		4.5	3.0–6.6	1.9	1.2–3.1	1.1	0.67–1.8

Clocinnamox treatment was administered alone or during treatment with doses of 20 mg/kg per day morphine.

↵1-150 Significantly different from control ED₅₀,P < 0.05.
↵1-151 Significantly different from ED₅₀ during treatment with 20 mg/kg per day morphine, P < 0.05.
↵1-a All non-linear regressions of stimulus effects or response rate on log₁₀ dose were statistically significant,P < 0.05. Unless noted, slopes of test curves did not differ from slopes of control curves.
↵1-b Ratio expressed as (ED₅₀ after treatment / ED₅₀ for control curve).
↵1-c Ratio expressed as (ED₅₀ after treatment / ED₅₀ following MS treatment).
↵1-d Slope differs from those of control curve and curve during treatment with 20 mg/kg per day morphine.