TABLE 3.

Cumulative doses of test compounds (mg/kg) studied in compound mixtures

Values in parentheses are S.E.M.

Compound	Cycle 1	Cycle 2	Cycle 3	Cycle 4	Cycle 5	Cycle 6
1 Morphine: 1 Lofexidine
Morphine	Vehicle	1.79 (0.447)	3.19 (0.795)	5.69 (1.42)	10.1 (2.52)	18.0 (4.48)
Lofexidine	Vehicle	0.0196 (0.00433)	0.0348 (0.00771)	0.0620 (0.0137)	0.110 (0.0244)	0.196 (0.0435)
1 Morphine: 2 Lofexidine
Morphine	Vehicle	0.897 (0.223)	1.60 (0.398)	2.84 (0.708)	5.06 (1.26)	9.01 (2.24)
Lofexidine	Vehicle	0.0293 (0.00650)	0.0522 (0.0116)	0.0930 (0.0206)	0.165 (0.0367)	0.295 (0.0652)
3 Morphine: 1 Lofexidine
Morphine	Vehicle	2.69 (0.670)	4.79 (1.19)	8.53 (2.12)	15.2 (3.78)	27.0 (6.73)
Lofexidine	Vehicle	0.00978 (0.00217)	0.0174 (0.00386)	0.0310 (0.00686)	0.0552 (0.0122)	0.0982 (0.0217)
2 Morphine: 1 Clonidine
Morphine	Vehicle	1.79 (0.447)	3.19 (0.795)	5.69 (1.42)	10.1 (2.52)	18.0 (4.48)
Clonidine	Vehicle	0.00379 (0.000994)	0.00675 (0.00177)	0.0120 (0.00315)	0.0214 (0.00561)	0.0381 (0.00998)
1 Morphine: 2 Clonidine
Morphine	Vehicle	0.897 (0.223)	1.60 (0.398)	2.84 (0.708)	5.06 (1.26)	9.01 (2.24)
Clonidine	Vehicle	0.00569 (0.00149)	0.0101 (0.00266)	0.0180 (0.00473)	0.0321 (0.00841)	0.0571 (0.0150)
3 Morphine: 1 Clonidine
Morphine	Vehicle	2.69 (0.670)	4.79 (1.19)	8.53 (2.12)	15.2 (3.78)	27.0 (6.73)
Clonidine	Vehicle	0.00190 (0.000497)	0.00338 (0.000885)	0.00601 (0.00158)	0.0107 (0.00280)	0.0190 (0.00499)
1 Methadone: 1 Lofexidine
Methadone	Vehicle	0.144 (0.0429)	0.257 (0.0764)	0.457 (0.136)	0.813 (0.242)	1.45 (0.431)
Lofexidine	Vehicle	0.0196 (0.00433)	0.0348 (0.00771)	0.0620 (0.0137)	0.110 (0.0244)	0.196 (0.0435)
1 Methadone: 2 Lofexidine
Methadone	Vehicle	0.0721 (0.0215)	0.128 (0.0382)	0.228 (0.0680)	0.407 (0.121)	0.724 (0.215)
Lofexidine	Vehicle	0.0293 (0.00650)	0.0522 (0.0166)	0.0930 (0.0206)	0.165 (0.0367)	0.295 (0.0652)
3 Methadone: 1 Lofexidine
Methadone	Vehicle	0.216 (0.0644)	0.385 (0.115)	0.685 (0.204)	1.22 (0.363)	2.17 (0.646)
Lofexidine	Vehicle	0.00978 (0.00217)	0.0174 (0.00386)	0.0310 (0.00686)	0.0552 (0.0122)	0.0982 (0.0217)
2 Methadone: 1 Clonidine
Methadone	Vehicle	0.144 (0.0429)	0.257 (0.0764)	0.457 (0.136)	0.813 (0.242)	1.45 (0.431)
Clonidine	Vehicle	0.00379 (0.000994)	0.00675 (0.00177)	0.0120 (0.00315)	0.0214 (0.00561)	0.0381 (0.00998)
1 Methadone: 1 Clonidine
Methadone	Vehicle	0.0721 (0.0215)	0.128 (0.0382)	0.228 (0.0680)	0.406 (0.121)	0.724 (0.215)
Clonidine	Vehicle	0.00569 (0.00149)	0.0101 (0.00266)	0.0180 (0.00473)	0.0321 (0.00841)	0.0571 (0.0150)
4 Methadone: 1 Clonidine
Methadone	Vehicle	0.216 (0.0644)	0.385 (0.115)	0.685 (0.204)	1.22 (0.363)	2.17 (0.646)
Clonidine	Vehicle	0.00190 (0.000467)	0.00338 (0.000885)	0.00601 (0.00158)	0.0107 (0.00280)	0.0190 (0.00499)
1 U69,593: 1 Lofexidine
U69,593	Vehicle	0.346 (0.0471)	0.616 (0.0839)	1.10 (0.149)	1.95 (0.266)	3.47 (0.473)
Lofexidine	Vehicle	0.0177 (0.00346)	0.0316 (0.00616)	0.0562 (0.0110)	0.100 (0.0195)	0.178 (0.0348)
1 U69,593: 2 Lofexidine
U69,593	Vehicle	0.173 (0.0236)	0.308 (0.0420)	0.548 (0.0747)	0.975 (0.133)	1.74 (0.237)
Lofexidine	Vehicle	0.0339 (0.00757)	0.0603 (0.135)	0.107 (0.0240)	0.191 (0.0427)	0.340 (0.760)
2 U69,593: 1 Lofexidine
U69,593	Vehicle	0.519 (0.0707)	0.923 (0.126)	1.64 (0.224)	2.93 (0.399)	5.21 (0.710)
Lofexidine	Vehicle	0.0113 (0.00252)	0.0201 (0.00449)	0.0358 (0.00800)	0.0637 (0.0142)	0.113 (0.0253)
2 U69,593: 1 Clonidine
U69,593	Vehicle	0.346 (0.0471)	0.616 (0.0839)	1.10 (0.149)	1.95 (0.266)	3.47 (0.473)
Clonidine	Vehicle	0.00382 (0.000956)	0.00680 (0.00170)	0.0121 (0.00303)	0.0215 (0.00539)	0.0384 (0.00960)
1 U69,593: 2 Clonidine
U69,593	Vehicle	0.173 (0.0236)	0.308 (0.0420)	0.548 (0.0747)	0.975 (0.133)	1.74 (0.237)
Clonidine	Vehicle	0.00761 (0.00215)	0.0135 (0.00383)	0.0241 (0.00681)	0.0429 (0.0121)	0.0764 (0.0216)
3 U69,593: 1 Clonidine
U69,593	Vehicle	0.519 (0.0707)	0.923 (0.126)	1.64 (0.224)	2.93 (0.399)	5.21 (0.710)
Clonidine	Vehicle	0.00254 (0.000717)	0.00451 (0.00128)	0.00803 (0.00227)	0.0143 (0.00404)	0.0255 (0.00720)