Table 4

Degree of antinociceptive cross-tolerance (%CT) between oxycodone and morphine, administered supraspinally (i.c.v.) and/or i.v.

Opioid Drug Administered%CT
%
i.c.v. oxycodone to morphine-tolerant rats8.3
i.v. oxycodone to morphine-tolerant rats23.7
i.c.v. morphine to oxycodone-tolerant rats53.9
i.v. morphine to oxycodone-tolerant rats71.3