TABLE 1

Opioid receptor Ki and selectivity ratios for hydrocodone, hydromorphone, and norhydrocodone in mouse spinal cord tissue homogenate

DrugMean Ki (95% Cl)aSelectivity Ratiosb
μδκδ/μκ/μκ/δ
nMnMnM
HYC56 (40–80)1429 (974–2097)4321 (2210–8450)25.577.23.0
HYM1.3 (0.9–2.0)35 (23–55)79 (32–209)26.960.82.3
NHYC142 (96–210)2166 (1472–3188)6498 (2930–15382)15.345.83.0

  • ↵a Data are means of three independent experiments.

  • ↵b Selectivity ratios were determined by dividing the respective Ki values. See Materials and Methods for details.