TABLE 1

Average maximum codeine, cocaine, and metabolite concentrations in hair samples from 10 participants during a controlled codeine and cocaine administration study

Baseline hair shavings were collected at the end of the 3-week washout period, immediately preceding the start of drug dosing, representing previously self-administered cocaine (mean ± S.E.M.). The number of specimens exceeding the assay LOQ = 10, 9, 4, and 5 for cocaine, benzoylecgonine, norcocaine, and cocaethylene, respectively. Cocaethylene Cmax were approximately 2% of cocaine Cmax. Cocaine hydrolysis controls showed 0.91 ± 0.05% cocaethylene (n = 15) formed during sample extraction and analysis.

Baseline
Maximum Concentrations (Cmax)
Low Dosea
 High Dosea
Cocaine (pg/mg) 464 ± 176 2997 ± 619 6419 ± 1698*
Benzoylecgonine (pg/mg) 82 ± 19 314 ± 51 708 ± 163*
Ecgonine methylester (pg/mg) <LOQb 187 ± 27 425 ± 65*
Norcocaine (pg/mg) 32 ± 6.7 84 ± 21c 218 ± 46*
Cocaethylene (pg/mg) 60 ± 20 71 ± 17 143 ± 38*
Codeine (pg/mg)
<LOQ
1291 ± 182
2725 ± 426*

  • ↵ a Maximum concentrations observed 1 to 3 weeks after start of drug dosing (mean ± S.E.M., n = 10).

  • ↵ b Concentrations did not exceed the assay LOQ.

  • ↵ c One sample did not exceed LOQ (n = 9).

  • ↵* p < 0.05 compared with low-dose Cmax using paired t test.