Addiction Research Center, IRP, NIDA, NIH, Baltimore, MD, USA
* Sudormed, Inc., Santa Ana, CA, USA

PharmChek sweat patches were applied to the torso to collect sweat during intervals ranging from 1 hr to 7 days. Sweat was also collected with a heated sweat patch device (Fast Patch) that was applied to the palm and torso for 5 to 30 min intervals. Patches were analyzed by GC-MS for codeine and metabolites.

Codeine was the primary analyte detected in Fast Patches and PharmChek patches; metabolites were not generally detected. Peak secretion of codeine usually occurred within 4-8 hr. Peak codeine concentrations ranged from 34-681 ng/Fast Patch and from 13-46 ng/PharmChek patch following the low dose. Peak codeine concentrations ranged from 54-1,123 ng/Fast Patch and from 10-13 ng/PharmChek patch following the high dose. Codeine was present in Fast Patches (worn for 30 min intervals) for 1-3 days following dosing. In comparison, codeine was only occasionally detected in PharmChek patches after dosing. No definitive relationship was evident between dose and the amount of codeine in patches. These data suggest that sweat testing with the PharmChek patch may be beneficial in monitoring drug use when the patch is worn for days to weeks. In comparison, the Fast Patch device provides a rapid method for sweat collection that may be highly effective in monitoring individuals for recent drug use.