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

Sweat was collected from the palm and torso with a heated sweat patch device (Fast Patch) for 5 to 30 min intervals. The Fast Patch device contains a heating unit to stimulate sweat production. Sweat was also collected with PharmChek sweat patches worn on the torso for intervals ranging from 1 hr to 7 days. Patches were analyzed by GC-MS for cocaine and metabolites.

Cocaine secretion in sweat typically peaked within 2 hr after dosing. Peak cocaine concentrations ranged from 237-2,085 ng/Fast Patch and from 44-124 ng/PharmChek patch for the low dose and from 120-3,579 ng/Fast Patch and from 52-87 ng/PharmChek patch for the high dose. Cocaine was present in Fast Patches (worn for 30 min intervals) for up to 3 days after dosing. In comparison, cocaine was detected for approximately 1 day in PharmChek patches worn for 1 to 16 hr intervals after dosing. A clear relationship was not evident between dose and drug concentration in patches.

The primary cocaine metabolites in patches were benzoylecgonine and ecgonine methyl ester. Concentrations of these metabolites were generally less than 10% of cocaine. These data suggest that sweat testing with the PharmChek patch is beneficial in monitoring drug use when the patch is worn for days to weeks. Sweat testing with the Fast Patch device may be a practical alternative to urine drug testing since the Fast Patch device allows for rapid, noninvasive specimen collections, and drug can be detected for up to 3 days after use.