SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

P18
SCREENING BY ELISA FOR CARISOPRODOL IN POST-MORTEM BLOOD
F. Nunes-Daniel and D. Boehme
Ventura County Sheriff Forensic Sciences Laboratory; 800 S. Victoria Ave; Ventura, CA 93009
Carisoprodol is an unscheduled substance widely prescribed in the USA to promote skeletal muscle
relaxation. The use of carisoprodol is associated with CNS depression, which can lead to impairment in
driving and other psychomotor activities. Therefore, it is very important to have a reliable method to test
post-mortem blood sample for carisoprodol. Using Immunalysis Direct Elisa Kit and the PersonnalLABTM
as the analyzer we developed an application to screen carisoprodol in post-mortem blood. We tested a
variety of samples using different sample volumes and cutoffs. Using 25uL as the sample volume and
500nglmL as the cutoff, thirty-two samples were analyzed by ELISA v. GCfMS and GCfNPD. Ten were
positive by both the immunoassay and the chromatographic methods. One sample screened between the
negative control and the cutoff calibrator, and was found to contain 4.78 mglmL of carisoprodol. The
concentrations of carisoprodol in samples that screened positive ranged from 0.12 mgIL to 45.2 mgIL.
These samples also contained meprobamate, ranging in concentration from 2.26 mg/L to 20.2 mgIL. None
of the ELISA-negative samples contained carisoprodol at greater than 500 ngimL. The twenty-one samples
that were negative by both the ELISA and by the chromatographic methods contained a broad range of
other drugs, including cocaine, benzoylecgonine, codeine, morphine, hydrocodone, methadone,
amitriptyline, nortriptyline, diazepam, nordiazepam, temazepam, alprazolam, acetaminophen, bupropion
and its metabolites, norchlorcyclizine, nicotine, cotinine, caffeine, olanzapine, fluoxetine, norfluoxetine,
norpropoxyphene, doxylamine, tripolidine, and metoclopramide. A precision study was conducted by
analyzing 10 replicates each of the negative calibrator, a 250 ng/mL control, the 500 ng/mL calibrator, and
a positive control containing 1000 nglmL carisoprodol. The OD's were tracked and the results were as
follows: negative calibrator: 1.386 ±..0.051 (CV= 3.7%); 250 ng/mL control: 0.510 ± 0.015 (CV= 2.9%);
500 nglmL calibrator: 0.440 ± 0.024 (CV= 5.4%); and 1000 ng/mL control: 0.410 ± 0.014 (CV= 3.4%).
Keywords: Carisoprodol; immunoassay; postmortem blood
Page 353