TY - JOUR
T1 - Methadone and metabolite urine concentrations in patients maintained on methadone
AU - Preston, Kenzie L.
AU - Epstein, David H.
AU - Davoudzadeh, David
AU - Huestis, Marilyn A.
N1 - Funding Information:
This work was supported by the Intramural Research Program of the National Institute on Drug Abuse Intramural Research Program.
PY - 2003/9
Y1 - 2003/9
N2 - As regulatory control over methadone maintenance relaxes, the need for methods of monitoring compliance will increase. In community clinics, monitoring would most likely involve immunoassays of outpatients' trough urine specimens. There are no published norms for such data. Therefore, we determined concentrations of methadone in 1093 urine specimens collected thrice weekly in 27 outpatients during up to 17 weeks of observed methadone ingestion (35 to 80 mg/day) using a semiquantitative homogeneous enzyme immunoassay (CEDIA). We used a separate CEDIA assay to measure methadone's main metabolite, 2-ethylidene-3,3-diphenylpyrrolidine (EDDP), which may help detect compliance in fast metabolizers or patients who adulterate samples to simulate compliance. Methadone concentrations were more variable than those of EDDP. Concentrations of methadone were < 100 ng/mL in one specimen, between 100 and 300 ng/mL in 27, and ≥ 300 ng/mL in all others. EDPP concentrations were ≥ 100 ng/mL in all specimens, suggesting that EDDP should be detectable in urine from compliant patients. Methadone and EDDP concentrations significantly increased with methadone dose and (in one participant with poor clinic attendance) significantly decreased following missed methadone doses. Nevertheless, variability was too great to permit estimation of methadone dose (or detect a single missed administration) from any single specimen.
AB - As regulatory control over methadone maintenance relaxes, the need for methods of monitoring compliance will increase. In community clinics, monitoring would most likely involve immunoassays of outpatients' trough urine specimens. There are no published norms for such data. Therefore, we determined concentrations of methadone in 1093 urine specimens collected thrice weekly in 27 outpatients during up to 17 weeks of observed methadone ingestion (35 to 80 mg/day) using a semiquantitative homogeneous enzyme immunoassay (CEDIA). We used a separate CEDIA assay to measure methadone's main metabolite, 2-ethylidene-3,3-diphenylpyrrolidine (EDDP), which may help detect compliance in fast metabolizers or patients who adulterate samples to simulate compliance. Methadone concentrations were more variable than those of EDDP. Concentrations of methadone were < 100 ng/mL in one specimen, between 100 and 300 ng/mL in 27, and ≥ 300 ng/mL in all others. EDPP concentrations were ≥ 100 ng/mL in all specimens, suggesting that EDDP should be detectable in urine from compliant patients. Methadone and EDDP concentrations significantly increased with methadone dose and (in one participant with poor clinic attendance) significantly decreased following missed methadone doses. Nevertheless, variability was too great to permit estimation of methadone dose (or detect a single missed administration) from any single specimen.
UR - http://www.scopus.com/inward/record.url?scp=0042934163&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0042934163&partnerID=8YFLogxK
U2 - 10.1093/jat/27.6.332
DO - 10.1093/jat/27.6.332
M3 - Article
C2 - 14516485
AN - SCOPUS:0042934163
SN - 0146-4760
VL - 27
SP - 332
EP - 341
JO - Journal of analytical toxicology
JF - Journal of analytical toxicology
IS - 6
ER -