Dose, Plasma Level, and Treatment Outcome Among Methadone Patients in Shanghai, China.
The purpose of this study was to investigate the blood levels of methadone in participants receiving methadone for the treatment of opioid dependence. After stabilization on methadone for four weeks, blood samples from 95 participants were collected between treatment weeks 4 and 12, before and after receiving doses of methadone, and its blood levels were measured. A multiple linear regression model was used to examine the association between methadone blood levels and the outcomes of methadone maintenance treatment (MMT). Outcome differences between participants who had high (≥2) or low (<2) peak-to-trough ratios were also compared using an independent sample t-test. The blood level of methadone was not correlated with the clinical outcome of MMT with the moderate range of doses given. However, the retention of patients who had a free peak-to-trough ratio >2 was significantly poorer than those whose ratio was <2. Thus, monitoring plasma methadone levels is unlikely to be effective for guiding dosing decisions in situations where compliance with MMT is already very high or when the methadone dose is no longer the dominant factor in determining the clinical outcome. However, monitoring plasma methadone levels is still helpful for guiding the dosage for patients with a rapid metabolism.
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China.
Haifeng
H
Jiang
Department of Psychiatry, Integrated Substance Abuse Program, University of California at Los Angeles, Los Angeles, CA, 90025, USA.
Maureen
M
Hillhouse
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China.
Jiang
J
Du
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China.
Shujun
S
Pan
Department of Psychiatry, Integrated Substance Abuse Program, University of California at Los Angeles, Los Angeles, CA, 90025, USA.
Ang
A
Alfonso
Shanghai Yangpu District Mental Health Center, Shanghai, 200093, China.
Jun
J
Wang
Shanghai Xuhui District Mental Health Center, Shanghai, 200232, China.
Zhirong
Z
Zhou
Shanghai Hongkou District Mental Health Center, Shanghai, 200083, China.
Weijun
W
Yuan
Department of Psychiatry, Integrated Substance Abuse Program, University of California at Los Angeles, Los Angeles, CA, 90025, USA.
Walter
W
Ling
Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China. drminzhao@gmail.com.
Min
M
Zhao
D000328:Adult; D002681:China; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008691:Methadone / Q000097:blood* / Q000627:therapeutic use*; D008875:Middle Aged; D058850:Opiate Substitution Treatment / Q000379:methods*; D009293:Opioid-Related Disorders / Q000097:blood* / Q000188:drug therapy*; D013223:Statistics as Topic; D016896:Treatment Outcome
D008691:Methadone
Metabolism; Methadone; Plasma level; Treatment outcome