Methadone concentrations in plasma and their relationship to drug dosage.
We have developed a sensitive HPLC method for measuring methadone in plasma and have used it to establish that there is a linear relationship between plasma concentration and methadone dose over the range of 3-100 mg of methadone per day in a group of 31 addicts. We found a good correlation between dose and plasma concentration (r = 0.89), with the plasma methadone concentration increasing by 0.263 mg/L for every milligram of methadone consumed per kilogram of body weight. Five patients had unexpected high or low concentrations; this finding is discussed.
Wolff
K
K
Department of Chemical Pathology, Old Medical School, University of Leeds, U.K.
Sanderson
M
M
Hay
A W
AW
Raistrick
D
D
D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008691:Methadone / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics; D009293:Opioid-Related Disorders / Q000188:drug therapy
D008691:Methadone