title: Methadone concentrations in plasma and their relationship to drug dosage.
abstract: 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.
authors.affiliation: Department of Chemical Pathology, Old Medical School, University of Leeds, U.K.
authors.forename: K
authors.initials: K
authors.lastname: Wolff
authors.forename: M
authors.initials: M
authors.lastname: Sanderson
authors.forename: A W
authors.initials: AW
authors.lastname: Hay
authors.forename: D
authors.initials: D
authors.lastname: Raistrick
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008691:Methadone / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics; D009293:Opioid-Related Disorders / Q000188:drug therapy
chemical_list: D008691:Methadone