Lynn R K, Olsen G D, Leger R M, Gordon W P, Smith R G, Gerber N
Drug Metab Dispos. 1976 Sep-Oct;4(5):504-9.
Four healthy subjects and four addicts on high daily maintenance doses of methadone each received a parenteral dose of methadone hydrochloride following an overnight fast. The concentration of methadone in blood was compared with that in the gastric juice obtained over 8 hr by continuous low-pressure suction via a nasogastric tube. The concentration in the gastric juice was 25-200 times that measured at the same time in the blood. Thus, 8 hr after the injection mean blood concentrations of 28 and 210 ng of methadone per ml were recorded in the normal subjects and the addicts, respectively. The corresponding concentrations in gastric juice were 2,200 ng/ml and 18,000 ng/ml, respectively. In the normal subjects about 2% of the administered dose was recovered in the gastric juice in 8 hr, whereas in addicts about 7% was recovered. The greater recovery of methadone from the addicts appears to be the result of the larger volume of gastric juice recovered from the latter subjects. Methadone was also excreted in the saliva of both groups of subjects. In addicts, salivary concentrations were often 10 times those recorded in the blood. The N-monodemethylated metabolite of methadone was identified in the gastric juice of addicts by gas chromatography and mass spectrometry.
四名健康受试者和四名每天服用大剂量美沙酮维持治疗的成瘾者在禁食过夜后均接受了一次盐酸美沙酮的肠胃外给药。将血液中美沙酮的浓度与通过鼻胃管持续低压抽吸8小时所获得的胃液中的浓度进行比较。胃液中的浓度是同一时间血液中所测浓度的25至200倍。因此，注射8小时后，正常受试者和成瘾者的血液中平均美沙酮浓度分别为每毫升28纳克和210纳克。胃液中的相应浓度分别为2200纳克/毫升和18000纳克/毫升。在正常受试者中，8小时内胃液中回收了约2%的给药剂量，而成瘾者中约为7%。成瘾者中美沙酮回收率较高似乎是因为从这些受试者中回收的胃液量较大。美沙酮也在两组受试者的唾液中排出。在成瘾者中，唾液浓度通常是血液中所测浓度的10倍。通过气相色谱法和质谱法在成瘾者的胃液中鉴定出了美沙酮的N-单去甲基代谢物。
