Several reports suggest a prolonged elimination of cocaine and metabolites after chronic use compared with single or occasional use. This study was designed to measure the half-lives of cocaine in plasma and saliva of individuals who consumed cocaine on a frequent basis. The disposition and elimination patterns of cocaine and metabolites in the body fluids of chronic high-dose cocaine users during acute cessation of use were investigated. Plasma and saliva specimens were collected over a 12-h period during cessation and analyzed by gas chromatography-mass spectrometry. Pharmacokinetic parameters were derived by noncompartmental analysis of plasma and saliva data. Results indicated a cocaine terminal T½ of 3.8 h in plasma and 7.9 h in saliva. The terminal T½ of benzoylecgonine was 6.6 h in plasma and 9.2 h in saliva. Compared with prior studies of acute low-dose cocaine administration, these findings suggest that cocaine's half-life is longer in active street users than in occasional users though the half-life of its main metabolite benzoylecgonine remains similar (as do cocaine saliva-to-plasma ratios). Thus, regular use of cocaine appears to alter the disposition and elimination of cocaine when compared to single or occasional use.
一些报告表明,与单次或偶尔使用相比,长期使用
可卡因和代谢物的消除时间更长。本研究旨在测量经常食用
可卡因的个体血浆和唾液中
可卡因的半衰期。研究了长期高剂量
可卡因使用者在急性停止使用期间体液中
可卡因和代谢物的处置和消除模式。在戒烟期间 12 小时内收集血浆和唾液样本,并通过气相色谱-质谱法进行分析。通过血浆和唾液数据的非房室分析得出药代动力学参数。结果表明,血浆中
可卡因末端 T½ 为 3.8 小时,唾液中为 7.9 小时。苯甲酰爱
康宁的末端 T½ 在血浆中为 6.6 小时,在唾液中为 9.2 小时。与之前对急性低剂量
可卡因给药的研究相比,这些研究结果表明,
可卡因在活跃的街头使用者中的半衰期比偶尔使用者中的要长,尽管其主要代谢物苯甲酰爱
康宁的半衰期仍然相似(
可卡因唾液与
可卡因的半衰期相似)。血浆比率)。因此,与单次或偶尔使用相比,定期使用
可卡因似乎会改变
可卡因的处置和消除。