Pharmacokinetics And Pharmacodynamics Of Drugs Of Abuse

影响药物成瘾性的因素有很多。给药途径是药物进入体内和到达中枢神经系统受体速度的主要决定因素。临床研究正在进行中，以确定不同给药途径的重要性以及药物和活性代谢物的血药浓度与伴随药物效应的关系。关于海洛因、可卡因、甲基苯丙胺、可待因和大麻静脉、烟熏、鼻内和口服给药的研究正在进行或处于数据分析阶段。药效学效应包括主观，认知和精神运动表现，生理测量和特定的大脑活动，由功能磁共振成像评估。通过固相萃取-气相色谱/质谱和液相色谱/质谱分析血浆、尿液、口服液、汗液、头发和皮肤的药物和代谢物。静脉注射和烟熏途径产生迅速的药理作用，并在血液中早期出现药物和代谢物。吸食大麻后观察到效应部位分布延迟的证据，但服用海洛因和可卡因后的药物效应与同时的血液浓度更密切相关。鼻内给药后，特别是口服给药后，效果的发作延迟。

There are many factors that influence the addictiveness of a drug. The route of administration is a major determinant of the speed of drug entry into the body and to receptors in the central nervous system. Clinical studies are in progress which determine the importance of different routes of administration and the relationship of blood concentrations of drug and active metabolites to concomitant drug effects. Studies of heroin, cocaine, methamphetamine, codeine and cannabis administration by the intravenous, smoked, intranasal and oral routes are underway or in the data analysis stage. Pharmacodynamic effects include subjective, cognitive and psychomotor performance, physiological measures and specific brain activity as assessed by fMRI. Plasma, urine, oral fluid, sweat, hair and skin are analyzed for drug and metabolites by solid phase extraction-gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. The intravenous and smoked routes produce a rapid onset of pharmacological effects together with an early appearance of drug and metabolites in blood. Evidence of delays in distribution to effector sites are observed following cannabis smoking, but drug effects following heroin and cocaine administration coincided more closely with concurrent blood concentrations. Onset of effects is delayed following intranasal and especially after oral administration.