Ruksee Nootchanart, Tongjaroenbuangam Walaiporn, Casalotti Stefano O, Govitrapong Piyarat
Neuro-Behavioral Biology Center, Institute of Science and Technology, Research and Development, Mahidol University, Salaya, Nakornpathom, 73170, Thailand.
BMC Neurosci. 2008 Oct 6;9:99. doi: 10.1186/1471-2202-9-99.
Pseudoephedrine is a drug commonly prescribed as a nasal decongestant and bronchodilator and is also freely available in cold remedies and medications. The structural and pharmacological similarity of pseudoephedrine to amphetamine has led to evaluation of its psychomotor stimulant properties within the central nervous system. Previous investigations have shown that the acute responses to pseudoephedrine were similar to those of amphetamine and other psychostimulants.
This study examined the effect of chronic administration of pseudoephedrine in rat nucleus accumbens and striatum and identified three further similarities to amphetamine. (i) Chronic exposure to pseudoephedrine reduced the c-Fos response to acute pseudoephedrine treatment suggesting that pseudoephedrine induced tolerance in the animals. (ii) In animals chronically treated with amphetamine or pseudoephedrine the acute c-Fos response to pseudoephedrine and amphetamine was reduced respectively as compared to naïve animals indicating cross-tolerance for the two drugs. (iii)The known involvement of the dopamine system in the response to amphetamine and pseudoephedrine was further confirmed in this study by demonstrating that pseudoephedrine similarly to amphetamine, but with lower potency, inhibited [3H]dopamine uptake in synaptosomal preparations.
This work has demonstrated further similarities of the effect of pseudoephedrine to those of amphetamine in brain areas known to be associated with drug addiction. The most significant result presented here is the cross tolerance effect of amphetamine and pseudoephedrine. This suggests that both drugs induce similar mechanisms of action in the brain. Further studies are required to establish whether despite its considerable lower potency, pseudoephedrine could pose health and addiction risks in humans similar to that of known psychostimulants.
伪麻黄碱是一种常用作鼻减充血剂和支气管扩张剂的药物，在感冒药和药物中也可随意获取。伪麻黄碱与苯丙胺在结构和药理上的相似性促使人们对其在中枢神经系统中的精神运动刺激特性进行评估。先前的研究表明，对伪麻黄碱的急性反应与苯丙胺和其他精神兴奋剂的反应相似。
本研究检测了长期给予伪麻黄碱对大鼠伏隔核和纹状体的影响，并确定了与苯丙胺的另外三个相似之处。（i）长期接触伪麻黄碱会降低急性伪麻黄碱治疗引起的c-Fos反应，这表明伪麻黄碱在动物中诱导了耐受性。（ii）与未处理的动物相比，长期用苯丙胺或伪麻黄碱处理的动物对伪麻黄碱和苯丙胺的急性c-Fos反应分别降低，表明这两种药物存在交叉耐受性。（iii）本研究进一步证实了多巴胺系统在对苯丙胺和伪麻黄碱反应中的已知作用，通过证明伪麻黄碱与苯丙胺类似，但效力较低，可抑制突触体制剂中[3H]多巴胺的摄取。
这项工作进一步证明了伪麻黄碱与苯丙胺在已知与药物成瘾相关的脑区中的作用相似性。此处呈现的最显著结果是苯丙胺和伪麻黄碱的交叉耐受效应。这表明这两种药物在大脑中诱导相似的作用机制。需要进一步研究以确定尽管伪麻黄碱的效力低得多，但它是否会给人类带来与已知精神兴奋剂类似的健康和成瘾风险。
