6.17: Drugs Affecting Neurotransmitter Release or Uptake
Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking neurotransmitter release and uptake by targeting the catecholamine transporter NET. It can also enter synaptic vesicles and displace noradrenaline. Some other drugs like duloxetine, imipramine, and cocaine also inhibit this transporter. Cocaine, in particular, enhances sympathetic activity by obstructing the reuptake of catecholamines. While these drugs have been studied experimentally, only a few have been used clinically. Newer and more selective drugs have made some of these compounds outdated. However, understanding how these drugs affect the release and reuptake of catecholamines is essential for potential treatments of various disorders.
