A synthetic derivative of benzoquinolysine, has a specific effect on the central nervous system, similar to reserpine, but unlike the latter, tetrabenazine has a slight peripheral activity and a shorter duration of action. Tetrabenazine interferes with the metabolism of biogenic amines such as serotonin and norepinephrine in the brain.
Inhibits the reuptake of monoamines in the nerve endings of the presynaptic neurons of the central nervous system, which leads to a decrease in the amount of monoamines, incl. dopamine in the brain.
Dopamine depletion leads to hypokinesia, which helps reduce the severity of chorea. In synaptic nerve endings, tetrabenazine inhibits monoamine reuptake through reversible and short-term binding of the vesicular monoamine transporter (VMAT). VMAT 2 transports monoamines to peripheral and central neurons, while VMAT 1 regulates transport in peripheral chromaffin tissues. Tetrabenazine has a higher affinity for VMAT 2 than for VMAT 1, so the drug has a short-term insignificant peripheral effect.