How to counteract the deterioration of speech in stutterers by targeting sympathetic arousal? I am quoting a good overview from a Quora member about the reasons why people stutter when exposed to stress:

...The underlying physiological basis of why stress provokes stuttering
has been addressed by Weber &amp; Smith, (1990). It shows that speaking
increases autonomic activity (elevated blood flow, increased heart
rate, sweating) and that this sympathetic arousal was correlated with
increased stuttering behaviors in stutterers. Interestingly, the
sympathetic arousal of stutterers was found not to be outside the
range of controls. The authors bring up several hypotheses as to why
sympathetic activity may deteriorate speech fluency in stutterers:
Increased autonomic activity has been associated with irregular
breathing, which may affect speaking;
Release of the stress hormone adrenalin may induce muscle tremor and spasms that can affect speech production;
Sympathetic regulation of afferent control of the
sensitivity of sensory receptors (muscle spindles and
mechanoreceptors) in the oralmotor, laryngeal and respiratory system
may affect speech motor processes;
The gain of reflex arches
(feedback) involved in the musculature engaged in speech may be
modulated such that speech fluency is negatively impacted.

Unfortunately, clinical research in this field is not that advanced and good evidence on human studies is yet to be seen.
My question is whether we already know compounds whose mechanisms can in theory help to deal or ameliorate these pathological process in stutterers?
The first line treatment for stuttering (I'm a stutterer myself) is speech therapy. Such therapies generally focus on helping stutterers to learn ways to minimize stuttering when they speak, such as by speaking more slowly, regulating their breathing, or gradually progressing from single-syllable responses to longer words and more complex sentences. Most of these therapies also help address the anxiety a person who stutters may feel in certain speaking situations (source: NIH). Anxiety management has especially worked well for me.

No drug therapy is currently approved against stuttering. I also don't know of any drug that targets the sympathetic nervous system. Having said that, there are a few interesting drugs investigated in clinical trials so far:


Dopamine-blocking medications against bipolar disorder, Tourette’s Disorder and Schizophrenia have been found to be effective in reducing the symptoms of stuttering (source: NSA). Their side effects, however, don't seem to weigh up against their effectiveness.
Pagoclone, a GABA-agonist used as anxiolytic has shown some effectiveness, but not enough to warrant it to be marked as anti-stutter therapy (source: BSA)