Because the cause of stuttering has never been clearly defined, the use of pharmacological agents has not been encouraged ever since. In addition, people who stutter experience different effects of drugs prescribed for treatment.
As such, there are different perspectives being taken in drug treatment for stuttering. From the etiological theories, experts view mainly the cause of stuttering as a psychological problem. It further explains that stuttering is a result of repressed needs or unconscious expression of internal conflicts.
Theories later see stuttering as a series of learned behaviours arising from psychological causes such as fear and anxiety. There are some theories that view stuttering as a genetic disorder. Scientific evidences later developed based on neurological motor and sensory deficits. These genetic abnormalities are combined with motor control deficits, learned behaviours, and psychological deficits as combined cause of stuttering.
Following these theories, still several pharmaceutical agents are invented to cure the disorder. Examples of agents based on these etiological theories are antipsychotics, neuroleptics, and sedatives and tranquilizers.
Antipsychotics include the use of carbon dioxide inhalation in 1948. This treatment would leave the stutterer unconscious for a moment and then followed by psychomotor excitement. Several psychological-related conditions such as phobias, hysteria, and disassociative states are treated with carbon dioxide. However, some experiments proved the ineffectiveness of carbon dioxide treatment in stuttering.
The neuroleptics are antipsychotic drugs that affect the psychomotor activity. Fortunately, they do not have hypnotic effects nor are sleep-inducing agents. Examples of neuroleptics used in treating stuttering are thioridaxine, trifluoperazine, and haloperidol. Experiments showed that thioridaxine and trifluoperazine reduce the severity of stuttering but not the frequency. Meanwhile, haloperidol is the most effective drug that improves stuttering symptoms as of to date but seldom prescribed because of its adverse effects such as dizziness.
Because of the popular theory of fear and anxiety as probable cause of stuttering, many experts have prescribed the use of sedatives and tranquilizers. An example of drug that has been tried but with little effect is the antihistamine, which has anti-anxiety and hypnotic effects.
Other minor tranquilizers include reserpine and meprobamate. Both are effective in lessening anxiety and physical tension.
Meanwhile, there are also drugs being prescribed based on a symptomatic and serendipitous basis. Some drugs are prescribed to cure the symptom of stuttering rather than the underlying etiology. For instance, neostignine was used because it was effective in treating spastic conditions, which some studies consider stuttering as a form of spasm. Luckily, some experiments showed positive results.
In addition, verapamil is a drug prescribed due to serendipitous basisa calcium channel blocker is used in treating cardiac arrhythmia. Like neostignine, experiments also showed favourable results. It is believed that verapamil might also reduce spasm in the muscles of articulation the way it does in the cardiac muscles. Other types of cardiac medications also showed positive effects on stuttering.
Yet, there are two vital factors in treating stuttering. One, there is no single drug approach that has been proven better quality. Second, even experiments showed favourable results, these drugs did not eradicate the stuttering.