Unintended, repetitive movements of the mouth and tongue, such as chewing or licking, can be unsettling. These motions are a recognized medical side effect and warrant professional medical attention to determine their origin and management.
What Are These Involuntary Movements?
These involuntary movements, often impacting the mouth and face, are called orofacial dyskinesia. This condition involves repetitive, uncontrollable motions of the tongue, lips, jaw, and other facial muscles. Common examples include tongue protrusion, lip smacking, grimacing, chewing, and teeth grinding.
Because these movements are involuntary, the person experiencing them typically cannot control or suppress them. They can sometimes be more noticeable to others than to the individual themselves.
Medications Linked to These Movements
When chronic, these involuntary movements are often a symptom of Tardive Dyskinesia (TD). This movement disorder is most commonly associated with medications that affect dopamine pathways in the brain. Antipsychotic medications, used to manage mental health conditions, are primary culprits.
First-generation (“typical”) antipsychotics like haloperidol and chlorpromazine are particularly known for causing TD due to their strong dopamine-blocking effects. While second-generation (“atypical”) antipsychotics such as risperidone, olanzapine, and quetiapine generally carry a lower risk, they can still induce TD, especially with prolonged use. The risk of TD with second-generation antipsychotics is estimated to be around 7% for those without prior exposure to first-generation drugs.
Beyond antipsychotics, other medications can also contribute to these involuntary movements. Metoclopramide, an anti-nausea drug, carries a significant risk of TD, prompting a “black box” warning due to its dopamine-blocking action. Certain antidepressants, including some tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs), have also been linked to TD in rare cases. Additionally, some anti-seizure medications, lithium, and even stimulants like methylphenidate and amphetamines, have been reported to cause similar dyskinetic symptoms.
The Underlying Neurological Explanation
The development of these involuntary movements is largely attributed to how certain medications interact with dopamine in the brain. Dopamine is a neurotransmitter involved in regulating movement, mood, and pleasure. Many implicated drugs, especially antipsychotics, work by blocking dopamine receptors, particularly D2 receptors, in specific brain regions.
Long-term blocking of these dopamine receptors, particularly in areas like the basal ganglia which control voluntary movement, can lead to changes in brain sensitivity. Over time, the receptors may become hypersensitive to dopamine, leading to an imbalance in neurotransmitter activity. This heightened sensitivity can result in the uncontrolled, repetitive movements characteristic of tardive dyskinesia. While dopamine’s role is central, other neurotransmitters like serotonin and acetylcholine may also be involved in these drug-induced movement disorders.
Managing and Seeking Help for These Symptoms
Experiencing new or worsening involuntary movements warrants immediate consultation with a healthcare professional. Self-diagnosing or abruptly stopping medication without medical guidance is not advisable, as it can lead to withdrawal symptoms or worsen the underlying condition being treated. A healthcare professional can accurately assess the symptoms and determine the most appropriate course of action.
Treatment often involves adjusting medication dosage or switching to a different medication. If a first-generation antipsychotic is the cause, a doctor might consider transitioning to a second-generation antipsychotic, which generally carries a lower risk of TD. For established tardive dyskinesia, specific Vesicular Monoamine Transporter 2 (VMAT2) inhibitors, such as valbenazine and deutetrabenazine, are approved and recommended as first-line treatments. These medications work by regulating dopamine levels in the brain to reduce the involuntary movements.