Understanding Tardive Dyskinesia: A Side Effect of Risperidone

Understanding Risperidone and Tardive Dyskinesia

Risperidone is an atypical antipsychotic drug that is used to treat schizophrenia, bipolar disorder, and irritability associated with autism spectrum disorder. Like other antipsychotics, risperidone works by blocking dopamine receptors in the brain. This helps control hallucinations, delusions, and disordered thinking. However, blocking dopamine can also cause motor side effects known as extrapyramidal symptoms (EPS).

What is Tardive Dyskinesia?

One problematic EPS associated with antipsychotics like risperidone is tardive dyskinesia. Tardive dyskinesia causes involuntary and repetitive body movements, such as lip smacking, grimacing, tongue protrusion, puckering and smacking of lips, or blinking. These movements can be mild or severe and can be very distressing for patients.

Tardive dyskinesia is caused by the dopamine blocking effects of antipsychotics. Dopamine helps control coordinated muscle movement, so reducing dopamine signaling can result in abnormal muscle control. The "tardive" in tardive dyskinesia refers to this side effect emerging after long-term treatment. In some cases, symptoms may persist or even become permanent after stopping the medication.

Risk of Tardive Dyskinesia with Risperidone

All antipsychotic medications carry a risk of tardive dyskinesia, including the atypical or second generation drug risperidone. However, risperidone and other newer atypical antipsychotics are believed to have a lower risk compared to older typical antipsychotics.

According to research, rates of tardive dyskinesia are around 5% for risperidone and other newer antipsychotics per year. For older drugs the rate can be closer to 7.7% per year. So while the risk is lower with risperidone, it is still possible to experience this side effect.

Factors that Increase the Risk

While any patient taking risperidone can experience tardive dyskinesia, some factors place certain people at an even greater risk:

• Older age
• Taking higher doses of antipsychotics
• Use for longer periods of time
• Having diabetes
• Alcohol abuse or dependence
• Cognitive impairment

Additionally, female gender may also increase susceptibility to tardive dyskinesia with antipsychotic use based on some studies.

Identifying Tardive Dyskinesia Symptoms

The early symptoms of tardive dyskinesia often start in the facial muscles and can easily be mistaken for nervous tics or restlessness. Some of the most common facial movements associated with this condition include:

• Lip smacking
• Puckering or pursing lips
• Excessive eye blinking
• Rapid movements of the arms, legs, fingers or toes

As tardive dyskinesia progresses, symptoms generally spread to other parts of the body and can become more severe. Movements may appear more dance-like involving larger muscle groups like the arms or legs. Patients also report symptoms getting worse with stress.

Abnormal Movements and Muscle Control

In addition to involuntary choreic movements, tardive dyskinesia affects muscle control in other ways. Many patients with this condition also experience muscle stiffness or spasms, impaired control and coordination, restlessness, or tremors.

Since symptoms can be tricky to identify, having an experienced clinician evaluate for early signs of tardive dyskinesia is important. Detecting subtle changes right away provides the best chance to reverse or minimize long-term damage before symptoms become severe.

Available Treatment Options for Tardive Dyskinesia

If tardive dyskinesia is identified, the first step is to re-evaluate the antipsychotic medication regimen. Lowering the dose, switching medications, or possibly discontinuing antipsychotics altogether may stop or relieve symptoms.

New Medications to Treat Tardive Dyskinesia

For moderate-severe tardive dyskinesia that continues despite antipsychotic changes, adding a VMAT2 inhibitor medication can help reduce symptoms. The FDA has approved deutetrabenazine (Austedo), valbenazine (Ingrezza), and several generic VMAT2 inhibitors for treating tardive dyskinesia specifically.

These drugs work by regulating dopamine signaling. This helps smooth out disrupted communication between brain cells that control movement. Clinical trials have found using VMAT2 inhibitor medications leads to significantly improved tardive dyskinesia symptoms on assessments of abnormal involuntary movements.

Botulinum Toxin Injections

Botulinum toxin (Botox) injections for tardive dyskinesia have also shown efficacy in clinical studies. Tiny doses carefully injected into the affected muscle can provide temporary relief from spasms, tics, or repetitive movements. Results typically peak in 1-2 weeks then fade over 3 or so months before needing to be repeated.

For severe cases unresponsive to medication, deep brain stimulation (DBS) may be an option too. This involves surgically implanting electrodes to send electrical pulses that regulate abnormal signals causing uncontrolled movements. DBS can successfully suppress symptoms of tardive dyskinesia but does carry more risks compared to medication or Botox.

Preventing Antipsychotic-Induced Tardive Dyskinesia

While treatment is available for existing cases of tardive dyskinesia, prevention is always the best approach. The American Psychiatric Association (APA) has provided recommendations for minimizing the risk of tardive dyskinesia with antipsychotic treatment based on clinical evidence and expert consensus.

Careful Patient Selection and Monitoring

Strategies include carefully selecting appropriate patients for antipsychotics, choosing the effective lowest dose, avoiding combinations of drugs that increase risk, and closely monitoring for any emerging side effects. Catching early symptoms and making changes promptly gives the best chance of avoiding lasting complications of tardive dyskinesia.

Following APA and FDA guidelines for safe antipsychotic use minimizes the likelihood of side effects. However, as risperidone and other similar medications do still carry a risk of tardive dyskinesia, being aware of potential signs and symptoms is an important aspect of patient education as well.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.