Tardive Dyskinesia (TD) is a neurological disorder that causes involuntary, rapid movements of the face and body. The definition of tardive is "delayed," and dyskinesia means "abnormal movement." This condition is a serious side effect of taking antipsychotic medications called neuroleptics, such as those taken to control schizophrenia.
Because no large-scale study of the condition exists, it is unclear how many people have TD, but it is estimated that 50-60 percent of people on neuroleptics will develop the disorder during their lifetimes. People who are 65 or older also show a higher risk for developing it.
Tardive dyskinesia typically affects someone's face, often causing uncontrolled grimaces and movement in the eyes, lips, tongue and jaw. Arms, fingers, toes, legs, hips and torso are also affected and may twitch and move rapidly and uncontrollably. These random body movements can be uncomfortable and painful as well as embarrassing and difficult to control, making it a social handicap. Severe cases of this disorder can be debilitating and make it difficult to perform simple tasks like talking, walking and eating.
Depending on the person, TD symptoms may be mild and only last for a short time or they may continue indefinitely. Regardless of the severity of symptoms, the condition has no known cure, and people who develop it are simply forced to live with it.
While tardive dyskinesia is a well-known side effect of neuroleptics, some drugs not classified as antipsychotics that can also cause tardive dyskinesia. One of them is Reglan (metoclopramide) – a drug approved by the U.S. Food and Drug Administration (FDA) for the short-term treatment of stomach ailments such as gastroesopahgeal reflux disease (GERD) and gastroparesis. It is also used to treat nausea and vomiting during pregnancy and after chemotherapy.
People who were diagnosed with tardive dyskinesia as a result of taking Reglan have filed lawsuits against the drug's manufacturer for concealing the side effects of the drug and failing to warn the public.
Reglan is used to treat acid reflux, migraines and heartburn. But the drug is also linked to a neurological disorder called tardive dyskinesia that causes involuntary muscle movements.
What are the Symptoms of Tardive Dyskinesia?
The symptoms of tardive dyskinesia often resemble Tourette's syndrome or Parkinson's disease. People with Tardive Dyskinesia have difficulty controlling their bodies and are prone to random, repetitive movements that can be mild or physically disabling.
Doctors use the Abnormal Involuntary Movement Scale (AIMS) to rate symptom severity. Movements are scored on a scale of 0 (none) to 4 (severe), and there are a total of 12 items that correspond to each part of the face and body.
|Physical symptoms include:
||Lip puckering or pursing
|Rapid eye blinking
||Rapid movements of the trunk, legs and arms
|Random movements of the fingers
||Random movements of the toes
||Grunting and gasping
What Causes Tardive Dyskinesia and Are You at Risk?
The cause of tardive dyskinesia is unknown but is linked to the use of neuroleptics that affect the way the brain processes a chemical called dopamine. Dopamine controls the reward and pleasure centers of the brain and helps regulate movement and emotional response. Imbalances of this chemical are linked to diseases like Parkinson's, schizophrenia, bipolar disorder and attention deficit hyperactivity disorder (ADHD).
Most antipsychotic drugs lower a person's level of dopamine activity to control mental disorders like schizophrenia. These drugs specifically work by targeting and blocking D2 dopamine receptors. Because these drugs affect dopamine, they are also called dopamine antagonists. Unfortunately, while these drugs can control the symptoms of mental illness, they also can cause spontaneous muscle contractions that can lead to tardive dyskinesia.
Anyone who takes or has taken an antipsychotic medication is at risk of developing TD. The risk increases if you take the medication for several months or years, though there have been cases that occurred after just a few weeks of use. Older neuroleptic drugs are more likely to cause TD, though the risk still exists with newer drugs.
|Drugs Commonly Linked to Tardive Dyskinesia
|Flunarizine (Subelium) (treats migraines)
||Prochlorperazine (treats nausea)
|Reglan (metoclopramide) (treats nausea, heart burn, gastric disorders)
There are other drugs that are similar to antipsychotic drugs that can also cause tardive dyskinesia, including flunarizine (Sibelium ) – a medicine used to treat migraines – and a drug used to treat nausea called prochlorperazine.
Other factors can increase your risk of developing TD, such as:
- Older age
- Being a female of post-menopausal age
- Having a history of substance and alcohol abuse
- Having a history of diabetes
- Suffering from a mental handicap or organic brain dysfunction
Reglan & Tardive Dyskinesia
Reglan is the brand name of the drug metoclopramide sold in the United States and is linked to TD. It was approved by the FDA in 1980 and was marketed by A.H. Robins, now Wyeth – which is owned by Pfizer. The drug is used to treat acid reflux, migraines, heart burn, nausea and vomiting, as well as gastroparesis, a condition where food moves too slowly through the digestive system. In 2011, doctors dispensed nearly 1 million prescriptions for Reglan oral tablets.
While this drug is not considered an antipsychotic, it is also a dopamine antagonist and can cause the same side effects – namely tardive dyskinesia. Pharmaceutical companies have known about the risks of this drug for decades. In fact, evidence of serious side effects related to metoclopramide has been published in various medical journals.
In one review of the drug dating back to 1970 published in Archives of Disease in Childhood, doctors reported that children who were given metoclopramide for minor stomach ailments manifested "alarming side-reactions during treatment." The symptoms manifested within 1-3 days and included pain and inability to move the neck, random eye movements, restless movements of the arms and torso, inability to speak and facial grimacing.
Reglan is the only drug approved to treat gastroparesis. A recent review of Reglan found no benefit to taking the drug for gastroparesis past 1 month, while the risk of developing TD increases with prolonged use. In the first quarter of 2011, the Institute for Safe Medication Practices reported that 1,180 cases of TD resulted from the use of Reglan and contributed to growing litigation against the drug's manufacturer.
FDA Requires Black-Box Warning for Reglan
According to an FDA study conducted in 2007, a number of patients were prescribed Reglan for long-term use (defined as longer than 3 months) and this increased the number of people who suffered side effects. This led to the FDA requiring a black-box warning in 2009. The warning advises patients about the dangers of developing tardive dyskinesia after long-term use of Reglan and its generic counterparts.
In fact, the risk for developing tardive dyskinesia is 100 times greater than disclosed in the package inserts for the drug. Many patients didn't find out about the risk of tardive dyskinesia until the FDA forced the drug companies to include a black-box warning on packages of Reglan in 2009.
What are the Treatment Options?
There is no typical treatment for tardive dyskinesia, and it varies on an individual basis. Usually, doctors start by stopping or minimizing the neuroleptic drug dose. Unfortunately, for patients who have severe mental illness, such as those with schizophrenia, this is not always an option. There are other drugs that may be an option for some patients, and using a newer generation of antipsychotic medication may be helpful in reducing the severity of the symptoms.
The only approved drug to treat TD is tetrabenazine. In studies, the drug was shown to be effective at controlling the symptoms of TD. Tetrabenazine works by reducing the levels of dopamine as well as blocking dopamine receptors. The most common side effects of tetrabenzanine include: drowsiness, parkinsonism–a condition characterized by body tremors– depression, insomnia, nervousness or anxiety, and restless leg syndrome.
|Other drugs can be used to treat TD, but they have not had well-documented results. These include:
||Calcium channel blockers
|Botulinum toxin (Botox)
|Atypical neuroleptics (newer antipsychotics)
Because Reglan has been shown to cause tardive dyskinesia, there have been more than 5,000 tardive dyskinesia lawsuits filed against multiple drug companies that market Reglan or a generic version of the drug. Despite the high volume of cases, the lawsuits were not consolidated into multidistrict litigation (MDL) because of the large number of defendant companies.
According to complaints filed in federal court, the defendant drug companies are accused of negligence, fraud and deceptive marketing practices. According to the plaintiffs, the defendant companies failed to adequately warn patients and doctors and published misleading information about the risk of developing neurological disorders when using Reglan.
Plaintiffs say that because of the negligence of drug companies, they suffered permanent neurologic damage – including tardive dyskinesia and other nervous system disorders – disfigurement and aggravation of preexisting conditions. The injured people who filed lawsuits demanded compensation for medical expenses, lost wages and earning capacity, and loss of quality of life. The plaintiffs also demanded punitive damages.
To date, companies have paid millions in compensation to those suffering from tardive dyskinesia after taking Reglan/metoclopramide.
|Tardive dyskinesia lawsuits also allege drug companies failed to:
|Ensure that Reglan/metoclopramide warnings were accurate.
|Adequately warn patients and doctors about the dangers of inappropriate long-term use of Reglan/metoclopramide.
|Report all information about the risks of the drug to the FDA.
|Engage in proper testing and research practices of the risks of long-term and short-term Reglan/metoclopramide use.