Weak Evidence for Vitamin E as Tardive Dyskinesia Treatment
FEBRUARY 13, 2018
William Ondo, MDA review of studies investigating the efficacy of vitamin E as a treatment for tardive dyskinesia (TD) has found weak evidence that it may improve the symptoms of TD.
According to the lead study author, Hanna Bergman, PhD, the primary objective of this review was to determine if vitamin E provides a clinically significant improvement in people with schizophrenia or other chronic mental illness, who developed TD from taking antipsychotic medications.
Other goals were to investigate whether studies indicate that any improvement in TD was maintained as the duration of follow-up was increased, and to test the hypothesis that the vitamin E is most effective at the early onset (less than five years) of TD.
Reports were included if they were controlled trials that dealt with patients experiencing antipsychotic-induced TD and schizophrenia who stayed on antipsychotic medication and were randomly allocated to either:
- A vitamin E or placebo group
- No intervention, or any other intervention group
Current treatment options
William Ondo, MD, Houston Methodist neurologist, director of the Houston Methodist Movement Disorders Clinic, recapped the benefits of TD’s limited therapies to MD Magazine. He noted that US Food and Drug Administration-approved therapies valbenazine (Ingrezza) and deutetrabenazine (Austedo), as well as non-approved tetrabenazine, are very effective “although they do have significant potential side effects.”
“Amantadine is a different, milder medicine which may help some cases,” Ondo said.
Effectiveness of non-pharmaceutical interventions
Ondo noted there is some evidence that taking branched chain neutral amino acids may help TD.
“This requires at least 6 doses per day but is otherwise considered to be very safe,” Ondo said. “There is 1 research group who has touted high-dose Vitamin B6 for tardive dyskinesia. This actually has some potential side effects as it has been associated with the development of neuropathy.”
The results of the review
The review included 13 randomized trials that involved a total of 478 people. Every participant was an adult with a chronic psychiatric disorder; most experienced schizophrenia and had antipsychotic-induced TD.
There was no discernable difference between vitamin E and a placebo in the outcome of TD. However, there was some evidence that individuals allocated to a placebo group did show more deterioration of TD symptoms when compared to those who received vitamin E.
Ondo agreed, saying that despite the extensive study of vitamin E for TD, most well-controlled trials have not shown any benefit.
“There have been several other medicines touted including ginkgo biloba, melatonin, and Yi-gan san – none of those have any controlled data supporting them,” Ondo said.
Vitamin E and preventing TD
While studies indicate that vitamin E isn’t practical for TD, it could have a role in prevention. Ondo said that while some would advocate administering vitamin E, the data that this reduces risk is inconsistent.
“Otherwise, vitamin E supplements are quite benign,” Ondo said.
Ondo added there is no absolute strategy established to prevent TD if drugs that block dopamine receptors are necessary.
“It turns out that taking drug holidays from dopamine blocking drugs is not an effective strategy, as there may be increased risk immediately after stopping an offending drug,” Ondo said. “Certainly taking the minimal effective dose is recommended.”
The study, "Vitamin E for antipsychotic-induced tardive dyskinesia," was published online in Cochrane Library last month.
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