Outside-The-Box Treatments for Tardive Dyskinesia

Karla Soares-Weiser, PhD

The use of valbenazine and extract of Ginkgo biloba could be novel therapies for tardive dyskenesia (TD), according to a new review that intended to examine the merits of “miscellaneous” treatments not examined elsewhere in medical literature.

An international team of researchers, led by Karla Soares-Weiser, PhD, collected 31 randomized controlled trials in order to determine which non-traditional treatments were effective and safe for people with antipsychotic-induced TD. The investigators looked at drugs, hormone-, dietary- and herbal supplements, surgical interventions, electroconvulsive therapy, and mind body therapies in their review.

The trial registers were published between July 2015 and April 2017 with the Cochrane Schizophrenia Group’s Study Based Register of Trials, and the data included nearly 1,300 patients. Researchers said they assumed people who were reported to have left early showed no improvement.

The reports were only included in the review if the patients had TD and schizophrenia, or other chronic mental illness, remained on their antipsychotic medication, and were randomly allocated to the intervention versus placebo, no intervention, or any other intervention.

Nearly two-thirds (61%) of the study were published more than 20 years ago, but 7 were still ongoing, the researchers wrote. A further 5 studies were still awaiting classification. Most often, the studies lasted between 3 and 6 weeks and included small sample sizes, between 10-157 patients.

A majority of the studies concluded that there was no clinically important improvement in the TD symptoms, though 2 studies found moderate evidence for a benefit from the intervention versus placebo. The researchers wrote that valbenazine and extract of Gingko biloba seemed to have some effect, but the small sample sizes in those studies made the findings uncertain.

Researchers explained that valbenazine seemed to reduce TD symptoms to a clinically significant extent compared to placebo. This study had 92 patients in the United States. But, an ongoing study and some other investigations that were recently completed are hoping to confirm these results.

Additionally, extract of Ginkgo biloba seemed to reduce TD symptoms to a clinically significant extent compared to placebo. The study had 157 patients and was conducted in China. Just like the valbenazine investigation, more studies into Ginkgo biloba extract are being performed in order to hopefully confirm these findings, the investigators said.

A number of studies proved low to very low quality evidence that was inconclusive with the use of their interventions: buspirone, dihydrogenated ergot alkaloids, hypnosis or relaxation, pemoline, promethazine, insulin, branched chain amino acids, or isocarboxazid.

More evidence proved low to very low certainty with use of the interventions: melatonin, lithium, ritanserin, selegiline, estrogen, and gamma-linolenic acid.

The researchers said that none of the studies in their review reported any “clinically significant extrapyramidal adverse effects.”

“This review has found that the use of valbenazine or extract of Ginkgo biloba may be effective in relieving the symptoms of tardive dyskinesia,” the study authors concluded. “However, since only one RCT has investigated each one of these compounds, we are awaiting results from ongoing trials to confirm these results.”

The study, “Miscellaneous treatments for antipsychotic-induced tardive dyskinesia,” was published in the Cocharne Database of Systematic Reviews 2018.