Drug therapies for tardive dyskinesia: part 2

Efficacy and safety of different pharmacological interventions in the treatment of tardive dyskinesia: a systematic review and network meta-analysis

OBJECTIVES

The aim of this study is to indirectly compare and rank the different drugs that have been studied in randomized clinical trials (RCTs) in patients with tardive dyskinesia (TD) in terms of their efficacy in ameliorating the symptoms of TD and safety.

DESIGN

A network meta-analysis and a systematic review were registered prospectively on PROSPERO under the ID: CRD42023407823 and were conducted in accordance with the PRISMA-NMA guidelines.

DATA SOURCES

PubMed, Scopus, The Cochrane Central Register of Controlled Trials (CENTRAL), Web of Sciences, and Clinicaltrials.gov were searched to identify relevant records.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Any parallel randomized blinded controlled clinical trials that studied the use of any medications in treating TD and assessed the symptoms using a functional scale that has been previously validated.

DATA EXTRACTION

The standardized mean difference of improvement along with the reported adverse events for each drug was extracted from each trial, and a network meta-analysis was conducted using a random-effects model.

RESULTS

One thousand eight hundred seventeen patients in 33 RCTs were included in the analysis. Twenty-three different drugs were compared to placebo in terms of reduction in TD symptoms. Among these, valbenazine 80 mg (SMD =  - 1.66, 95%CI = [- 2.55; - 0.78]), valbenazine 40 mg (- 1.00, [- 1.89; - 0.11]), and vitamin E (- 0.77, [- 1.45; - 0.1]) significantly reduced TD symptoms in comparison to placebo, while deutetrabenazine 36 mg (- 1.00, [- 2.12; 0.11]) and reserpine (- 0.54, [- 1.09; 0.02]) did not significantly reduce symptoms. Some serious adverse events were reported for valbenazine and deutetrabenazine, which included mainly psychiatric symptoms such as depression, worsening of schizophrenia, and suicidal ideation, while mild adverse events were reported for other drugs, and their incidence in the treatment arms was comparable to those in the placebo arm.

CONCLUSIONS

Valbenazine (80 and 40 mg) and vitamin E demonstrated efficacy in treating tardive dyskinesia. However, the significant side effects of valbenazine should prompt further investigation of alternative treatment modalities.

Adjunctive Melatonin for Tardive Dyskinesia in Patients with Schizophrenia: A Meta-Analysis

Background

Tardive dyskinesia (TD) is characterized by abnormal and involuntary movements. Importantly, TD could cause considerable personal suffering and social and physical disabilities.

Aims

This meta-analysis based on randomized controlled trials (RCTs) systematically assessed the therapeutic effect and tolerability of melatonin for TD in schizophrenia.

Methods

A computerized and systematical search of both Chinese (Wanfang Data, Chinese National Knowledge Infrastructure (CNKI), SINOMED) and English (PubMed, PsycINFO, Embase, Cochrane Library databases) databases, from their inception until June 8, 2017, was conducted by two independent authors. The severity of TD symptoms were the primary outcome measure and analyzed using a random effects model by the Review Manager (RevMan) Version 5.3. Quality evaluation of included RCTs was conducted using the Cochrane risk of bias and Jadad scale. The GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) system recommendation grading method was used to assess the overall quality level of meta-analytic outcomes.

Results

Four RCTs (n=130) were identified and analyzed. Three RCTs used double blind and 1 RCT used masked assessors using the Cochrane risk of bias, and 3 RCTs were rated as high quality based on Jadad scale. Compared with the control group, adjunctive melatonin was superior in reducing the severity of TD as measured by the Abnormal Involuntary Movement Scale (AIMS) (4 RCTs, n=130, weighted mean difference (WMD): -1.52 (95% confidence intervals (CI): -3.24, 0.20), p=0.08; I²=0%) although the improvement did not reach a significant level. The overall evidence quality of the improvement of TD symptoms, according to GRADE approach, was rated as “Low”. The data on the ADRs and cognitive effect were limited.

Conclusions

This meta-analysis shows that melatonin has potential for improving TD symptoms in schizophrenia. Future higher quality and larger RCTs are warranted to confirm the findings.

Altered IL-2, IL-6 and IL-8 serum levels in schizophrenia patients with tardive dyskinesia

Immune deregulation has been postulated to be one of the mechanisms underlying the pathogenesis of tardive dyskinesia (TD). We hypothesized that interleukins would have a link with TD in schizophrenia patients. In this study, the serum IL-2, IL-6 and IL-8 levels were examined by enzyme-linked immunosorbent assay (ELISA) in schizophrenia patients with TD (n=48) and without TD (n=45), and healthy controls (n=44). The psychopathological symptoms of schizophrenia were assessed by the Positive and Negative Syndrome Scale (PANSS). The severity of TD was evaluated using Abnormal Involuntary Movement Scale (AIMS). The results showed that serum IL-2, IL-6 and IL-8 levels were significantly different among schizophrenia patients with TD and without TD and normal controls. Moreover, IL-2 level was significantly correlated with PANSS positive subscale and general subscale in patients with TD and without TD. In addition, IL-2 level was positively correlated with AIMS score in TD patients. The results supported that immune disturbance is related to the schizophrenia patients, especially to the patients with TD and ILs might play an important role in the pathophysiology of schizophrenia patients with TD.

New and emerging treatments for symptomatic tardive dyskinesia

The aim of this review is to assess new, emerging, and experimental treatment options for tardive dyskinesia (TD). The methods to obtain relevant studies for review included a MEDLINE search and a review of studies in English, along with checking reference lists of articles. The leading explanatory models of TD development include dopamine receptor supersensitivity, GABA depletion, cholinergic deficiency, neurotoxicity, oxidative stress, changes in synaptic plasticity, and defective neuroadaptive signaling. As such, a wide range of treatment options are available. To provide a complete summary of choices we review atypical antipsychotics along with resveratrol, botulinum toxin, Ginkgo biloba, tetrabenazine, clonazepam, melatonin, essential fatty acids, zonisamide, levetiracetam, branched-chain amino acids, drug combinations, and invasive surgical treatments. There is currently no US Food and Drug Administration-approved treatment for TD; however, prudent use of atypical antipsychotics with routine monitoring remain the cornerstone of therapy, with experimental treatment options available for further management.