VMAT2 inhibitors for the treatment of tardive dyskinesia: a narrative review.

Two vesicular monoamine transporter 2 (VMAT2) inhibitors, valbenazine and deutetrabenazine, are approved for the treatment of tardive dyskinesia (TD), a persistent and potentially disabling movement disorder associated with prolonged exposure to antipsychotics and other dopamine receptor blocking agents. Since their initial approval in 2017, new formulations and doses for both medications have become available, including a sprinkle capsule for valbenazine and a once-daily tablet for deutetrabenazine. In light of these new therapeutic options, a comprehensive scoping review was conducted to consolidate the current knowledge about these medications. Both valbenazine and deutetrabenazine are safe and effective in treating TD. However, as they are different drugs, one objective of this review is to describe their pharmacology and pharmacokinetics. Another objective is to summarize the similarities and differences as to how these medications are prescribed, specifically in terms of their warnings and precautions, their use in special populations, and recommendations for dosing when taken with concomitant medications. Results from double-blind, placebo-controlled clinical trials are presented, along with post hoc analyses that provide benchmarks for clinical relevance (eg, effect size, number needed to treat, minimal clinically important difference). As most patients with TD will require ongoing treatment, findings from long-term studies provide evidence for the safety and effectiveness of these medications.