Use Of VMAT2 Inhibitors For Tardive Dyskinesia In Geriatric Populations - A Case Study

Background: Tardive dyskinesia is a persistent, often irreversible movement disorder that may develop after chronic, cumulative exposure to antipsychotics. Geriatric populations are at increased risk of developing tardive dyskinesia as they age, leading to increased risk of injuries secondary to resulting impairments in gait and balance. VMAT2 inhibitors such as valbenazine, deutetrabenazine, and tetrabenazine are the first-line treatment for control of tardive dyskinesia symptoms. Case Presentation: After developing abnormal movements after one year on aripiprazole, our 80 year old patient was started on valbenazine before developing Parkinsonian symptoms. Due to the unclear etiology on initial presentation, both neurology and psychiatry followed with her for consideration of Parkinson's versus tardive dyskinesia with multiple trials of VMAT2 inhibitors and carbidopa-levodopa. Eventually, tardive dyskinesia was diagnosed and she was switched to deutetrabenazine with improvement, however it has taken years of trial and error to adequately manage her symptoms without significant untoward effects. Conclusion: As use of VMAT2 inhibitors in managing antipsychotic induced tardive dyskinesia increases, special consideration regarding their efficacy and safety must be taken when starting in older patients. The case presented here highlights the increased risk of development of movement disorders in older adults on even short courses of antipsychotics, as well as the variability in response to VMAT2 inhibitors in resultant treatment. This case also represents the need for caution and concern when prescribing antipsychotics in patients >55, as older adults may have increased susceptibility to the development of tardive dyskinesia even with short-term second generation antipsychotic use.