Can Amantadine Tame Tardive Dyskinesia? Exploring the Evidence and Potential Benefits

In my practice, I see many patients who have been on high doses of antipsychotics for extended periods, particularly first-generation antipsychotics, which carry a higher risk of developing tardive dyskinesia (TD). While two FDA-approved treatments for TD exist, their high cost and limited availability can make access challenging in community mental health settings. This has led me to explore alternative treatments like amantadine. Like many of you, I wanted to understand the evidence supporting its use, so let’s take a closer look at what the research says about amantadine as a treatment option for TD.

The evidence for the use of amantadine in treating tardive dyskinesia (TD) has been explored in several small randomized controlled trials (RCTs), though it remains limited compared to other treatments.

1. Efficacy of Amantadine: Some studies suggest that amantadine, an NMDA receptor antagonist, may offer mild to moderate improvement in TD symptoms by modulating dopaminergic pathways. For instance, an early RCT (2007) tested amantadine in schizophrenia patients with TD and reported some improvements in abnormal involuntary movements compared to placebo. However, the sample size was small, and results were modest.
2. Comparative Effectiveness: Few trials directly compare amantadine to other TD treatments like VMAT-2 inhibitors (e.g., valbenazine, deutetrabenazine), which are the preferred treatment options due to stronger RCT evidence. Amantadine’s effects may be less pronounced, though some patients have reported partial symptom relief, especially when TD is not severe.
3. Safety Profile: In RCTs, amantadine is generally well-tolerated in TD patients, with few serious side effects. However, common side effects include dizziness, insomnia, and gastrointestinal issues, which may limit its use in certain patients, particularly those with cognitive or movement comorbidities.

Overall, while RCTs support some benefit of amantadine in TD, the effect size is generally moderate. VMAT-2 inhibitors are preferred based on stronger, more consistent RCT data, although amantadine may still be considered for patients who cannot tolerate or do not respond to these primary therapies.