Benztropine Should NOT Be Used for Tardive Dyskinesia
Benztropine and other anticholinergic medications are contraindicated for the treatment of tardive dyskinesia (TD) and may actually worsen the condition. 1, 2
Why Anticholinergics Worsen TD
- Anticholinergic agents like benztropine can exacerbate tardive dyskinesia symptoms rather than improve them, making them inappropriate for TD management 1
- A controlled study demonstrated that benztropine-treated patients had a significant increase in tardive dyskinesia compared to their baseline condition, suggesting benztropine is not the anticholinergic of choice even when treating drug-induced parkinsonism in patients who may develop TD 2
- The pathophysiology differs critically: TD involves dopamine hypersensitivity, while drug-induced parkinsonism (which benztropine treats) involves decreased dopamine concentrations 1
Evidence Base
- A 2018 Cochrane systematic review found no confident statement can be made about the effectiveness of anticholinergics to treat antipsychotic-induced tardive dyskinesia based on available evidence 3
- The limited trial data (only 30 patients total) showed very low quality evidence with no benefit demonstrated 3
- One case report documented acute-onset dyskinesia induced by benztropine withdrawal, further highlighting the complex and potentially harmful relationship between anticholinergics and movement disorders 4
Appropriate TD Treatment Options
- Vesicular monoamine 2 (VMAT2) transporter inhibitors (valbenazine and deutetrabenazine) are the evidence-based pharmacologic treatments for TD 1
- If a patient has both drug-induced parkinsonism AND TD, amantadine (a non-anticholinergic agent) may be preferred over benztropine to avoid worsening the TD 1
- Switching to an antipsychotic with lower propensity for movement disorders should be considered 1
Critical Clinical Pitfall
The most dangerous error is confusing drug-induced parkinsonism with tardive dyskinesia. Treatment for one condition worsens the other. Key distinguishing features: DIP presents within hours to weeks with bradykinesia, rigidity, and tremor; TD appears after ≥3 months with involuntary facial movements (lip smacking, tongue protrusion, chewing) 1