Can Artane (trihexyphenidyl) be used to treat tardive dyskinesia?

No, Artane (trihexyphenidyl) Should NOT Be Used to Treat Tardive Dyskinesia

Anticholinergic medications like Artane are contraindicated for tardive dyskinesia and may actually worsen the involuntary movements. 1, 2, 3

Why Artane Worsens Tardive Dyskinesia

The FDA drug label for trihexyphenidyl explicitly states: "Antiparkinsonism agents do not alleviate the symptoms of tardive dyskinesia, and in some instances may aggravate them" and "Trihexyphenidyl HCl is not recommended for use in patients with tardive dyskinesia unless they have concomitant Parkinson's disease." 4

Key mechanistic points:

• Anticholinergics block acetylcholine receptors, which further disrupts the already imbalanced dopamine-acetylcholine ratio in TD 4
• The American Psychiatric Association explicitly warns that anticholinergics are indicated for acute dystonia and drug-induced parkinsonism, NOT tardive dyskinesia 3
• There is increased risk for developing or worsening TD during concomitant administration of anticholinergics and neuroleptics 4

Critical Distinction: Drug-Induced Parkinsonism vs. Tardive Dyskinesia

This is a common clinical pitfall. Anticholinergics like Artane may be beneficial for drug-induced parkinsonism but worsen tardive dyskinesia. 1

How to distinguish:

• TD features: Choreiform and athetoid movements, rapid involuntary facial movements (blinking, grimacing, chewing, tongue movements), NOT tremor as primary feature 3
• Drug-induced parkinsonism: Tremor, rigidity, bradykinesia—these may respond to anticholinergics 1
• If both conditions coexist (which is common), anticholinergic therapy may relieve parkinsonism symptoms but worsen TD 4

What TO Do Instead: Evidence-Based Treatment Algorithm

First-line approach:

1. Gradually withdraw the offending antipsychotic if clinically feasible 1, 2
2. If antipsychotic must continue: Switch to atypical antipsychotics with lower D2 affinity, with clozapine being the preferred option given its lowest risk profile for movement disorders 2, 3

For moderate to severe or disabling TD:

• Treat with VMAT2 inhibitors (valbenazine or deutetrabenazine) as first-line pharmacotherapy 2, 3, 5, 6
• This represents Level 1A evidence from the American Psychiatric Association 2
• These are the only FDA-approved medications specifically for TD 3, 6

Monitoring:

• Use the Abnormal Involuntary Movement Scale (AIMS) to assess treatment response at least every 3-6 months 2, 3

Special Populations at Higher Risk

Elderly patients: The American Academy of Family Physicians specifically recommends avoiding benztropine or trihexyphenidyl when extrapyramidal symptoms occur in elderly patients on typical antipsychotics 1, 2

Additional concerns in elderly:

• Increased sensitivity to anticholinergic effects after age 60 4
• Cognitive dysfunction including confusion and memory impairment 4, 7

Cognitive Benefits of Discontinuing Anticholinergics

If a patient with TD is already on Artane, discontinuation may provide cognitive benefits. Studies show significant improvement in composite cognitive scores, motor tasks, and symbol-coding tasks after anticholinergic withdrawal, without worsening movement disorders in most patients. 7