Is benztropine (anticholinergic) or propranolol (beta blocker) more suitable for managing restlessness or pacing due to anxiety?

Propranolol is Superior to Benztropine for Restlessness or Pacing Due to Anxiety

For restlessness or pacing caused by anxiety, propranolol is the appropriate choice, not benztropine. Benztropine is an anticholinergic agent indicated specifically for drug-induced extrapyramidal symptoms (EPS) from antipsychotic medications, not for anxiety-related restlessness 1.

Understanding the Critical Distinction

When Benztropine is Indicated

• Benztropine treats akathisia (drug-induced restlessness) from antipsychotic medications, not anxiety-related restlessness 2
• The American Academy of Child and Adolescent Psychiatry guidelines specifically state that akathisia from antipsychotics is often misinterpreted as psychotic agitation or anxiety 2
• For antipsychotic-induced akathisia, lowering the antipsychotic dose should be attempted first; if not feasible, β-blockers and benzodiazepines are recommended over anticholinergics 2
• Guidelines explicitly recommend avoiding benztropine use when treating extrapyramidal symptoms in elderly patients with dementia 2

When Propranolol is Indicated

• Propranolol blocks peripheral effects of adrenaline, reducing rapid heart rate, tremors, and nervousness that characterize anxiety-related restlessness 3
• Multiple controlled trials demonstrate propranolol's efficacy for anxiety disorders, particularly those with prominent somatic symptoms like restlessness and pacing 4, 5, 6
• Propranolol is effective for performance anxiety and anxiety disorders with cardiovascular manifestations 3, 7

Practical Dosing Algorithm

For Anxiety-Related Restlessness

• Start with propranolol 20-40 mg once to three times daily 4
• Titrate based on response; therapeutic doses typically range from 80-320 mg daily in divided doses 8
• For situational anxiety (e.g., specific performance situations), use 20-40 mg as a single dose 1 hour before the triggering event 3

Critical Contraindications to Screen For

• Absolute contraindications: asthma, COPD, bradycardia, heart block, decompensated heart failure 3, 9
• Use with caution in diabetes as propranolol may mask hypoglycemia symptoms 3, 9
• Never discontinue abruptly after regular use due to rebound symptoms 3, 9

Common Clinical Pitfall

The most dangerous error is misidentifying the cause of restlessness. If the patient is on antipsychotic medications and develops restlessness:

• First consider akathisia (drug-induced), not anxiety 2
• Reduce the antipsychotic dose if clinically feasible 2
• If medication adjustment isn't possible, use propranolol or benzodiazepines—not benztropine—as anticholinergics are not consistently helpful for akathisia 2

Evidence Quality Assessment

The recommendation for propranolol over benztropine is supported by:

• Multiple placebo-controlled trials showing propranolol reduces both somatic and psychic anxiety symptoms 5, 6
• Long-term studies (up to 10 years) demonstrating sustained efficacy 8
• Guideline consensus that β-blockers are preferred over anticholinergics for drug-induced akathisia 2
• FDA labeling confirming benztropine is indicated only for parkinsonism and drug-induced EPS, not anxiety 1

Side Effect Profile

Propranolol

• Common: bradycardia, hypotension, fatigue, cold extremities, sleep disturbances 3, 9
• Potential for depression and sleep disorders in 2-18.5% of patients 9

Benztropine

• Anticholinergic effects: sedation, memory deficits, confusion (particularly problematic in elderly) 2, 1
• Should be avoided in older patients who cannot tolerate anticholinergic burden 2