• See Also
  1. Trihexyphenidyl
  2. Anticholinergic Medication
  3. Anticholinergic Toxicity
  4. Parasympathetic Nervous System
  • Indications
  1. Drug-Induced Extrapyramidal Side Effects
  2. Parkinsonism
    1. Adjunctive, symptomatic management of Tremor or Drooling
  • Contraindications
  1. Narrow Angle Glaucoma
  2. Acute Bowel Obstruction
  3. Megacolon
  4. Elderly (relative)
    1. On Beer's List, due to risk of Delirium, pscyhosis, Fall Risk
  • Mechanism
  1. Centrally acting Muscarinic Antagonist
  2. Decreases imbalance of Acetylcholine to Dopamine ratio within corpus striatum (Basal Ganglia)
  1. Start: 0.5 to 1 mg/day orally, IM or IV divided once at bedtime to four times daily
  2. Increase by 0.5 mg/day each week as needed
  3. Maximum: 6 mg/day
  1. Acute Dystonic Reaction
    1. Administer 1 to 2 mg orally, IM or IV
  2. Chronic
    1. Start 1 to 4 mg orally, IM or IV once to twice daily
    2. Consider taper off after 1-2 weeks
  • Adverse Effects
  1. See Anticholinergic Symptoms
  2. Avoid in pregnancy (may be Teratogenic)
  3. Unknown safety in Lactation
  4. Withdrawal symptoms with severe increase in Parkinsonism symptoms
    1. Titrate medication off without abruptly stopping
  • Resources
  1. Benztropine (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3d2732f9-b8a9-4e83-91e7-da616ddcb786
  • References
  1. (2021) Med Lett Drugs Ther 63(1618): 25-32
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 46-7
  3. Hamilton (2020) Tarascon Pocket Pharmacopoeia