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Benztropine: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on July 14, 2022.

1. How it works

  • Benztropine is a synthetic (man-made) compound that may be used for the treatment of Parkinson's disease or to counteract the side effects of some antipsychotics.
  • Benztropine has both anticholinergic and antihistaminic effects. Benztropine's anticholinergic effects arise from its blockade of the neurotransmitter, acetylcholine. Acetylcholine is involved in transmitting messages that affect muscle contractions in the body and learning and memory in the brain. Anticholinergic drugs tend to cause side effects such as blurred vision, confusion, constipation, dizziness, drowsiness or sedation, dry mouth, and urinary retention.
  • Benztropine's antihistaminic effects arise from its blockade of the effects of the neurotransmitter histamine in the brain as well as histamine release from histamine-1 receptors. Most antihistamine drugs are used to treat allergies; however, antihistamines that work within the brain can also affect many brain functions such as arousal, pituitary hormone secretion, and cognitive functions.
  • Only the anticholinergic effect is targeted when benztropine is used in the management of parkinsonism.
  • Benztropine belongs to the class of medicines known as anticholinergics. Benztropine may also be called an antimuscarinic.

2. Upsides

  • Benztropine may be used in addition to other treatments for Parkinson's disease. it may help with muscle stiffness and rigidity.
  • Benztropine may be used to counteract extrapyramidal side effects caused by antipsychotic drugs. Extrapyramidal side effects are involuntary movement disorders such as akathisia (inability to sit or stand still), dystonia (continuous spasms and muscle contractions), muscle rigidity, and tremor. Benztropine will not alleviate the symptoms of tardive dyskinesia (involuntary movements of the tongue, lips, face, trunk, and extremities).
  • Available as oral tablets and as an injection.
  • Generic benztropine is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Blurred vision, confusion, constipation, dizziness, drowsiness or sedation, dry mouth, tachycardia (fast heart rate), and urinary retention.
  • Benztropine may affect a person's ability to drive or operate machinery or the performance of other hazardous tasks.
  • May cause weakness and an inability to move particular muscle groups. A reduction in dosage may be needed.
  • Visual hallucinations and mental confusion may occur in susceptible people or with large doses.
  • May cause potentially fatal anhidrosis (an inability to sweat normally). This may be particularly problematic in hot weather, particularly in those who chronically drink alcohol, who are frail or chronically ill, with pre-existing central nervous system disease, or who do manual labor.
  • May accumulate with repeated use, increasing the risk of side effects.
  • Use with caution in children. Not recommended for those under 3 years of age.
  • May not be suitable for some people including those with pre-existing urinary problems or kidney disease, glaucoma, mental instability, heart disease, a history of alcoholism, or the frail.
  • Benztropine may interact with several other drugs including antipsychotics, antidepressants, other atropine-like drugs, and anticonvulsants.
  • Benztropine accumulates with repeated dosing and should be started at a low dose which is increased slowly by 0.5mg increments at five to six-day intervals, to the dosage necessary to provide relief (maximum dosage is 6mg/day).
  • Safe use in pregnancy has not been established.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

  • Benztropine may be used to treat symptoms of Parkinson's disease or alleviate side effects that affect movement caused by antipsychotics. However, it may cause unwanted effects such as blurred vision, confusion, constipation, dizziness, drowsiness or sedation, a dry mouth, fast heartbeat, or urinary retention.

5. Tips

  • Take benztropine exactly as directed by your doctor. Do not increase or decrease the dosage without his or her advice. It may take several weeks to find the correct dosage of benztropine for you. Do not stop taking benztropine suddenly.
  • Benztropine may be taken once daily at bedtime; however, some people react more favorably to two to four times daily dosing.
  • Talk to your doctor if you notice a reduction in your ability to sweat.
  • If your mouth feels dry while taking benztropine, try sucking on a piece of sugar-free hard candy, chewing sugar-free gum, chewing ice chips, or use a saliva substitute. Having a dry mouth increases your risk of developing gum disease and cavities. Brush and floss your teeth regularly and visit your dentist every six months for a check-up.
  • Drink plenty of water while taking benztropine and try not to let yourself become dehydrated.
  • Do not drive or operate machinery or perform other hazardous tasks if benztropine affects your judgment or makes you drowsy.
  • Take exactly as directed. Do not take more than recommended.
  • Talk to your doctor or pharmacist before taking any other medicines, including those bought over the counter for coughs, colds, or allergies.
  • Talk to your doctor if you develop severe constipation, severe drowsiness, irregular or fast heartbeat, or any other intolerable side effects from benztropine that are affecting your quality of life.

6. Response and effectiveness

  • Benztropine has a long duration of effect so may be taken once daily, usually at bedtime.
  • Dosage increases should only be done at five to six-day intervals if deemed necessary, as benztropine accumulates with repeated dosing. It may take up to three days before an improvement in symptoms is noticed.

7. Interactions

Medicines that interact with benztropine may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with benztropine. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with benztropine include:

  • antidepressants, such as amitriptyline, clomipramine, desipramine, doxepin, escitalopram, imipramine, or nortriptyline
  • antihistamines, such as diphenhydramine
  • antifungals, such as voriconazole
  • antipsychotics, such as haloperidol, chlorpromazine, clozapine, thioridazine, or ziprasidone
  • barbiturates, such as phenobarbital
  • benzodiazepines, such as diazepam, oxazepam, and temazepam
  • betel nut
  • botulinum-containing agents
  • bupropion
  • cannabinoid-containing products
  • dextromethorphan
  • diuretics, such as hydrochlorothiazide
  • droperidol
  • famotidine
  • glucagon
  • glycopyrrolate
  • heart medications, such as atenolol, betaxolol, carisoprodol, or metoprolol
  • metoclopramide
  • nitroglycerin
  • opioids, such as oxycodone, methadone, morphine, or codeine
  • other anticholinergics, such as ipratropium or tiotropium
  • Parkinson's disease medications, such as levodopa
  • potassium chloride or potassium citrate
  • sedatives, or any medication that causes sedation, such as sleeping pills, or muscle relaxants
  • topiramate
  • zonisamide.

Alcohol may enhance the sedative effects of benztropine.

Note that this list is not all-inclusive and includes only common medications that may interact with benztropine. You should refer to the prescribing information for benztropine for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use benztropine only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: July 14, 2022.