Benztropine

Benztropine is used to treat symptoms of Parkinson's disease or involuntary movements due to the side effects of certain psychiatric drugs (antipsychotics such as chlorpromazine/haloperidol). Benztropine belongs to a class of medication called anticholinergics that work by blocking a certain natural substance (acetylcholine). This helps decrease muscle stiffness, sweating, and the production of saliva, and helps improve walking ability in people with Parkinson's disease.

Anticholinergics such as benztropine can stop severe muscle spasms of the back, neck, and eyes that are sometimes caused by psychiatric drugs. It can also decrease other side effects such as muscle stiffness/rigidity (extrapyramidal signs-EPS). It is not helpful in treating movement problems caused by tardive dyskinesia and may worsen them. Benztropine should not be used in children younger than 3 years.

• Benztropine is available under the following different brand names: Cogentin.

Adult and Pediatric Dosage Forms and Strengths

Tablet

• 0.5mg
• 1mg
• 2mg

Injectable solution

• 1 mg/MmL

Dosage Considerations – Should be Given as Follows:

Parkinsonism

Adult:

• Postencephalitic parkinsonism: 1-2 mg/day (range, 0.5-6 mg/day) orally/intravenously/intramuscularly at bedtime or divided every 6-12 hours; may consider lower dose or 0.5 mg at bedtime in highly sensitive patients; not to exceed 6 mg/day
• Idiopathic parkinsonism: 0.5-1 mg at bedtime initially; titrate dose in 0.5-mg increments every 5-6 days (range 0.5-6 mg daily; some patients may need 4-6 mg/day); not to exceed 6 mg/day

Geriatric:

• 0.5 mg orally once daily or every 12 hours; titrate dose in 0.5-mg increments every 5-6 days; not to exceed 4 mg/day

Drug-Induced Extrapyramidal Disorders

• Adult: 1-2 mg intravenously/intramuscularly/orally every 8-12 hours; reevaluate after 1-2 weeks
• Acute dystonia: 1-2 mg intravenously (IV), then 1-2 mg orally once or twice daily for 7-28 days to prevent a recurrence
• Children over 3 years: 0.02-0.05 mg/kg intravenously/intramuscularly/orally once daily or every 12 hours
• Children under 3 years: Not recommended

Dosing considerations, geriatric

• Non-anticholinergic anti-Parkinson agents should be considered first for treatment of Parkinson disease (Beers criteria)
• Not well tolerated in elderly, because of the bowel, bladder, and central nervous system (CNS) effects; avoid use if possible
• Should not be used as prophylaxis against extrapyramidal symptoms in elderly

Common side effects of benztropine include:

• Blurred vision
• Confusion
• Constipation
• Depression
• Dilated pupils
• Disorientation
• Dizziness
• Double vision
• Drowsiness
• Dry mouth or throat
• Elevated core body temperature (hyperthermia)
• Excitability
• Fast heart rate
• Headache
• Increased sensitivity to light
• Loss of appetite
• Memory problems
• Nausea
• Nervousness
• Numbness in your fingers
• Paralytic ileus
• Psychosis
• Sleeplessness
• Stomach upset
• Trembling of the hands
• Urinary retention
• Vision changes
• Visual hallucinations
• Vomiting

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Benztropine has no known severe or serious interactions with other drugs.
• Benztropine has moderate interactions with at least 73 different drugs.
• Mild Interactions of benztropine include:
  • desipramine
  • levodopa
  • trazodone

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

Warnings

• This medication contains benztropine. Do not take Cogentin if you are allergic to benztropine or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Hypersensitivity
• Age under 3 years

Effects of Drug Abuse

• No information available

Short-Term Effects

• May cause anticholinergic effects (constipation, dry mouth, blurred vision, urinary retention).
• See "What Are Side Effects Associated with Using Benztropine?"

Long-Term Effects

• Long-term use increases the risk of neoplasia.
• See "What Are Side Effects Associated with Using Benztropine?"

Cautions

• Monitor patients with a history of tachyarrhythmia and benign prostatic hyperplasia.
• May cause lack of sweating (anhidrosis)/hyperthermia, which may become severe; use with caution in hot weather and during exercise; risk is increased in a hot environment; consider lowering the dose to prevent impairing heat equilibrium by perspiration.
• May cause anticholinergic effects (constipation, dry mouth, blurred vision, urinary retention).
• At higher doses, may be associated with confusion, visual hallucinations, or excitement; intensification of symptoms or toxic psychosis may occur in patients with mental disorders.
• May cause central nervous system (CNS depression), which may impair the ability to operate heavy machinery and tasks that require mental alertness
• In susceptible patients, large doses may cause weakness and inability to move particular muscles.
• Use caution in patients with gastrointestinal (GI) obstruction, fast heart rate (tachycardia), prostatic hyperplasia/urinary stricture, and glaucoma.
• Response in the elderly over 65 years of age may be altered; initiate at low doses and increase as needed while monitoring adverse effects.
• Use with caution in children over 3 years of age due to anticholinergic effects.
• Not recommended for patients with tardive dyskinesia; does not relieve symptoms and may potentially exacerbate symptoms.

Pregnancy and Lactation

• Use benztropine with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
• Benztropine excretion in milk is unknown; use with caution if breastfeeding.