Cogentin (Benztropine) Uses for Bipolar Disorder

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Medications often used to treat bipolar disorder, such as typical and atypical antipsychotic drugs, may cause drug-induced parkinsonism, the medical term for symptoms that mimic Parkinson's disease. 

Drug-induced parkinsonism may cause: 

  • A decrease in facial expressions
  • Difficulty starting and controlling movement
  • Slowed movement
  • Soft voice
  • Stiffness of the trunk, arms, or legs
  • Tremor

What Is Cogentin?

Cogentin (benztropine) is used for treatment of Parkinson's disease and is in a class of drugs called anticholinergics. These drugs help rebalance irregular activity of acetylcholine neurotransmitters, which are crucial to brain and muscle function. Cogentin improves muscle control and has been shown to decrease rigidity and tremors associated with Parkinson's disease.

Cogentin is also sometimes used to treat people with bipolar disorder who have developed parkinsonism. 

Cogentin comes in 0.5, 1, and 2 mg tablets to be taken orally, usually at bedtime, and in some cases, an injection is provided. One dose per day will typically suffice to treat symptoms of parkinsonism. Your doctor may start you on a small dose to see how you respond. 


Cogentin may interact with certain drugs, including antidepressants, sleeping pills, painkillers, antihistamines, anti-diarrheal medications, some antacids, and other medications.

It's important that you speak with your doctor about any potential interactions. 

Common Side Effects 

The following are common side effects of ​Cogentin. You should check with your doctor if they don't go away or worsen:

  • Blurred vision 
  • Constipation 
  • Decreased sweating
  • Difficult or painful urination (especially in older men)
  • Drowsiness
  • Dryness of mouth, nose, or throat

Less Common Side Effects 

The following are less common side effects of Cogentin. 

  • Dizziness or lightheadedness when getting up from a lying down or sitting position
  • Euphoria
  • Headache
  • Memory impairments (especially in the elderly)
  • Nervousness
  • Stomach upset or pain
  • Unusual excitement

When to Contact Your Doctor

Notify your doctor immediately if you experience any of the above rare side effects of Cogentin, as well as these below:

  • Confusion
  • Eye pain
  • Skin rash
  • Rapid heart rate
  • Hallucinations

Overdose Effects

If you or a loved one have potentially overdosed on Cogentin, call your local poison control center and/or 911 immediately. Symptoms of overdose include:

  • Clumsiness or unsteadiness
  • Severe drowsiness 
  • Severe dryness of mouth, nose, or throat
  • Fast heartbeat
  • Hallucinations (seeing, hearing, or feeling things that are not there)
  • Mood or mental changes
  • Seizures
  • Shortness of breath or troubled breathing
  • Trouble sleeping
  • Warmth, dryness, and flushing of the skin

Other Cogentin side effects not listed above may also occur in some patients. If you notice any other side effects, be sure to check with your doctor.

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7 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Shin HW, Chung SJ. Drug-induced parkinsonismJ Clin Neurol. 2012;8(1):15–21. doi:10.3988/jcn.2012.8.1.15

  2. Stoker T, Greenland J. Parkinson’s Disease - Pathogenesis and Clinical Aspects

    Brisbane (AU): Codon Publications; 2018. doi: 10.15586/codonpublications.parkinsonsdisease.2018.ch9

  3. Ward KM, Citrome L. Antipsychotic-Related Movement Disorders: Drug-Induced Parkinsonism vs. Tardive Dyskinesia-Key Differences in Pathophysiology and Clinical ManagementNeurol Ther. 2018;7(2):233–248. doi:10.1007/s40120-018-0105-0

  4. Cogentin Dosage. Updated November 11, 2019.

  5. Cogentin (benztropine) Drug Interactions.

  6. Cogentin Side Effects. Updated November 16, 2019.

  7. American College of Cardiology. benztropine.

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