This medication belongs to the class of medications called antiparkinsonians. It is used to treat the symptoms of Parkinson's disease. It may also be used to reduce the shakiness and restlessness that can be caused by some tranquilizers. It acts on the nervous system and corrects some of the chemical imbalances that cause the symptoms of Parkinson's disease.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of benztropine to treat Parkinsonism is usually 1 mg to 2 mg daily, although the dose can range from 0.5 mg to 6 mg daily depending on circumstances. Benztropine can be taken with or without food.

The recommended dose to reduce movement symptoms caused by other medications ranges from 1 mg to 4 mg once or twice daily. Doses for children are calculated based on body weight.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

This medication is available as a 1 mg/mL injectable solution.

Do not take this medication if you:

• are allergic to benztropine or any ingredients of the medication
• have angle-closure glaucoma

Do not give this medication to children under 3 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• agitation
• blurred vision
• bowel obstruction (e.g., abdominal pain and discomfort, constipation, nausea, vomiting, excessive burping)
• confusion (more common in seniors or with high doses)
• difficult or painful urination (especially in older men)
• eye pain
• fast heartbeat
• fever
• hallucinations (e.g., hearing or seeing things that aren't there)
• painful or difficult urination
• severe dry mouth (e.g., difficulty swallowing or speaking, loss of appetite and weight)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• skin rash
• symptoms of glaucoma (e.g., blurred vision, seeing halos of bright colours around lights, red eyes, increased pressure in your eyes, eye pain or discomfort)
• visual hallucinations
• weakness, inability to move certain muscles
• worsening mental symptoms

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Drowsiness/reduced alertness: Benztropine may impair the mental or physical abilities required to do tasks such as operating machinery or driving a vehicle. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.

Gastrointestinal problems: Benztropine can slow down the speed that material passes through the digestive system. If you have digestive system problems, such as slow movement through the digestive tract, or colitis, discuss with your doctor how this medication may affect the medical condition, how the medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Glaucoma: This medication may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.

Heart problems: This medication can cause fast heartbeat and may worsen symptoms of heart disease. If you have heart disease such as angina, congestive heart failure, or arrhythmia, discuss with your doctor how this medication may affect the medical condition, how the medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Large doses: In large doses, benztropine may cause weakness and an inability to move certain muscle groups. For example, if the neck has been rigid and suddenly relaxes, it may feel weak, causing some concern. If this happens, report it to your doctor. Mental confusion and excitement may occur with large doses.

Mental health: Benztropine can cause symptoms of mental health conditions to become worse when it is taken to control certain side effects of medication used to treat mental health conditions. If you notice your symptoms of schizophrenia or other mental health conditions are becoming worse, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.

Perspiration: Benztropine may impair some people's ability to sweat, which can lead to dangerous increases in body temperature. People who are most at risk include people who do manual labor or heavy exercise in a hot environment, seniors, and people with alcoholism, certain conditions of the central nervous system, or chronic illnesses. The risk is also higher in hot weather.

Urinary problems: Benztropine may cause difficulty in starting urine flow or in completely emptying the bladder, or contribute to incontinence (urine leakage). If you have a history of urinary retention or benign prostatic hypertrophy, or other prostate problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: The safe use of this medication by pregnant women has not been established. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if benztropine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: Benztropine should not be taken by children under 3 years of age. Children over 3 years of age should be monitored by their doctor while taking this medication.

Seniors: Seniors may be more sensitive to the side effects of this medication and may need lower doses.

There may be an interaction between benztropine and any of the following:

• aclidinium
• alcohol
• amandatine
• antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• certain anti-Alzheimer's medications known as cholinesterase inhibitors (e.g., donepezil, galantamine, rivastigmine)
• atropine
• azelastine
• certain types of antinausea medications (e.g., chlorpromazine, metoclopramide, and prochlorperazine)
• belladonna
• botulinum toxin
• cannabis
• cyclobenzaprine
• darifenacin
• disopyramide
• domperidone
• eluxadoline
• fesoterodine
• flavoxate
• glycopyrrolate
• ipratropium
• ketotifen
• methadone
• metoclopramide
• mirabegron
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, tranylcypromine, phenelzine)
• nabilone
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone)
• orphenadrine
• oxybutynin
• potassium chloride
• pramlintide
• quinidine
• scopolamine
• solifenacin
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
• tiotropium
• tolterodine
• topiramate
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• umeclidinium

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.