Benztropine

# Disclaimer
WikiDoc MAKES NO GUARANTEE OF VALIDITY. WikiDoc is not a professional health care provider, nor is it a suitable replacement for a licensed healthcare provider.  WikiDoc is intended to be an educational tool, not a tool for any form of healthcare delivery.  The educational content on WikiDoc drug pages is based upon the FDA package insert, National Library of Medicine content and practice guidelines / consensus statements.  WikiDoc does not promote the administration of any medication or device that is not consistent with its labeling. Please read our full disclaimer here.

# Overview
Benztropine is an anticholinergic that is FDA approved for the treatment of postencephalitic and idiopathic parkinsonism and drug-induced|extrapyramidal disorders.   Common adverse reactions include tachycardia, constipation, nausea, xerostomia, blurred vision, dysuria, and urinary retention.

# Adult Indications and Dosage

## FDA-Labeled Indications and Dosage (Adult)
- The usual daily dose is 1 to 2 mg, with a range of 0.5 to 6 mg orally.
- As with any agent used in parkinsonism, dosage must be individualized accordingto age and weight. and the type of parkinsonism being treated. Generally, older patients, and thin patients cannot tolerate large doses. Most patients with postencephalitic parkinsonism need fairly large doses and tolerate them well. Patients with a poor mental outlook are usually poor candidates for therapy.
- In idiopathic parkinsonism, therapy may be initiated with a single daily dose of 0.5 to 1 mg at bedtime. In some patients, this will be adequate; in others 4 to 6 mg a day may be required.
- In postencephalitic parkinsonism, therapy may be initiated in most patients with 2 mg a day in one or more doses. In highly sensitive patients, therapy may be initiated with 0.5 mg at bedtime, and increased as necessary.
- Some patients experience greatest relief by taking the entire dose at bedtime; others react more favorably to divided doses, two to four times a day. Frequently, one dose a day is sufficient, and divided doses may be unnecessary or undesirable.
- The long duration of action of this drug makes it particularly suitable for bedtime medication when its effects may last throughout the night, enabling patients to turn in bed during the night more easily, and to rise in the morning.
- When benztropine mesylate is started, do not terminate therapy with other antiparkinsonian agents abruptly. If the other agents are to be reduced or discontinued, it must be done gradually. Many patients obtain greatest relief with combination therapy.
- Benztropine mesylate may be used concomitantly with Carbidopa-Levodopa, or with levodopa, in which case periodic dosage adjustment may be required in order to maintain optimum response.
- In treating extrapyramidal disorders due to neuroleptic drugs (e.g., phenothiazines), the recommended dosage is 1 to 4 mg once or twice a day orally. Dosage must be individualized according to the need of the patient. Some patients require more than recommended; others do not need as much.
- In acute dystonic reactions, 1 to 2 mL of the injection usually relieves the condition quickly. After that, the tablets 1 to 2 mg twice a day, usually prevents recurrence.
- When extrapyramidal disorders develop soon after initiation of treatment with neuroleptic drugs (e.g., phenothiazines), they are likely to be transient. One to 2 mgof benztropine mesylate tablets two or three times a day usually provides relief within one or two days. After one or two weeks the drug should be withdrawn to determine the continued need for it. If such disorders recur, benztropine mesylate can be reinstituted.
- Certain drug-induced extrapyramidal disorders that develop slowly may not respond to benztropine mesylate.

## Off-Label Use and Dosage (Adult)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Benztropine in adult patients.

### NonGuideline-Supported Use
- Benztropine daily doses of 3.8 mg.

# Pediatric Indications and Dosage

## FDA-Labeled Indications and Dosage (Pediatric)
There is limited information regarding FDA-Labeled Use of Benztropine in pediatric patients.

## Off-Label Use and Dosage (Pediatric)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Benztropine in pediatric patients.

### NonGuideline-Supported Use
- Benztropine daily doses of 3.8 mg.

# Contraindications
- Hypersensitivity to benztropine mesylate tablets.
- Because of its atropine-like side effects, this drug is contraindicated in pediatric patients under three years of age, and should be used with caution in older pediatric patients.

# Warnings
- Safe use in pregnancy has not been established.
- Benztropine mesylate may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motorvehicle.
- When benztropine mesylate is given concomitantly with phenothiazines, haloperidol,or other drugs with anticholinergic or antidopaminergic activity, patients should be advised to report gastrointestinal complaints, fever or heat intolerance promptly. Paralytic ileus, hyperthermia and heat stroke, all of which have sometimes been fatal, have occurred in patients taking anticholinergic-type antiparkinsonism drugs, including benztropine mesylate, in combination with phenothiazines and/or tricyclic antidepressants.
- Since benztropine mesylate contains structural features of atropine, it may produce anhidrosis. For this reason, it should be administered with caution during hot weather, especially when given concomitantly with other atropine-like drugs to thechronically ill, the alcoholic, those who have central nervous system disease, and those who do manual labor in a hot environment. Anhidrosis may occur more readily when some disturbance of sweating already exists. If there is evidence of anhidrosis, the possibility of hyperthermia should be considered.Dosage should be decreased at the discretion of the physician so that the ability to maintain body heat equilibrium by perspiration is not impaired. Severe anhidrosis and fatal hyperthermia have occurred.

### Precautions
- Since benztropine mesylate has cumulative action, continued supervision is advisable. Patients with a tendency to tachycardia and patients with prostatic hypertrophy should be observed closely during treatment.
- Dysuria may occur, but rarely becomes a problem. Urinary retention has been reported with benztropine mesylate.
- The drug may cause complaints of weakness and inability to move particular muscle groups, especially in large doses. For example, if the neck has been rigid and suddenly relaxes, it may feel weak, causing some concern. In this event, dosage adjustment is required.
- Mental confusion and excitement may occur with large doses, or in susceptible patients. Visual hallucinations have been reported occasionally. Furthermore, in the treatment of extrapyramidal disorders due to neuroleptic drugs (e.g.,phenothiazines), in patients with mental disorders, occasionally there may be intensification of mental symptoms. In such cases, antiparkinsonian drugs can precipitate a toxic psychosis. Patients with mental disorders should be kept under careful observation, especially at the beginning of treatment or if dosage is increased.
- Tardive dyskinesia may appear in some patients on long-term therapy with phenothiazines and related agents, or may occur after therapy with these drugs has been discontinued. Antiparkinsonism agents do not alleviate the symptoms of tardive dyskinesia, and in some instances may aggravate them. Benztropine mesylate is not recommended for use in patients with tardive dyskinesia.
- The physician should be aware of the possible occurrence of glaucoma. Although the drug does not appear to have any adverse effect on simple glaucoma, it probably should not be used in angle-closure glaucoma.

# Adverse Reactions

## Clinical Trials Experience
- The adverse reactions below, most of which are antichlolinergic in nature, have been reported and within each category are listed in order of decreasing severity.
Tachycardia.
Paralytic ileus, constipation, vomiting, nausea, dry mouth.
If dry mouth is so severe that there is difficulty in swallowing or speaking, or loss of appetite and weight, reduce dosage, or discontinue the drug temporarily.
Slight reduction in dosage may control nausea and still give sufficient relief of symptoms. Vomiting may be controlled by temporary discontinuation, followed by resumption at a lower dosage.
Toxic psychosis, including confusion, disorientation, memory impairment, visual hallucinations; exacerbation of pre-existing psychotic symptoms; nervousness; depression; listlessness; numbness of fingers.
Blurred vision, dilated pupils.
Urinary retention, dysuria.
Occasionally, an allergic reaction, e.g., skin rash, develops. If this cannot be controlled by dosage reduction, the medication should be discontinued.
Heat stroke, hyperthermia, fever.

## Postmarketing Experience
There is limited information regarding Postmarketing Experience of Benztropine in the drug label.

# Drug Interactions
There is limited information regarding Benztropine Drug Interactions in the drug label.

# Use in Specific Populations

### Pregnancy
Pregnancy Category (FDA): 
There is no FDA guidance on use of Benztropine in women who are pregnant.
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Benztropine in women who are pregnant.

### Labor and Delivery
There is no FDA guidance on use of Benztropine during labor and delivery.

### Nursing Mothers
There is no FDA guidance on the use of Benztropine with respect to nursing mothers.

### Pediatric Use
- Because of the atropine-like side effects, benztropine mesylate should be used with caution in pediatric patients over three years of age.

### Geriatic Use
There is no FDA guidance on the use of Benztropine with respect to geriatric patients.

### Gender
There is no FDA guidance on the use of Benztropine with respect to specific gender populations.

### Race
There is no FDA guidance on the use of Benztropine with respect to specific racial populations.

### Renal Impairment
There is no FDA guidance on the use of Benztropine in patients with renal impairment.

### Hepatic Impairment
There is no FDA guidance on the use of Benztropine in patients with hepatic impairment.

### Females of Reproductive Potential and Males
There is no FDA guidance on the use of Benztropine in women of reproductive potentials and males.

### Immunocompromised Patients
There is no FDA guidance one the use of Benztropine in patients who are immunocompromised.

# Administration and Monitoring

### Administration
- Oral
- Intravenous

### Monitoring
There is limited information regarding Monitoring of Benztropine in the drug label.

# IV Compatibility
There is limited information regarding IV Compatibility of Benztropine in the drug label.

# Overdosage

## Acute Overdose

### Signs and Symptoms
- May be any of those seen in atropine poisoning or antihistamine overdosage: CNS depression, preceded or followed by stimulation; confusion; nervousness; listlessness; intensification of mental symptoms or toxic psychosis in patients with mental illness being treated with neuroleptic drugs (e.g.,phenothiazines); hallucinations (especially visual); dizziness; muscle weakness; ataxia; dry mouth; mydriasis; blurred vision; palpitations; tachycardia; elevated blood pressure; nausea; vomiting; dysuria; numbness of fingers; dysphagia; allergic reactions, e.g., skin rash; headache; hot, dry, flushed skin; delirium; coma; shock; convulsions; respiratory arrest; anhidrosis; hyperthermia; glaucoma; constipation.

### Management
- Physostigmine salicylate, 1 to 2 mg, SC or IV, reportedly will reverse symptoms of anticholinergic intoxication.- A second injection may be given after 2 hours if required. Otherwise treatment is symptomatic and supportive. Induce emesis or perform gastric lavage (contraindicated in precomatose convulsive, or psychotic states). Maintain respiration. A short-acting barbiturate may be used for CNS excitement, but with caution to avoid subsequent depression; supportive care for depression (avoid convulsant stimulants such as picrotoxin, pentylenetetrazol,or bemegride); artificial respiration for severe respiratory depression; a local miotic for mydriasis and cycloplegia; ice bags or other cold applications and alcohol sponges for hyperpyrexia, a vasopressor and fluids for circulatory collapse. Darken room for photophobia.

## Chronic Overdose
There is limited information regarding Chronic Overdose of Benztropine in the drug label.

# Pharmacology

## Mechanism of Action
- Benztropine mesylate possesses both anticholinergic and antihistaminic effects,although only the former have been established as therapeutically significant in the management of parkinsonism.

## Structure
- Benztropine Mesylate is a synthetic compound containing structural features found in atropine and diphenhydramine.
- It is a crystalline white powder, very soluble in water, designated as 3-(Diphenylmethoxy)-1H, 5H-tropane methanesulfonate, with the following structural formula:
- Each tablet, for oral administration, contains 0.5 mg, 1 mg or 2 mg of benztropine mesylate.
- Each tablet contains the following inactive ingredients: dibasic calcium phosphate lactose monohydrate, lactose anhydrous, microcrystalline cellulose, cornstarch,talc and hydrogenated vegetable oil.

## Pharmacodynamics
There is limited information regarding Pharmacodynamics of Benztropine in the drug label.

## Pharmacokinetics
There is limited information regarding Pharmacokinetics of Benztropine in the drug label.

## Nonclinical Toxicology
There is limited information regarding Nonclinical Toxicology of Benztropine in the drug label.

# Clinical Studies
There is limited information regarding Clinical Studies of Benztropine in the drug label.

# How Supplied
- Benztropine Mesylate Tablets, USP are available as follows:
- 0.5 mg white, round, bisected, compressed tablets, debossed EP 136, in bottles of 100 (NDC 64125-136-01) and 1000 (NDC 64125-136-10) tablets.
- 1 mg white, oval, bisected, compressed tablets debossed EP 137, in bottles of 100 (NDC 64125-137-01) and 1000 (NDC 64125-137-10) tablets.
- 2 mg white, round, bisected, compressed tablets, debossed EP 138, in bottles of100 (NDC 64125-138-01) and 1000 (NDC 64125-138-10) tablets.
- Dispense in a well-closed container as defined in the USP, with a child-resistant closure.
- Store at 20-25C (68-77F).

## Storage
There is limited information regarding Benztropine Storage in the drug label.

# Images

## Drug Images

## Package and Label Display Panel

### PRINCIPAL DISPLAY PANEL
NDC 17478-012-02
Benztropine Mesylate
Injection, USP
2 mg/2 mL (1 mg/mL)
2 mL Ampule
Rx only Akorn Logo
NDC 17478-012-02
Benztropine Mesylate
Injection, USP
2 mg/2 mL
(1 mg/mL)
For Intravenous or Intramuscular Use
5 Ampules (2 mL each)
Rx only Akorn Logo

# Patient Counseling Information
There is limited information regarding Patient Counseling Information of Benztropine in the drug label.

# Precautions with Alcohol
- Alcohol-Benztropine interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

# Brand Names
- BENZTROPINE MESYLATE

# Look-Alike Drug Names
There is limited information regarding Benztropine Look-Alike Drug Names in the drug label.

# Drug Shortage Status

# Price