United States - English - NLM (National Library of Medicine)
BENZTROPINE MESYLATE- benztropine mesylate injection
Benztropine Mesylate Injection, USP
Benztropine mesylate is a synthetic compound containing structural features found in atropine and
It is designated chemically as 8-azabicyclo[3.2.1] octane, 3-(diphenylmethoxy)-,endo, methanesulfonate.
Its empirical formula is C
H NOCH O S, and its structural formula is:
Benztropine mesylate is a crystalline white powder, very soluble in water, and has a molecular weight
Benztropine mesylate injection, USP is supplied as a sterile injection for intravenous and intramuscular
Each milliliter of the injection contains:
Benztropine mesylate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 mg
Sodium chloride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 mg
Water for injection q.s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 mL
Benztropine mesylate injection, USP possesses both anticholinergic and antihistaminic effects, although
only the former have been established as therapeutically significant in the management of parkinsonism.
In the isolated guinea pig ileum, the anticholinergic activity of this drug is about equal to that of
atropine; however, when administered orally to unanesthetized cats, it is only about half as active as
In laboratory animals, its antihistaminic activity and duration of action approach those of pyrilamine
For use as an adjunct in the therapy of all forms of parkinsonism (see DOSAGE AND
Useful also in the control of extrapyramidal disorders (except tardive dyskinesia – see
PRECAUTIONS) due to neuroleptic drugs (e.g., phenothiazines).
Hypersensitivity to any component of benztropine mesylate injection, USP.
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.
Safe use in pregnancy has not been established.
Benztropine mesylate injection, USP may impair mental and/or physical abilities required for
performance of hazardous tasks, such as operating machinery or driving a motor vehicle.
When benztropine mesylate injection, USP 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 injection, in combination with phenothiazines
and/or tricyclic antidepressants.
Since benztropine mesylate injection 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 the chronically 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 occured.
General: Since benztropine mesylate injection, USP 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 injection, USP.
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 when these drugs have been discontinued. Antiparkinsonism agents
do not alleviate the symptoms of tardive dyskinesia, and in some instances may aggravate them.
Benztropine mesylate injection, USP 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
Drug Interactions: Antipsychotic drugs such as phenothiazines or haloperidol; tricyclic
antidepressants (see WARNINGS).
Pediatric use: Because of the atropine-like side effects, benztropine mesylate injection, USP should be
used with caution in pediatric patients over three years of age (see CONTRAINDICATIONS).
Geriatric Use: Clinical studies of benztropine mesylate did not include sufficient numbers of subjects
aged 65 and over to determine whether they respond differently from younger subjects. Other reported
clinical experience has not identified differences in responses between the elderly and younger
patients. In general, dose selection for an elderly patient should start at the low end of the dosing range
(see DOSAGE AND ADMINISTRATION) and the dose should be increased only as needed with
monitoring for the emergence of adverse events (see PRECAUTIONS and ADVERSE REACTIONS).
The adverse reactions below, most of which are anticholinergic in nature, have been reported and
within each category are listed in order of decreasing severity.
Digestive: 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.
Nervous System: Toxic psychosis, including confusion, disorientation, memory impairment, visual
hallucinations; exacerbation of pre-existing psychotic symptoms; nervousness; depression; listlessness;
numbness of fingers.
Special Senses: Blurred vision, dilated pupils.
Urogenital: Urinary retention, dysuria.
Metabolic/Immune or Skin: Occasionally, an allergic reaction, e.g., skin rash, develops. If this cannot
be controlled by dosage reduction, the medication should be discontinued.
Other: Heat stroke, hyperthermia, fever.
To report SUSPECTED ADVERSE REACTIONS, contact Akorn, Inc. at 1-800-932-5676 or
FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
DOSAGE AND ADMINISTRATION
Since there is no significant difference in onset of effect after intravenous or intramuscular injection,
usually there is no need to use the intravenous route. The drug is quickly effective after either route,
with improvement sometimes noticeable a few minutes after injection. In emergency situations, when the
condition of the patient is alarming, 1 to 2 mL of the injection normally will provide quick relief. If the
parkinsonian effect begins to return, the dose can be repeated.
Because of cumulative action, therapy should be initiated with a low dose which is increased gradually
at five or six-day intervals to the smallest amount necessary for optimal relief. Increases should be
made in increments of 0.5 mg, to a maximum of 6 mg, or until optimal results are obtained without
excessive adverse reactions.
Postencephalitic and Idiopathic Parkinsonism: The following dosing guidelines were written in
reference to both benztropine mesylate tablets and COGENTIN Injection. Benztropine mesylate tablets
should be used when patients are able to take oral medication.
The usual daily dose is 1 to 2 mg, with a range of 0.5 to 6 mg parenterally.
As with any agent used in parkinsonism, dosage must be individualized according to 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
Some patients experience greatest relief when given 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 injection, USP 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 injection, USP may be used concomitantly with, SINEMET (Carbidopa-
Levodopalevodopa), or with levodopa, in which case dosage adjustment may be required in order to
maintain optimum response.
Drug-Induced Extrapyramidal Disorders: In treating extrapyramidal disorders due to neuroleptic
drugs (e.g., phenothiazines), the recommended dosage is 1 to 4 mg once or twice a day parenterally.
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.
When extrapyramidal disorders develop soon after initiation of treatment with neuroleptic drugs (e.g.,
phenothiazines), they are likely to be transient. One to 2 mg of benztropine mesylate injection, USP two
or three times a day usually provides relief within one or two days. If such disorders recur,
COGENTIN can be reinstituted.
Certain drug-induced extrapyramidal disorders that develop slowly may not respond to benztropine
mesylate injection, USP.
Manifestations: 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;
Treatment: 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. 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.
** Duvoisin, R.C.; Katz, R.J.; Amer. Med. Ass. 206: 1963-1965, Nov. 25, 1968
Benztropine Mesylate Injection, USP 1 mg per mL, is a clear, colorless solution and is supplied as
NDC 17478-012-02 in boxes of 5 x 2 mL ampuls.
Storage: Store at 20º to 25ºC (68º to 77ºF) [see USP Controlled Room Temperature].
Distributed by: Akorn, Inc.
Lake Forest, IL 60045
BZ00N Rev. 09/16
Principal Display Panel Text for Container Label:
2 mg/2 mL (1 mg/mL)
2 mL Ampule
Principal Display Panel Text for Carton Label:
2 mg/2 mL
For Intravenous or Intramuscular Use
5 Ampules (2 mL each)
Rx only Akorn Logo
benztropine mesylate injection
Product T ype
HUMAN PRESCRIPTION DRUG
Ite m Code (Source )
NDC:17478 -0 12
Route of Administration
Active Ingredient/Active Moiety
Basis of Strength
Stre ng th
Benztro pine Mesyla te (UNII: WMJ8 TL7510 ) (Benztro pine - UNII:1NHL2J4X8 K)
Benztro pine Mesylate
1 mg in 1 mL
Stre ng th
So dium Chlo ride (UNII: 451W47IQ8 X)
9 mg in 1 mL
Wa ter (UNII: 0 59 QF0 KO0 R)
Marketing Start Date
Marketing End Date
NDC:17478 -0 12-0 2
5 in 1 CARTON
0 8 /0 8 /20 12
2 mL in 1 AMPULE; Type 0 : No t a Co mbinatio n Pro duct
Marke ting Cate gory
Application Numbe r or Monograph Citation
Marke ting Start Date
Marke ting End Date
NDA autho rized generic
NDA0 120 15
0 8 /0 8 /20 12
Akorn, Inc. (062649876)