Cogentin Information
Cogentin (Benztropine mesylate) Description
Benztropine mesylate is a synthetic compound containing structural features found in atropine and diphenhydramine.
It is designated chemically as 8-azabicyclo[3.2.1] octane, 3-(diphenylmethoxy)-,, methanesulfonate. Its empirical formula is CHNO•CHOS, and its structural formula is:
Benztropine mesylate is a crystalline white powder, very soluble in water, and has a molecular weight of 403.54.
Cogentin (Benztropine mesylate) is supplied as a sterile injection for intravenous and intramuscular use.
Each milliliter of the injection contains:
Benztropine mesylate - 1 mg
Sodium chloride - 9 mg
Water for injection q.s - 1 mL
Cogentin (Benztropine mesylate) Actions
Cogentin (Benztropine mesylate) possesses both anticholinergic and antihistaminic effects, although only the former have 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 atropine.
In laboratory animals, its antihistaminic activity and duration of action approach those of pyrilamine maleate.
Cogentin (Benztropine mesylate) Indications
For use as an adjunct in the therapy of all forms of parkinsonism.
Useful also in the control of extrapyramidal disorders (except tardive dyskinesia - see ) due to neuroleptic drugs (e.g., phenothiazines).
Cogentin (Benztropine mesylate) Contraindications
Hypersensitivity to any component of Cogentin (Benztropine mesylate) injection.
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.
Cogentin (Benztropine mesylate) Warnings
Safe use in pregnancy has not been established.
Cogentin (Benztropine mesylate) may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle.
When Cogentin (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 Cogentin (Benztropine mesylate) , in combination with phenothiazines and/or tricyclic antidepressants.
Since Cogentin (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 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 occurred.
Cogentin (Benztropine mesylate) Precautions
Since Cogentin (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 Cogentin (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 when these drugs have been discontinued. Antiparkinsonism agents do not alleviate the symptoms of tardive dyskinesia, and in some instances may aggravate them. Cogentin (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.
Cogentin (Benztropine mesylate) 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.
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.
Cogentin (Benztropine mesylate) 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.
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 as necessary.
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 Cogentin (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.
Cogentin (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 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 Cogentin (Benztropine mesylate) 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, Cogentin (Benztropine mesylate) can be reinstituted.
Certain drug-induced extrapyramidal disorders that develop slowly may not respond to Cogentin (Benztropine mesylate) .
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.
Cogentin (Benztropine mesylate) Overdosage
** Duvoisin, R.C.; Katz, R.J.; Amer. Med. Ass. 206: 1963-1965, Nov. 25, 1968
Cogentin (Benztropine mesylate) How Supplied
Injection Cogentin (Benztropine mesylate) , 1 mg per mL, is a clear, colorless solution and is supplied in boxes of 5 x 2 mL ampuls.
NDC 67386-611-52
Recommended Storage: Store at 20-25°C (68-77°F). See USP controlled room temperature.
Manufactured by: Hospira, Inc., McPherson, KS 67460, U.S.A.
For: Lundbeck Inc., Deerfield, IL 60015, U.S.A.
® Registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.
Revised: December 2009
Cogentin (Benztropine mesylate) Principal Display Panel
NDC 67386-611-52
Cogentin (Benztropine mesylate) (benztropine mesylate injection)2 mg per 2 mL12 x (5 x 2 mL Ampuls)
