Overview
DESCRIPTION Benztropine mesylate, USP is a synthetic compound containing structural features found in atropine and diphenhydramine. It is designated chemically as 3α-(Diphenylmethoxy) -1α-H,5 α H-tropane methanesulfonate. Its molecular formula is C 21 H 25 NO•CH 4 O 3 S, and its structural formula is: Benztropine mesylate, USP is a crystalline white powder, very soluble in water, and has a...
Mechanism of Action
CLINICAL PHARMACOLOGY Benztropine mesylate 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 atropine. In laboratory animals, its antihistaminic activity and duration of action approach those of pyrilamine maleate.
Indications
- INDICATIONS AND USAGE Benztropine mesylate tablets, USP are indicated 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 PRECAUTIONS ) due to neuroleptic drugs (e.g., phenothiazines).
Common Doses
- 0.5 mg
- 6 mg
- 2 mg
- 1 mg
Dosage
DOSAGE AND ADMINISTRATION Benztropine mesylate tablets should be used when patients are able to take oral medication. The injection is especially useful for psychotic patients with acute dystonic reactions or other reactions that make oral medication difficult or impossible. It is recommended also when a more rapid response is desired than can be obtained with the tablets. 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.
Contraindications
- CONTRAINDICATIONS Hypersensitivity to benztropine mesylate tablets or to any component of the 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.
Side Effects
- ADVERSE REACTIONS 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. Cardiovascular Tachycardia. 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.
Interactions
- Drug Interactions Antipsychotic drugs such as phenothiazines or haloperidol; tricyclic antidepressants (see WARNINGS ).