Yes: Tablet

Anticholinergic Agent; Anti-Parkinson's Agent (Anticholinergic)

Adjunctive treatment of Parkinson's disease; also used in treatment of drug-induced extrapyramidal effects (except tardive dyskinesia)

C

Children <3 years of age; hypersensitivity to benztropine or any component of the formulation; pyloric or duodenal obstruction, stenosing peptic ulcers; bladder neck obstructions; achalasia; myasthenia gravis

Use with caution in older children (dose has not been established). Use with caution in hot weather or during exercise. May cause anhydrosis and hyperthermia, which may be severe. The risk is increased in hot environments, particularly in the elderly, alcoholics, patients with CNS disease, and those with prolonged outdoor exposure.

May be associated with confusion or hallucinations (generally at higher dosages). Intensification of symptoms or toxic psychosis may occur in patients with mental disorders. Benztropine does not relieve symptoms of tardive dyskinesia.

Cardiovascular: Tachycardia

Central nervous system: Confusion, disorientation, memory impairment, toxic psychosis, visual hallucinations

Dermatologic: Rash

Endocrine & metabolic: Heat stroke, hyperthermia

Gastrointestinal: Xerostomia, nausea, vomiting, constipation, ileus

Genitourinary: Urinary retention, dysuria

Ocular: Blurred vision, mydriasis

Miscellaneous: Fever

Symptoms of overdose include CNS depression, confusion, nervousness, hallucinations, dizziness, blurred vision, nausea, vomiting, hyperthermia

For anticholinergic overdose with severe life-threatening symptoms, physostigmine 1-2 mg (0.5 mg or 0.02 mg/kg for children) S.C. or I.V., slowly may be given to reverse these effects. Anticholinergic toxicity is caused by strong binding of the drug to cholinergic receptors. Anticholinesterase inhibitors reduce acetylcholinesterase, the enzyme that breaks down acetylcholine and thereby allows acetylcholine to accumulate and compete for receptor binding with the offending anticholinergic.

Decreased effect: May increase gastric degradation of levodopa and decrease the amount of levodopa absorbed by delaying gastric emptying; the opposite may be true for digoxin

Therapeutic effects of cholinergic agents (tacrine, donepezil) and neuroleptics may be antagonized

Increased toxicity: Central and/or peripheral anticholinergic syndrome can occur when administered with amantadine, rimantadine, narcotic analgesics, phenothiazines and other antipsychotics (especially with high anticholinergic activity), tricyclic antidepressants, quinidine and some other antiarrhythmics, and antihistamines

Possesses both anticholinergic and antihistaminic effects. In vitro anticholinergic activity approximates that of atropine; in vivo it is only about half as active as atropine. Animal data suggest its antihistaminic activity and duration of action approach that of pyrilamine maleate. May also inhibit the reuptake and storage of dopamine and thereby, prolong the action of dopamine.

Onset of action: Oral: Within 1 hour; Parenteral: Within 15 minutes

Duration of action: 6-48 hours (wide range)

Use in children <3 years of age should be reserved for life-threatening emergencies

Children >3 years: 0.02-0.05 mg/kg/dose 1-2 times/day

Adults: 1-4 mg/dose 1-2 times/day

Acute dystonia: Adults: I.M., I.V.: 1-2 mg

Parkinsonism: Oral:

Adults: 0.5-6 mg/day in 1-2 divided doses; if one dose is greater, administer at bedtime; titrate dose in 0.5 mg increments at 5- to 6-day intervals

Elderly: Initial: 0.5 mg once or twice daily; increase by 0.5 mg as needed at 5-6 days; maximum: 4 mg/day

Alcohol: Additive CNS effects, avoid use

No information available to require special precautions

Dry mouth, nose, and throat very prevalent in patients taking this drug

Take exactly as directed; do not increase, decrease, or discontinue without consulting prescriber. Take at the same time each day. Do not use alcohol and all prescription or OTC sedatives or CNS depressants without consulting prescriber. You may experience drowsiness, dizziness, confusion, and blurred vision (use caution when driving, climbing stairs, or engaging in tasks requiring alertness until response to drug is known); increased susceptibility to heat stroke, decreased perspiration (use caution in hot weather - maintain adequate fluids and reduce exercise activity); constipation (increased exercise, fluids, or dietary fruit and fiber may help). Report unresolved nausea, vomiting, or gastric disturbances; rapid or pounding heartbeat, chest pain or palpitation; difficulty breathing; CNS changes (hallucination, loss of memory, nervousness, etc); eye pain; prolonged fever; painful or difficult urination; unresolved constipation; increased muscle spasticity or rigidity; skin rash; or significant worsening of condition. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Consult prescriber if breast-feeding.

No significant difference in onset of I.M. or I.V. injection, therefore, there is usually no need to use the I.V. route. Improvement is sometimes noticeable a few minutes after injection.

Injection, as mesylate: 1 mg/mL (2 mL)

Tablet, as mesylate: 0.5 mg, 1 mg, 2 mg

Catterson ML and Martin RL, "Anticholinergic Toxicity Masquerading as Neuroleptic Malignant Syndrome: A Case Report and Review," Ann Clin Psychiatry, 1995, 6:267-9.

Erwin WG and Turco TF, "Current Concepts in Clinical Therapeutics: Parkinson's Disease," Clin Pharm, 1986, 5(9):742-53.

Fahy P, Arnold P, Curry SC, et al, "Serial Serum Drug Concentrations and Prolonged Anticholinergic Toxicity After Benztropine (Cogentin®) Overdose," Am J Emerg Med, 1989, 7(2):199-202.

Feinberg M, "The Problems of Anticholinergic Adverse Effects in Older Patients," Drugs Aging, 1993, 3(4):335-48.

Goff DC, Arana GW, Greenblatt DJ, et al, "The Effect of Benztropine on Haloperidol-Induced Dystonia, Clinical Efficacy and Pharmacokinetics: A Prospective, Double-Blind Trial," J Clin Psychopharmacol, 1991, 11(2):106-12.

Harper G, Dawes M, Azlin C, et al, "Small Bowel Obstruction in a Child on an Antipsychotic," J Child Adolesc Psychopharm, 1995, 5:81-4.

Mackie A and Hill HF, "Prophylactic Benztropine for Antiemetic Precipitated Extrapyramidal Symptoms During Cancer Chemotherapy," J Pain Symptom Manage, 1989, 4(3):109-10.

McEvoy JP, "The Clinical Use of Anticholinergic Drugs as Treatment for Extrapyramidal Side Effects of Neuroleptic Drugs," J Clin Psychopharmacol, 1983, 3(5):288-302.

Rosano TG, Meola JM, Wolf BC, et al, "Benztropine Identification and Quantitation in a Suicidal Overdose," J Anal Toxicol, 1994, 18(6):348-53.

Roth A, Akyol S, and Nelson JC, "Delirium Associated With the Combination of a Neuroleptic, an SSRI, and Benztropine," J Clin Psychiatry, 1994, 55(11):492-5.