Dosing and uses of Cogentin (benztropine)
Adult dosage forms and strengths
tablet
- 0.5mg
- 1mg
- 2mg
injectable solution
- 1mg/mL
Parkinsonism
Postencephalitic parkinsonism: 1-2 mg/day (range, 0.5-6 mg/day) PO/IV/IM at bedtime or divided q6-12hr; may consider lower dose or 0.5 mg at bedtime in highly sensitive patients; not to exceed 6 mg/day
Idiopathic parkinsonism: 0.5-1 mg qHS initially; titrate dose in 0.5-mg increments every 5-6 days (range 0.5-6 mg daily; some patients may need 4-6 mg/day); not to exceed 6 mg/day
Drug-Induced Extrapyramidal Disorders
1-2 mg IV/IM/PO q8-12hr; reevaluate after 1-2 weeks
Acute dystonia: 1-2 mg IV, then 1-2 mg PO once or twice daily for 7-28 days to prevent recurrence
Pediatric dosage forms and strengths
tablet
- 0.5mg
- 1mg
- 2mg
injectable solution
- 1mg/mL
Drug-Induced Extrapyramidal Disorders
<3 years: Not recommended
>3 years: 0.02-0.05 mg/kg IV/IM/PO once daily or q12hr
Geriatric dosage forms and strengths
Nonanticholinergic antiparkinson agents should be considered first for treatment of Parkinson disease (Beers criteria)
Not well tolerated in elderly, because of bowel, bladder, and CNS effects; avoid use if possible
Should not be used as prophylaxis against extrapyramidal symptoms in elderly
Parkinsonism
0.5 mg PO once daily or q12hr; titrate dose in 0.5-mg increments every 5-6 days; not to exceed 4 mg/day
Cogentin (benztropine) adverse (side) effects
Frequency not defined
Blurred vision
Confusion
Constipation
Disorientation
Dry mouth or throat
Hyperthermia
Mydriasis
Nausea
Paralytic ileus
Psychosis
Tachycardia
Urinary retention
Visual hallucinations
Vomiting
Warnings
Contraindications
Hypersensitivity
Age <3 years
Cautions
Monitor patients with a history of tachyarrhythmia and benign prostatic hyperplasia
May cause anhidrosis/hyperthermia, which may become severe; use with catuion in hot weather and during exercise; risk is increased in hot environment; consider lowering the dose to prevent impairing heat equilibrium by perspiration
May cause anticholinergic effects (constipation, xerostomia, blurred vision, urinary retention)
At higher doses, may be associated with confusion, visual hallucinations or excitement; intensification of symptoms or toxic psychosis may occur in patients with mental disorders
May cause CNS depression, which may impair ability to operate heavy machinery and tasks that require mental alertness
In susceptible patients, large doses may cause weakness and inability to move perticular muscles
Use caution in patients with GI obstruction, tachycardia, prostatic hyperplasia/urinary stricture, and glaucoma
Response in the elderly >65 years of age may be altered; initiate at low doses and increase PRN while monitoring adverse effects
Use with caution in children >3 years of age due to anticholinergic effects
Not recommended for patients with tardive dyskinesia; does not relieve symptoms and may potentially exacerbate symptoms
Pregnancy and lactation
Pregnancy category: C
Lactation: Excretion in milk unknown; use with caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Cogentin (benztropine)
Mechanism of action
Exerts anticholinergic and antihistaminic effects; may prolong action of dopamine by inhibiting its reuptake and storage
Absorption
Bioavailability: 29%
Onset: PO, 1 hr; parenteral, 15 min
Duration: 6-48 hr
Distribution
Protein bound: 95%
Elimination
Trace amounts found unchanged in feces
Administration
IV Incompatibilities
Syringe: HaloperidoL
IV Compatibilities
Syringe: Chlorpromazine, fluphenazine, metoclopramide, perphenazine
Y-site: Tacrolimus, fluconazole
IV Administration
IV route rarely necessary; use only when PO and IM routes unavailable
