benztropine COGENTIN
Class: AnticholinergicFDA Indications: Parkinsonism, Drug-induced Extrapyramidal Reactions
Off-Label Use: Idiopathic Generalized Dystonia, Focal Dystonias, Dopa-responsive Dystonia, Acute Dystonia
Prescribing
Forms: 0.5, 1, 2mg tablet; 1mg/mL IV; 1 mg/mL IMDose Range: 1-8 mg/day
Starting: For EPS, recommended dosage is 1–4 mg qd-bid. Taking benztropine with meals can reduce side effects.
Precautions
Contraindications: Do not use in children ages 3 and youngerSerious Side Effects: Angle-closure glaucoma, heat stroke, especially in elderly patients, tachycardia, cardiac arrhythmias, hypotension; can exacerbate or unmask tardive dyskinesia
Side Effects: confusion, anticholinergic side effects, erectile dysfunction
Pharmacodynamics
1° MOA: Centrally-acting antimuscarinic agent; reinstates balance of dopaminergic to cholinergic activity in the nigrostriatal pathway (as dopaminergic activity ↓ d/t D2-blockade, the anti-ACh aims to likewise ↓ cholineric activity and restore the DA/ACh ratio)2° MOA: Inhibit the reuptake and storage of dopamine at central dopamine receptors, prolonging dopamine action
Target: M1, H1, DAT
Pharmacokinetics
t½: 24° TMAX: 1-2°Substrate of: Renally cleared
Inhibits: ∅ ; Induces: ∅
Active Metabolites: ∅
DDIs
- - amantadine may amplify such adverse anticholinergic effects as confusion and hallucinations
- - caution with co-prescribed CNS depressants which can ↑ sedative effects
Misc
- - First-line agent for extrapyramidal disorders related to antipsychotic use
- - Patients with cognitive impairment may do poorly; can cause cognitive side effects with chronic use, so periodic trials of discontinuation may be useful to justify continuous use
- - Commonly used in an oral or intramuscular formulation as needed with concomitant antipsychotics to reduce or prevent EPS
Special Populations
Category C—Limited Human Data—probably Compatible. One surveillance study found a possible association between benztropine and cardiovascular defects, but confirmation is required. Exposure near term has been associated with paralytic ileus in the newborn.
No reports describing the use of benztropine during human lactation have been located. In general, however, agents in this class are probably compatible with breast feeding.
Elderly patients may be more susceptible to side effects (especially sedation)
No known effects, but use with caution
No known effects, but use with caution
