THERAPEUTICS

Brands

• Cogentin

Generic?

• Yes

Class

• Antiparkinson agent, anticholinergic

Commonly Prescribed for

(FDA approved in bold)

• Extrapyramidal disorders

• Parkinsonism

• Acute dystonic reactions

• Idiopathic generalized dystonia

• Focal dystonias

• Dopa-responsive dystonia

How the Drug Works

• In Parkinson's disease (PD), there is a relative excess of cholinergic input. Benztropine is a synthetic anticholinergic with relatively greater CNS activity than most other anticholinergics. May also inhibit the reuptake and storage of dopamine at central dopamine receptors, prolonging dopamine action

How Long Until It Works

• PD/extrapyramidal disorders: minutes to hours

If It Works

• PD: do not abruptly discontinue or change doses of other PD treatments. Usually most effective in combination with other antiparkinsonian medications

If It Doesn't Work

• PD: generally benztropine is an adjunctive medication for common PD symptoms, such as tremor, rigidity, and drooling. Other cardinal PD symptoms, such as bradykinesia and gait difficulties, are most likely to improve with other PD treatments, such as levodopa, dopamine agonists, amantadine, or monoamine oxidase (MAO)-B inhibitors

• Acute dystonic reactions: diphenhydramine is another option, if not effective consider benzodiazepines. If possible, discontinue the agent that precipitated the extrapyramidal AE

Best Augmenting Combos for Partial Response or Treatment-Resistance

• For bradykinesia or gait disturbances causing significant functional disturbance, levodopa is most effective. For idiopathic PD patients, especially younger patients with normal cognition and milder disability, dopamine agonists are a good first choice. Amantadine and MAO-B inhibitors may also be useful

• Depression is common in PD and may respond to low-dose SSRIs

Tests

• None

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• Prevents the action of acetylcholine on muscarinic receptors

Notable AEs

• Dry mouth, tachycardia, palpitations, hypotension, disorientation, confusion, hallucinations, constipation, nausea/vomiting, dilation of colon, rash, blurred vision, diplopia, urinary retention, elevated temperature, decreased sweating, erectile dysfunction