Medications in the Class of Cogentin (Benztropine)
Benztropine (Cogentin) belongs to the anticholinergic class of medications used to treat Parkinson's disease and drug-induced extrapyramidal symptoms, and other medications in this same therapeutic class include trihexyphenidyl (Artane), biperiden, procyclidine, ethopropazine, orphenadrine, and diphenhydramine. 1
Primary Anticholinergic Agents for Parkinsonism and Extrapyramidal Symptoms
The anticholinergic drug class encompasses several agents with similar mechanisms of action:
Benztropine (Cogentin) - Available in oral and injectable formulations, with typical dosing of 1-4 mg once or twice daily for drug-induced extrapyramidal disorders, and 1-2 mg IM/IV for acute dystonic reactions 2
Trihexyphenidyl (Artane) - Another commonly used anticholinergic agent, with typical maintenance dosing of 2-5 mg daily roughly equivalent to benztropine 1-2 mg daily 3
Biperiden - Part of the anticholinergic class used for similar indications 1
Procyclidine - An anticholinergic agent that has been compared to benztropine in clinical trials for neuroleptic-induced parkinsonism 4
Ethopropazine - A phenothiazine derivative with anticholinergic properties, found to be equally effective as benztropine for controlling parkinsonian symptoms but with potentially fewer adverse effects on tardive dyskinesia 4
Orphenadrine - Another member of the anticholinergic class 1
Diphenhydramine - An antihistamine with significant anticholinergic properties, used at 12.5-25 mg every 4-6 hours for acute dystonic reactions 5
Important Clinical Distinctions Within the Class
While these medications share anticholinergic mechanisms, there are critical differences in their use:
Benztropine has a particularly long duration of action, making it suitable for bedtime dosing when effects can last throughout the night 2
Ethopropazine may have advantages over benztropine in patients receiving long-term neuroleptic therapy, as benztropine-treated patients showed significantly more tardive dyskinesia, anxiety, and depression compared to ethopropazine in controlled studies 4
The American Academy of Family Physicians explicitly recommends avoiding benztropine or trihexyphenidyl when treating haloperidol-induced extrapyramidal symptoms in elderly patients with Alzheimer's disease due to heightened anticholinergic sensitivity 6, 3
Critical Prescribing Caveats
These anticholinergic agents should not be used routinely for preventing extrapyramidal symptoms but should be reserved for treatment after symptoms develop, particularly when dose reduction and switching to lower-risk antipsychotics have failed 5
Elderly patients tolerate these drugs less well than younger patients and require lower starting doses due to increased risk of delirium, confusion, and paradoxical agitation 5, 1
All drugs in this class are rapidly absorbed after oral administration with oral bioavailability ranging from 30% to over 70%, possess large volumes of distribution, and are extensively metabolized primarily to N-dealkylated and hydroxylated metabolites 1
There is a notable lack of pharmacokinetic information for multiple-dose administration in the elderly, which may hinder safe and effective use in Parkinson's disease patients 1