Would Banophen (Diphenhydramine) Worsen Tardive Dyskinesia?
Yes, Banophen (diphenhydramine), as an anticholinergic medication, should be avoided in patients with tardive dyskinesia because anticholinergics can worsen the involuntary movements characteristic of this condition. 1
Why Anticholinergics Worsen TD
The American Academy of Family Physicians explicitly states that anticholinergics should not be used to treat tardive dyskinesia and may actually worsen the condition. 1
Clinical guidelines emphasize avoiding benztropine or trihexyphenidyl (other anticholinergics) when extrapyramidal symptoms occur in elderly patients on typical antipsychotics, and this recommendation extends to tardive dyskinesia management where anticholinergics can worsen the involuntary movements. 1
The American Psychiatric Association specifically advises against using anticholinergic medications for tardive dyskinesia, noting that while they are indicated for acute dystonia and parkinsonism, they are contraindicated for TD. 2
Critical Distinction to Understand
It is essential to distinguish between drug-induced parkinsonism and tardive dyskinesia, as anticholinergics may be beneficial for the former but worsen the latter. 1
This is a common clinical pitfall—using anticholinergics like diphenhydramine to treat what appears to be extrapyramidal symptoms without recognizing that the patient has developed TD rather than acute parkinsonism. 1
Additional Concerns with Anticholinergics in TD Patients
- The American Academy of Child and Adolescent Psychiatry warns that in patients with mental disorders on neuroleptics, antiparkinsonian drugs (including anticholinergics) can precipitate toxic psychosis and may intensify mental symptoms, particularly at the beginning of treatment or with dosage increases. 1
What Should Be Done Instead
If TD is present and clinically feasible, gradually withdraw the offending antipsychotic medication. 1, 2
For moderate to severe or disabling tardive dyskinesia, treat with FDA-approved VMAT2 inhibitors (valbenazine or deutetrabenazine) as first-line pharmacotherapy. 1, 2, 3
If continued antipsychotic treatment is necessary, switch to atypical antipsychotics with lower D2 affinity such as clozapine or quetiapine. 1, 2, 3