Does benztropine (anticholinergic) need to be stopped before restarting an antipsychotic?

Benztropine Discontinuation Before Restarting Antipsychotics

Benztropine does not need to be stopped before restarting an antipsychotic; in fact, anticholinergics like benztropine should not be used routinely or prophylactically at all, but only prescribed short-term if significant extrapyramidal symptoms develop after dose reduction or switching strategies have failed. 1

Evidence-Based Approach to Anticholinergic Use

Primary Guideline Recommendation

• Anticholinergics should not be used routinely for preventing extrapyramidal side effects when starting or restarting antipsychotics 1
• Short-term use may only be considered in individuals with significant extrapyramidal side effects when dose reduction and switching strategies have proven ineffective, or when these side effects are acute or severe 1

When to Use Benztropine with Antipsychotics

• Prophylactic antiparkinsonian agents may be considered only in patients at high risk for acute dystonias (young age, male gender, high-potency agents) or those with a documented history of dystonic reactions 1
• This is particularly relevant for patients whose compliance may be compromised by fear of side effects, such as those who are paranoid or distrust medication 1

Specific Populations Where Benztropine Should Be Avoided

• In elderly patients with Alzheimer's disease receiving typical antipsychotics, avoid use of benztropine or trihexyphenidyl entirely 1
• In patients with cognitive impairment, constipation, diabetes, diabetic neuropathy, xerophthalmia, or xerostomia, avoid antipsychotics with anticholinergic properties and their adjunctive anticholinergics 2

Reassessment Strategy

• The need for antiparkinsonian agents should be reevaluated after the acute phase of treatment or if antipsychotic doses are lowered, as many patients no longer need them during long-term therapy 1
• Only 14.2% of chronic schizophrenic patients withdrawn from benztropine experienced extrapyramidal symptoms severe enough to require resumption of therapy 3
• Withdrawal of benztropine in chronic patients actually improved cognitive function, particularly attention and concentration 3

Clinical Algorithm for Restarting Antipsychotics

1. Start the antipsychotic without benztropine unless the patient has a documented history of severe dystonic reactions 1
2. Monitor closely for extrapyramidal symptoms during the first 4-6 weeks 1
3. If extrapyramidal symptoms develop, first attempt dose reduction of the antipsychotic 1
4. If dose reduction is not feasible, consider switching to an atypical antipsychotic with lower extrapyramidal risk 1
5. Only add benztropine if symptoms persist despite these strategies or if symptoms are acute and severe (e.g., dystonia, laryngospasm) 1

Important Caveats

• Benztropine itself can cause cognitive impairment, particularly deficits in attention and concentration, which may be mistaken for negative symptoms of schizophrenia 3
• Anticholinergic agents do not consistently help akathisia; beta-blockers and benzodiazepines are more effective for this specific extrapyramidal symptom 1
• If benztropine was being used chronically before the antipsychotic was stopped, consider discontinuing it rather than continuing it when restarting, as most patients do not require long-term anticholinergic therapy 1, 3