Investigating Real-World Benztropine Usage Patterns in Movement Disorders: Claims Analysis and Health Care Provider Survey Results

Objective: To evaluate real-world treatment patterns for patients initiating benztropine and to understand treatment approaches in patients with drug-induced movement disorders from a health care provider perspective.

Methods: A retrospective claims analysis was conducted among patients with evidence of benztropine initiation from January 2017 through March 2020 to assess treatment patterns and patient health care resource utilization. Subsequently, a 30-minute, United States-based online survey fielded from December 2021 to January 2022 was sent to physicians, nurse practitioners, and physician assistants who reported a primary care or psychiatry specialty currently treating drug-induced movement disorders and prescribed benztropine.

Results: The health care claims analysis included 112,542 patients. Polypharmacy and multiple comorbidities were frequent characteristics in this population; 54.1% of patients had ≥ 2 comorbidities at baseline, and 59.1% had claims for > 10 medications. Benztropine was used for > 3 months in > 50% of the population. Health care costs and resource utilization were high, with mean all-cause pharmacy and outpatient costs totaling $11,755. Survey results from 349 primary care or psychiatry health care providers indicated that benztropine is often used in non-tardive dyskinesia drug-induced movement disorders but frequently continued for > 3 months or used in tardive dyskinesia. In this study, psychiatry providers prescribed benztropine in line with guideline recommendations more often than primary care providers; however, < 40% indicated familiarity with 2020 American Psychiatric Association Practice Guideline for the Treatment of Patients with Schizophrenia.

Conclusions: These complementary analyses suggest that benztropine is used long-term in non-tardive dyskinesia drug-induced movement disorders and in tardive dyskinesia despite risks of worsening tardive dyskinesia or adverse effects.

Prim Care Companion CNS Disord 2023;25(4):22m03472.

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Misuse of anticholinergic drugs by people with serious mental illness

This study assessed misuse of anticholinergic drugs in a population of 50 patients with serious mental illness who were assertively managed by a community-based outreach team in Sydney, Australia. One-third of the subjects reported having misused anticholinergics over the previous month. All anticholinergics were misused, and trihexyphenidyl (benzhexol) was misused most frequently. Most subjects misused at least one other drug as well. On direct questioning, the reason given most frequently was "to get high"; on indirect questioning, reasons were related more to peer participation and feelings of futility. Marginalized patients living in the community are vulnerable to the misuse of anticholinergic drugs.

[Regional distribution of the muscarinic cholinergic receptor in the human brain studied with 11C-benztropine and PET using an anatomical standardization technique]

We measured regional distribution of the muscarinic cholinergic receptor in the normal human brain with 11C-benztropine (BZT) and positron emission tomography (PET) using an anatomical standardization technique. Seven normal volunteers who gave informed consents were involved in this study. Immediately after intravenous injection of 11C-BZT into the subjects, we started dynamic PET scanning and serial frequent arterial blood sampling. Analyses of plasma metabolites were also performed at selected time points and plasma time activity curves (TAC) of unmetabolized ligand were generated. From these PET and TAC data, we obtained Patlak plot slope calculation images. Using the HBA (human brain atlas) system, the Patlak plot slope calculation image of each subject was transformed into the shape of the standard brain. Mean and standard deviation (SD) calculation images were generated from those anatomically standardized images. On these mean and SD images, we placed regions of interest which were previously outlined on a MR image of the standard brain. From those data, we found the highest receptor distribution in the striatum and occipital cortex, as well as high distribution in the frontal, parietal, and temporal cortices, which were consistent with previous reports. These results suggested that anatomical standardization of PET receptor images with 11C-BZT will be useful for delineating the physiological or pathological alterations of the muscarinic cholinergic receptor in the human brain.

On-line [11C]methylation using [11C]methyl iodide for the automated preparation of 11C-radiopharmaceuticals

A novel method for the efficient preparation of 11C-radiopharmaceuticals by on-line [11C]methylation using [11C]methyl iodide has been developed and applied to a rapid, convenient automated system. [11C]Methyl iodide is first trapped in a short column, containing an adsorber and coated substrate, which is connected to an HPLC injector. DMF is then introduced. Alternatively the substrate is added with the DMF. A whole reaction mixture can be easily injected onto an HPLC column for purification by switching the injector valve immediately after the reaction. Thus, radiochemical yields in the preparation of 11C-labeled doxepin, benztropine, cyproheptadine and N-methylspiperone have been improved remarkably and the synthetic procedure simplified.

Abuse of antiparkinsonian drugs

Abuse of the antiparkinsonian agents for their hallucinogenic and euphoriant effects is likely more prevalent than reported. Two clinical cases are presented, with discussion of symptoms and response to a diagnostic trial of physostigmine.

Abuse of the antiparkinson drugs: a review of the literature

A review of the literature indicates that the anticholinergic antiparkinson drugs can be abused by some patients to achieve pleasurable effects ranging from a mild euphoria with increased sociability at the lower doses to a toxic anticholinergic psychosis with disorientation and hallucinations at higher doses. Trihexyphenidyl may have a greater potential for abuse but there has been no systematic data on this issue. While the abuse of these drugs may not be widespread, it is yet another factor arguing for their judicious use.