Anticholinergic medication burden important consideration in schizophrenia

Anticholinergic medication burden is substantial among individuals with schizophrenia, according to results of a cross-sectional data analysis published in American Journal of Psychiatry.

“The sources of cognitive impairment in schizophrenia are multifactorial, but among the molecular and neural circuit abnormalities identified in the disorder, central cholinergic dysfunction has consistently been reported,” Yash B. Joshi, MD, PhD, of the department of psychiatry at the University of California, San Diego, and colleagues wrote. “Cholinergic dysfunction is particularly relevant since psychotropic medications commonly used in the treatment of schizophrenia often possess strong anticholinergic properties, and medications with high anticholinergic burden are frequently used to treat the side effects of acute and chronic psychotropic use. Patients with schizophrenia are also more vulnerable to medical comorbidities, which independently increase the chance of being exposed to additional medications with anticholinergic properties.”

According to the researchers, better understanding the effects of cognitive impairment linked to anticholinergic medication burden may aid in the optimization of cognitive outcomes in schizophrenia. In the current study, they sought to outline how this burden affects functioning across multiple domains among schizophrenia outpatients. They used inferential statistics and exploratory structural equation modeling to analyze cross-sectional data and thus elucidate the association between anticholinergic medication burden and cognition among 1,120 patients aged 18 to 65 years diagnosed with schizophrenia or schizoaffective disorder who participated in the Consortium on the Genetics of Schizophrenia at five U.S. universities.

The researchers rated and summed each participant’s prescribed medications according to a modified Anticholinergic Cognitive Burden (ACB) scale, which is a “validated expert rating scale of the anticholinergic properties of medications,” Joshi and colleagues noted. They evaluated cognitive functioning according to performance on domains of the Penn Computerized Neurocognitive Battery (PCNB), which contains accuracy and speed measures in eight domains.

Results showed a significant association between ACB score and cognitive performance. Higher ACB groups scored worse than lower ACB groups on all domains tested via the PCNB. The researchers observed similar effects on other cognitive tests. After having controlled for demographic characteristics and potential illness severity proxies, including clinical symptoms and chlorpromazine-equivalent antipsychotic dosage, effects remained significant.

“Cumulative anticholinergic medication burden should be considered when prescribing medications (psychotropic as well as nonpsychotropic) for patients with schizophrenia,” Joshi and colleagues wrote. “Efforts to limit or avoid excessive anticholinergic medication burden — regardless of source — may have a beneficial impact on cognitive outcomes in schizophrenia. Algorithms for anticholinergic burden calculations may be deployable within electronic medical record systems to guide providers in medication choices.”