Anticholinergic discontinuation and cognitive functions in patients with schizophrenia: a pharmacist–physician collaboration in the outpatient department

Abstract

IntroductionCognitive impairment is a core feature and shows the highest impact on functional outcome in patients with schizophrenia. There have been no previous studies investigating the role of the pharmacist in a multidisciplinary team on cognitive outcomes in patients with schizophrenia.PurposeWe evaluated the impact of pharmacist intervention on cognitive outcomes in patients with schizophrenia by focusing on anticholinergic discontinuation.Patients and methodsA prospective, open-label, randomized, controlled study was conducted. Patients with schizophrenia were randomly assigned to either the pharmacist intervention or usual care groups. In the pharmacist intervention group, the pharmacist identified drug-related problems (DRPs) and provided a pharmacotherapy suggestion, while there was no intervention in the usual care group. The primary outcome was mean change from baseline of executive function by using Wisconsin Card Sorting Test (WCST) perseverative errors within the pharmacist intervention group at week 12.ResultsA total of 30 patients completed the study (13 in the pharmacist intervention group and 17 in the usual care group). WCST perseverative errors at the end of the study within the pharmacist intervention group improved significantly from baseline (P=0.003). DRPs at week 12 were reduced by 85.19% and 9.76% in the pharmacist intervention and usual care groups, respectively. The most common intervention was the discontinuation of anticholinergics in patients without extrapyramidal side effects.ConclusionAdded-on pharmacist intervention in a multidisciplinary team could help to improve cognitive functions in patients with schizophrenia by reducing DRPs and optimizing the drug therapy regimen, especially for anticholinergic discontinuation.

Nature and Correlates of Executive Dysfunction in Schizophrenia: An Exploratory Study

“… 44 The discontinuation of anticholinergic agents, as well as a reduction to the lowest effective dose of the antipsychotic drug, is recommended to reduce adverse effects, including the cognitive effects attributable to the medication. 49 , 50 The results of this study reiterate the findings of Rehse et al that care should be taken in the prescription of antipsychotic agents. While small positive effects on cognitive functions are seen with normal or lower doses of antipsychotics, higher doses and polypharmacy may be deleterious and magnify disease-related deficits, further interfering with the patient’s functional recovery.…”

Anticholinergic Drugs in Geriatric Psychopharmacology

“…M1, M2 and M4 are, to date, muscarinic receptors that appear to be more related to the possible anticholinergic deleterious effects. M1 receptors are the most common in the CNS and have a crucial role related to executive functions and episodic memory in the prefrontal cortex and hippocampus, respectively (Sathienluckana et al, 2018). M2 receptors participate in memory processing and M4 receptors regulate acetylcholine levels.…”

“…Eliminating or reducing the anticholinergic load can improve cognition, adverse effects and quality of life (Lupu et al, 2017). For example, in patients with schizophrenia younger than 50 years, the discontinuation of anticholinergics improved the results in the Wisconsin Card Sorting Test, a measurement of executive dysfunction (Sathienluckana et al, 2018).…”

Irreversible effects of anticholinergic withdrawal in the elderly: a case report

“…To decrease this risk of these adverse effects, many recommend tapering of anticholinergics rather than abrupt discontinuation [3,19]. While there are no guidelines to indicate an appropriate anticholinergic taper, one recommendation is to decrease the dose by 2-5 mg equivalents of trihexyphenidyl every six weeks [21]. Based on these recommendations, it would have been most appropriate to decrease the dose of trihexyphenidyl from 2 mg twice daily to 2 mg once daily for six weeks, and then discontinue the dose thereafter for our patient.…”