Background and Importance Pluripathology, polymedication, dependence and frailty are common situations in institutionalised populations. Due to these circumstances is very important to monitor drug safety in these patients, especially the risk of anticholinergic effects that can significantly affect quality of life.

Aim and Objectives To identify the drugs that add anticholinergic burden (AB) prescribed in nursing home residents, as well as to quantify the overall AB.

Material and Methods Cross-sectional study carried out in nursing home residents attached to a hospital pharmacy service. All patients institutionalised in September 2023 were included. Variables collected: Age, sex and number of drugs prescribed.

The Anticholinergic Burden Calculator was used to identify drugs with AB according to the 10 scales included in the calculator. The anticholinergic risk (AR) obtained was quantified with the Anticholinergic Cognitive Burden Scale (ACB), which classifies the patient with a high (>3), medium (2) and low (1) risk of presenting anticholinergic adverse effects.

Subsequently, patients were categorised into four groups according to the number of drugs prescribed (1–5, 6–10, 11–15 and >15) and the AB was quantified according to ACB of each group.

Data sources electronic medical sources and electronic prescribing software. Microsoft Excel 2020® was used to process the data.

Results Eighty-two patients were included, male 69.5% (n=57), mean age 74.5±8.5 years, with a mean of 9.0±4.3 prescribed medications per resident.

According to ACB 32.9% (n=27) had low, 4.9% (n=4) medium and 24.4% (n=20) high risk of manifesting anticholinergic adverse effects; 37.8% (n=31) of patients had no AR.

The most prescribed drugs with AB were: furosemide 7.1% (n=15), tamsulosin 6.2% (n=13), tramadol 6.2% (n=13) and metformin 5.2% (n=11); the drugs with the highest AB were: oxybutynin 0.5% (n=1), paroxetine 0.9% (n=2) and olanzapine 1.4% (n=3).

The mean AB found according to the number of drugs prescribed was: 0.2±0.4 for the 1–5 group (n=16,19.5%),1.5±1.7 in 6–10 (n=39,47.6%), 1.4±1.2 in 11–15 (n=20,24.4%) and 3.3±1.6 in patients with >15 (n=7,8.5%) drugs prescribed.

Conclusion and Relevance In our study a high percentage of patients showed AR, however the most prescribed drugs had low AB. On the other hand, AB was higher as the number of drugs prescribed increased.

References and/or Acknowledgements 1. https://www.anticholinergicscales.es/

Conflict of Interest No conflict of interest.