Development of a Brazilian anticholinergic activity drug scale

To develop a scale of anticholinergic activity drugs used in Brazil, to be applied in health care and pharmacoepidemiology research.

We performed a literature review on PubMed/MEDLINE® to identify previously published scales of anticholinergic drugs. This scale started with anticholinergic drugs, and those with known anticholinergic activity as per the 4th level, chemical-therapeutic subgroup, of the Anatomical Therapeutic Chemical classification. We also included drugs with high anticholinergic activity, as described in a list of potentially inappropriate medications for use in older adults, according to the 2015 American Geriatrics Society Beers Criteria. Drugs listed in at least two anticholinergic scales were added. Then we verified which drugs in the previous steps were marketed in Brazil. We assigned a score of 1, 2 and 3, based on their anticholinergic action.

A total of 273 anticholinergic drugs were identified, of which 125 were included in the scale. We identified 45 (36.0%) drugs with a score of 3, 13 (10.4%) with a score of 2, and 67 (53.6%) with a score of 1. Drugs for the nervous and respiratory systems were the most frequent in the scale. Eight drugs were not present in previous scales.

The methodology used for development of the Brazilian anticholinergic activity scale is simple, systematized, reproducible and easy to update. The scale allows evaluating the impact of anticholinergic burden on health outcomes, and can potentially contribute to pharmacoepidemiology research, leading to more accurate measurements of anticholinergic activity.