Influence of the use of medicinal plants in medication adherence in elderly people.

Abstract

The objective of this study was to investigate the relationship between the use of medicinal plants and medication adherence in elderly people. Observational, cross-sectional study of elderly residents in Cuité-PB, Northeastern Brazil, through a household survey. A stratified proportional and systematic random sample of 240 elders was interviewed in their homes and the use of pharmaceutical medicines and of medicinal plants was assessed by direct examination. The association of medication adherence with socio-demographic, clinical, medication and use of medicinal plants was analysed with multiple logistic regression. The results showed that medication non-adherence increases with use of herbal medicines (adjusted odds ratio 2.022, 95% CI 1.059-3.862, p = 0.03), as well as with the number of different medicinal plants used (adjusted odds ratio 1.937, 95% CI 1.265-2.965, p = 0.002). This study provides first-hand evidence that the use of herbal medicines is associated with poor medication adherence. Given the high frequency of the use of herbal medicines, further research into the mechanisms of this association is justified.