Study results published in Frontiers in Pharmacology demonstrated an increased risk of drug–drug interactions (DDIs) in patients with dementia, the majority of which were pharmacodynamic in nature and often involved psychotropic agents.

In this observational study conducted in Spain between 2018 and 2021, researchers analyzed electronic prescription data and medical records to assess the prevalence and type of DDIs in individuals with Alzheimer disease and other dementias. The Lexi-Interact/Lexicomp database was used to classify interactions based on severity and mechanism.

Key findings include the following:

  • 87% of participants had ≥1 DDI, and 83% of treatments included ≥5 drugs.
  • 689 total DDIs were identified, with 680 deemed clinically relevant.
  • 89.8% of DDIs were of moderate severity.
  • Pharmacodynamic interactions accounted for 89.5% of all DDIs.
  • Quetiapine and acetylsalicylic acid were the most commonly implicated drugs in DDIs.
  • Adlarity (donepezil; Corium, Boston, MA) and rivastigmine were frequently involved in DDIs with quetiapine.
  • The presence of drug interactions was most strongly linked to the use of acetylcholinesterase inhibitors (P=.01) and the number of drugs taken by participants (P=.014).

Researchers note that the findings underscore the challenge of assessing drug–drug interactions in clinical settings, largely due to the complexities of polypharmacy and multiple comorbidities.

Source: Muñoz-Contreras MC, Cerdá B, López-Román FJ and Segarra I. Patients with dementia: prevalence and type of drug–drug interactions. Front. Pharmacol. 2024;15. doi:10.3389/fphar.2024.1472932