Risk of drug interactions and prescription appropriateness in elderly patients

  • Elisa Petrini
  • Gian Paolo Caviglia
  • Rinaldo Pellicano
  • Giorgio Maria Saracco
  • Mario Morino
  • Davide Giuseppe RibaldoneEmail author
Original Article



In Europe, adverse drug reactions and drug interactions are the cause of considerable morbidity and mortality. In over 75s, hospital access due to adverse drug reactions can be as high as 1 in every 3.


To assess the quality of the prescribed polytherapies in the territory, in terms of the risk of drug interactions and of prescription appropriateness, in over 75s.


Randomly selected patients, over 75s, were analysed among the patients of 3 general practitioners. Their data were analysed with the INTERCheck® software. This software provided the list of drug interactions deriving from the chronic therapies. The program also provided the Beers criteria and the STOPP criteria related to the drugs, highlighting potentially inappropriate drugs.


A total of 188 patients were included in the study. A total of 216 serious or very serious drug interactions have been identified. A total of 92 patients (48.9%) were at risk of at least one serious or very serious interaction. The cut-off of the correlation between the number of drugs taken and the risk of incurring a serious or very serious interaction was found to be 5 (AUC = 0.833, sensitivity = 87%, p < 0.001). Patients on ≥ 4 drugs were at risk of prescriptive inappropriateness with a sensitivity of 84% (AUC = 0.781, p < 0.0001).


Focusing on patients with at least 4 drugs in therapy is the right strategy to reduce the risks associated with polypharmacy.


Acetylsalicylic acid Benzodiazepines Escitalopram Furosemide PPI Sertraline 



The authors thank Dr. Rinaldi, Dr. Verdi and Dr. Perosino for making their databases, their patients and their work available to the study.

Compliance with ethical standards

Informed consent was obtained from all individual participants included in the study.

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

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Copyright information

© Royal Academy of Medicine in Ireland 2019

Authors and Affiliations

  1. 1.ASL Città di TorinoTurinItaly
  2. 2.Department of Medical Sciences, Division of GastroenterologyUniversity of TurinTurinItaly
  3. 3.Unit of GastroenterologyMolinette HospitalTurinItaly
  4. 4.Department of Surgical SciencesUniversity of TurinTurinItaly

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