Aim: Primary endpoint was to report polypharmacy distribution in the general population vs 6565 years old people and to examine the frequency of drug\u2013drug interactions (DDIs) in the Health Local Unit of Palermo, Italy, in relationship with patients\u2019 age.
Methods: Drug prescription data for the year 2014 were extracted from the database of the Local Health Unit of Palermo Province, Italy. Patients were divided into five age groups (0\u201313, 14\u201364, 65\u201369, 70\u201374, and 6575 year old). The detection of potential DDIs in polypharmacy profiles was performed with NavFarma software (Infologic srl, Padova, Italia), with DDI classification provided by tool Micromedex Drug Reax (Truven Health Analitics, Michigan, USA).
Results: We analyzed data of 1,324,641 patients, and 15,801,191 medical prescription were recorded; of these, 11,337,796 regarded chronic conditions. The drug prescriptions reached the highest values in the 65\u201369 and 70\u201374 age groups (p = 0.005 and p = 0.008 vs age 14\u201364 respectively).
An overall amount of 6,094,373 DDIs were detected, of which 47,173 were contraindicated. Median number of DDIs was higher in 65\u201369 and 70\u201374 age groups (p = 0.008 and p = 0.012 vs age 14\u201364, respectively). Regarding contraindicated DDIs a significant difference was detected comparing 14\u201364 vs 6565 age groups (p = 0.010 vs 65\u201369 group, p= 0.005 vs 70\u201374 group and 6575 group).
Conclusions: Polypharmacy is a phenomenon acquiring increasing dimensions also in our province. It interests particularly the older subjects, and assumes a dramatic accent when it is put in relationship with the frequency of DDIs. A proactive vigilance about potential life threatening drug interactions is mandatory
