Medicine use in older patients must be appropriate and evaluated regularly. According to explicit criteria, PIPs were found to be common in older patients registered on the database. Monitoring of PIPs may increase the quality of prescribing, but explicit criteria cannot substitute for clinical judgement based on the individual patient.

Our study is the first to report the prevalence of potentially serious DDIs among an elderly population in the South African private health sector utilising the Mimica Matanović/Vlahović-Palčevski DDI protocol. Overall, we identified DDIs in approximately 26% of the prescriptions in our study. Age and gender were not found to be predictors of potentially serious DDIs.