**5. Conclusions**

The frequency and severity of pDDIs could be a ffected by the type and number of drugs per patient, which, at the same time, could be influenced by comorbidities and age. On the other hand, the advancement of CKD increases the risk of a major cardiac event and the possibility of hospitalization, which increases the number of medications [25,26].

It should be noted that in CKD patients, the association of medications is sometimes inevitable, and according to the present results, the use of programs for determination of pDDIs (such as Lexicomp ®) are recommended in clinical practice for CKD patients in order to avoid serious adverse effects, paying attention to the contraindicated drug combinations. Therefore, as a way to classify and

identify pDDIs according to interaction risk, severity, and reliability, it would be convenient to consider and evaluate pDDIs in clinical practice in order to avoid or prevent some avoidable adverse effects.

**Author Contributions:** Conceptualization, G.S.-D., P.D., M.Á.S.-S.; methodology, G.S.-D. and P.D.; software, G.S.-D. and P.D.; investigation, G.S.-D., A.M.P.-P., M.Á.S.-S., V.G.-B., R.M. and P.D.; writing—original draft preparation, G.S.-D. and P.D.; writing—review and editing, G.S.-D., A.M.P.-P., M.Á.S.-S., V.G.-B., R.M. and P.D.; supervision, P.D.; project administration, P.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work is supported by Junta de Extremadura and European Regional Development Fund (FEDER) (grant IB16138; V Plan Regional de I+D+i).

**Acknowledgments:** The authors thank all patients who kindly participated in the study, as well as the clinical assistance of Laura Piquero Calleja and Anika Tyszkiewiez. This work was supported.

**Conflicts of Interest:** The authors declare no conflicts of interest.
