4CPS-217 Netupitant–palonosetron in breast cancer: potential drugs interactions

Background and importance Neurokinin-1 (NK1) receptor antagonist (RA), netupitant, is usually co-administered with the serotonin (5-HT3) RA, palonosetron, to prevent chemotherapy induced nausea and vomiting. Aim and objectives To analyse potential drug interactions (PDI) between netupitant–palonosetron (NEPA) with breast cancer treatment. Material and methods This was a retrospective observational study including all patients who started with epirrubicine and cyclophosphamide in a third level hospital from January to August 2020 (8 months). At the beginning of treatment, the pharmacist reviewed the medication during the pharmaceutical consultation. PDI were identified using Micromedex, Uptodateintreactions, Medinteract (Spanish Society of Hospital Pharmacy) and Drug Interaction checker (Food and Drugs Administration). Results 130 medicines were reviewed in 79 patients from January to August 2020. Mean age was 61±6.5 years. 48 patients (60.78%) were polymedicated; the average number of medications per patient was 4.25. At the pharmacokinetic level, the main interaction was CYP3A4 substrate concentrations were increased, and at the pharmacodynamic level, the risk of QT syndrome and serotoninergic syndrome were increased. 61 PDI were founded in 40 patients (51.89%); 10 were severe and 21 were moderate. The most common types of drugs involved were steroids, proton pump inhibitors and antidepressants. Eight (80%) severe PDI were accepted and moderate recommendations led to reduction in dosage or concomitant use. Conclusion and relevance This study showed that more than half of patients with NEPA has at least one PDI. Clinical pharmacists are essential in detecting PDI, which is a positive influence on physician prescriptions and patient treatment outcomes, improving the safety and effectiveness of oncological treatment References and/or acknowledgements Jordan K, Gralla R, Jahn F, al. International antiemetic guidelines on chemotherapy-induced nausea and vomiting (CINV): content and implementation in daily routine practice. Eur J Pharmacol 2014;722:197–202. Conflict of interest No conflict of interest