Methods: An narrative literature review was carried out using the descriptors "Polypharmacy", "Pharmacological interactions", "Geriatrics" and "Antineoplastic agents", in the ScienceDirect, MEDLINE, and CAPLUS databases. Results: One hundred and ten articles were identified, of which 82 were included in this review. The articles showed the importance of evaluating drug interactions in the treatment of cancer in oncogeriatric patients due to the high amount of drugs that these patients use, which can exceed 6 drugs per day, and that these interactions can compromise the treatment of the patient, as well as induce serious toxic effects, causing the patient to be hospitalized or even die. Conclusion: The inclusion of the pharmacist in the care of oncogeriatric patients reduces the risk of interaction through pharmacotherapeutic monitoring.