A pilot study on the impact of known drug-drug interactions in cancer patients

Silvia Ussai, Riccardo Petelin, Antonio Giordano, Mario Malinconico, Donatella Cirillo, Francesca Pentimalli

Research output: Contribution to journalArticlepeer-review


Background: When a patient concomitantly uses two or more drugs, a drug-drug interaction (DDI) can possibly occur, potentially leading to an increased or decreased clinical effect of a given treatment. Cancer patients are at high risk of such interactions because they commonly receive multiple medications. Moreover, most cancer patients are elderly and require additional medications for comorbidities. Aim of this preliminary observational study was to evaluate the incidence of well known and established DDIs in a cohort of cancer outpatients undergoing multiple treatments. Methods: Anamnestic and clinical data were collected for 64 adult patients in the ambulatory setting with malignant solid tumors who were receiving systemic anticancer treatment. Patients also declared all drugs prescribed by other specialists or self-taken in the previous 2 weeks. DDIs were divided into two different groups: 'neoplastic DDIs' (NDDIs), involving antitumoral drugs, and 'not neoplastic DDIs' (nDDIs), involving all other classes of drugs. The severity of DDIs was classified as major, moderate and minor, according to the 'Institute for Pharmacological Research Mario Negri' definition. Results: About 34 % of cancer outpatients within our cohort were prescribed/assumed interacting drug combinations. The most frequent major NDDIs involved the anticoagulant warfarin (33 % of total NDDIs) that, in association with tamoxifen, or capecitabine and paclitaxel, increased the risk of haemorrhage. About 60 % of nDDIs involved acetylsalicylic acid. Conclusions: Overall, 16 % of DDIs were related to an A-level strength of recommendation to be avoided. The lack of effective communication among specialists and patients might have a role in determining therapeutic errors. Our pilot study, although limited by a small cohort size, highlights the urgent need of implementing the clinical management of cancer outpatients with new strategies to prevent or minimize potential harmful DDIs.

Original languageEnglish
Article number89
JournalJournal of Experimental and Clinical Cancer Research
Issue number1
Publication statusPublished - Aug 25 2015


  • Adverse drug reactions
  • Clinical relevance
  • Drug toxicity
  • Drug-drug interaction (DDI)
  • Oncology

ASJC Scopus subject areas

  • Cancer Research
  • Oncology


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