title: A pilot study on the impact of known drug-drug interactions in cancer patients.
abstract: 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.
authors: Young Against Pain (YAP) Group, Parma, Italy. ussai.silvia@gamil.com.|Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA. ussai.silvia@gamil.com.|Medigenia, Distretto BioHighTech FVG, Gorizia, Italy. ussai.silvia@gamil.com.
authors: Silvia
authors: S
authors: Ussai
authors: Medigenia, Distretto BioHighTech FVG, Gorizia, Italy. riccardo.petelin@gmail.com.
authors: Riccardo
authors: R
authors: Petelin
authors: Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA. president@shro.org.|Department of Medicine, Surgery and Neuroscience, University of Siena and Istituto Toscano Tumori (ITT), Siena, Italy. president@shro.org.
authors: Antonio
authors: A
authors: Giordano
authors: Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori ''Fodazione G. Pascale'' - IRCCS, Naples, Italy. mariomalinconico2@gmail.com.
authors: Mario
authors: M
authors: Malinconico
authors: Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori ''Fodazione G. Pascale'' - IRCCS, Naples, Italy. d.cirillo@istitutotumori.na.it.
authors: Donatella
authors: D
authors: Cirillo
authors: Oncology Research Center of Mercogliano (CROM), Istituto Nazionale Tumori ''Fodazione G. Pascale'' - IRCCS, Naples, Italy. f.pentimalli@istituto.tumori.na.it.
authors: Francesca
authors: F
authors: Pentimalli
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000188:drug therapy*; D010865:Pilot Projects
chemical_list: D000970:Antineoplastic Agents