Drug interactions in oncology: how common are they?
BACKGROUND
Drug-drug interactions (DDIs) comprise an important problem in medical oncology practice. We systematically reviewed the frequency of DDIs in oncology.


METHODS
We searched PubMed for eligible articles and on-line databases for abstracts of major oncology meetings.


RESULTS
Eight studies reported on the frequency of DDIs: six evaluated the frequency of potential DDIs, while two studies reported on real DDIs, i.e. interactions that had clinical consequences. Studies of potential DDIs found that approximately one-third of patients are exposed to dangerous drug doublets, with the most common ones involving warfarin and anticonvulsants. One study of real DDIs found that 2% of hospitalized cancer patients had a DDI as the cause of admission.


CONCLUSIONS
Drug interactions comprise an important issue in oncology, with approximately one-third of ambulatory cancer patients being at risk of DDIs. Data are limited on the clinical consequences of drug interactions among cancer patients.
Riechelmann
R P
RP
Internal Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil. rachelri@terra.com.br
Del Giglio
A
A
D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004347:Drug Interactions; D006801:Humans; D008495:Medical Oncology
D000970:Antineoplastic Agents