Drug Prescription Including Interactions with Anticancer Treatments in the Elderly: A Global Approach.

Background: Consequences of inappropriate prescriptions and polymedication in patients suffering from cancer are beginning to be well documented. However, the methods used to evaluate these consequences are often discussed. Few studies evaluate the risk of interaction with anticancer drugs in elderly patients suffering from cancer.

Objectives: To describe the prevalence (i) of polypharmacy, (ii) of potentially inappropriate drug prescriptions and (iii) of drug interactions involving anticancer treatments, using a multiple reference tools.

Design: A retrospective, cross-sectional, multicenter study performed from January to December 2012.

Participants: Patients aged 65 years or older suffering from cancer presented at the oncogeriatric multidisciplinary meeting.

Measurements: Polymedication (>6 drugs), potentially inappropriate prescriptions and drug interactions involving anticancer treatment were analyzed in combination with explicit and implicit criteria within a global approach.

Results: Among the 106 patients included in this study, polypharmacy was present in 60.4% of cases, potentially inappropriate drug prescription in 63.1% and drug interactions in 16% of case, of which 47% involved anti-cancer treatments. Twenty-seven major drug interactions were identified and eight interactions involved chemotherapy.

Conclusion: Polymedication, inappropriate prescribing and drug interactions involving anti-cancer drugs are common and largely underestimated in elderly cancer patients.