Abstract
BACKGROUND: Polymedication increases the risk of developing drug interactions, and this risk is higher as the number of drugs used increases. At the hospital, medication review is performed for patients receiving treatment with drugs subject to additional monitoring. PURPOSE: Characterise the profile of drug interactions in oncological/haematological patients proposed for treatment with drugs subject to justification. MATERIAL AND METHODS: Descriptive, observational, retrospective study conducted between January and December 2016 in a central general hospital. Oncological/haematological patients with drug prescription subject to justification were included. Information was collected through consultation of the clinical process and other hospital records. Drug interactions were manually screened and classified using Lexi-interact database risk rating. Data were recorded and processed in Microsoft Excel 2010. RESULTS: A total of 174 patients that had drugs subject to justification were included. We identified 57 drug interactions between the drug for other comorbidities and the proposed therapy, corresponding to 32.7% of the patients. The majority of patients in this group were on five or more drugs. Drug-drug interactions identified had the following risk classification: 48 with risk C, five with risk D and four with risk X. The groups with the highest number of interactions were the cardiovascular system, CNS and drugs used to treat endocrine diseases. Everolimus (three drug interactions/two requests) followed by bortezomib (28 drug interactions/23 requests) had the highest number of drug interactions/number of requests. A management plan for patients’ therapy that included monitoring (risk C interactions), suggestions to change therapy (risk D interactions) and therapy modification (risk X interactions) was established with the oncologist. CONCLUSION: The present study allowed the identification of the need for pharmaceutical intervention in the pharmacotherapy review. Knowledge of potential drug interactions can lead to the development of institutional strategies to minimise it and to prevent significant changes in therapy goal. Thus, it is important to identify thecriteria for selecting patients who can benefit most from this type of evaluation. REFERENCES AND/OR ACKNOWLEDGEMENTS: 1. Riechelmann RP, Girardi D. Drug interactions in cancer patients: a hidden risk? J Res Pharm Pract2016Apr–Jun;5(2):77–78. 2. Blenkinsopp A, Bond C, Raynor DK. Medication reviews. Br J Clin Pharmacol2012Oct;74(4):573–580. No conflict of interest