Identification and evaluation of potential undesirable drug interactions involving oral antineoplastics in patients at a university hospital
DOI:
https://doi.org/10.30968/jhphs.2026.171.1238Abstract
Objective: to characterize the clinical profile of patients and the pharmacological profile of undesirable drug interactions in cancer patients with outpatient follow-up. Methods: cross-sectional, descriptive and quantitative study carried out in the oncology outpatient clinic of a university hospital. Data were collected from the medical records of 232 patients records on sex, age, pharmacotherapy, diagnosis of neoplasia and other comorbidities. Drug interactions, as well as clinical severity, pharmacological mechanisms, and possible clinical effects were identified and evaluated by the Drug Interactions Checker Software. Results: Thirty-one types of undesirable interactions were identified in 23.3% of the medical records of patients whose mean age was 65.5 years, with 59.0% of patients classified as polypharmacy. It was found that 16.0% were of major severity, 81.0% moderate and 3.0% minor. The most common involved: bicalutamide and simvastatin (20.6%), capecitabine and hydrochlorothiazide (14.2%), duloxetine and tamoxifen (7.9%). The pharmacokinetic mechanism was responsible for 35.4% and the pharmacodynamic mechanism, for 45.2% of the interactions. The main clinical effects observed were: prolongation of the cardiac QT interval (41.9%) and reduction of the efficacy of the antineoplastic agent (32.2%). The main comorbidities include: hypertension (63.8%), diabetes (29.7%) and dyslipidemia (18.5%). Conclusion: the identified drug interactions are clinically relevant with regard to their potential effects. However, there is a low frequency of interactions, partly due to the limited sample of medical records with data on medications in use duly recorded.
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