Drug-drug interactions in older patients with cancer: a report from the 15th Conference of the International Society of Geriatric Oncology, Prague, Czech Republic, November 2015

Abstract

Drugs taken for cancer can interact with each other, with agents taken as part of supportive care, with drugs taken for comorbid conditions (which are particularly common in the elderly patients), and with herbal supplements and complementary medicines. We tend to focus on the narrow therapeutic window of cytotoxics, but the metabolism of tyrosine kinase inhibitors by the cytochrome P450 3A4 enzyme (CYP3A4) makes some TKIs particularly prone to interference with or from other agents sharing this pathway. There is also potential for adverse pharmacokinetic interactions with new hormonal agents used in advanced prostate cancer.

Geriatric assessment-driven polypharmacy discussions between oncologists, older patients, and their caregivers

“…5 Older adults are at higher risk for PP/PIM, ADEs, and drug-drug, drug-chemotherapy, and drug-condition interactions compared to younger patients. 31–33 These are potentially modifiable risk factors associated with adverse outcomes such as functional decline, morbidity, and mortality. Although several screening tools exist for the identification of PP/PIM in older adults, 17 oncologists may lack the time, resources, and/or training to assess and intervene on medication issues, particularly those unrelated to the cancer diagnosis.…”

Drug–Drug Interactions and Pharmacogenomic Evaluation in Colorectal Cancer Patients: The New Drug-PIN® System Comprehensive Approach

“…In contrast to previous studies investigating pharmacodynamic, pharmacokinetic [ 2 , 5 , 6 ], and pharmacogenomic features [ 21 , 23 , 25 ], or involving other DDI software [ 24 ], we did not base our analysis solely on DDI aspects [ 1 , 2 , 5 , 6 ], link a single SNP with a certain drug toxicity [ 12 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ], or study a single drug-related toxicity [ 16 , 17 , 18 , 19 , 20 ].…”

“…This study prospectively enrolled GI cancer patients who underwent multidisciplinary team treatment from January 2018 at our center. Inclusion criteria included: (i) histologically confirmed diagnosis of colorectal cancer (stage II–IV); (ii) age ≥ 18 years; (iii) ECOG performance status ≤ 2; (iv) taking at least 5 drugs for comorbidities, by definition of polypharmacy [ 5 , 6 , 44 , 45 ]; (v) no previous chemotherapy treatment; and (vi) adequate renal, hepatic, and bone marrow function. Meanwhile, the presence of one of the following criteria excluded a patient’s participation in the study: GI tumors that had received any standard treatment(s), cardiovascular or central nervous system (CNS) disease, previously untreated CNS metastases, pregnant or breast-feeding patients, organ dysfunction that usually contraindicate the use of cytotoxic drugs, and/or substance abuse and any other psychological condition that may interfere with the evaluation of study results.…”

“…Aside from well-known anticancer drugs, patients often take other medications to treat different conditions, such as diabetes and hypertension, among others, which could lead to severe changes in pharmacokinetic (absorption, distribution, metabolism, elimination) and pharmacodynamic properties, making this an even more complex scenario [ 2 , 3 , 4 ]. This is particularly relevant in older patients because cancer and ageing are both causes of polypharmacy in this population [ 5 , 6 , 7 ].…”

Advances in geriatric oncology: a multidisciplinary perspective

“…In a recent US study, ambulatory cancer patients were taking a mean of 9 different medications (3). Hence there is plentiful opportunity for adverse drug interactions (4).…”