THE USE OF oral chemotherapy drugs is becoming more and more prevalent—for many types and stages of cancer, during different treatment phases, and for varying lengths of time. So it’s vital that physicians, nurses, and advanced practitioners understand all the potential adverse events of these drugs and have monitoring and treatment plans in place to handle them when they arise.
Lisa Lohr, PharmD, BCOP, BCPS
“We need to manage these adverse effects well so we can keep people on treatment—at least long enough to tell if [the treatment is] working for them,” Lisa Lohr, PharmD, BCOP, BCPS, a clinical oncology pharmacy specialist at the University of Minnesota/Fairview, said during an ambulatory practice breakout session at the 2018 Hematology/Oncology Pharmacy Association Annual Conference in Denver.1
Dr. Lohr’s discussion focused on six particular cardiovascular and metabolic adverse events from oral chemotherapy agents: QTc prolongation, hypertension, left-ventricular dysfunction/ heart failure, hypothyroidism, hyperglycemia, and hyperlipidemia. For each potential adverse event, she presented the oral chemotherapies known to cause it, patient risk factors, National Cancer Institute Common Terminology Criteria for Adverse Events, and a proposed management strategy.
Cardiovascular Effects
QTc PROLONGATION should be monitored closely, because it increases the risk for torsades de pointes—a ventricular tachyarrhythmia that can be fatal. Dr. Lohr noted that chemotherapy drugs may not always be the culprit in QTc prolongation.
“There are a lot of nonchemotherapy agents we give our patients with cancer [that can cause QTc prolongation], including antibiotics such as fluoroquinolones, azole antifungals, many antiemetics, and many antidepressants, unfortunately,” she said.
For hypertension—another oral chemotherapy–induced adverse event—Dr. Lohr noted that although it typically develops within the first couple of months of chemotherapy treatment, she’s seen patients’ blood pressure increase within the first week. She also highlighted the 2017 American College of Cardiology/American Heart Association hypertension guidelines, which advocate a lower blood pressure control level for most patients, even elderly patients, which may not be applicable to people with cancer.2
Dr. Lohr reviewed a management strategy for oral chemotherapy–induced left-ventricular dysfunction/heart failure that included four stages based on the patients’ characteristics and cancer treatment. She explained that the health-care team could follow the U.S. Food and Drug Administration–approved monitoring schedule for each chemotherapy drug or test left-ventricular dysfunction/heart failure at baseline and then periodically during treatment, or more frequently in elderly patients and patients at higher risk.
“We need to manage these adverse effects well so we can keep people on treatment—at least long enough to tell if [the treatment is] working for them.”— Lisa Lohr, PharmD, BCOP, BCPS
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Metabolic Effects
MOVING INTO the metabolic adverse events, Dr. Lohr stressed that when it comes to hypothyroidism, patients’ symptoms and thyroid function levels can be variable. This adverse event can occur within the first month of beginning oral chemotherapy treatment but continue to increase over time.
“Some people are not symptomatic at all, and other people are very [symptomatic],” she said. “But remember: There’s a lot of overlap between the symptoms of cancer and cancer treatment and that of hypothyroidism. So it’s going to be hard to differentiate that…. And with cyclic vascular endothelial growth factor inhibitors, like sunitinib [Sutent], there can be a fluctuation in the patient’s thyroid function.”
Dr. Lohr advised that before beginning oral chemotherapy that can cause hyperglycemia, the health-care team should take the patient’s baseline A1C. Many patients with cancer begin treatment with either undiagnosed or poorly controlled diabetes, so it’s vital to monitor their glucose based on their normal levels.
“It’s important to control blood sugar because patients with poorly controlled glucose levels have more infections, greater chemotherapy toxicities, higher mortalitity rates, and higher recurrence rates,” she said.
And when managing hyperlipidemia in patients on oral chemotherapy, Dr. Lohr noted that considering life expectancy is key. She said that adverse events should be managed differently for patients with a moderate to short life expectancy than for those with a long life expectancy.
“If the patient is not going to experience the long-term benefit, then there’s no reason to treat,” she commented.
Finally, Dr. Lohr impressed upon attendees the importance of having monitoring and treatment plans in place for oral chemotherapy–induced adverse events. She encouraged the audience to use the plans she described during her discussion or to create their own with buy-in from oncologists, nurses, and midlevel practitioners.
“I would recommend constructing your clinic-specific treatment algorithms so there’s a consistent approach to reducing side effects,” she said. “If it’s possible, consider making a collaborative practice agreement…. And you definitely want to develop patient materials for management of these side effects.” ■
DISCLOSURE: Dr. Lohr reported no conflicts of interest.
REFERENCES
1. Lohr L: Management of cardiovascular and metabolic adverse effects of oral chemotherapy. 2018 Hematology/Oncology Pharmacy Association Annual Conference. Presented March 22, 2018.
2. Whelton PK, Carey RM, Aronow WS, et al: 2017 ACC/AHA/AAPA/ABC/ ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. November 7, 2017 (early release online).
