Taking 8-Plus Medications Before Cancer Treatment May Affect Effectiveness in Older Patients

Patients with cancer aged 70 years and older who took at least eight prescribed medications may have negative cancer treatment outcomes, according to a recent study.

Findings from this study, which were published in the journal Cancer, demonstrated that these negative outcomes may be associated with potentially inappropriate medications and potential drug-drug interactions, which may impact a cancer treatment’s effectiveness.

“This study adds to the evidence that the number and types of medications that an older adult with cancer takes can impact their experience with chemotherapy and possibly the effectiveness of that therapy as well,” said Dr. Erika E. Ramsdale, associate professor of medicine in the department of hematology/oncology at University of Rochester in New York, in an interview with CURE®. “In this study, the higher the number of medications the patient was taking prior to starting chemotherapy, the higher the toxicity of chemotherapy tended to be.”

Ramsdale and her colleagues conducted this study to determine whether medications that patients with cancer were on prior to starting cancer treatment would impact how successful or tolerable that treatment was. In particular, they focused on the concept of polypharmacy.

“Polypharmacy simply means taking multiple concurrent medications,” Ramsdale told CURE®. “There is not an agreed-upon ‘number’ that defines polypharmacy. I like to think of polypharmacy in context. Is a person taking more medications than they need? Is there an ongoing indication for all medications? Are the potential benefits still higher than the potential risks as someone ages?”

Ramsdale noted that although medical literature typically defines polypharmacy as five or more medications, her team determined that eight or more medications is a “more useful cut-off,” she said.

Polypharmacy is often a topic of focus for older patients with advanced cancer.

“It is a topic of interest because all medications have the potential to harm us, and that risk can increase as we age,” she explained. “Medications accumulate and interact. We are metabolizing them less effectively, and we can become more sensitive to side effects (as we age). As a geriatrician and oncologist, I want to make sure that I continually evaluate whether the benefit of the medication is continuing to outweigh the risks as my patient ages and goes through cancer treatment.”

Ramsdale and colleagues conducted this current study in 718 patients (mean age, 77 years) aged 70 years and older with advanced cancer who were planning on starting a new treatment regimen. Of note, 57% of patients in the study had lung or gastrointestinal cancers.

The researchers assessed the medications a patient was taking before starting cancer treatment, and defined polypharmacy as taking eight or more medications.

Dr. Erika E. Ramsdale offers tips on medication management for older adults with cancer.

“It was important to do this study because most older adults are taking multiple medications, and some data suggest this is even more common in people with cancer,” she explained. “The relative benefits and risks of medications can change as we age, and/or with a new event like a cancer diagnosis. A cancer diagnosis can also mean someone is starting new treatment (such as chemotherapy plus supportive care medications to control nausea or other symptoms).”

Researchers evaluated potentially inappropriate medications taken by the patients, the number of side effects that occurred within three months of cancer treatment, early treatment discontinuation and cancer treatment-related unplanned hospitalizations.

Patients in the study were taking an average of five medications, and the number of medications ranged from zero to 24. In particular, 28% of patients were taking eight or more medications and 67% received one or more potentially inappropriate medications. Also, 25% had one or more major potential drug-drug interactions, which is a change in the way a drug acts in the body when taking other drugs.

The average number of moderate or worse side effects in patients with polypharmacy was 9.8 compared with 7.7 in those without polypharmacy. Patients with polypharmacy also had a higher number of severe or worse side effects (2.9 versus 2.2).

Researchers observed that patients who had one or more major potential drug-drug interactions were 59% more likely to discontinue their cancer treatment early than those who did not experience these interactions.

Patients with who had one or more major PDI had 59% higher odds of early treatment discontinuation.

“We don’t know why they stopped treatment early, but it may have to do with medications,” Ramsdale said. “We don’t believe it is simply because people who take more medications were sicker. We tried to control for how many medical conditions they had and how physically fit they were as part of our model. These results potentially impact any older adult starting cancer treatment, especially those on a lot of medications.”

Ramsdale offered some advice for older patients who may be taking many medications before starting treatment for advanced cancer.

“Review your medications with your primary care physician, oncologist or pharmacist prior to starting cancer treatment,” she said. “Make sure you still need all your medications. Make sure you understand why you are taking each medication. Ask, ‘Can I take fewer medications?’ Often the answer is yes.”

She also advised older patients with advanced cancer to not take new medications without reviewing them with the cancer care team.

“This includes vitamins, over-the-counter medications and the herbal tea or supplement recommended by a well-meaning family member or friend,” she added. “Even things you might think are not worth mentioning may have risk higher than benefit and/or interact with your cancer treatment.”

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